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-rw-r--r--ipc/Makefile3
-rw-r--r--ipc/compat.c255
-rw-r--r--ipc/compat_mq.c58
-rw-r--r--ipc/ipc_sysctl.c248
-rw-r--r--ipc/ipcns_notifier.c92
-rw-r--r--ipc/mq_sysctl.c124
-rw-r--r--ipc/mqueue.c1116
-rw-r--r--ipc/msg.c812
-rw-r--r--ipc/msgutil.c147
-rw-r--r--ipc/namespace.c155
-rw-r--r--ipc/sem.c1934
-rw-r--r--ipc/shm.c919
-rw-r--r--ipc/syscall.c99
-rw-r--r--ipc/util.c793
-rw-r--r--ipc/util.h124
15 files changed, 4433 insertions, 2446 deletions
diff --git a/ipc/Makefile b/ipc/Makefile
index 5fc5e33ea04..9075e172e52 100644
--- a/ipc/Makefile
+++ b/ipc/Makefile
@@ -3,9 +3,10 @@
#
obj-$(CONFIG_SYSVIPC_COMPAT) += compat.o
-obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o
+obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o ipcns_notifier.o syscall.o
obj-$(CONFIG_SYSVIPC_SYSCTL) += ipc_sysctl.o
obj_mq-$(CONFIG_COMPAT) += compat_mq.o
obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o $(obj_mq-y)
obj-$(CONFIG_IPC_NS) += namespace.o
+obj-$(CONFIG_POSIX_MQUEUE_SYSCTL) += mq_sysctl.o
diff --git a/ipc/compat.c b/ipc/compat.c
index ab76fb0ef84..b5ef4f7946d 100644
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -26,11 +26,11 @@
#include <linux/init.h>
#include <linux/msg.h>
#include <linux/shm.h>
-#include <linux/slab.h>
#include <linux/syscalls.h>
+#include <linux/ptrace.h>
#include <linux/mutex.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include "util.h"
@@ -113,11 +113,9 @@ struct compat_shm_info {
compat_ulong_t swap_attempts, swap_successes;
};
-extern int sem_ctls[];
-#define sc_semopm (sem_ctls[2])
-
static inline int compat_ipc_parse_version(int *cmd)
{
+#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
int version = *cmd & IPC_64;
/* this is tricky: architectures that have support for the old
@@ -129,6 +127,10 @@ static inline int compat_ipc_parse_version(int *cmd)
*cmd &= ~IPC_64;
#endif
return version;
+#else
+ /* With the asm-generic APIs, we always use the 64-bit versions. */
+ return IPC_64;
+#endif
}
static inline int __get_compat_ipc64_perm(struct ipc64_perm *p64,
@@ -192,7 +194,7 @@ static inline int __put_compat_ipc_perm(struct ipc64_perm *p,
static inline int get_compat_semid64_ds(struct semid64_ds *s64,
struct compat_semid64_ds __user *up64)
{
- if (!access_ok (VERIFY_READ, up64, sizeof(*up64)))
+ if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
return -EFAULT;
return __get_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
}
@@ -200,7 +202,7 @@ static inline int get_compat_semid64_ds(struct semid64_ds *s64,
static inline int get_compat_semid_ds(struct semid64_ds *s,
struct compat_semid_ds __user *up)
{
- if (!access_ok (VERIFY_READ, up, sizeof(*up)))
+ if (!access_ok(VERIFY_READ, up, sizeof(*up)))
return -EFAULT;
return __get_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
}
@@ -210,7 +212,7 @@ static inline int put_compat_semid64_ds(struct semid64_ds *s64,
{
int err;
- if (!access_ok (VERIFY_WRITE, up64, sizeof(*up64)))
+ if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
return -EFAULT;
err = __put_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
err |= __put_user(s64->sem_otime, &up64->sem_otime);
@@ -224,7 +226,7 @@ static inline int put_compat_semid_ds(struct semid64_ds *s,
{
int err;
- if (!access_ok (VERIFY_WRITE, up, sizeof(*up)))
+ if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
return -EFAULT;
err = __put_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
err |= __put_user(s->sem_otime, &up->sem_otime);
@@ -233,23 +235,24 @@ static inline int put_compat_semid_ds(struct semid64_ds *s,
return err;
}
-long compat_sys_semctl(int first, int second, int third, void __user *uptr)
+static long do_compat_semctl(int first, int second, int third, u32 pad)
{
- union semun fourth;
- u32 pad;
+ unsigned long fourth;
int err, err2;
struct semid64_ds s64;
struct semid64_ds __user *up64;
int version = compat_ipc_parse_version(&third);
- if (!uptr)
- return -EINVAL;
- if (get_user(pad, (u32 __user *) uptr))
- return -EFAULT;
+ memset(&s64, 0, sizeof(s64));
+
if ((third & (~IPC_64)) == SETVAL)
- fourth.val = (int) pad;
+#ifdef __BIG_ENDIAN
+ fourth = (unsigned long)pad << 32;
+#else
+ fourth = pad;
+#endif
else
- fourth.__pad = compat_ptr(pad);
+ fourth = (unsigned long)compat_ptr(pad);
switch (third & (~IPC_64)) {
case IPC_INFO:
case IPC_RMID:
@@ -267,7 +270,7 @@ long compat_sys_semctl(int first, int second, int third, void __user *uptr)
case IPC_STAT:
case SEM_STAT:
up64 = compat_alloc_user_space(sizeof(s64));
- fourth.__pad = up64;
+ fourth = (unsigned long)up64;
err = sys_semctl(first, second, third, fourth);
if (err < 0)
break;
@@ -282,18 +285,18 @@ long compat_sys_semctl(int first, int second, int third, void __user *uptr)
break;
case IPC_SET:
- if (version == IPC_64) {
+ if (version == IPC_64)
err = get_compat_semid64_ds(&s64, compat_ptr(pad));
- } else {
+ else
err = get_compat_semid_ds(&s64, compat_ptr(pad));
- }
+
up64 = compat_alloc_user_space(sizeof(s64));
if (copy_to_user(up64, &s64, sizeof(s64)))
err = -EFAULT;
if (err)
break;
- fourth.__pad = up64;
+ fourth = (unsigned long)up64;
err = sys_semctl(first, second, third, fourth);
break;
@@ -304,53 +307,130 @@ long compat_sys_semctl(int first, int second, int third, void __user *uptr)
return err;
}
-long compat_sys_msgsnd(int first, int second, int third, void __user *uptr)
+static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
{
- struct compat_msgbuf __user *up = uptr;
- long type;
+ struct compat_msgbuf __user *msgp = dest;
+ size_t msgsz;
- if (first < 0)
- return -EINVAL;
- if (second < 0)
- return -EINVAL;
-
- if (get_user(type, &up->mtype))
+ if (put_user(msg->m_type, &msgp->mtype))
return -EFAULT;
- return do_msgsnd(first, type, up->mtext, second, third);
+ msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
+ if (store_msg(msgp->mtext, msg, msgsz))
+ return -EFAULT;
+ return msgsz;
}
-long compat_sys_msgrcv(int first, int second, int msgtyp, int third,
- int version, void __user *uptr)
+#ifndef COMPAT_SHMLBA
+#define COMPAT_SHMLBA SHMLBA
+#endif
+
+#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
+COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
+ u32, third, compat_uptr_t, ptr, u32, fifth)
{
- struct compat_msgbuf __user *up;
- long type;
- int err;
+ int version;
+ u32 pad;
- if (first < 0)
- return -EINVAL;
- if (second < 0)
- return -EINVAL;
+ version = call >> 16; /* hack for backward compatibility */
+ call &= 0xffff;
+
+ switch (call) {
+ case SEMOP:
+ /* struct sembuf is the same on 32 and 64bit :)) */
+ return sys_semtimedop(first, compat_ptr(ptr), second, NULL);
+ case SEMTIMEDOP:
+ return compat_sys_semtimedop(first, compat_ptr(ptr), second,
+ compat_ptr(fifth));
+ case SEMGET:
+ return sys_semget(first, second, third);
+ case SEMCTL:
+ if (!ptr)
+ return -EINVAL;
+ if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
+ return -EFAULT;
+ return do_compat_semctl(first, second, third, pad);
- if (!version) {
- struct compat_ipc_kludge ipck;
- err = -EINVAL;
- if (!uptr)
- goto out;
- err = -EFAULT;
- if (copy_from_user (&ipck, uptr, sizeof(ipck)))
- goto out;
- uptr = compat_ptr(ipck.msgp);
- msgtyp = ipck.msgtyp;
+ case MSGSND: {
+ struct compat_msgbuf __user *up = compat_ptr(ptr);
+ compat_long_t type;
+
+ if (first < 0 || second < 0)
+ return -EINVAL;
+
+ if (get_user(type, &up->mtype))
+ return -EFAULT;
+
+ return do_msgsnd(first, type, up->mtext, second, third);
}
- up = uptr;
- err = do_msgrcv(first, &type, up->mtext, second, msgtyp, third);
- if (err < 0)
- goto out;
- if (put_user(type, &up->mtype))
- err = -EFAULT;
-out:
- return err;
+ case MSGRCV: {
+ void __user *uptr = compat_ptr(ptr);
+
+ if (first < 0 || second < 0)
+ return -EINVAL;
+
+ if (!version) {
+ struct compat_ipc_kludge ipck;
+ if (!uptr)
+ return -EINVAL;
+ if (copy_from_user(&ipck, uptr, sizeof(ipck)))
+ return -EFAULT;
+ uptr = compat_ptr(ipck.msgp);
+ fifth = ipck.msgtyp;
+ }
+ return do_msgrcv(first, uptr, second, (s32)fifth, third,
+ compat_do_msg_fill);
+ }
+ case MSGGET:
+ return sys_msgget(first, second);
+ case MSGCTL:
+ return compat_sys_msgctl(first, second, compat_ptr(ptr));
+
+ case SHMAT: {
+ int err;
+ unsigned long raddr;
+
+ if (version == 1)
+ return -EINVAL;
+ err = do_shmat(first, compat_ptr(ptr), second, &raddr,
+ COMPAT_SHMLBA);
+ if (err < 0)
+ return err;
+ return put_user(raddr, (compat_ulong_t *)compat_ptr(third));
+ }
+ case SHMDT:
+ return sys_shmdt(compat_ptr(ptr));
+ case SHMGET:
+ return sys_shmget(first, (unsigned)second, third);
+ case SHMCTL:
+ return compat_sys_shmctl(first, second, compat_ptr(ptr));
+ }
+
+ return -ENOSYS;
+}
+#endif
+
+COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
+{
+ return do_compat_semctl(semid, semnum, cmd, arg);
+}
+
+COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
+ compat_ssize_t, msgsz, int, msgflg)
+{
+ struct compat_msgbuf __user *up = compat_ptr(msgp);
+ compat_long_t mtype;
+
+ if (get_user(mtype, &up->mtype))
+ return -EFAULT;
+ return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg);
+}
+
+COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp,
+ compat_ssize_t, msgsz, compat_long_t, msgtyp, int, msgflg)
+{
+ return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp,
+ msgflg, compat_do_msg_fill);
}
static inline int get_compat_msqid64(struct msqid64_ds *m64,
@@ -415,13 +495,15 @@ static inline int put_compat_msqid_ds(struct msqid64_ds *m,
return err;
}
-long compat_sys_msgctl(int first, int second, void __user *uptr)
+COMPAT_SYSCALL_DEFINE3(msgctl, int, first, int, second, void __user *, uptr)
{
int err, err2;
struct msqid64_ds m64;
int version = compat_ipc_parse_version(&second);
void __user *p;
+ memset(&m64, 0, sizeof(m64));
+
switch (second & (~IPC_64)) {
case IPC_INFO:
case IPC_RMID:
@@ -430,11 +512,11 @@ long compat_sys_msgctl(int first, int second, void __user *uptr)
break;
case IPC_SET:
- if (version == IPC_64) {
+ if (version == IPC_64)
err = get_compat_msqid64(&m64, uptr);
- } else {
+ else
err = get_compat_msqid(&m64, uptr);
- }
+
if (err)
break;
p = compat_alloc_user_space(sizeof(m64));
@@ -467,20 +549,16 @@ long compat_sys_msgctl(int first, int second, void __user *uptr)
return err;
}
-long compat_sys_shmat(int first, int second, compat_uptr_t third, int version,
- void __user *uptr)
+COMPAT_SYSCALL_DEFINE3(shmat, int, shmid, compat_uptr_t, shmaddr, int, shmflg)
{
- int err;
- unsigned long raddr;
- compat_ulong_t __user *uaddr;
+ unsigned long ret;
+ long err;
- if (version == 1)
- return -EINVAL;
- err = do_shmat(first, uptr, second, &raddr);
- if (err < 0)
+ err = do_shmat(shmid, compat_ptr(shmaddr), shmflg, &ret, COMPAT_SHMLBA);
+ if (err)
return err;
- uaddr = compat_ptr(third);
- return put_user(raddr, uaddr);
+ force_successful_syscall_return();
+ return (long)ret;
}
static inline int get_compat_shmid64_ds(struct shmid64_ds *s64,
@@ -587,7 +665,7 @@ static inline int put_compat_shm_info(struct shm_info __user *ip,
return err;
}
-long compat_sys_shmctl(int first, int second, void __user *uptr)
+COMPAT_SYSCALL_DEFINE3(shmctl, int, first, int, second, void __user *, uptr)
{
void __user *p;
struct shmid64_ds s64;
@@ -595,6 +673,8 @@ long compat_sys_shmctl(int first, int second, void __user *uptr)
int err, err2;
int version = compat_ipc_parse_version(&second);
+ memset(&s64, 0, sizeof(s64));
+
switch (second & (~IPC_64)) {
case IPC_RMID:
case SHM_LOCK:
@@ -619,11 +699,11 @@ long compat_sys_shmctl(int first, int second, void __user *uptr)
case IPC_SET:
- if (version == IPC_64) {
+ if (version == IPC_64)
err = get_compat_shmid64_ds(&s64, uptr);
- } else {
+ else
err = get_compat_shmid_ds(&s64, uptr);
- }
+
if (err)
break;
p = compat_alloc_user_space(sizeof(s64));
@@ -666,17 +746,12 @@ long compat_sys_shmctl(int first, int second, void __user *uptr)
return err;
}
-long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,
- unsigned nsops, const struct compat_timespec __user *timeout)
+COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems,
+ unsigned, nsops,
+ const struct compat_timespec __user *, timeout)
{
- struct timespec __user *ts64 = NULL;
- if (timeout) {
- struct timespec ts;
- ts64 = compat_alloc_user_space(sizeof(*ts64));
- if (get_compat_timespec(&ts, timeout))
- return -EFAULT;
- if (copy_to_user(ts64, &ts, sizeof(ts)))
- return -EFAULT;
- }
+ struct timespec __user *ts64;
+ if (compat_convert_timespec(&ts64, timeout))
+ return -EFAULT;
return sys_semtimedop(semid, tsems, nsops, ts64);
}
diff --git a/ipc/compat_mq.c b/ipc/compat_mq.c
index d8d1e9ff4e8..ef6f91cc449 100644
--- a/ipc/compat_mq.c
+++ b/ipc/compat_mq.c
@@ -12,7 +12,7 @@
#include <linux/mqueue.h>
#include <linux/syscalls.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
struct compat_mq_attr {
compat_long_t mq_flags; /* message queue flags */
@@ -46,13 +46,16 @@ static inline int put_compat_mq_attr(const struct mq_attr *attr,
| __put_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
}
-asmlinkage long compat_sys_mq_open(const char __user *u_name,
- int oflag, compat_mode_t mode,
- struct compat_mq_attr __user *u_attr)
+COMPAT_SYSCALL_DEFINE4(mq_open, const char __user *, u_name,
+ int, oflag, compat_mode_t, mode,
+ struct compat_mq_attr __user *, u_attr)
{
void __user *p = NULL;
if (u_attr && oflag & O_CREAT) {
struct mq_attr attr;
+
+ memset(&attr, 0, sizeof(attr));
+
p = compat_alloc_user_space(sizeof(attr));
if (get_compat_mq_attr(&attr, u_attr) ||
copy_to_user(p, &attr, sizeof(attr)))
@@ -61,49 +64,36 @@ asmlinkage long compat_sys_mq_open(const char __user *u_name,
return sys_mq_open(u_name, oflag, mode, p);
}
-static int compat_prepare_timeout(struct timespec __user * *p,
- const struct compat_timespec __user *u)
-{
- struct timespec ts;
- if (!u) {
- *p = NULL;
- return 0;
- }
- *p = compat_alloc_user_space(sizeof(ts));
- if (get_compat_timespec(&ts, u) || copy_to_user(*p, &ts, sizeof(ts)))
- return -EFAULT;
- return 0;
-}
-
-asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes,
- const char __user *u_msg_ptr,
- size_t msg_len, unsigned int msg_prio,
- const struct compat_timespec __user *u_abs_timeout)
+COMPAT_SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes,
+ const char __user *, u_msg_ptr,
+ compat_size_t, msg_len, unsigned int, msg_prio,
+ const struct compat_timespec __user *, u_abs_timeout)
{
struct timespec __user *u_ts;
- if (compat_prepare_timeout(&u_ts, u_abs_timeout))
+ if (compat_convert_timespec(&u_ts, u_abs_timeout))
return -EFAULT;
return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len,
msg_prio, u_ts);
}
-asmlinkage ssize_t compat_sys_mq_timedreceive(mqd_t mqdes,
- char __user *u_msg_ptr,
- size_t msg_len, unsigned int __user *u_msg_prio,
- const struct compat_timespec __user *u_abs_timeout)
+COMPAT_SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes,
+ char __user *, u_msg_ptr,
+ compat_size_t, msg_len, unsigned int __user *, u_msg_prio,
+ const struct compat_timespec __user *, u_abs_timeout)
{
struct timespec __user *u_ts;
- if (compat_prepare_timeout(&u_ts, u_abs_timeout))
+
+ if (compat_convert_timespec(&u_ts, u_abs_timeout))
return -EFAULT;
return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len,
u_msg_prio, u_ts);
}
-asmlinkage long compat_sys_mq_notify(mqd_t mqdes,
- const struct compat_sigevent __user *u_notification)
+COMPAT_SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
+ const struct compat_sigevent __user *, u_notification)
{
struct sigevent __user *p = NULL;
if (u_notification) {
@@ -119,14 +109,16 @@ asmlinkage long compat_sys_mq_notify(mqd_t mqdes,
return sys_mq_notify(mqdes, p);
}
-asmlinkage long compat_sys_mq_getsetattr(mqd_t mqdes,
- const struct compat_mq_attr __user *u_mqstat,
- struct compat_mq_attr __user *u_omqstat)
+COMPAT_SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
+ const struct compat_mq_attr __user *, u_mqstat,
+ struct compat_mq_attr __user *, u_omqstat)
{
struct mq_attr mqstat;
struct mq_attr __user *p = compat_alloc_user_space(2 * sizeof(*p));
long ret;
+ memset(&mqstat, 0, sizeof(mqstat));
+
if (u_mqstat) {
if (get_compat_mq_attr(&mqstat, u_mqstat) ||
copy_to_user(p, &mqstat, sizeof(mqstat)))
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index 7f4235bed51..c3f0326e98d 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -15,8 +15,10 @@
#include <linux/sysctl.h>
#include <linux/uaccess.h>
#include <linux/ipc_namespace.h>
+#include <linux/msg.h>
+#include "util.h"
-static void *get_ipc(ctl_table *table)
+static void *get_ipc(struct ctl_table *table)
{
char *which = table->data;
struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
@@ -24,146 +26,248 @@ static void *get_ipc(ctl_table *table)
return which;
}
-#ifdef CONFIG_PROC_FS
-static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
+#ifdef CONFIG_PROC_SYSCTL
+static int proc_ipc_dointvec(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table ipc_table;
+
memcpy(&ipc_table, table, sizeof(ipc_table));
ipc_table.data = get_ipc(table);
- return proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos);
+ return proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
}
-static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
- struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
+static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table ipc_table;
+
memcpy(&ipc_table, table, sizeof(ipc_table));
ipc_table.data = get_ipc(table);
- return proc_doulongvec_minmax(&ipc_table, write, filp, buffer,
- lenp, ppos);
+ return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
}
-#else
-#define proc_ipc_doulongvec_minmax NULL
-#define proc_ipc_dointvec NULL
-#endif
+static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ipc_namespace *ns = current->nsproxy->ipc_ns;
+ int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
+
+ if (err < 0)
+ return err;
+ if (ns->shm_rmid_forced)
+ shm_destroy_orphaned(ns);
+ return err;
+}
+
+static int proc_ipc_callback_dointvec_minmax(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table ipc_table;
+ size_t lenp_bef = *lenp;
+ int rc;
-#ifdef CONFIG_SYSCTL_SYSCALL
-/* The generic sysctl ipc data routine. */
-static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
- void __user *oldval, size_t __user *oldlenp,
- void __user *newval, size_t newlen)
+ memcpy(&ipc_table, table, sizeof(ipc_table));
+ ipc_table.data = get_ipc(table);
+
+ rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
+
+ if (write && !rc && lenp_bef == *lenp)
+ /*
+ * Tunable has successfully been changed by hand. Disable its
+ * automatic adjustment. This simply requires unregistering
+ * the notifiers that trigger recalculation.
+ */
+ unregister_ipcns_notifier(current->nsproxy->ipc_ns);
+
+ return rc;
+}
+
+static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table ipc_table;
+ memcpy(&ipc_table, table, sizeof(ipc_table));
+ ipc_table.data = get_ipc(table);
+
+ return proc_doulongvec_minmax(&ipc_table, write, buffer,
+ lenp, ppos);
+}
+
+/*
+ * Routine that is called when the file "auto_msgmni" has successfully been
+ * written.
+ * Two values are allowed:
+ * 0: unregister msgmni's callback routine from the ipc namespace notifier
+ * chain. This means that msgmni won't be recomputed anymore upon memory
+ * add/remove or ipc namespace creation/removal.
+ * 1: register back the callback routine.
+ */
+static void ipc_auto_callback(int val)
{
- size_t len;
- void *data;
-
- /* Get out of I don't have a variable */
- if (!table->data || !table->maxlen)
- return -ENOTDIR;
-
- data = get_ipc(table);
- if (!data)
- return -ENOTDIR;
-
- if (oldval && oldlenp) {
- if (get_user(len, oldlenp))
- return -EFAULT;
- if (len) {
- if (len > table->maxlen)
- len = table->maxlen;
- if (copy_to_user(oldval, data, len))
- return -EFAULT;
- if (put_user(len, oldlenp))
- return -EFAULT;
- }
+ if (!val)
+ unregister_ipcns_notifier(current->nsproxy->ipc_ns);
+ else {
+ /*
+ * Re-enable automatic recomputing only if not already
+ * enabled.
+ */
+ recompute_msgmni(current->nsproxy->ipc_ns);
+ cond_register_ipcns_notifier(current->nsproxy->ipc_ns);
}
+}
+
+static int proc_ipcauto_dointvec_minmax(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table ipc_table;
+ size_t lenp_bef = *lenp;
+ int oldval;
+ int rc;
+
+ memcpy(&ipc_table, table, sizeof(ipc_table));
+ ipc_table.data = get_ipc(table);
+ oldval = *((int *)(ipc_table.data));
- if (newval && newlen) {
- if (newlen > table->maxlen)
- newlen = table->maxlen;
+ rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
- if (copy_from_user(data, newval, newlen))
- return -EFAULT;
+ if (write && !rc && lenp_bef == *lenp) {
+ int newval = *((int *)(ipc_table.data));
+ /*
+ * The file "auto_msgmni" has correctly been set.
+ * React by (un)registering the corresponding tunable, if the
+ * value has changed.
+ */
+ if (newval != oldval)
+ ipc_auto_callback(newval);
}
- return 1;
+
+ return rc;
}
+
#else
-#define sysctl_ipc_data NULL
+#define proc_ipc_doulongvec_minmax NULL
+#define proc_ipc_dointvec NULL
+#define proc_ipc_dointvec_minmax NULL
+#define proc_ipc_dointvec_minmax_orphans NULL
+#define proc_ipc_callback_dointvec_minmax NULL
+#define proc_ipcauto_dointvec_minmax NULL
#endif
+static int zero;
+static int one = 1;
+static int int_max = INT_MAX;
+
static struct ctl_table ipc_kern_table[] = {
{
- .ctl_name = KERN_SHMMAX,
.procname = "shmmax",
.data = &init_ipc_ns.shm_ctlmax,
- .maxlen = sizeof (init_ipc_ns.shm_ctlmax),
+ .maxlen = sizeof(init_ipc_ns.shm_ctlmax),
.mode = 0644,
.proc_handler = proc_ipc_doulongvec_minmax,
- .strategy = sysctl_ipc_data,
},
{
- .ctl_name = KERN_SHMALL,
.procname = "shmall",
.data = &init_ipc_ns.shm_ctlall,
- .maxlen = sizeof (init_ipc_ns.shm_ctlall),
+ .maxlen = sizeof(init_ipc_ns.shm_ctlall),
.mode = 0644,
.proc_handler = proc_ipc_doulongvec_minmax,
- .strategy = sysctl_ipc_data,
},
{
- .ctl_name = KERN_SHMMNI,
.procname = "shmmni",
.data = &init_ipc_ns.shm_ctlmni,
- .maxlen = sizeof (init_ipc_ns.shm_ctlmni),
+ .maxlen = sizeof(init_ipc_ns.shm_ctlmni),
.mode = 0644,
.proc_handler = proc_ipc_dointvec,
- .strategy = sysctl_ipc_data,
},
{
- .ctl_name = KERN_MSGMAX,
+ .procname = "shm_rmid_forced",
+ .data = &init_ipc_ns.shm_rmid_forced,
+ .maxlen = sizeof(init_ipc_ns.shm_rmid_forced),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax_orphans,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+ {
.procname = "msgmax",
.data = &init_ipc_ns.msg_ctlmax,
- .maxlen = sizeof (init_ipc_ns.msg_ctlmax),
+ .maxlen = sizeof(init_ipc_ns.msg_ctlmax),
.mode = 0644,
- .proc_handler = proc_ipc_dointvec,
- .strategy = sysctl_ipc_data,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
},
{
- .ctl_name = KERN_MSGMNI,
.procname = "msgmni",
.data = &init_ipc_ns.msg_ctlmni,
- .maxlen = sizeof (init_ipc_ns.msg_ctlmni),
+ .maxlen = sizeof(init_ipc_ns.msg_ctlmni),
.mode = 0644,
- .proc_handler = proc_ipc_dointvec,
- .strategy = sysctl_ipc_data,
+ .proc_handler = proc_ipc_callback_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
},
{
- .ctl_name = KERN_MSGMNB,
.procname = "msgmnb",
.data = &init_ipc_ns.msg_ctlmnb,
- .maxlen = sizeof (init_ipc_ns.msg_ctlmnb),
+ .maxlen = sizeof(init_ipc_ns.msg_ctlmnb),
.mode = 0644,
- .proc_handler = proc_ipc_dointvec,
- .strategy = sysctl_ipc_data,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
},
{
- .ctl_name = KERN_SEM,
.procname = "sem",
.data = &init_ipc_ns.sem_ctls,
- .maxlen = 4*sizeof (int),
+ .maxlen = 4*sizeof(int),
.mode = 0644,
.proc_handler = proc_ipc_dointvec,
- .strategy = sysctl_ipc_data,
},
+ {
+ .procname = "auto_msgmni",
+ .data = &init_ipc_ns.auto_msgmni,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_ipcauto_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+#ifdef CONFIG_CHECKPOINT_RESTORE
+ {
+ .procname = "sem_next_id",
+ .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
+ .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
+ },
+ {
+ .procname = "msg_next_id",
+ .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
+ .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
+ },
+ {
+ .procname = "shm_next_id",
+ .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
+ .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
+ .mode = 0644,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
+ },
+#endif
{}
};
static struct ctl_table ipc_root_table[] = {
{
- .ctl_name = CTL_KERN,
.procname = "kernel",
.mode = 0555,
.child = ipc_kern_table,
@@ -177,4 +281,4 @@ static int __init ipc_sysctl_init(void)
return 0;
}
-__initcall(ipc_sysctl_init);
+device_initcall(ipc_sysctl_init);
diff --git a/ipc/ipcns_notifier.c b/ipc/ipcns_notifier.c
new file mode 100644
index 00000000000..b9b31a4f77e
--- /dev/null
+++ b/ipc/ipcns_notifier.c
@@ -0,0 +1,92 @@
+/*
+ * linux/ipc/ipcns_notifier.c
+ * Copyright (C) 2007 BULL SA. Nadia Derbey
+ *
+ * Notification mechanism for ipc namespaces:
+ * The callback routine registered in the memory chain invokes the ipcns
+ * notifier chain with the IPCNS_MEMCHANGED event.
+ * Each callback routine registered in the ipcns namespace recomputes msgmni
+ * for the owning namespace.
+ */
+
+#include <linux/msg.h>
+#include <linux/rcupdate.h>
+#include <linux/notifier.h>
+#include <linux/nsproxy.h>
+#include <linux/ipc_namespace.h>
+
+#include "util.h"
+
+
+
+static BLOCKING_NOTIFIER_HEAD(ipcns_chain);
+
+
+static int ipcns_callback(struct notifier_block *self,
+ unsigned long action, void *arg)
+{
+ struct ipc_namespace *ns;
+
+ switch (action) {
+ case IPCNS_MEMCHANGED: /* amount of lowmem has changed */
+ case IPCNS_CREATED:
+ case IPCNS_REMOVED:
+ /*
+ * It's time to recompute msgmni
+ */
+ ns = container_of(self, struct ipc_namespace, ipcns_nb);
+ /*
+ * No need to get a reference on the ns: the 1st job of
+ * free_ipc_ns() is to unregister the callback routine.
+ * blocking_notifier_chain_unregister takes the wr lock to do
+ * it.
+ * When this callback routine is called the rd lock is held by
+ * blocking_notifier_call_chain.
+ * So the ipc ns cannot be freed while we are here.
+ */
+ recompute_msgmni(ns);
+ break;
+ default:
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+int register_ipcns_notifier(struct ipc_namespace *ns)
+{
+ int rc;
+
+ memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
+ ns->ipcns_nb.notifier_call = ipcns_callback;
+ ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
+ rc = blocking_notifier_chain_register(&ipcns_chain, &ns->ipcns_nb);
+ if (!rc)
+ ns->auto_msgmni = 1;
+ return rc;
+}
+
+int cond_register_ipcns_notifier(struct ipc_namespace *ns)
+{
+ int rc;
+
+ memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
+ ns->ipcns_nb.notifier_call = ipcns_callback;
+ ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
+ rc = blocking_notifier_chain_cond_register(&ipcns_chain,
+ &ns->ipcns_nb);
+ if (!rc)
+ ns->auto_msgmni = 1;
+ return rc;
+}
+
+void unregister_ipcns_notifier(struct ipc_namespace *ns)
+{
+ blocking_notifier_chain_unregister(&ipcns_chain, &ns->ipcns_nb);
+ ns->auto_msgmni = 0;
+}
+
+int ipcns_notify(unsigned long val)
+{
+ return blocking_notifier_call_chain(&ipcns_chain, val, NULL);
+}
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c
new file mode 100644
index 00000000000..68d4e953762
--- /dev/null
+++ b/ipc/mq_sysctl.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2007 IBM Corporation
+ *
+ * Author: Cedric Le Goater <clg@fr.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#include <linux/nsproxy.h>
+#include <linux/ipc_namespace.h>
+#include <linux/sysctl.h>
+
+#ifdef CONFIG_PROC_SYSCTL
+static void *get_mq(struct ctl_table *table)
+{
+ char *which = table->data;
+ struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
+ which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
+ return which;
+}
+
+static int proc_mq_dointvec(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table mq_table;
+ memcpy(&mq_table, table, sizeof(mq_table));
+ mq_table.data = get_mq(table);
+
+ return proc_dointvec(&mq_table, write, buffer, lenp, ppos);
+}
+
+static int proc_mq_dointvec_minmax(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table mq_table;
+ memcpy(&mq_table, table, sizeof(mq_table));
+ mq_table.data = get_mq(table);
+
+ return proc_dointvec_minmax(&mq_table, write, buffer,
+ lenp, ppos);
+}
+#else
+#define proc_mq_dointvec NULL
+#define proc_mq_dointvec_minmax NULL
+#endif
+
+static int msg_max_limit_min = MIN_MSGMAX;
+static int msg_max_limit_max = HARD_MSGMAX;
+
+static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
+static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
+
+static struct ctl_table mq_sysctls[] = {
+ {
+ .procname = "queues_max",
+ .data = &init_ipc_ns.mq_queues_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec,
+ },
+ {
+ .procname = "msg_max",
+ .data = &init_ipc_ns.mq_msg_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_max_limit_min,
+ .extra2 = &msg_max_limit_max,
+ },
+ {
+ .procname = "msgsize_max",
+ .data = &init_ipc_ns.mq_msgsize_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_maxsize_limit_min,
+ .extra2 = &msg_maxsize_limit_max,
+ },
+ {
+ .procname = "msg_default",
+ .data = &init_ipc_ns.mq_msg_default,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_max_limit_min,
+ .extra2 = &msg_max_limit_max,
+ },
+ {
+ .procname = "msgsize_default",
+ .data = &init_ipc_ns.mq_msgsize_default,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_maxsize_limit_min,
+ .extra2 = &msg_maxsize_limit_max,
+ },
+ {}
+};
+
+static struct ctl_table mq_sysctl_dir[] = {
+ {
+ .procname = "mqueue",
+ .mode = 0555,
+ .child = mq_sysctls,
+ },
+ {}
+};
+
+static struct ctl_table mq_sysctl_root[] = {
+ {
+ .procname = "fs",
+ .mode = 0555,
+ .child = mq_sysctl_dir,
+ },
+ {}
+};
+
+struct ctl_table_header *mq_register_sysctl_table(void)
+{
+ return register_sysctl_table(mq_sysctl_root);
+}
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 60f7a27f7a9..4fcf39af177 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -6,7 +6,7 @@
*
* Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com)
* Lockless receive & send, fd based notify:
- * Manfred Spraul (manfred@colorfullife.com)
+ * Manfred Spraul (manfred@colorfullife.com)
*
* Audit: George Wilson (ltcgcw@us.ibm.com)
*
@@ -24,6 +24,7 @@
#include <linux/mqueue.h>
#include <linux/msg.h>
#include <linux/skbuff.h>
+#include <linux/vmalloc.h>
#include <linux/netlink.h>
#include <linux/syscalls.h>
#include <linux/audit.h>
@@ -31,6 +32,9 @@
#include <linux/mutex.h>
#include <linux/nsproxy.h>
#include <linux/pid.h>
+#include <linux/ipc_namespace.h>
+#include <linux/user_namespace.h>
+#include <linux/slab.h>
#include <net/sock.h>
#include "util.h"
@@ -46,12 +50,11 @@
#define STATE_PENDING 1
#define STATE_READY 2
-/* default values */
-#define DFLT_QUEUESMAX 256 /* max number of message queues */
-#define DFLT_MSGMAX 10 /* max number of messages in each queue */
-#define HARD_MSGMAX (131072/sizeof(void*))
-#define DFLT_MSGSIZEMAX 8192 /* max message size */
-
+struct posix_msg_tree_node {
+ struct rb_node rb_node;
+ struct list_head msg_list;
+ int priority;
+};
struct ext_wait_queue { /* queue of sleeping tasks */
struct task_struct *task;
@@ -65,11 +68,13 @@ struct mqueue_inode_info {
struct inode vfs_inode;
wait_queue_head_t wait_q;
- struct msg_msg **messages;
+ struct rb_root msg_tree;
+ struct posix_msg_tree_node *node_cache;
struct mq_attr attr;
struct sigevent notify;
- struct pid* notify_owner;
+ struct pid *notify_owner;
+ struct user_namespace *notify_user_ns;
struct user_struct *user; /* user who created, for accounting */
struct sock *notify_sock;
struct sk_buff *notify_cookie;
@@ -82,132 +87,263 @@ struct mqueue_inode_info {
static const struct inode_operations mqueue_dir_inode_operations;
static const struct file_operations mqueue_file_operations;
-static struct super_operations mqueue_super_ops;
+static const struct super_operations mqueue_super_ops;
static void remove_notification(struct mqueue_inode_info *info);
-static spinlock_t mq_lock;
static struct kmem_cache *mqueue_inode_cachep;
-static struct vfsmount *mqueue_mnt;
-static unsigned int queues_count;
-static unsigned int queues_max = DFLT_QUEUESMAX;
-static unsigned int msg_max = DFLT_MSGMAX;
-static unsigned int msgsize_max = DFLT_MSGSIZEMAX;
-
-static struct ctl_table_header * mq_sysctl_table;
+static struct ctl_table_header *mq_sysctl_table;
static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
{
return container_of(inode, struct mqueue_inode_info, vfs_inode);
}
-static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
- struct mq_attr *attr)
+/*
+ * This routine should be called with the mq_lock held.
+ */
+static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode)
+{
+ return get_ipc_ns(inode->i_sb->s_fs_info);
+}
+
+static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
+{
+ struct ipc_namespace *ns;
+
+ spin_lock(&mq_lock);
+ ns = __get_ns_from_inode(inode);
+ spin_unlock(&mq_lock);
+ return ns;
+}
+
+/* Auxiliary functions to manipulate messages' list */
+static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info)
+{
+ struct rb_node **p, *parent = NULL;
+ struct posix_msg_tree_node *leaf;
+
+ p = &info->msg_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
+
+ if (likely(leaf->priority == msg->m_type))
+ goto insert_msg;
+ else if (msg->m_type < leaf->priority)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+ if (info->node_cache) {
+ leaf = info->node_cache;
+ info->node_cache = NULL;
+ } else {
+ leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC);
+ if (!leaf)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&leaf->msg_list);
+ info->qsize += sizeof(*leaf);
+ }
+ leaf->priority = msg->m_type;
+ rb_link_node(&leaf->rb_node, parent, p);
+ rb_insert_color(&leaf->rb_node, &info->msg_tree);
+insert_msg:
+ info->attr.mq_curmsgs++;
+ info->qsize += msg->m_ts;
+ list_add_tail(&msg->m_list, &leaf->msg_list);
+ return 0;
+}
+
+static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
+{
+ struct rb_node **p, *parent = NULL;
+ struct posix_msg_tree_node *leaf;
+ struct msg_msg *msg;
+
+try_again:
+ p = &info->msg_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ /*
+ * During insert, low priorities go to the left and high to the
+ * right. On receive, we want the highest priorities first, so
+ * walk all the way to the right.
+ */
+ p = &(*p)->rb_right;
+ }
+ if (!parent) {
+ if (info->attr.mq_curmsgs) {
+ pr_warn_once("Inconsistency in POSIX message queue, "
+ "no tree element, but supposedly messages "
+ "should exist!\n");
+ info->attr.mq_curmsgs = 0;
+ }
+ return NULL;
+ }
+ leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
+ if (unlikely(list_empty(&leaf->msg_list))) {
+ pr_warn_once("Inconsistency in POSIX message queue, "
+ "empty leaf node but we haven't implemented "
+ "lazy leaf delete!\n");
+ rb_erase(&leaf->rb_node, &info->msg_tree);
+ if (info->node_cache) {
+ info->qsize -= sizeof(*leaf);
+ kfree(leaf);
+ } else {
+ info->node_cache = leaf;
+ }
+ goto try_again;
+ } else {
+ msg = list_first_entry(&leaf->msg_list,
+ struct msg_msg, m_list);
+ list_del(&msg->m_list);
+ if (list_empty(&leaf->msg_list)) {
+ rb_erase(&leaf->rb_node, &info->msg_tree);
+ if (info->node_cache) {
+ info->qsize -= sizeof(*leaf);
+ kfree(leaf);
+ } else {
+ info->node_cache = leaf;
+ }
+ }
+ }
+ info->attr.mq_curmsgs--;
+ info->qsize -= msg->m_ts;
+ return msg;
+}
+
+static struct inode *mqueue_get_inode(struct super_block *sb,
+ struct ipc_namespace *ipc_ns, umode_t mode,
+ struct mq_attr *attr)
{
+ struct user_struct *u = current_user();
struct inode *inode;
+ int ret = -ENOMEM;
inode = new_inode(sb);
- if (inode) {
- inode->i_mode = mode;
- inode->i_uid = current->fsuid;
- inode->i_gid = current->fsgid;
- inode->i_blocks = 0;
- inode->i_mtime = inode->i_ctime = inode->i_atime =
- CURRENT_TIME;
+ if (!inode)
+ goto err;
+
+ inode->i_ino = get_next_ino();
+ inode->i_mode = mode;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
+ inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME;
+
+ if (S_ISREG(mode)) {
+ struct mqueue_inode_info *info;
+ unsigned long mq_bytes, mq_treesize;
+
+ inode->i_fop = &mqueue_file_operations;
+ inode->i_size = FILENT_SIZE;
+ /* mqueue specific info */
+ info = MQUEUE_I(inode);
+ spin_lock_init(&info->lock);
+ init_waitqueue_head(&info->wait_q);
+ INIT_LIST_HEAD(&info->e_wait_q[0].list);
+ INIT_LIST_HEAD(&info->e_wait_q[1].list);
+ info->notify_owner = NULL;
+ info->notify_user_ns = NULL;
+ info->qsize = 0;
+ info->user = NULL; /* set when all is ok */
+ info->msg_tree = RB_ROOT;
+ info->node_cache = NULL;
+ memset(&info->attr, 0, sizeof(info->attr));
+ info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
+ ipc_ns->mq_msg_default);
+ info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
+ ipc_ns->mq_msgsize_default);
+ if (attr) {
+ info->attr.mq_maxmsg = attr->mq_maxmsg;
+ info->attr.mq_msgsize = attr->mq_msgsize;
+ }
+ /*
+ * We used to allocate a static array of pointers and account
+ * the size of that array as well as one msg_msg struct per
+ * possible message into the queue size. That's no longer
+ * accurate as the queue is now an rbtree and will grow and
+ * shrink depending on usage patterns. We can, however, still
+ * account one msg_msg struct per message, but the nodes are
+ * allocated depending on priority usage, and most programs
+ * only use one, or a handful, of priorities. However, since
+ * this is pinned memory, we need to assume worst case, so
+ * that means the min(mq_maxmsg, max_priorities) * struct
+ * posix_msg_tree_node.
+ */
+ mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
+ min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
+ sizeof(struct posix_msg_tree_node);
+
+ mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
+ info->attr.mq_msgsize);
- if (S_ISREG(mode)) {
- struct mqueue_inode_info *info;
- struct task_struct *p = current;
- struct user_struct *u = p->user;
- unsigned long mq_bytes, mq_msg_tblsz;
-
- inode->i_fop = &mqueue_file_operations;
- inode->i_size = FILENT_SIZE;
- /* mqueue specific info */
- info = MQUEUE_I(inode);
- spin_lock_init(&info->lock);
- init_waitqueue_head(&info->wait_q);
- INIT_LIST_HEAD(&info->e_wait_q[0].list);
- INIT_LIST_HEAD(&info->e_wait_q[1].list);
- info->messages = NULL;
- info->notify_owner = NULL;
- info->qsize = 0;
- info->user = NULL; /* set when all is ok */
- memset(&info->attr, 0, sizeof(info->attr));
- info->attr.mq_maxmsg = DFLT_MSGMAX;
- info->attr.mq_msgsize = DFLT_MSGSIZEMAX;
- if (attr) {
- info->attr.mq_maxmsg = attr->mq_maxmsg;
- info->attr.mq_msgsize = attr->mq_msgsize;
- }
- mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
- mq_bytes = (mq_msg_tblsz +
- (info->attr.mq_maxmsg * info->attr.mq_msgsize));
-
- spin_lock(&mq_lock);
- if (u->mq_bytes + mq_bytes < u->mq_bytes ||
- u->mq_bytes + mq_bytes >
- p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) {
- spin_unlock(&mq_lock);
- goto out_inode;
- }
- u->mq_bytes += mq_bytes;
+ spin_lock(&mq_lock);
+ if (u->mq_bytes + mq_bytes < u->mq_bytes ||
+ u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) {
spin_unlock(&mq_lock);
-
- info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
- if (!info->messages) {
- spin_lock(&mq_lock);
- u->mq_bytes -= mq_bytes;
- spin_unlock(&mq_lock);
- goto out_inode;
- }
- /* all is ok */
- info->user = get_uid(u);
- } else if (S_ISDIR(mode)) {
- inc_nlink(inode);
- /* Some things misbehave if size == 0 on a directory */
- inode->i_size = 2 * DIRENT_SIZE;
- inode->i_op = &mqueue_dir_inode_operations;
- inode->i_fop = &simple_dir_operations;
+ /* mqueue_evict_inode() releases info->messages */
+ ret = -EMFILE;
+ goto out_inode;
}
+ u->mq_bytes += mq_bytes;
+ spin_unlock(&mq_lock);
+
+ /* all is ok */
+ info->user = get_uid(u);
+ } else if (S_ISDIR(mode)) {
+ inc_nlink(inode);
+ /* Some things misbehave if size == 0 on a directory */
+ inode->i_size = 2 * DIRENT_SIZE;
+ inode->i_op = &mqueue_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
}
+
return inode;
out_inode:
- make_bad_inode(inode);
iput(inode);
- return NULL;
+err:
+ return ERR_PTR(ret);
}
static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode;
+ struct ipc_namespace *ns = data;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = MQUEUE_MAGIC;
sb->s_op = &mqueue_super_ops;
- inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL);
- if (!inode)
- return -ENOMEM;
+ inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
- sb->s_root = d_alloc_root(inode);
- if (!sb->s_root) {
- iput(inode);
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root)
return -ENOMEM;
- }
-
return 0;
}
-static int mqueue_get_sb(struct file_system_type *fs_type,
+static struct dentry *mqueue_mount(struct file_system_type *fs_type,
int flags, const char *dev_name,
- void *data, struct vfsmount *mnt)
+ void *data)
{
- return get_sb_single(fs_type, flags, data, mqueue_fill_super, mnt);
+ if (!(flags & MS_KERNMOUNT)) {
+ struct ipc_namespace *ns = current->nsproxy->ipc_ns;
+ /* Don't allow mounting unless the caller has CAP_SYS_ADMIN
+ * over the ipc namespace.
+ */
+ if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN))
+ return ERR_PTR(-EPERM);
+
+ data = ns;
+ }
+ return mount_ns(fs_type, flags, data, mqueue_fill_super);
}
-static void init_once(struct kmem_cache *cachep, void *foo)
+static void init_once(void *foo)
{
struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
@@ -224,86 +360,119 @@ static struct inode *mqueue_alloc_inode(struct super_block *sb)
return &ei->vfs_inode;
}
-static void mqueue_destroy_inode(struct inode *inode)
+static void mqueue_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
}
-static void mqueue_delete_inode(struct inode *inode)
+static void mqueue_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, mqueue_i_callback);
+}
+
+static void mqueue_evict_inode(struct inode *inode)
{
struct mqueue_inode_info *info;
struct user_struct *user;
- unsigned long mq_bytes;
- int i;
+ unsigned long mq_bytes, mq_treesize;
+ struct ipc_namespace *ipc_ns;
+ struct msg_msg *msg;
+
+ clear_inode(inode);
- if (S_ISDIR(inode->i_mode)) {
- clear_inode(inode);
+ if (S_ISDIR(inode->i_mode))
return;
- }
+
+ ipc_ns = get_ns_from_inode(inode);
info = MQUEUE_I(inode);
spin_lock(&info->lock);
- for (i = 0; i < info->attr.mq_curmsgs; i++)
- free_msg(info->messages[i]);
- kfree(info->messages);
+ while ((msg = msg_get(info)) != NULL)
+ free_msg(msg);
+ kfree(info->node_cache);
spin_unlock(&info->lock);
- clear_inode(inode);
+ /* Total amount of bytes accounted for the mqueue */
+ mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
+ min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
+ sizeof(struct posix_msg_tree_node);
+
+ mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
+ info->attr.mq_msgsize);
- mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) +
- (info->attr.mq_maxmsg * info->attr.mq_msgsize));
user = info->user;
if (user) {
spin_lock(&mq_lock);
user->mq_bytes -= mq_bytes;
- queues_count--;
+ /*
+ * get_ns_from_inode() ensures that the
+ * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
+ * to which we now hold a reference, or it is NULL.
+ * We can't put it here under mq_lock, though.
+ */
+ if (ipc_ns)
+ ipc_ns->mq_queues_count--;
spin_unlock(&mq_lock);
free_uid(user);
}
+ if (ipc_ns)
+ put_ipc_ns(ipc_ns);
}
static int mqueue_create(struct inode *dir, struct dentry *dentry,
- int mode, struct nameidata *nd)
+ umode_t mode, bool excl)
{
struct inode *inode;
struct mq_attr *attr = dentry->d_fsdata;
int error;
+ struct ipc_namespace *ipc_ns;
spin_lock(&mq_lock);
- if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) {
+ ipc_ns = __get_ns_from_inode(dir);
+ if (!ipc_ns) {
+ error = -EACCES;
+ goto out_unlock;
+ }
+
+ if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
+ !capable(CAP_SYS_RESOURCE)) {
error = -ENOSPC;
- goto out_lock;
+ goto out_unlock;
}
- queues_count++;
+ ipc_ns->mq_queues_count++;
spin_unlock(&mq_lock);
- inode = mqueue_get_inode(dir->i_sb, mode, attr);
- if (!inode) {
- error = -ENOMEM;
+ inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
+ if (IS_ERR(inode)) {
+ error = PTR_ERR(inode);
spin_lock(&mq_lock);
- queues_count--;
- goto out_lock;
+ ipc_ns->mq_queues_count--;
+ goto out_unlock;
}
+ put_ipc_ns(ipc_ns);
dir->i_size += DIRENT_SIZE;
dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
d_instantiate(dentry, inode);
dget(dentry);
return 0;
-out_lock:
+out_unlock:
spin_unlock(&mq_lock);
+ if (ipc_ns)
+ put_ipc_ns(ipc_ns);
return error;
}
static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = dentry->d_inode;
dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
dir->i_size -= DIRENT_SIZE;
- drop_nlink(inode);
- dput(dentry);
- return 0;
+ drop_nlink(inode);
+ dput(dentry);
+ return 0;
}
/*
@@ -314,15 +483,11 @@ static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
* through std routines)
*/
static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
- size_t count, loff_t * off)
+ size_t count, loff_t *off)
{
- struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
+ struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
char buffer[FILENT_SIZE];
- size_t slen;
- loff_t o;
-
- if (!count)
- return 0;
+ ssize_t ret;
spin_lock(&info->lock);
snprintf(buffer, sizeof(buffer),
@@ -335,26 +500,19 @@ static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
pid_vnr(info->notify_owner));
spin_unlock(&info->lock);
buffer[sizeof(buffer)-1] = '\0';
- slen = strlen(buffer)+1;
-
- o = *off;
- if (o > slen)
- return 0;
-
- if (o + count > slen)
- count = slen - o;
- if (copy_to_user(u_data, buffer + o, count))
- return -EFAULT;
+ ret = simple_read_from_buffer(u_data, count, off, buffer,
+ strlen(buffer));
+ if (ret <= 0)
+ return ret;
- *off = o + count;
- filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME;
- return count;
+ file_inode(filp)->i_atime = file_inode(filp)->i_ctime = CURRENT_TIME;
+ return ret;
}
static int mqueue_flush_file(struct file *filp, fl_owner_t id)
{
- struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
+ struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
spin_lock(&info->lock);
if (task_tgid(current) == info->notify_owner)
@@ -366,7 +524,7 @@ static int mqueue_flush_file(struct file *filp, fl_owner_t id)
static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
{
- struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
+ struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
int retval = 0;
poll_wait(filp, &info->wait_q, poll_tab);
@@ -405,7 +563,7 @@ static void wq_add(struct mqueue_inode_info *info, int sr,
* sr: SEND or RECV
*/
static int wq_sleep(struct mqueue_inode_info *info, int sr,
- long timeout, struct ext_wait_queue *ewp)
+ ktime_t *timeout, struct ext_wait_queue *ewp)
{
int retval;
signed long time;
@@ -416,7 +574,8 @@ static int wq_sleep(struct mqueue_inode_info *info, int sr,
set_current_state(TASK_INTERRUPTIBLE);
spin_unlock(&info->lock);
- time = schedule_timeout(timeout);
+ time = schedule_hrtimeout_range_clock(timeout, 0,
+ HRTIMER_MODE_ABS, CLOCK_REALTIME);
while (ewp->state == STATE_PENDING)
cpu_relax();
@@ -460,30 +619,10 @@ static struct ext_wait_queue *wq_get_first_waiter(
return list_entry(ptr, struct ext_wait_queue, list);
}
-/* Auxiliary functions to manipulate messages' list */
-static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
-{
- int k;
-
- k = info->attr.mq_curmsgs - 1;
- while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
- info->messages[k + 1] = info->messages[k];
- k--;
- }
- info->attr.mq_curmsgs++;
- info->qsize += ptr->m_ts;
- info->messages[k + 1] = ptr;
-}
-
-static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
-{
- info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
- return info->messages[info->attr.mq_curmsgs];
-}
static inline void set_cookie(struct sk_buff *skb, char code)
{
- ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
+ ((char *)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
}
/*
@@ -509,8 +648,12 @@ static void __do_notify(struct mqueue_inode_info *info)
sig_i.si_errno = 0;
sig_i.si_code = SI_MESGQ;
sig_i.si_value = info->notify.sigev_value;
- sig_i.si_pid = task_tgid_vnr(current);
- sig_i.si_uid = current->uid;
+ /* map current pid/uid into info->owner's namespaces */
+ rcu_read_lock();
+ sig_i.si_pid = task_tgid_nr_ns(current,
+ ns_of_pid(info->notify_owner));
+ sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid());
+ rcu_read_unlock();
kill_pid_info(info->notify.sigev_signo,
&sig_i, info->notify_owner);
@@ -522,40 +665,23 @@ static void __do_notify(struct mqueue_inode_info *info)
}
/* after notification unregisters process */
put_pid(info->notify_owner);
+ put_user_ns(info->notify_user_ns);
info->notify_owner = NULL;
+ info->notify_user_ns = NULL;
}
wake_up(&info->wait_q);
}
-static long prepare_timeout(const struct timespec __user *u_arg)
+static int prepare_timeout(const struct timespec __user *u_abs_timeout,
+ ktime_t *expires, struct timespec *ts)
{
- struct timespec ts, nowts;
- long timeout;
-
- if (u_arg) {
- if (unlikely(copy_from_user(&ts, u_arg,
- sizeof(struct timespec))))
- return -EFAULT;
-
- if (unlikely(ts.tv_nsec < 0 || ts.tv_sec < 0
- || ts.tv_nsec >= NSEC_PER_SEC))
- return -EINVAL;
- nowts = CURRENT_TIME;
- /* first subtract as jiffies can't be too big */
- ts.tv_sec -= nowts.tv_sec;
- if (ts.tv_nsec < nowts.tv_nsec) {
- ts.tv_nsec += NSEC_PER_SEC;
- ts.tv_sec--;
- }
- ts.tv_nsec -= nowts.tv_nsec;
- if (ts.tv_sec < 0)
- return 0;
-
- timeout = timespec_to_jiffies(&ts) + 1;
- } else
- return MAX_SCHEDULE_TIMEOUT;
+ if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec)))
+ return -EFAULT;
+ if (!timespec_valid(ts))
+ return -EINVAL;
- return timeout;
+ *expires = timespec_to_ktime(*ts);
+ return 0;
}
static void remove_notification(struct mqueue_inode_info *info)
@@ -566,192 +692,211 @@ static void remove_notification(struct mqueue_inode_info *info)
netlink_sendskb(info->notify_sock, info->notify_cookie);
}
put_pid(info->notify_owner);
+ put_user_ns(info->notify_user_ns);
info->notify_owner = NULL;
+ info->notify_user_ns = NULL;
}
-static int mq_attr_ok(struct mq_attr *attr)
+static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
{
+ int mq_treesize;
+ unsigned long total_size;
+
if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
- return 0;
+ return -EINVAL;
if (capable(CAP_SYS_RESOURCE)) {
- if (attr->mq_maxmsg > HARD_MSGMAX)
- return 0;
+ if (attr->mq_maxmsg > HARD_MSGMAX ||
+ attr->mq_msgsize > HARD_MSGSIZEMAX)
+ return -EINVAL;
} else {
- if (attr->mq_maxmsg > msg_max ||
- attr->mq_msgsize > msgsize_max)
- return 0;
+ if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
+ attr->mq_msgsize > ipc_ns->mq_msgsize_max)
+ return -EINVAL;
}
/* check for overflow */
if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
- return 0;
- if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) +
- (attr->mq_maxmsg * sizeof (struct msg_msg *)) <
- (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
- return 0;
- return 1;
+ return -EOVERFLOW;
+ mq_treesize = attr->mq_maxmsg * sizeof(struct msg_msg) +
+ min_t(unsigned int, attr->mq_maxmsg, MQ_PRIO_MAX) *
+ sizeof(struct posix_msg_tree_node);
+ total_size = attr->mq_maxmsg * attr->mq_msgsize;
+ if (total_size + mq_treesize < total_size)
+ return -EOVERFLOW;
+ return 0;
}
/*
* Invoked when creating a new queue via sys_mq_open
*/
-static struct file *do_create(struct dentry *dir, struct dentry *dentry,
- int oflag, mode_t mode, struct mq_attr __user *u_attr)
+static struct file *do_create(struct ipc_namespace *ipc_ns, struct inode *dir,
+ struct path *path, int oflag, umode_t mode,
+ struct mq_attr *attr)
{
- struct mq_attr attr;
+ const struct cred *cred = current_cred();
int ret;
- if (u_attr) {
- ret = -EFAULT;
- if (copy_from_user(&attr, u_attr, sizeof(attr)))
- goto out;
- ret = -EINVAL;
- if (!mq_attr_ok(&attr))
- goto out;
+ if (attr) {
+ ret = mq_attr_ok(ipc_ns, attr);
+ if (ret)
+ return ERR_PTR(ret);
/* store for use during create */
- dentry->d_fsdata = &attr;
+ path->dentry->d_fsdata = attr;
+ } else {
+ struct mq_attr def_attr;
+
+ def_attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
+ ipc_ns->mq_msg_default);
+ def_attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
+ ipc_ns->mq_msgsize_default);
+ ret = mq_attr_ok(ipc_ns, &def_attr);
+ if (ret)
+ return ERR_PTR(ret);
}
- mode &= ~current->fs->umask;
- ret = vfs_create(dir->d_inode, dentry, mode, NULL);
- dentry->d_fsdata = NULL;
+ mode &= ~current_umask();
+ ret = vfs_create(dir, path->dentry, mode, true);
+ path->dentry->d_fsdata = NULL;
if (ret)
- goto out;
-
- return dentry_open(dentry, mqueue_mnt, oflag);
-
-out:
- dput(dentry);
- mntput(mqueue_mnt);
- return ERR_PTR(ret);
+ return ERR_PTR(ret);
+ return dentry_open(path, oflag, cred);
}
/* Opens existing queue */
-static struct file *do_open(struct dentry *dentry, int oflag)
+static struct file *do_open(struct path *path, int oflag)
{
-static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
- MAY_READ | MAY_WRITE };
-
- if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
- dput(dentry);
- mntput(mqueue_mnt);
+ static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
+ MAY_READ | MAY_WRITE };
+ int acc;
+ if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
return ERR_PTR(-EINVAL);
- }
-
- if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL)) {
- dput(dentry);
- mntput(mqueue_mnt);
+ acc = oflag2acc[oflag & O_ACCMODE];
+ if (inode_permission(path->dentry->d_inode, acc))
return ERR_PTR(-EACCES);
- }
-
- return dentry_open(dentry, mqueue_mnt, oflag);
+ return dentry_open(path, oflag, current_cred());
}
-asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
- struct mq_attr __user *u_attr)
+SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode,
+ struct mq_attr __user *, u_attr)
{
- struct dentry *dentry;
+ struct path path;
struct file *filp;
- char *name;
+ struct filename *name;
+ struct mq_attr attr;
int fd, error;
+ struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
+ struct vfsmount *mnt = ipc_ns->mq_mnt;
+ struct dentry *root = mnt->mnt_root;
+ int ro;
- error = audit_mq_open(oflag, mode, u_attr);
- if (error != 0)
- return error;
+ if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
+ return -EFAULT;
+
+ audit_mq_open(oflag, mode, u_attr ? &attr : NULL);
if (IS_ERR(name = getname(u_name)))
return PTR_ERR(name);
- fd = get_unused_fd();
+ fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0)
goto out_putname;
- mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
- dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
- if (IS_ERR(dentry)) {
- error = PTR_ERR(dentry);
- goto out_err;
+ ro = mnt_want_write(mnt); /* we'll drop it in any case */
+ error = 0;
+ mutex_lock(&root->d_inode->i_mutex);
+ path.dentry = lookup_one_len(name->name, root, strlen(name->name));
+ if (IS_ERR(path.dentry)) {
+ error = PTR_ERR(path.dentry);
+ goto out_putfd;
}
- mntget(mqueue_mnt);
+ path.mnt = mntget(mnt);
if (oflag & O_CREAT) {
- if (dentry->d_inode) { /* entry already exists */
- audit_inode(name, dentry);
- error = -EEXIST;
- if (oflag & O_EXCL)
+ if (path.dentry->d_inode) { /* entry already exists */
+ audit_inode(name, path.dentry, 0);
+ if (oflag & O_EXCL) {
+ error = -EEXIST;
goto out;
- filp = do_open(dentry, oflag);
+ }
+ filp = do_open(&path, oflag);
} else {
- filp = do_create(mqueue_mnt->mnt_root, dentry,
- oflag, mode, u_attr);
+ if (ro) {
+ error = ro;
+ goto out;
+ }
+ audit_inode_parent_hidden(name, root);
+ filp = do_create(ipc_ns, root->d_inode,
+ &path, oflag, mode,
+ u_attr ? &attr : NULL);
}
} else {
- error = -ENOENT;
- if (!dentry->d_inode)
+ if (!path.dentry->d_inode) {
+ error = -ENOENT;
goto out;
- audit_inode(name, dentry);
- filp = do_open(dentry, oflag);
+ }
+ audit_inode(name, path.dentry, 0);
+ filp = do_open(&path, oflag);
}
- if (IS_ERR(filp)) {
+ if (!IS_ERR(filp))
+ fd_install(fd, filp);
+ else
error = PTR_ERR(filp);
- goto out_putfd;
- }
-
- set_close_on_exec(fd, 1);
- fd_install(fd, filp);
- goto out_upsem;
-
out:
- dput(dentry);
- mntput(mqueue_mnt);
+ path_put(&path);
out_putfd:
- put_unused_fd(fd);
-out_err:
- fd = error;
-out_upsem:
- mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
+ if (error) {
+ put_unused_fd(fd);
+ fd = error;
+ }
+ mutex_unlock(&root->d_inode->i_mutex);
+ if (!ro)
+ mnt_drop_write(mnt);
out_putname:
putname(name);
return fd;
}
-asmlinkage long sys_mq_unlink(const char __user *u_name)
+SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
{
int err;
- char *name;
+ struct filename *name;
struct dentry *dentry;
struct inode *inode = NULL;
+ struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
+ struct vfsmount *mnt = ipc_ns->mq_mnt;
name = getname(u_name);
if (IS_ERR(name))
return PTR_ERR(name);
- mutex_lock_nested(&mqueue_mnt->mnt_root->d_inode->i_mutex,
- I_MUTEX_PARENT);
- dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+ audit_inode_parent_hidden(name, mnt->mnt_root);
+ err = mnt_want_write(mnt);
+ if (err)
+ goto out_name;
+ mutex_lock_nested(&mnt->mnt_root->d_inode->i_mutex, I_MUTEX_PARENT);
+ dentry = lookup_one_len(name->name, mnt->mnt_root,
+ strlen(name->name));
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out_unlock;
}
- if (!dentry->d_inode) {
+ inode = dentry->d_inode;
+ if (!inode) {
err = -ENOENT;
- goto out_err;
+ } else {
+ ihold(inode);
+ err = vfs_unlink(dentry->d_parent->d_inode, dentry, NULL);
}
-
- inode = dentry->d_inode;
- if (inode)
- atomic_inc(&inode->i_count);
-
- err = vfs_unlink(dentry->d_parent->d_inode, dentry);
-out_err:
dput(dentry);
out_unlock:
- mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
- putname(name);
+ mutex_unlock(&mnt->mnt_root->d_inode->i_mutex);
if (inode)
iput(inode);
+ mnt_drop_write(mnt);
+out_name:
+ putname(name);
return err;
}
@@ -797,7 +942,8 @@ static inline void pipelined_receive(struct mqueue_inode_info *info)
wake_up_interruptible(&info->wait_q);
return;
}
- msg_insert(sender->msg, info);
+ if (msg_insert(sender->msg, info))
+ return;
list_del(&sender->list);
sender->state = STATE_PENDING;
wake_up_process(sender->task);
@@ -805,41 +951,51 @@ static inline void pipelined_receive(struct mqueue_inode_info *info)
sender->state = STATE_READY;
}
-asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
- size_t msg_len, unsigned int msg_prio,
- const struct timespec __user *u_abs_timeout)
+SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
+ size_t, msg_len, unsigned int, msg_prio,
+ const struct timespec __user *, u_abs_timeout)
{
- struct file *filp;
+ struct fd f;
struct inode *inode;
struct ext_wait_queue wait;
struct ext_wait_queue *receiver;
struct msg_msg *msg_ptr;
struct mqueue_inode_info *info;
- long timeout;
- int ret;
-
- ret = audit_mq_timedsend(mqdes, msg_len, msg_prio, u_abs_timeout);
- if (ret != 0)
- return ret;
+ ktime_t expires, *timeout = NULL;
+ struct timespec ts;
+ struct posix_msg_tree_node *new_leaf = NULL;
+ int ret = 0;
+
+ if (u_abs_timeout) {
+ int res = prepare_timeout(u_abs_timeout, &expires, &ts);
+ if (res)
+ return res;
+ timeout = &expires;
+ }
if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
return -EINVAL;
- timeout = prepare_timeout(u_abs_timeout);
+ audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL);
- ret = -EBADF;
- filp = fget(mqdes);
- if (unlikely(!filp))
+ f = fdget(mqdes);
+ if (unlikely(!f.file)) {
+ ret = -EBADF;
goto out;
+ }
- inode = filp->f_path.dentry->d_inode;
- if (unlikely(filp->f_op != &mqueue_file_operations))
+ inode = file_inode(f.file);
+ if (unlikely(f.file->f_op != &mqueue_file_operations)) {
+ ret = -EBADF;
goto out_fput;
+ }
info = MQUEUE_I(inode);
- audit_inode(NULL, filp->f_path.dentry);
+ audit_inode(NULL, f.file->f_path.dentry, 0);
- if (unlikely(!(filp->f_mode & FMODE_WRITE)))
+ if (unlikely(!(f.file->f_mode & FMODE_WRITE))) {
+ ret = -EBADF;
goto out_fput;
+ }
if (unlikely(msg_len > info->attr.mq_msgsize)) {
ret = -EMSGSIZE;
@@ -856,74 +1012,106 @@ asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
msg_ptr->m_ts = msg_len;
msg_ptr->m_type = msg_prio;
+ /*
+ * msg_insert really wants us to have a valid, spare node struct so
+ * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
+ * fall back to that if necessary.
+ */
+ if (!info->node_cache)
+ new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);
+
spin_lock(&info->lock);
+ if (!info->node_cache && new_leaf) {
+ /* Save our speculative allocation into the cache */
+ INIT_LIST_HEAD(&new_leaf->msg_list);
+ info->node_cache = new_leaf;
+ info->qsize += sizeof(*new_leaf);
+ new_leaf = NULL;
+ } else {
+ kfree(new_leaf);
+ }
+
if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
- if (filp->f_flags & O_NONBLOCK) {
- spin_unlock(&info->lock);
+ if (f.file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
- } else if (unlikely(timeout < 0)) {
- spin_unlock(&info->lock);
- ret = timeout;
} else {
wait.task = current;
wait.msg = (void *) msg_ptr;
wait.state = STATE_NONE;
ret = wq_sleep(info, SEND, timeout, &wait);
+ /*
+ * wq_sleep must be called with info->lock held, and
+ * returns with the lock released
+ */
+ goto out_free;
}
- if (ret < 0)
- free_msg(msg_ptr);
} else {
receiver = wq_get_first_waiter(info, RECV);
if (receiver) {
pipelined_send(info, msg_ptr, receiver);
} else {
/* adds message to the queue */
- msg_insert(msg_ptr, info);
+ ret = msg_insert(msg_ptr, info);
+ if (ret)
+ goto out_unlock;
__do_notify(info);
}
inode->i_atime = inode->i_mtime = inode->i_ctime =
CURRENT_TIME;
- spin_unlock(&info->lock);
- ret = 0;
}
+out_unlock:
+ spin_unlock(&info->lock);
+out_free:
+ if (ret)
+ free_msg(msg_ptr);
out_fput:
- fput(filp);
+ fdput(f);
out:
return ret;
}
-asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
- size_t msg_len, unsigned int __user *u_msg_prio,
- const struct timespec __user *u_abs_timeout)
+SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
+ size_t, msg_len, unsigned int __user *, u_msg_prio,
+ const struct timespec __user *, u_abs_timeout)
{
- long timeout;
ssize_t ret;
struct msg_msg *msg_ptr;
- struct file *filp;
+ struct fd f;
struct inode *inode;
struct mqueue_inode_info *info;
struct ext_wait_queue wait;
+ ktime_t expires, *timeout = NULL;
+ struct timespec ts;
+ struct posix_msg_tree_node *new_leaf = NULL;
+
+ if (u_abs_timeout) {
+ int res = prepare_timeout(u_abs_timeout, &expires, &ts);
+ if (res)
+ return res;
+ timeout = &expires;
+ }
- ret = audit_mq_timedreceive(mqdes, msg_len, u_msg_prio, u_abs_timeout);
- if (ret != 0)
- return ret;
-
- timeout = prepare_timeout(u_abs_timeout);
+ audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL);
- ret = -EBADF;
- filp = fget(mqdes);
- if (unlikely(!filp))
+ f = fdget(mqdes);
+ if (unlikely(!f.file)) {
+ ret = -EBADF;
goto out;
+ }
- inode = filp->f_path.dentry->d_inode;
- if (unlikely(filp->f_op != &mqueue_file_operations))
+ inode = file_inode(f.file);
+ if (unlikely(f.file->f_op != &mqueue_file_operations)) {
+ ret = -EBADF;
goto out_fput;
+ }
info = MQUEUE_I(inode);
- audit_inode(NULL, filp->f_path.dentry);
+ audit_inode(NULL, f.file->f_path.dentry, 0);
- if (unlikely(!(filp->f_mode & FMODE_READ)))
+ if (unlikely(!(f.file->f_mode & FMODE_READ))) {
+ ret = -EBADF;
goto out_fput;
+ }
/* checks if buffer is big enough */
if (unlikely(msg_len < info->attr.mq_msgsize)) {
@@ -931,16 +1119,29 @@ asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
goto out_fput;
}
+ /*
+ * msg_insert really wants us to have a valid, spare node struct so
+ * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
+ * fall back to that if necessary.
+ */
+ if (!info->node_cache)
+ new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);
+
spin_lock(&info->lock);
+
+ if (!info->node_cache && new_leaf) {
+ /* Save our speculative allocation into the cache */
+ INIT_LIST_HEAD(&new_leaf->msg_list);
+ info->node_cache = new_leaf;
+ info->qsize += sizeof(*new_leaf);
+ } else {
+ kfree(new_leaf);
+ }
+
if (info->attr.mq_curmsgs == 0) {
- if (filp->f_flags & O_NONBLOCK) {
+ if (f.file->f_flags & O_NONBLOCK) {
spin_unlock(&info->lock);
ret = -EAGAIN;
- msg_ptr = NULL;
- } else if (unlikely(timeout < 0)) {
- spin_unlock(&info->lock);
- ret = timeout;
- msg_ptr = NULL;
} else {
wait.task = current;
wait.state = STATE_NONE;
@@ -968,7 +1169,7 @@ asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
free_msg(msg_ptr);
}
out_fput:
- fput(filp);
+ fdput(f);
out:
return ret;
}
@@ -978,28 +1179,28 @@ out:
* and he isn't currently owner of notification, will be silently discarded.
* It isn't explicitly defined in the POSIX.
*/
-asmlinkage long sys_mq_notify(mqd_t mqdes,
- const struct sigevent __user *u_notification)
+SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
+ const struct sigevent __user *, u_notification)
{
int ret;
- struct file *filp;
+ struct fd f;
struct sock *sock;
struct inode *inode;
struct sigevent notification;
struct mqueue_inode_info *info;
struct sk_buff *nc;
- ret = audit_mq_notify(mqdes, u_notification);
- if (ret != 0)
- return ret;
-
- nc = NULL;
- sock = NULL;
- if (u_notification != NULL) {
+ if (u_notification) {
if (copy_from_user(&notification, u_notification,
sizeof(struct sigevent)))
return -EFAULT;
+ }
+
+ audit_mq_notify(mqdes, u_notification ? &notification : NULL);
+ nc = NULL;
+ sock = NULL;
+ if (u_notification != NULL) {
if (unlikely(notification.sigev_notify != SIGEV_NONE &&
notification.sigev_notify != SIGEV_SIGNAL &&
notification.sigev_notify != SIGEV_THREAD))
@@ -1013,13 +1214,14 @@ asmlinkage long sys_mq_notify(mqd_t mqdes,
/* create the notify skb */
nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
- ret = -ENOMEM;
- if (!nc)
+ if (!nc) {
+ ret = -ENOMEM;
goto out;
- ret = -EFAULT;
+ }
if (copy_from_user(nc->data,
notification.sigev_value.sival_ptr,
NOTIFY_COOKIE_LEN)) {
+ ret = -EFAULT;
goto out;
}
@@ -1027,12 +1229,13 @@ asmlinkage long sys_mq_notify(mqd_t mqdes,
skb_put(nc, NOTIFY_COOKIE_LEN);
/* and attach it to the socket */
retry:
- filp = fget(notification.sigev_signo);
- ret = -EBADF;
- if (!filp)
+ f = fdget(notification.sigev_signo);
+ if (!f.file) {
+ ret = -EBADF;
goto out;
- sock = netlink_getsockbyfilp(filp);
- fput(filp);
+ }
+ sock = netlink_getsockbyfilp(f.file);
+ fdput(f);
if (IS_ERR(sock)) {
ret = PTR_ERR(sock);
sock = NULL;
@@ -1040,9 +1243,9 @@ retry:
}
timeo = MAX_SCHEDULE_TIMEOUT;
- ret = netlink_attachskb(sock, nc, 0, &timeo, NULL);
+ ret = netlink_attachskb(sock, nc, &timeo, NULL);
if (ret == 1)
- goto retry;
+ goto retry;
if (ret) {
sock = NULL;
nc = NULL;
@@ -1051,14 +1254,17 @@ retry:
}
}
- ret = -EBADF;
- filp = fget(mqdes);
- if (!filp)
+ f = fdget(mqdes);
+ if (!f.file) {
+ ret = -EBADF;
goto out;
+ }
- inode = filp->f_path.dentry->d_inode;
- if (unlikely(filp->f_op != &mqueue_file_operations))
+ inode = file_inode(f.file);
+ if (unlikely(f.file->f_op != &mqueue_file_operations)) {
+ ret = -EBADF;
goto out_fput;
+ }
info = MQUEUE_I(inode);
ret = 0;
@@ -1090,27 +1296,28 @@ retry:
}
info->notify_owner = get_pid(task_tgid(current));
+ info->notify_user_ns = get_user_ns(current_user_ns());
inode->i_atime = inode->i_ctime = CURRENT_TIME;
}
spin_unlock(&info->lock);
out_fput:
- fput(filp);
+ fdput(f);
out:
- if (sock) {
+ if (sock)
netlink_detachskb(sock, nc);
- } else if (nc) {
+ else if (nc)
dev_kfree_skb(nc);
- }
+
return ret;
}
-asmlinkage long sys_mq_getsetattr(mqd_t mqdes,
- const struct mq_attr __user *u_mqstat,
- struct mq_attr __user *u_omqstat)
+SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
+ const struct mq_attr __user *, u_mqstat,
+ struct mq_attr __user *, u_omqstat)
{
int ret;
struct mq_attr mqstat, omqstat;
- struct file *filp;
+ struct fd f;
struct inode *inode;
struct mqueue_inode_info *info;
@@ -1121,30 +1328,31 @@ asmlinkage long sys_mq_getsetattr(mqd_t mqdes,
return -EINVAL;
}
- ret = -EBADF;
- filp = fget(mqdes);
- if (!filp)
+ f = fdget(mqdes);
+ if (!f.file) {
+ ret = -EBADF;
goto out;
+ }
- inode = filp->f_path.dentry->d_inode;
- if (unlikely(filp->f_op != &mqueue_file_operations))
+ inode = file_inode(f.file);
+ if (unlikely(f.file->f_op != &mqueue_file_operations)) {
+ ret = -EBADF;
goto out_fput;
+ }
info = MQUEUE_I(inode);
spin_lock(&info->lock);
omqstat = info->attr;
- omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
+ omqstat.mq_flags = f.file->f_flags & O_NONBLOCK;
if (u_mqstat) {
- ret = audit_mq_getsetattr(mqdes, &mqstat);
- if (ret != 0) {
- spin_unlock(&info->lock);
- goto out_fput;
- }
+ audit_mq_getsetattr(mqdes, &mqstat);
+ spin_lock(&f.file->f_lock);
if (mqstat.mq_flags & O_NONBLOCK)
- filp->f_flags |= O_NONBLOCK;
+ f.file->f_flags |= O_NONBLOCK;
else
- filp->f_flags &= ~O_NONBLOCK;
+ f.file->f_flags &= ~O_NONBLOCK;
+ spin_unlock(&f.file->f_lock);
inode->i_atime = inode->i_ctime = CURRENT_TIME;
}
@@ -1157,7 +1365,7 @@ asmlinkage long sys_mq_getsetattr(mqd_t mqdes,
ret = -EFAULT;
out_fput:
- fput(filp);
+ fdput(f);
out:
return ret;
}
@@ -1172,75 +1380,50 @@ static const struct file_operations mqueue_file_operations = {
.flush = mqueue_flush_file,
.poll = mqueue_poll_file,
.read = mqueue_read_file,
+ .llseek = default_llseek,
};
-static struct super_operations mqueue_super_ops = {
+static const struct super_operations mqueue_super_ops = {
.alloc_inode = mqueue_alloc_inode,
.destroy_inode = mqueue_destroy_inode,
+ .evict_inode = mqueue_evict_inode,
.statfs = simple_statfs,
- .delete_inode = mqueue_delete_inode,
- .drop_inode = generic_delete_inode,
};
static struct file_system_type mqueue_fs_type = {
.name = "mqueue",
- .get_sb = mqueue_get_sb,
+ .mount = mqueue_mount,
.kill_sb = kill_litter_super,
+ .fs_flags = FS_USERNS_MOUNT,
};
-static int msg_max_limit_min = DFLT_MSGMAX;
-static int msg_max_limit_max = HARD_MSGMAX;
-
-static int msg_maxsize_limit_min = DFLT_MSGSIZEMAX;
-static int msg_maxsize_limit_max = INT_MAX;
-
-static ctl_table mq_sysctls[] = {
- {
- .procname = "queues_max",
- .data = &queues_max,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .procname = "msg_max",
- .data = &msg_max,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec_minmax,
- .extra1 = &msg_max_limit_min,
- .extra2 = &msg_max_limit_max,
- },
- {
- .procname = "msgsize_max",
- .data = &msgsize_max,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec_minmax,
- .extra1 = &msg_maxsize_limit_min,
- .extra2 = &msg_maxsize_limit_max,
- },
- { .ctl_name = 0 }
-};
+int mq_init_ns(struct ipc_namespace *ns)
+{
+ ns->mq_queues_count = 0;
+ ns->mq_queues_max = DFLT_QUEUESMAX;
+ ns->mq_msg_max = DFLT_MSGMAX;
+ ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
+ ns->mq_msg_default = DFLT_MSG;
+ ns->mq_msgsize_default = DFLT_MSGSIZE;
+
+ ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
+ if (IS_ERR(ns->mq_mnt)) {
+ int err = PTR_ERR(ns->mq_mnt);
+ ns->mq_mnt = NULL;
+ return err;
+ }
+ return 0;
+}
-static ctl_table mq_sysctl_dir[] = {
- {
- .procname = "mqueue",
- .mode = 0555,
- .child = mq_sysctls,
- },
- { .ctl_name = 0 }
-};
+void mq_clear_sbinfo(struct ipc_namespace *ns)
+{
+ ns->mq_mnt->mnt_sb->s_fs_info = NULL;
+}
-static ctl_table mq_sysctl_root[] = {
- {
- .ctl_name = CTL_FS,
- .procname = "fs",
- .mode = 0555,
- .child = mq_sysctl_dir,
- },
- { .ctl_name = 0 }
-};
+void mq_put_mnt(struct ipc_namespace *ns)
+{
+ kern_unmount(ns->mq_mnt);
+}
static int __init init_mqueue_fs(void)
{
@@ -1252,22 +1435,19 @@ static int __init init_mqueue_fs(void)
if (mqueue_inode_cachep == NULL)
return -ENOMEM;
- /* ignore failues - they are not fatal */
- mq_sysctl_table = register_sysctl_table(mq_sysctl_root);
+ /* ignore failures - they are not fatal */
+ mq_sysctl_table = mq_register_sysctl_table();
error = register_filesystem(&mqueue_fs_type);
if (error)
goto out_sysctl;
- if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) {
- error = PTR_ERR(mqueue_mnt);
- goto out_filesystem;
- }
-
- /* internal initialization - not common for vfs */
- queues_count = 0;
spin_lock_init(&mq_lock);
+ error = mq_init_ns(&init_ipc_ns);
+ if (error)
+ goto out_filesystem;
+
return 0;
out_filesystem:
@@ -1279,4 +1459,4 @@ out_sysctl:
return error;
}
-__initcall(init_mqueue_fs);
+device_initcall(init_mqueue_fs);
diff --git a/ipc/msg.c b/ipc/msg.c
index 46585a05473..c5d8e374998 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -23,10 +23,10 @@
*/
#include <linux/capability.h>
-#include <linux/slab.h>
#include <linux/msg.h>
#include <linux/spinlock.h>
#include <linux/init.h>
+#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/list.h>
#include <linux/security.h>
@@ -39,12 +39,10 @@
#include <linux/ipc_namespace.h>
#include <asm/current.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include "util.h"
-/*
- * one msg_receiver structure for each sleeping receiver:
- */
+/* one msg_receiver structure for each sleeping receiver */
struct msg_receiver {
struct list_head r_list;
struct task_struct *r_tsk;
@@ -53,6 +51,12 @@ struct msg_receiver {
long r_msgtype;
long r_maxsize;
+ /*
+ * Mark r_msg volatile so that the compiler
+ * does not try to get smart and optimize
+ * it. We rely on this for the lockless
+ * receive algorithm.
+ */
struct msg_msg *volatile r_msg;
};
@@ -66,86 +70,43 @@ struct msg_sender {
#define SEARCH_EQUAL 2
#define SEARCH_NOTEQUAL 3
#define SEARCH_LESSEQUAL 4
+#define SEARCH_NUMBER 5
#define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS])
-#define msg_unlock(msq) ipc_unlock(&(msq)->q_perm)
-#define msg_buildid(id, seq) ipc_buildid(id, seq)
-
-static void freeque(struct ipc_namespace *, struct kern_ipc_perm *);
-static int newque(struct ipc_namespace *, struct ipc_params *);
-#ifdef CONFIG_PROC_FS
-static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
-#endif
-
-void msg_init_ns(struct ipc_namespace *ns)
-{
- ns->msg_ctlmax = MSGMAX;
- ns->msg_ctlmnb = MSGMNB;
- ns->msg_ctlmni = MSGMNI;
- atomic_set(&ns->msg_bytes, 0);
- atomic_set(&ns->msg_hdrs, 0);
- ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
-}
-
-#ifdef CONFIG_IPC_NS
-void msg_exit_ns(struct ipc_namespace *ns)
-{
- free_ipcs(ns, &msg_ids(ns), freeque);
-}
-#endif
-
-void __init msg_init(void)
-{
- msg_init_ns(&init_ipc_ns);
- ipc_init_proc_interface("sysvipc/msg",
- " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n",
- IPC_MSG_IDS, sysvipc_msg_proc_show);
-}
-
-/*
- * This routine is called in the paths where the rw_mutex is held to protect
- * access to the idr tree.
- */
-static inline struct msg_queue *msg_lock_check_down(struct ipc_namespace *ns,
- int id)
+static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id)
{
- struct kern_ipc_perm *ipcp = ipc_lock_check_down(&msg_ids(ns), id);
+ struct kern_ipc_perm *ipcp = ipc_obtain_object(&msg_ids(ns), id);
if (IS_ERR(ipcp))
- return (struct msg_queue *)ipcp;
+ return ERR_CAST(ipcp);
return container_of(ipcp, struct msg_queue, q_perm);
}
-/*
- * msg_lock_(check_) routines are called in the paths where the rw_mutex
- * is not held.
- */
-static inline struct msg_queue *msg_lock(struct ipc_namespace *ns, int id)
+static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns,
+ int id)
{
- struct kern_ipc_perm *ipcp = ipc_lock(&msg_ids(ns), id);
+ struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id);
if (IS_ERR(ipcp))
- return (struct msg_queue *)ipcp;
+ return ERR_CAST(ipcp);
return container_of(ipcp, struct msg_queue, q_perm);
}
-static inline struct msg_queue *msg_lock_check(struct ipc_namespace *ns,
- int id)
+static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
{
- struct kern_ipc_perm *ipcp = ipc_lock_check(&msg_ids(ns), id);
-
- if (IS_ERR(ipcp))
- return (struct msg_queue *)ipcp;
-
- return container_of(ipcp, struct msg_queue, q_perm);
+ ipc_rmid(&msg_ids(ns), &s->q_perm);
}
-static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
+static void msg_rcu_free(struct rcu_head *head)
{
- ipc_rmid(&msg_ids(ns), &s->q_perm);
+ struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
+ struct msg_queue *msq = ipc_rcu_to_struct(p);
+
+ security_msg_queue_free(msq);
+ ipc_rcu_free(head);
}
/**
@@ -153,7 +114,7 @@ static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
* @ns: namespace
* @params: ptr to the structure that contains the key and msgflg
*
- * Called with msg_ids.rw_mutex held (writer)
+ * Called with msg_ids.rwsem held (writer)
*/
static int newque(struct ipc_namespace *ns, struct ipc_params *params)
{
@@ -172,21 +133,17 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
msq->q_perm.security = NULL;
retval = security_msg_queue_alloc(msq);
if (retval) {
- ipc_rcu_putref(msq);
+ ipc_rcu_putref(msq, ipc_rcu_free);
return retval;
}
- /*
- * ipc_addid() locks msq
- */
+ /* ipc_addid() locks msq upon success. */
id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
if (id < 0) {
- security_msg_queue_free(msq);
- ipc_rcu_putref(msq);
+ ipc_rcu_putref(msq, msg_rcu_free);
return id;
}
- msq->q_perm.id = msg_buildid(id, msq->q_perm.seq);
msq->q_stime = msq->q_rtime = 0;
msq->q_ctime = get_seconds();
msq->q_cbytes = msq->q_qnum = 0;
@@ -196,7 +153,8 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
INIT_LIST_HEAD(&msq->q_receivers);
INIT_LIST_HEAD(&msq->q_senders);
- msg_unlock(msq);
+ ipc_unlock_object(&msq->q_perm);
+ rcu_read_unlock();
return msq->q_perm.id;
}
@@ -204,7 +162,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss)
{
mss->tsk = current;
- current->state = TASK_INTERRUPTIBLE;
+ __set_current_state(TASK_INTERRUPTIBLE);
list_add_tail(&mss->list, &msq->q_senders);
}
@@ -216,14 +174,9 @@ static inline void ss_del(struct msg_sender *mss)
static void ss_wakeup(struct list_head *h, int kill)
{
- struct list_head *tmp;
+ struct msg_sender *mss, *t;
- tmp = h->next;
- while (tmp != h) {
- struct msg_sender *mss;
-
- mss = list_entry(tmp, struct msg_sender, list);
- tmp = tmp->next;
+ list_for_each_entry_safe(mss, t, h, list) {
if (kill)
mss->list.next = NULL;
wake_up_process(mss->tsk);
@@ -232,16 +185,17 @@ static void ss_wakeup(struct list_head *h, int kill)
static void expunge_all(struct msg_queue *msq, int res)
{
- struct list_head *tmp;
-
- tmp = msq->q_receivers.next;
- while (tmp != &msq->q_receivers) {
- struct msg_receiver *msr;
+ struct msg_receiver *msr, *t;
- msr = list_entry(tmp, struct msg_receiver, r_list);
- tmp = tmp->next;
- msr->r_msg = NULL;
+ list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
+ msr->r_msg = NULL; /* initialize expunge ordering */
wake_up_process(msr->r_tsk);
+ /*
+ * Ensure that the wakeup is visible before setting r_msg as
+ * the receiving end depends on it: either spinning on a nil,
+ * or dealing with -EAGAIN cases. See lockless receive part 1
+ * and 2 in do_msgrcv().
+ */
smp_mb();
msr->r_msg = ERR_PTR(res);
}
@@ -252,34 +206,30 @@ static void expunge_all(struct msg_queue *msq, int res)
* removes the message queue from message queue ID IDR, and cleans up all the
* messages associated with this queue.
*
- * msg_ids.rw_mutex (writer) and the spinlock for this message queue are held
- * before freeque() is called. msg_ids.rw_mutex remains locked on exit.
+ * msg_ids.rwsem (writer) and the spinlock for this message queue are held
+ * before freeque() is called. msg_ids.rwsem remains locked on exit.
*/
static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
{
- struct list_head *tmp;
+ struct msg_msg *msg, *t;
struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
expunge_all(msq, -EIDRM);
ss_wakeup(&msq->q_senders, 1);
msg_rmid(ns, msq);
- msg_unlock(msq);
-
- tmp = msq->q_messages.next;
- while (tmp != &msq->q_messages) {
- struct msg_msg *msg = list_entry(tmp, struct msg_msg, m_list);
+ ipc_unlock_object(&msq->q_perm);
+ rcu_read_unlock();
- tmp = tmp->next;
+ list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
atomic_dec(&ns->msg_hdrs);
free_msg(msg);
}
atomic_sub(msq->q_cbytes, &ns->msg_bytes);
- security_msg_queue_free(msq);
- ipc_rcu_putref(msq);
+ ipc_rcu_putref(msq, msg_rcu_free);
}
/*
- * Called with msg_ids.rw_mutex and ipcp locked.
+ * Called with msg_ids.rwsem and ipcp locked.
*/
static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
{
@@ -288,18 +238,17 @@ static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
return security_msg_queue_associate(msq, msgflg);
}
-asmlinkage long sys_msgget(key_t key, int msgflg)
+SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
{
struct ipc_namespace *ns;
- struct ipc_ops msg_ops;
+ static const struct ipc_ops msg_ops = {
+ .getnew = newque,
+ .associate = msg_security,
+ };
struct ipc_params msg_params;
ns = current->nsproxy->ipc_ns;
- msg_ops.getnew = newque;
- msg_ops.associate = msg_security;
- msg_ops.more_checks = NULL;
-
msg_params.key = key;
msg_params.flg = msgflg;
@@ -309,7 +258,7 @@ asmlinkage long sys_msgget(key_t key, int msgflg)
static inline unsigned long
copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
return copy_to_user(buf, in, sizeof(*in));
case IPC_OLD:
@@ -351,31 +300,14 @@ copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
}
}
-struct msq_setbuf {
- unsigned long qbytes;
- uid_t uid;
- gid_t gid;
- mode_t mode;
-};
-
static inline unsigned long
-copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version)
+copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
- {
- struct msqid64_ds tbuf;
-
- if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
+ if (copy_from_user(out, buf, sizeof(*out)))
return -EFAULT;
-
- out->qbytes = tbuf.msg_qbytes;
- out->uid = tbuf.msg_perm.uid;
- out->gid = tbuf.msg_perm.gid;
- out->mode = tbuf.msg_perm.mode;
-
return 0;
- }
case IPC_OLD:
{
struct msqid_ds tbuf_old;
@@ -383,14 +315,14 @@ copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version)
if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
return -EFAULT;
- out->uid = tbuf_old.msg_perm.uid;
- out->gid = tbuf_old.msg_perm.gid;
- out->mode = tbuf_old.msg_perm.mode;
+ out->msg_perm.uid = tbuf_old.msg_perm.uid;
+ out->msg_perm.gid = tbuf_old.msg_perm.gid;
+ out->msg_perm.mode = tbuf_old.msg_perm.mode;
if (tbuf_old.msg_qbytes == 0)
- out->qbytes = tbuf_old.msg_lqbytes;
+ out->msg_qbytes = tbuf_old.msg_lqbytes;
else
- out->qbytes = tbuf_old.msg_qbytes;
+ out->msg_qbytes = tbuf_old.msg_qbytes;
return 0;
}
@@ -399,19 +331,89 @@ copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version)
}
}
-asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
+/*
+ * This function handles some msgctl commands which require the rwsem
+ * to be held in write mode.
+ * NOTE: no locks must be held, the rwsem is taken inside this function.
+ */
+static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
+ struct msqid_ds __user *buf, int version)
{
struct kern_ipc_perm *ipcp;
- struct msq_setbuf uninitialized_var(setbuf);
+ struct msqid64_ds uninitialized_var(msqid64);
struct msg_queue *msq;
- int err, version;
- struct ipc_namespace *ns;
+ int err;
- if (msqid < 0 || cmd < 0)
- return -EINVAL;
+ if (cmd == IPC_SET) {
+ if (copy_msqid_from_user(&msqid64, buf, version))
+ return -EFAULT;
+ }
- version = ipc_parse_version(&cmd);
- ns = current->nsproxy->ipc_ns;
+ down_write(&msg_ids(ns).rwsem);
+ rcu_read_lock();
+
+ ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd,
+ &msqid64.msg_perm, msqid64.msg_qbytes);
+ if (IS_ERR(ipcp)) {
+ err = PTR_ERR(ipcp);
+ goto out_unlock1;
+ }
+
+ msq = container_of(ipcp, struct msg_queue, q_perm);
+
+ err = security_msg_queue_msgctl(msq, cmd);
+ if (err)
+ goto out_unlock1;
+
+ switch (cmd) {
+ case IPC_RMID:
+ ipc_lock_object(&msq->q_perm);
+ /* freeque unlocks the ipc object and rcu */
+ freeque(ns, ipcp);
+ goto out_up;
+ case IPC_SET:
+ if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
+ !capable(CAP_SYS_RESOURCE)) {
+ err = -EPERM;
+ goto out_unlock1;
+ }
+
+ ipc_lock_object(&msq->q_perm);
+ err = ipc_update_perm(&msqid64.msg_perm, ipcp);
+ if (err)
+ goto out_unlock0;
+
+ msq->q_qbytes = msqid64.msg_qbytes;
+
+ msq->q_ctime = get_seconds();
+ /* sleeping receivers might be excluded by
+ * stricter permissions.
+ */
+ expunge_all(msq, -EAGAIN);
+ /* sleeping senders might be able to send
+ * due to a larger queue size.
+ */
+ ss_wakeup(&msq->q_senders, 0);
+ break;
+ default:
+ err = -EINVAL;
+ goto out_unlock1;
+ }
+
+out_unlock0:
+ ipc_unlock_object(&msq->q_perm);
+out_unlock1:
+ rcu_read_unlock();
+out_up:
+ up_write(&msg_ids(ns).rwsem);
+ return err;
+}
+
+static int msgctl_nolock(struct ipc_namespace *ns, int msqid,
+ int cmd, int version, void __user *buf)
+{
+ int err;
+ struct msg_queue *msq;
switch (cmd) {
case IPC_INFO:
@@ -422,6 +424,7 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
if (!buf)
return -EFAULT;
+
/*
* We must not return kernel stack data.
* due to padding, it's not enough
@@ -437,7 +440,7 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
msginfo.msgmnb = ns->msg_ctlmnb;
msginfo.msgssz = MSGSSZ;
msginfo.msgseg = MSGSEG;
- down_read(&msg_ids(ns).rw_mutex);
+ down_read(&msg_ids(ns).rwsem);
if (cmd == MSG_INFO) {
msginfo.msgpool = msg_ids(ns).in_use;
msginfo.msgmap = atomic_read(&ns->msg_hdrs);
@@ -448,12 +451,13 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
msginfo.msgtql = MSGTQL;
}
max_id = ipc_get_maxid(&msg_ids(ns));
- up_read(&msg_ids(ns).rw_mutex);
+ up_read(&msg_ids(ns).rwsem);
if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
return -EFAULT;
return (max_id < 0) ? 0 : max_id;
}
- case MSG_STAT: /* msqid is an index rather than a msg queue id */
+
+ case MSG_STAT:
case IPC_STAT:
{
struct msqid64_ds tbuf;
@@ -462,27 +466,33 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
if (!buf)
return -EFAULT;
+ memset(&tbuf, 0, sizeof(tbuf));
+
+ rcu_read_lock();
if (cmd == MSG_STAT) {
- msq = msg_lock(ns, msqid);
- if (IS_ERR(msq))
- return PTR_ERR(msq);
+ msq = msq_obtain_object(ns, msqid);
+ if (IS_ERR(msq)) {
+ err = PTR_ERR(msq);
+ goto out_unlock;
+ }
success_return = msq->q_perm.id;
} else {
- msq = msg_lock_check(ns, msqid);
- if (IS_ERR(msq))
- return PTR_ERR(msq);
+ msq = msq_obtain_object_check(ns, msqid);
+ if (IS_ERR(msq)) {
+ err = PTR_ERR(msq);
+ goto out_unlock;
+ }
success_return = 0;
}
+
err = -EACCES;
- if (ipcperms(&msq->q_perm, S_IRUGO))
+ if (ipcperms(ns, &msq->q_perm, S_IRUGO))
goto out_unlock;
err = security_msg_queue_msgctl(msq, cmd);
if (err)
goto out_unlock;
- memset(&tbuf, 0, sizeof(tbuf));
-
kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
tbuf.msg_stime = msq->q_stime;
tbuf.msg_rtime = msq->q_rtime;
@@ -492,140 +502,97 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
tbuf.msg_qbytes = msq->q_qbytes;
tbuf.msg_lspid = msq->q_lspid;
tbuf.msg_lrpid = msq->q_lrpid;
- msg_unlock(msq);
+ rcu_read_unlock();
+
if (copy_msqid_to_user(buf, &tbuf, version))
return -EFAULT;
return success_return;
}
- case IPC_SET:
- if (!buf)
- return -EFAULT;
- if (copy_msqid_from_user(&setbuf, buf, version))
- return -EFAULT;
- break;
- case IPC_RMID:
- break;
- default:
- return -EINVAL;
- }
- down_write(&msg_ids(ns).rw_mutex);
- msq = msg_lock_check_down(ns, msqid);
- if (IS_ERR(msq)) {
- err = PTR_ERR(msq);
- goto out_up;
+ default:
+ return -EINVAL;
}
- ipcp = &msq->q_perm;
+ return err;
+out_unlock:
+ rcu_read_unlock();
+ return err;
+}
- err = audit_ipc_obj(ipcp);
- if (err)
- goto out_unlock_up;
- if (cmd == IPC_SET) {
- err = audit_ipc_set_perm(setbuf.qbytes, setbuf.uid, setbuf.gid,
- setbuf.mode);
- if (err)
- goto out_unlock_up;
- }
+SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
+{
+ int version;
+ struct ipc_namespace *ns;
- err = -EPERM;
- if (current->euid != ipcp->cuid &&
- current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN))
- /* We _could_ check for CAP_CHOWN above, but we don't */
- goto out_unlock_up;
+ if (msqid < 0 || cmd < 0)
+ return -EINVAL;
- err = security_msg_queue_msgctl(msq, cmd);
- if (err)
- goto out_unlock_up;
+ version = ipc_parse_version(&cmd);
+ ns = current->nsproxy->ipc_ns;
switch (cmd) {
+ case IPC_INFO:
+ case MSG_INFO:
+ case MSG_STAT: /* msqid is an index rather than a msg queue id */
+ case IPC_STAT:
+ return msgctl_nolock(ns, msqid, cmd, version, buf);
case IPC_SET:
- {
- err = -EPERM;
- if (setbuf.qbytes > ns->msg_ctlmnb && !capable(CAP_SYS_RESOURCE))
- goto out_unlock_up;
-
- msq->q_qbytes = setbuf.qbytes;
-
- ipcp->uid = setbuf.uid;
- ipcp->gid = setbuf.gid;
- ipcp->mode = (ipcp->mode & ~S_IRWXUGO) |
- (S_IRWXUGO & setbuf.mode);
- msq->q_ctime = get_seconds();
- /* sleeping receivers might be excluded by
- * stricter permissions.
- */
- expunge_all(msq, -EAGAIN);
- /* sleeping senders might be able to send
- * due to a larger queue size.
- */
- ss_wakeup(&msq->q_senders, 0);
- msg_unlock(msq);
- break;
- }
case IPC_RMID:
- freeque(ns, &msq->q_perm);
- break;
+ return msgctl_down(ns, msqid, cmd, buf, version);
+ default:
+ return -EINVAL;
}
- err = 0;
-out_up:
- up_write(&msg_ids(ns).rw_mutex);
- return err;
-out_unlock_up:
- msg_unlock(msq);
- goto out_up;
-out_unlock:
- msg_unlock(msq);
- return err;
}
static int testmsg(struct msg_msg *msg, long type, int mode)
{
- switch(mode)
- {
- case SEARCH_ANY:
+ switch (mode) {
+ case SEARCH_ANY:
+ case SEARCH_NUMBER:
+ return 1;
+ case SEARCH_LESSEQUAL:
+ if (msg->m_type <= type)
return 1;
- case SEARCH_LESSEQUAL:
- if (msg->m_type <=type)
- return 1;
- break;
- case SEARCH_EQUAL:
- if (msg->m_type == type)
- return 1;
- break;
- case SEARCH_NOTEQUAL:
- if (msg->m_type != type)
- return 1;
- break;
+ break;
+ case SEARCH_EQUAL:
+ if (msg->m_type == type)
+ return 1;
+ break;
+ case SEARCH_NOTEQUAL:
+ if (msg->m_type != type)
+ return 1;
+ break;
}
return 0;
}
static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
{
- struct list_head *tmp;
+ struct msg_receiver *msr, *t;
- tmp = msq->q_receivers.next;
- while (tmp != &msq->q_receivers) {
- struct msg_receiver *msr;
-
- msr = list_entry(tmp, struct msg_receiver, r_list);
- tmp = tmp->next;
+ list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
!security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
msr->r_msgtype, msr->r_mode)) {
list_del(&msr->r_list);
if (msr->r_maxsize < msg->m_ts) {
+ /* initialize pipelined send ordering */
msr->r_msg = NULL;
wake_up_process(msr->r_tsk);
- smp_mb();
+ smp_mb(); /* see barrier comment below */
msr->r_msg = ERR_PTR(-E2BIG);
} else {
msr->r_msg = NULL;
msq->q_lrpid = task_pid_vnr(msr->r_tsk);
msq->q_rtime = get_seconds();
wake_up_process(msr->r_tsk);
+ /*
+ * Ensure that the wakeup is visible before
+ * setting r_msg, as the receiving end depends
+ * on it. See lockless receive part 1 and 2 in
+ * do_msgrcv().
+ */
smp_mb();
msr->r_msg = msg;
@@ -633,6 +600,7 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
}
}
}
+
return 0;
}
@@ -658,22 +626,31 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
msg->m_type = mtype;
msg->m_ts = msgsz;
- msq = msg_lock_check(ns, msqid);
+ rcu_read_lock();
+ msq = msq_obtain_object_check(ns, msqid);
if (IS_ERR(msq)) {
err = PTR_ERR(msq);
- goto out_free;
+ goto out_unlock1;
}
+ ipc_lock_object(&msq->q_perm);
+
for (;;) {
struct msg_sender s;
err = -EACCES;
- if (ipcperms(&msq->q_perm, S_IWUGO))
- goto out_unlock_free;
+ if (ipcperms(ns, &msq->q_perm, S_IWUGO))
+ goto out_unlock0;
+
+ /* raced with RMID? */
+ if (!ipc_valid_object(&msq->q_perm)) {
+ err = -EIDRM;
+ goto out_unlock0;
+ }
err = security_msg_queue_msgsnd(msq, msg, msgflg);
if (err)
- goto out_unlock_free;
+ goto out_unlock0;
if (msgsz + msq->q_cbytes <= msq->q_qbytes &&
1 + msq->q_qnum <= msq->q_qbytes) {
@@ -683,32 +660,44 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
/* queue full, wait: */
if (msgflg & IPC_NOWAIT) {
err = -EAGAIN;
- goto out_unlock_free;
+ goto out_unlock0;
}
+
+ /* enqueue the sender and prepare to block */
ss_add(msq, &s);
- ipc_rcu_getref(msq);
- msg_unlock(msq);
+
+ if (!ipc_rcu_getref(msq)) {
+ err = -EIDRM;
+ goto out_unlock0;
+ }
+
+ ipc_unlock_object(&msq->q_perm);
+ rcu_read_unlock();
schedule();
- ipc_lock_by_ptr(&msq->q_perm);
- ipc_rcu_putref(msq);
- if (msq->q_perm.deleted) {
+ rcu_read_lock();
+ ipc_lock_object(&msq->q_perm);
+
+ ipc_rcu_putref(msq, ipc_rcu_free);
+ /* raced with RMID? */
+ if (!ipc_valid_object(&msq->q_perm)) {
err = -EIDRM;
- goto out_unlock_free;
+ goto out_unlock0;
}
+
ss_del(&s);
if (signal_pending(current)) {
err = -ERESTARTNOHAND;
- goto out_unlock_free;
+ goto out_unlock0;
}
- }
+ }
msq->q_lspid = task_tgid_vnr(current);
msq->q_stime = get_seconds();
if (!pipelined_send(msq, msg)) {
- /* noone is waiting for this message, enqueue it */
+ /* no one is waiting for this message, enqueue it */
list_add_tail(&msg->m_list, &msq->q_messages);
msq->q_cbytes += msgsz;
msq->q_qnum++;
@@ -719,16 +708,17 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
err = 0;
msg = NULL;
-out_unlock_free:
- msg_unlock(msq);
-out_free:
+out_unlock0:
+ ipc_unlock_object(&msq->q_perm);
+out_unlock1:
+ rcu_read_unlock();
if (msg != NULL)
free_msg(msg);
return err;
}
-asmlinkage long
-sys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz, int msgflg)
+SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
+ int, msgflg)
{
long mtype;
@@ -739,6 +729,8 @@ sys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz, int msgflg)
static inline int convert_mode(long *msgtyp, int msgflg)
{
+ if (msgflg & MSG_COPY)
+ return SEARCH_NUMBER;
/*
* find message of correct type.
* msgtyp = 0 => get first.
@@ -756,62 +748,142 @@ static inline int convert_mode(long *msgtyp, int msgflg)
return SEARCH_EQUAL;
}
-long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
- size_t msgsz, long msgtyp, int msgflg)
+static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
+{
+ struct msgbuf __user *msgp = dest;
+ size_t msgsz;
+
+ if (put_user(msg->m_type, &msgp->mtype))
+ return -EFAULT;
+
+ msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
+ if (store_msg(msgp->mtext, msg, msgsz))
+ return -EFAULT;
+ return msgsz;
+}
+
+#ifdef CONFIG_CHECKPOINT_RESTORE
+/*
+ * This function creates new kernel message structure, large enough to store
+ * bufsz message bytes.
+ */
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
+{
+ struct msg_msg *copy;
+
+ /*
+ * Create dummy message to copy real message to.
+ */
+ copy = load_msg(buf, bufsz);
+ if (!IS_ERR(copy))
+ copy->m_ts = bufsz;
+ return copy;
+}
+
+static inline void free_copy(struct msg_msg *copy)
+{
+ if (copy)
+ free_msg(copy);
+}
+#else
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline void free_copy(struct msg_msg *copy)
+{
+}
+#endif
+
+static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
+{
+ struct msg_msg *msg, *found = NULL;
+ long count = 0;
+
+ list_for_each_entry(msg, &msq->q_messages, m_list) {
+ if (testmsg(msg, *msgtyp, mode) &&
+ !security_msg_queue_msgrcv(msq, msg, current,
+ *msgtyp, mode)) {
+ if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
+ *msgtyp = msg->m_type - 1;
+ found = msg;
+ } else if (mode == SEARCH_NUMBER) {
+ if (*msgtyp == count)
+ return msg;
+ } else
+ return msg;
+ count++;
+ }
+ }
+
+ return found ?: ERR_PTR(-EAGAIN);
+}
+
+long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
+ long (*msg_handler)(void __user *, struct msg_msg *, size_t))
{
- struct msg_queue *msq;
- struct msg_msg *msg;
int mode;
+ struct msg_queue *msq;
struct ipc_namespace *ns;
+ struct msg_msg *msg, *copy = NULL;
- if (msqid < 0 || (long) msgsz < 0)
+ ns = current->nsproxy->ipc_ns;
+
+ if (msqid < 0 || (long) bufsz < 0)
return -EINVAL;
+
+ if (msgflg & MSG_COPY) {
+ if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT))
+ return -EINVAL;
+ copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
+ if (IS_ERR(copy))
+ return PTR_ERR(copy);
+ }
mode = convert_mode(&msgtyp, msgflg);
- ns = current->nsproxy->ipc_ns;
- msq = msg_lock_check(ns, msqid);
- if (IS_ERR(msq))
+ rcu_read_lock();
+ msq = msq_obtain_object_check(ns, msqid);
+ if (IS_ERR(msq)) {
+ rcu_read_unlock();
+ free_copy(copy);
return PTR_ERR(msq);
+ }
for (;;) {
struct msg_receiver msr_d;
- struct list_head *tmp;
msg = ERR_PTR(-EACCES);
- if (ipcperms(&msq->q_perm, S_IRUGO))
- goto out_unlock;
+ if (ipcperms(ns, &msq->q_perm, S_IRUGO))
+ goto out_unlock1;
- msg = ERR_PTR(-EAGAIN);
- tmp = msq->q_messages.next;
- while (tmp != &msq->q_messages) {
- struct msg_msg *walk_msg;
-
- walk_msg = list_entry(tmp, struct msg_msg, m_list);
- if (testmsg(walk_msg, msgtyp, mode) &&
- !security_msg_queue_msgrcv(msq, walk_msg, current,
- msgtyp, mode)) {
-
- msg = walk_msg;
- if (mode == SEARCH_LESSEQUAL &&
- walk_msg->m_type != 1) {
- msg = walk_msg;
- msgtyp = walk_msg->m_type - 1;
- } else {
- msg = walk_msg;
- break;
- }
- }
- tmp = tmp->next;
+ ipc_lock_object(&msq->q_perm);
+
+ /* raced with RMID? */
+ if (!ipc_valid_object(&msq->q_perm)) {
+ msg = ERR_PTR(-EIDRM);
+ goto out_unlock0;
}
+
+ msg = find_msg(msq, &msgtyp, mode);
if (!IS_ERR(msg)) {
/*
* Found a suitable message.
* Unlink it from the queue.
*/
- if ((msgsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
+ if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
msg = ERR_PTR(-E2BIG);
- goto out_unlock;
+ goto out_unlock0;
}
+ /*
+ * If we are copying, then do not unlink message and do
+ * not update queue parameters.
+ */
+ if (msgflg & MSG_COPY) {
+ msg = copy_msg(msg, copy);
+ goto out_unlock0;
+ }
+
list_del(&msg->m_list);
msq->q_qnum--;
msq->q_rtime = get_seconds();
@@ -820,14 +892,16 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
atomic_sub(msg->m_ts, &ns->msg_bytes);
atomic_dec(&ns->msg_hdrs);
ss_wakeup(&msq->q_senders, 0);
- msg_unlock(msq);
- break;
+
+ goto out_unlock0;
}
+
/* No message waiting. Wait for a message */
if (msgflg & IPC_NOWAIT) {
msg = ERR_PTR(-ENOMSG);
- goto out_unlock;
+ goto out_unlock0;
}
+
list_add_tail(&msr_d.r_list, &msq->q_receivers);
msr_d.r_tsk = current;
msr_d.r_msgtype = msgtyp;
@@ -835,22 +909,23 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
if (msgflg & MSG_NOERROR)
msr_d.r_maxsize = INT_MAX;
else
- msr_d.r_maxsize = msgsz;
+ msr_d.r_maxsize = bufsz;
msr_d.r_msg = ERR_PTR(-EAGAIN);
- current->state = TASK_INTERRUPTIBLE;
- msg_unlock(msq);
+ __set_current_state(TASK_INTERRUPTIBLE);
+ ipc_unlock_object(&msq->q_perm);
+ rcu_read_unlock();
schedule();
/* Lockless receive, part 1:
* Disable preemption. We don't hold a reference to the queue
* and getting a reference would defeat the idea of a lockless
* operation, thus the code relies on rcu to guarantee the
- * existance of msq:
+ * existence of msq:
* Prior to destruction, expunge_all(-EIRDM) changes r_msg.
* Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
* rcu_read_lock() prevents preemption between reading r_msg
- * and the spin_lock() inside ipc_lock_by_ptr().
+ * and acquiring the q_perm.lock in ipc_lock_object().
*/
rcu_read_lock();
@@ -859,7 +934,7 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
* wake_up_process(). There is a race with exit(), see
* ipc/mqueue.c for the details.
*/
- msg = (struct msg_msg*)msr_d.r_msg;
+ msg = (struct msg_msg *)msr_d.r_msg;
while (msg == NULL) {
cpu_relax();
msg = (struct msg_msg *)msr_d.r_msg;
@@ -869,63 +944,106 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
* If there is a message or an error then accept it without
* locking.
*/
- if (msg != ERR_PTR(-EAGAIN)) {
- rcu_read_unlock();
- break;
- }
+ if (msg != ERR_PTR(-EAGAIN))
+ goto out_unlock1;
/* Lockless receive, part 3:
* Acquire the queue spinlock.
*/
- ipc_lock_by_ptr(&msq->q_perm);
- rcu_read_unlock();
+ ipc_lock_object(&msq->q_perm);
/* Lockless receive, part 4:
* Repeat test after acquiring the spinlock.
*/
- msg = (struct msg_msg*)msr_d.r_msg;
+ msg = (struct msg_msg *)msr_d.r_msg;
if (msg != ERR_PTR(-EAGAIN))
- goto out_unlock;
+ goto out_unlock0;
list_del(&msr_d.r_list);
if (signal_pending(current)) {
msg = ERR_PTR(-ERESTARTNOHAND);
-out_unlock:
- msg_unlock(msq);
- break;
+ goto out_unlock0;
}
+
+ ipc_unlock_object(&msq->q_perm);
}
- if (IS_ERR(msg))
- return PTR_ERR(msg);
- msgsz = (msgsz > msg->m_ts) ? msg->m_ts : msgsz;
- *pmtype = msg->m_type;
- if (store_msg(mtext, msg, msgsz))
- msgsz = -EFAULT;
+out_unlock0:
+ ipc_unlock_object(&msq->q_perm);
+out_unlock1:
+ rcu_read_unlock();
+ if (IS_ERR(msg)) {
+ free_copy(copy);
+ return PTR_ERR(msg);
+ }
+ bufsz = msg_handler(buf, msg, bufsz);
free_msg(msg);
- return msgsz;
+ return bufsz;
}
-asmlinkage long sys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
- long msgtyp, int msgflg)
+SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
+ long, msgtyp, int, msgflg)
{
- long err, mtype;
+ return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
+}
- err = do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg);
- if (err < 0)
- goto out;
+/*
+ * Scale msgmni with the available lowmem size: the memory dedicated to msg
+ * queues should occupy at most 1/MSG_MEM_SCALE of lowmem.
+ * Also take into account the number of nsproxies created so far.
+ * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range.
+ */
+void recompute_msgmni(struct ipc_namespace *ns)
+{
+ struct sysinfo i;
+ unsigned long allowed;
+ int nb_ns;
+
+ si_meminfo(&i);
+ allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
+ / MSGMNB;
+ nb_ns = atomic_read(&nr_ipc_ns);
+ allowed /= nb_ns;
+
+ if (allowed < MSGMNI) {
+ ns->msg_ctlmni = MSGMNI;
+ return;
+ }
- if (put_user(mtype, &msgp->mtype))
- err = -EFAULT;
-out:
- return err;
+ if (allowed > IPCMNI / nb_ns) {
+ ns->msg_ctlmni = IPCMNI / nb_ns;
+ return;
+ }
+
+ ns->msg_ctlmni = allowed;
}
+void msg_init_ns(struct ipc_namespace *ns)
+{
+ ns->msg_ctlmax = MSGMAX;
+ ns->msg_ctlmnb = MSGMNB;
+
+ recompute_msgmni(ns);
+
+ atomic_set(&ns->msg_bytes, 0);
+ atomic_set(&ns->msg_hdrs, 0);
+ ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
+}
+
+#ifdef CONFIG_IPC_NS
+void msg_exit_ns(struct ipc_namespace *ns)
+{
+ free_ipcs(ns, &msg_ids(ns), freeque);
+ idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
+}
+#endif
+
#ifdef CONFIG_PROC_FS
static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
{
+ struct user_namespace *user_ns = seq_user_ns(s);
struct msg_queue *msq = it;
return seq_printf(s,
@@ -937,12 +1055,24 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
msq->q_qnum,
msq->q_lspid,
msq->q_lrpid,
- msq->q_perm.uid,
- msq->q_perm.gid,
- msq->q_perm.cuid,
- msq->q_perm.cgid,
+ from_kuid_munged(user_ns, msq->q_perm.uid),
+ from_kgid_munged(user_ns, msq->q_perm.gid),
+ from_kuid_munged(user_ns, msq->q_perm.cuid),
+ from_kgid_munged(user_ns, msq->q_perm.cgid),
msq->q_stime,
msq->q_rtime,
msq->q_ctime);
}
#endif
+
+void __init msg_init(void)
+{
+ msg_init_ns(&init_ipc_ns);
+
+ printk(KERN_INFO "msgmni has been set to %d\n",
+ init_ipc_ns.msg_ctlmni);
+
+ ipc_init_proc_interface("sysvipc/msg",
+ " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n",
+ IPC_MSG_IDS, sysvipc_msg_proc_show);
+}
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index c82c215693d..7e7095974d5 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -13,64 +13,94 @@
#include <linux/security.h>
#include <linux/slab.h>
#include <linux/ipc.h>
-#include <asm/uaccess.h>
+#include <linux/msg.h>
+#include <linux/ipc_namespace.h>
+#include <linux/utsname.h>
+#include <linux/proc_ns.h>
+#include <linux/uaccess.h>
#include "util.h"
+DEFINE_SPINLOCK(mq_lock);
+
+/*
+ * The next 2 defines are here bc this is the only file
+ * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
+ * and not CONFIG_IPC_NS.
+ */
+struct ipc_namespace init_ipc_ns = {
+ .count = ATOMIC_INIT(1),
+ .user_ns = &init_user_ns,
+ .proc_inum = PROC_IPC_INIT_INO,
+};
+
+atomic_t nr_ipc_ns = ATOMIC_INIT(1);
+
struct msg_msgseg {
- struct msg_msgseg* next;
+ struct msg_msgseg *next;
/* the next part of the message follows immediately */
};
-#define DATALEN_MSG (PAGE_SIZE-sizeof(struct msg_msg))
-#define DATALEN_SEG (PAGE_SIZE-sizeof(struct msg_msgseg))
+#define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg))
+#define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
-struct msg_msg *load_msg(const void __user *src, int len)
+
+static struct msg_msg *alloc_msg(size_t len)
{
struct msg_msg *msg;
struct msg_msgseg **pseg;
- int err;
- int alen;
-
- alen = len;
- if (alen > DATALEN_MSG)
- alen = DATALEN_MSG;
+ size_t alen;
+ alen = min(len, DATALEN_MSG);
msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
if (msg == NULL)
- return ERR_PTR(-ENOMEM);
+ return NULL;
msg->next = NULL;
msg->security = NULL;
- if (copy_from_user(msg + 1, src, alen)) {
- err = -EFAULT;
- goto out_err;
- }
-
len -= alen;
- src = ((char __user *)src) + alen;
pseg = &msg->next;
while (len > 0) {
struct msg_msgseg *seg;
- alen = len;
- if (alen > DATALEN_SEG)
- alen = DATALEN_SEG;
- seg = kmalloc(sizeof(*seg) + alen,
- GFP_KERNEL);
- if (seg == NULL) {
- err = -ENOMEM;
+ alen = min(len, DATALEN_SEG);
+ seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL);
+ if (seg == NULL)
goto out_err;
- }
*pseg = seg;
seg->next = NULL;
- if (copy_from_user(seg + 1, src, alen)) {
- err = -EFAULT;
- goto out_err;
- }
pseg = &seg->next;
len -= alen;
- src = ((char __user *)src) + alen;
+ }
+
+ return msg;
+
+out_err:
+ free_msg(msg);
+ return NULL;
+}
+
+struct msg_msg *load_msg(const void __user *src, size_t len)
+{
+ struct msg_msg *msg;
+ struct msg_msgseg *seg;
+ int err = -EFAULT;
+ size_t alen;
+
+ msg = alloc_msg(len);
+ if (msg == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ alen = min(len, DATALEN_MSG);
+ if (copy_from_user(msg + 1, src, alen))
+ goto out_err;
+
+ for (seg = msg->next; seg != NULL; seg = seg->next) {
+ len -= alen;
+ src = (char __user *)src + alen;
+ alen = min(len, DATALEN_SEG);
+ if (copy_from_user(seg + 1, src, alen))
+ goto out_err;
}
err = security_msg_msg_alloc(msg);
@@ -83,30 +113,55 @@ out_err:
free_msg(msg);
return ERR_PTR(err);
}
+#ifdef CONFIG_CHECKPOINT_RESTORE
+struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
+{
+ struct msg_msgseg *dst_pseg, *src_pseg;
+ size_t len = src->m_ts;
+ size_t alen;
+
+ BUG_ON(dst == NULL);
+ if (src->m_ts > dst->m_ts)
+ return ERR_PTR(-EINVAL);
+
+ alen = min(len, DATALEN_MSG);
+ memcpy(dst + 1, src + 1, alen);
+
+ for (dst_pseg = dst->next, src_pseg = src->next;
+ src_pseg != NULL;
+ dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
-int store_msg(void __user *dest, struct msg_msg *msg, int len)
+ len -= alen;
+ alen = min(len, DATALEN_SEG);
+ memcpy(dst_pseg + 1, src_pseg + 1, alen);
+ }
+
+ dst->m_type = src->m_type;
+ dst->m_ts = src->m_ts;
+
+ return dst;
+}
+#else
+struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
+{
+ return ERR_PTR(-ENOSYS);
+}
+#endif
+int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
{
- int alen;
+ size_t alen;
struct msg_msgseg *seg;
- alen = len;
- if (alen > DATALEN_MSG)
- alen = DATALEN_MSG;
+ alen = min(len, DATALEN_MSG);
if (copy_to_user(dest, msg + 1, alen))
return -1;
- len -= alen;
- dest = ((char __user *)dest) + alen;
- seg = msg->next;
- while (len > 0) {
- alen = len;
- if (alen > DATALEN_SEG)
- alen = DATALEN_SEG;
+ for (seg = msg->next; seg != NULL; seg = seg->next) {
+ len -= alen;
+ dest = (char __user *)dest + alen;
+ alen = min(len, DATALEN_SEG);
if (copy_to_user(dest, seg + 1, alen))
return -1;
- len -= alen;
- dest = ((char __user *)dest) + alen;
- seg = seg->next;
}
return 0;
}
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 1b967655eb3..59451c1e214 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -9,39 +9,61 @@
#include <linux/rcupdate.h>
#include <linux/nsproxy.h>
#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/user_namespace.h>
+#include <linux/proc_ns.h>
#include "util.h"
-static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
+static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
+ struct ipc_namespace *old_ns)
{
struct ipc_namespace *ns;
+ int err;
ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
if (ns == NULL)
return ERR_PTR(-ENOMEM);
+ err = proc_alloc_inum(&ns->proc_inum);
+ if (err) {
+ kfree(ns);
+ return ERR_PTR(err);
+ }
+
+ atomic_set(&ns->count, 1);
+ err = mq_init_ns(ns);
+ if (err) {
+ proc_free_inum(ns->proc_inum);
+ kfree(ns);
+ return ERR_PTR(err);
+ }
+ atomic_inc(&nr_ipc_ns);
+
sem_init_ns(ns);
msg_init_ns(ns);
shm_init_ns(ns);
- kref_init(&ns->kref);
+ /*
+ * msgmni has already been computed for the new ipc ns.
+ * Thus, do the ipcns creation notification before registering that
+ * new ipcns in the chain.
+ */
+ ipcns_notify(IPCNS_CREATED);
+ register_ipcns_notifier(ns);
+
+ ns->user_ns = get_user_ns(user_ns);
+
return ns;
}
-struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns)
+struct ipc_namespace *copy_ipcs(unsigned long flags,
+ struct user_namespace *user_ns, struct ipc_namespace *ns)
{
- struct ipc_namespace *new_ns;
-
- BUG_ON(!ns);
- get_ipc_ns(ns);
-
if (!(flags & CLONE_NEWIPC))
- return ns;
-
- new_ns = clone_ipc_ns(ns);
-
- put_ipc_ns(ns);
- return new_ns;
+ return get_ipc_ns(ns);
+ return create_ipc_ns(user_ns, ns);
}
/*
@@ -59,7 +81,7 @@ void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
int next_id;
int total, in_use;
- down_write(&ids->rw_mutex);
+ down_write(&ids->rwsem);
in_use = ids->in_use;
@@ -67,20 +89,111 @@ void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
perm = idr_find(&ids->ipcs_idr, next_id);
if (perm == NULL)
continue;
- ipc_lock_by_ptr(perm);
+ rcu_read_lock();
+ ipc_lock_object(perm);
free(ns, perm);
total++;
}
- up_write(&ids->rw_mutex);
+ up_write(&ids->rwsem);
}
-void free_ipc_ns(struct kref *kref)
+static void free_ipc_ns(struct ipc_namespace *ns)
{
- struct ipc_namespace *ns;
-
- ns = container_of(kref, struct ipc_namespace, kref);
+ /*
+ * Unregistering the hotplug notifier at the beginning guarantees
+ * that the ipc namespace won't be freed while we are inside the
+ * callback routine. Since the blocking_notifier_chain_XXX routines
+ * hold a rw lock on the notifier list, unregister_ipcns_notifier()
+ * won't take the rw lock before blocking_notifier_call_chain() has
+ * released the rd lock.
+ */
+ unregister_ipcns_notifier(ns);
sem_exit_ns(ns);
msg_exit_ns(ns);
shm_exit_ns(ns);
+ atomic_dec(&nr_ipc_ns);
+
+ /*
+ * Do the ipcns removal notification after decrementing nr_ipc_ns in
+ * order to have a correct value when recomputing msgmni.
+ */
+ ipcns_notify(IPCNS_REMOVED);
+ put_user_ns(ns->user_ns);
+ proc_free_inum(ns->proc_inum);
kfree(ns);
}
+
+/*
+ * put_ipc_ns - drop a reference to an ipc namespace.
+ * @ns: the namespace to put
+ *
+ * If this is the last task in the namespace exiting, and
+ * it is dropping the refcount to 0, then it can race with
+ * a task in another ipc namespace but in a mounts namespace
+ * which has this ipcns's mqueuefs mounted, doing some action
+ * with one of the mqueuefs files. That can raise the refcount.
+ * So dropping the refcount, and raising the refcount when
+ * accessing it through the VFS, are protected with mq_lock.
+ *
+ * (Clearly, a task raising the refcount on its own ipc_ns
+ * needn't take mq_lock since it can't race with the last task
+ * in the ipcns exiting).
+ */
+void put_ipc_ns(struct ipc_namespace *ns)
+{
+ if (atomic_dec_and_lock(&ns->count, &mq_lock)) {
+ mq_clear_sbinfo(ns);
+ spin_unlock(&mq_lock);
+ mq_put_mnt(ns);
+ free_ipc_ns(ns);
+ }
+}
+
+static void *ipcns_get(struct task_struct *task)
+{
+ struct ipc_namespace *ns = NULL;
+ struct nsproxy *nsproxy;
+
+ rcu_read_lock();
+ nsproxy = task_nsproxy(task);
+ if (nsproxy)
+ ns = get_ipc_ns(nsproxy->ipc_ns);
+ rcu_read_unlock();
+
+ return ns;
+}
+
+static void ipcns_put(void *ns)
+{
+ return put_ipc_ns(ns);
+}
+
+static int ipcns_install(struct nsproxy *nsproxy, void *new)
+{
+ struct ipc_namespace *ns = new;
+ if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
+ !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
+ return -EPERM;
+
+ /* Ditch state from the old ipc namespace */
+ exit_sem(current);
+ put_ipc_ns(nsproxy->ipc_ns);
+ nsproxy->ipc_ns = get_ipc_ns(ns);
+ return 0;
+}
+
+static unsigned int ipcns_inum(void *vp)
+{
+ struct ipc_namespace *ns = vp;
+
+ return ns->proc_inum;
+}
+
+const struct proc_ns_operations ipcns_operations = {
+ .name = "ipc",
+ .type = CLONE_NEWIPC,
+ .get = ipcns_get,
+ .put = ipcns_put,
+ .install = ipcns_install,
+ .inum = ipcns_inum,
+};
diff --git a/ipc/sem.c b/ipc/sem.c
index 0b45a4d383c..454f6c6020a 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -3,64 +3,16 @@
* Copyright (C) 1992 Krishna Balasubramanian
* Copyright (C) 1995 Eric Schenk, Bruno Haible
*
- * IMPLEMENTATION NOTES ON CODE REWRITE (Eric Schenk, January 1995):
- * This code underwent a massive rewrite in order to solve some problems
- * with the original code. In particular the original code failed to
- * wake up processes that were waiting for semval to go to 0 if the
- * value went to 0 and was then incremented rapidly enough. In solving
- * this problem I have also modified the implementation so that it
- * processes pending operations in a FIFO manner, thus give a guarantee
- * that processes waiting for a lock on the semaphore won't starve
- * unless another locking process fails to unlock.
- * In addition the following two changes in behavior have been introduced:
- * - The original implementation of semop returned the value
- * last semaphore element examined on success. This does not
- * match the manual page specifications, and effectively
- * allows the user to read the semaphore even if they do not
- * have read permissions. The implementation now returns 0
- * on success as stated in the manual page.
- * - There is some confusion over whether the set of undo adjustments
- * to be performed at exit should be done in an atomic manner.
- * That is, if we are attempting to decrement the semval should we queue
- * up and wait until we can do so legally?
- * The original implementation attempted to do this.
- * The current implementation does not do so. This is because I don't
- * think it is the right thing (TM) to do, and because I couldn't
- * see a clean way to get the old behavior with the new design.
- * The POSIX standard and SVID should be consulted to determine
- * what behavior is mandated.
- *
- * Further notes on refinement (Christoph Rohland, December 1998):
- * - The POSIX standard says, that the undo adjustments simply should
- * redo. So the current implementation is o.K.
- * - The previous code had two flaws:
- * 1) It actively gave the semaphore to the next waiting process
- * sleeping on the semaphore. Since this process did not have the
- * cpu this led to many unnecessary context switches and bad
- * performance. Now we only check which process should be able to
- * get the semaphore and if this process wants to reduce some
- * semaphore value we simply wake it up without doing the
- * operation. So it has to try to get it later. Thus e.g. the
- * running process may reacquire the semaphore during the current
- * time slice. If it only waits for zero or increases the semaphore,
- * we do the operation in advance and wake it up.
- * 2) It did not wake up all zero waiting processes. We try to do
- * better but only get the semops right which only wait for zero or
- * increase. If there are decrement operations in the operations
- * array we do the same as before.
- *
- * With the incarnation of O(1) scheduler, it becomes unnecessary to perform
- * check/retry algorithm for waking up blocked processes as the new scheduler
- * is better at handling thread switch than the old one.
- *
* /proc/sysvipc/sem support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
*
* SMP-threaded, sysctl's added
* (c) 1999 Manfred Spraul <manfred@colorfullife.com>
* Enforced range limit on SEM_UNDO
- * (c) 2001 Red Hat Inc <alan@redhat.com>
+ * (c) 2001 Red Hat Inc
* Lockless wakeup
* (c) 2003 Manfred Spraul <manfred@colorfullife.com>
+ * Further wakeup optimizations, documentation
+ * (c) 2010 Manfred Spraul <manfred@colorfullife.com>
*
* support for audit of ipc object properties and permission changes
* Dustin Kirkland <dustin.kirkland@us.ibm.com>
@@ -68,6 +20,56 @@
* namespaces support
* OpenVZ, SWsoft Inc.
* Pavel Emelianov <xemul@openvz.org>
+ *
+ * Implementation notes: (May 2010)
+ * This file implements System V semaphores.
+ *
+ * User space visible behavior:
+ * - FIFO ordering for semop() operations (just FIFO, not starvation
+ * protection)
+ * - multiple semaphore operations that alter the same semaphore in
+ * one semop() are handled.
+ * - sem_ctime (time of last semctl()) is updated in the IPC_SET, SETVAL and
+ * SETALL calls.
+ * - two Linux specific semctl() commands: SEM_STAT, SEM_INFO.
+ * - undo adjustments at process exit are limited to 0..SEMVMX.
+ * - namespace are supported.
+ * - SEMMSL, SEMMNS, SEMOPM and SEMMNI can be configured at runtine by writing
+ * to /proc/sys/kernel/sem.
+ * - statistics about the usage are reported in /proc/sysvipc/sem.
+ *
+ * Internals:
+ * - scalability:
+ * - all global variables are read-mostly.
+ * - semop() calls and semctl(RMID) are synchronized by RCU.
+ * - most operations do write operations (actually: spin_lock calls) to
+ * the per-semaphore array structure.
+ * Thus: Perfect SMP scaling between independent semaphore arrays.
+ * If multiple semaphores in one array are used, then cache line
+ * trashing on the semaphore array spinlock will limit the scaling.
+ * - semncnt and semzcnt are calculated on demand in count_semcnt()
+ * - the task that performs a successful semop() scans the list of all
+ * sleeping tasks and completes any pending operations that can be fulfilled.
+ * Semaphores are actively given to waiting tasks (necessary for FIFO).
+ * (see update_queue())
+ * - To improve the scalability, the actual wake-up calls are performed after
+ * dropping all locks. (see wake_up_sem_queue_prepare(),
+ * wake_up_sem_queue_do())
+ * - All work is done by the waker, the woken up task does not have to do
+ * anything - not even acquiring a lock or dropping a refcount.
+ * - A woken up task may not even touch the semaphore array anymore, it may
+ * have been destroyed already by a semctl(RMID).
+ * - The synchronizations between wake-ups due to a timeout/signal and a
+ * wake-up due to a completed semaphore operation is achieved by using an
+ * intermediate state (IN_WAKEUP).
+ * - UNDO values are stored in an array (one per process and per
+ * semaphore array, lazily allocated). For backwards compatibility, multiple
+ * modes for the UNDO variables are supported (per process, per thread)
+ * (see copy_semundo, CLONE_SYSVSEM)
+ * - There are two lists of the pending operations: a per-array list
+ * and per-semaphore list (stored in the array). This allows to achieve FIFO
+ * ordering without always scanning all pending operations.
+ * The worst-case behavior is nevertheless O(N^2) for N wakeups.
*/
#include <linux/slab.h>
@@ -84,14 +86,63 @@
#include <linux/nsproxy.h>
#include <linux/ipc_namespace.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include "util.h"
+/* One semaphore structure for each semaphore in the system. */
+struct sem {
+ int semval; /* current value */
+ int sempid; /* pid of last operation */
+ spinlock_t lock; /* spinlock for fine-grained semtimedop */
+ struct list_head pending_alter; /* pending single-sop operations */
+ /* that alter the semaphore */
+ struct list_head pending_const; /* pending single-sop operations */
+ /* that do not alter the semaphore*/
+ time_t sem_otime; /* candidate for sem_otime */
+} ____cacheline_aligned_in_smp;
+
+/* One queue for each sleeping process in the system. */
+struct sem_queue {
+ struct list_head list; /* queue of pending operations */
+ struct task_struct *sleeper; /* this process */
+ struct sem_undo *undo; /* undo structure */
+ int pid; /* process id of requesting process */
+ int status; /* completion status of operation */
+ struct sembuf *sops; /* array of pending operations */
+ struct sembuf *blocking; /* the operation that blocked */
+ int nsops; /* number of operations */
+ int alter; /* does *sops alter the array? */
+};
+
+/* Each task has a list of undo requests. They are executed automatically
+ * when the process exits.
+ */
+struct sem_undo {
+ struct list_head list_proc; /* per-process list: *
+ * all undos from one process
+ * rcu protected */
+ struct rcu_head rcu; /* rcu struct for sem_undo */
+ struct sem_undo_list *ulp; /* back ptr to sem_undo_list */
+ struct list_head list_id; /* per semaphore array list:
+ * all undos for one array */
+ int semid; /* semaphore set identifier */
+ short *semadj; /* array of adjustments */
+ /* one per semaphore */
+};
+
+/* sem_undo_list controls shared access to the list of sem_undo structures
+ * that may be shared among all a CLONE_SYSVSEM task group.
+ */
+struct sem_undo_list {
+ atomic_t refcnt;
+ spinlock_t lock;
+ struct list_head list_proc;
+};
+
+
#define sem_ids(ns) ((ns)->ids[IPC_SEM_IDS])
-#define sem_unlock(sma) ipc_unlock(&(sma)->sem_perm)
#define sem_checkid(sma, semid) ipc_checkid(&sma->sem_perm, semid)
-#define sem_buildid(id, seq) ipc_buildid(id, seq)
static int newary(struct ipc_namespace *, struct ipc_params *);
static void freeary(struct ipc_namespace *, struct kern_ipc_perm *);
@@ -103,12 +154,15 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
#define SEMOPM_FAST 64 /* ~ 372 bytes on stack */
/*
- * linked list protection:
+ * Locking:
* sem_undo.id_next,
- * sem_array.sem_pending{,last},
- * sem_array.sem_undo: sem_lock() for read/write
+ * sem_array.complex_count,
+ * sem_array.pending{_alter,_cont},
+ * sem_array.sem_undo: global sem_lock() for read/write
* sem_undo.proc_next: only "current" is allowed to read/write that field.
- *
+ *
+ * sem_array.sem_base[i].pending_{const,alter}:
+ * global or semaphore sem_lock() for read/write
*/
#define sc_semmsl sem_ctls[0]
@@ -130,10 +184,11 @@ void sem_init_ns(struct ipc_namespace *ns)
void sem_exit_ns(struct ipc_namespace *ns)
{
free_ipcs(ns, &sem_ids(ns), freeary);
+ idr_destroy(&ns->ids[IPC_SEM_IDS].ipcs_idr);
}
#endif
-void __init sem_init (void)
+void __init sem_init(void)
{
sem_init_ns(&init_ipc_ns);
ipc_init_proc_interface("sysvipc/sem",
@@ -141,46 +196,238 @@ void __init sem_init (void)
IPC_SEM_IDS, sysvipc_sem_proc_show);
}
+/**
+ * unmerge_queues - unmerge queues, if possible.
+ * @sma: semaphore array
+ *
+ * The function unmerges the wait queues if complex_count is 0.
+ * It must be called prior to dropping the global semaphore array lock.
+ */
+static void unmerge_queues(struct sem_array *sma)
+{
+ struct sem_queue *q, *tq;
+
+ /* complex operations still around? */
+ if (sma->complex_count)
+ return;
+ /*
+ * We will switch back to simple mode.
+ * Move all pending operation back into the per-semaphore
+ * queues.
+ */
+ list_for_each_entry_safe(q, tq, &sma->pending_alter, list) {
+ struct sem *curr;
+ curr = &sma->sem_base[q->sops[0].sem_num];
+
+ list_add_tail(&q->list, &curr->pending_alter);
+ }
+ INIT_LIST_HEAD(&sma->pending_alter);
+}
+
+/**
+ * merge_queues - merge single semop queues into global queue
+ * @sma: semaphore array
+ *
+ * This function merges all per-semaphore queues into the global queue.
+ * It is necessary to achieve FIFO ordering for the pending single-sop
+ * operations when a multi-semop operation must sleep.
+ * Only the alter operations must be moved, the const operations can stay.
+ */
+static void merge_queues(struct sem_array *sma)
+{
+ int i;
+ for (i = 0; i < sma->sem_nsems; i++) {
+ struct sem *sem = sma->sem_base + i;
+
+ list_splice_init(&sem->pending_alter, &sma->pending_alter);
+ }
+}
+
+static void sem_rcu_free(struct rcu_head *head)
+{
+ struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
+ struct sem_array *sma = ipc_rcu_to_struct(p);
+
+ security_sem_free(sma);
+ ipc_rcu_free(head);
+}
+
/*
- * This routine is called in the paths where the rw_mutex is held to protect
- * access to the idr tree.
+ * Wait until all currently ongoing simple ops have completed.
+ * Caller must own sem_perm.lock.
+ * New simple ops cannot start, because simple ops first check
+ * that sem_perm.lock is free.
+ * that a) sem_perm.lock is free and b) complex_count is 0.
*/
-static inline struct sem_array *sem_lock_check_down(struct ipc_namespace *ns,
- int id)
+static void sem_wait_array(struct sem_array *sma)
{
- struct kern_ipc_perm *ipcp = ipc_lock_check_down(&sem_ids(ns), id);
+ int i;
+ struct sem *sem;
- if (IS_ERR(ipcp))
- return (struct sem_array *)ipcp;
+ if (sma->complex_count) {
+ /* The thread that increased sma->complex_count waited on
+ * all sem->lock locks. Thus we don't need to wait again.
+ */
+ return;
+ }
- return container_of(ipcp, struct sem_array, sem_perm);
+ for (i = 0; i < sma->sem_nsems; i++) {
+ sem = sma->sem_base + i;
+ spin_unlock_wait(&sem->lock);
+ }
}
/*
- * sem_lock_(check_) routines are called in the paths where the rw_mutex
+ * If the request contains only one semaphore operation, and there are
+ * no complex transactions pending, lock only the semaphore involved.
+ * Otherwise, lock the entire semaphore array, since we either have
+ * multiple semaphores in our own semops, or we need to look at
+ * semaphores from other pending complex operations.
+ */
+static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
+ int nsops)
+{
+ struct sem *sem;
+
+ if (nsops != 1) {
+ /* Complex operation - acquire a full lock */
+ ipc_lock_object(&sma->sem_perm);
+
+ /* And wait until all simple ops that are processed
+ * right now have dropped their locks.
+ */
+ sem_wait_array(sma);
+ return -1;
+ }
+
+ /*
+ * Only one semaphore affected - try to optimize locking.
+ * The rules are:
+ * - optimized locking is possible if no complex operation
+ * is either enqueued or processed right now.
+ * - The test for enqueued complex ops is simple:
+ * sma->complex_count != 0
+ * - Testing for complex ops that are processed right now is
+ * a bit more difficult. Complex ops acquire the full lock
+ * and first wait that the running simple ops have completed.
+ * (see above)
+ * Thus: If we own a simple lock and the global lock is free
+ * and complex_count is now 0, then it will stay 0 and
+ * thus just locking sem->lock is sufficient.
+ */
+ sem = sma->sem_base + sops->sem_num;
+
+ if (sma->complex_count == 0) {
+ /*
+ * It appears that no complex operation is around.
+ * Acquire the per-semaphore lock.
+ */
+ spin_lock(&sem->lock);
+
+ /* Then check that the global lock is free */
+ if (!spin_is_locked(&sma->sem_perm.lock)) {
+ /* spin_is_locked() is not a memory barrier */
+ smp_mb();
+
+ /* Now repeat the test of complex_count:
+ * It can't change anymore until we drop sem->lock.
+ * Thus: if is now 0, then it will stay 0.
+ */
+ if (sma->complex_count == 0) {
+ /* fast path successful! */
+ return sops->sem_num;
+ }
+ }
+ spin_unlock(&sem->lock);
+ }
+
+ /* slow path: acquire the full lock */
+ ipc_lock_object(&sma->sem_perm);
+
+ if (sma->complex_count == 0) {
+ /* False alarm:
+ * There is no complex operation, thus we can switch
+ * back to the fast path.
+ */
+ spin_lock(&sem->lock);
+ ipc_unlock_object(&sma->sem_perm);
+ return sops->sem_num;
+ } else {
+ /* Not a false alarm, thus complete the sequence for a
+ * full lock.
+ */
+ sem_wait_array(sma);
+ return -1;
+ }
+}
+
+static inline void sem_unlock(struct sem_array *sma, int locknum)
+{
+ if (locknum == -1) {
+ unmerge_queues(sma);
+ ipc_unlock_object(&sma->sem_perm);
+ } else {
+ struct sem *sem = sma->sem_base + locknum;
+ spin_unlock(&sem->lock);
+ }
+}
+
+/*
+ * sem_lock_(check_) routines are called in the paths where the rwsem
* is not held.
+ *
+ * The caller holds the RCU read lock.
*/
-static inline struct sem_array *sem_lock(struct ipc_namespace *ns, int id)
+static inline struct sem_array *sem_obtain_lock(struct ipc_namespace *ns,
+ int id, struct sembuf *sops, int nsops, int *locknum)
{
- struct kern_ipc_perm *ipcp = ipc_lock(&sem_ids(ns), id);
+ struct kern_ipc_perm *ipcp;
+ struct sem_array *sma;
+ ipcp = ipc_obtain_object(&sem_ids(ns), id);
if (IS_ERR(ipcp))
- return (struct sem_array *)ipcp;
+ return ERR_CAST(ipcp);
+
+ sma = container_of(ipcp, struct sem_array, sem_perm);
+ *locknum = sem_lock(sma, sops, nsops);
+
+ /* ipc_rmid() may have already freed the ID while sem_lock
+ * was spinning: verify that the structure is still valid
+ */
+ if (ipc_valid_object(ipcp))
+ return container_of(ipcp, struct sem_array, sem_perm);
+
+ sem_unlock(sma, *locknum);
+ return ERR_PTR(-EINVAL);
+}
+
+static inline struct sem_array *sem_obtain_object(struct ipc_namespace *ns, int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_obtain_object(&sem_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return ERR_CAST(ipcp);
return container_of(ipcp, struct sem_array, sem_perm);
}
-static inline struct sem_array *sem_lock_check(struct ipc_namespace *ns,
- int id)
+static inline struct sem_array *sem_obtain_object_check(struct ipc_namespace *ns,
+ int id)
{
- struct kern_ipc_perm *ipcp = ipc_lock_check(&sem_ids(ns), id);
+ struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&sem_ids(ns), id);
if (IS_ERR(ipcp))
- return (struct sem_array *)ipcp;
+ return ERR_CAST(ipcp);
return container_of(ipcp, struct sem_array, sem_perm);
}
+static inline void sem_lock_and_putref(struct sem_array *sma)
+{
+ sem_lock(sma, NULL, -1);
+ ipc_rcu_putref(sma, ipc_rcu_free);
+}
+
static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
{
ipc_rmid(&sem_ids(ns), &s->sem_perm);
@@ -191,18 +438,18 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
* Without the check/retry algorithm a lockless wakeup is possible:
* - queue.status is initialized to -EINTR before blocking.
* - wakeup is performed by
- * * unlinking the queue entry from sma->sem_pending
+ * * unlinking the queue entry from the pending list
* * setting queue.status to IN_WAKEUP
* This is the notification for the blocked thread that a
* result value is imminent.
* * call wake_up_process
* * set queue.status to the final value.
* - the previously blocked thread checks queue.status:
- * * if it's IN_WAKEUP, then it must wait until the value changes
- * * if it's not -EINTR, then the operation was completed by
- * update_queue. semtimedop can return queue.status without
- * performing any operation on the sem array.
- * * otherwise it must acquire the spinlock and check what's up.
+ * * if it's IN_WAKEUP, then it must wait until the value changes
+ * * if it's not -EINTR, then the operation was completed by
+ * update_queue. semtimedop can return queue.status without
+ * performing any operation on the sem array.
+ * * otherwise it must acquire the spinlock and check what's up.
*
* The two-stage algorithm is necessary to protect against the following
* races:
@@ -225,9 +472,8 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
* @ns: namespace
* @params: ptr to the structure that contains key, semflg and nsems
*
- * Called with sem_ids.rw_mutex held (as a writer)
+ * Called with sem_ids.rwsem held (as a writer)
*/
-
static int newary(struct ipc_namespace *ns, struct ipc_params *params)
{
int id;
@@ -237,18 +483,19 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
key_t key = params->key;
int nsems = params->u.nsems;
int semflg = params->flg;
+ int i;
if (!nsems)
return -EINVAL;
if (ns->used_sems + nsems > ns->sc_semmns)
return -ENOSPC;
- size = sizeof (*sma) + nsems * sizeof (struct sem);
+ size = sizeof(*sma) + nsems * sizeof(struct sem);
sma = ipc_rcu_alloc(size);
- if (!sma) {
+ if (!sma)
return -ENOMEM;
- }
- memset (sma, 0, size);
+
+ memset(sma, 0, size);
sma->sem_perm.mode = (semflg & S_IRWXUGO);
sma->sem_perm.key = key;
@@ -256,33 +503,40 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
sma->sem_perm.security = NULL;
retval = security_sem_alloc(sma);
if (retval) {
- ipc_rcu_putref(sma);
+ ipc_rcu_putref(sma, ipc_rcu_free);
return retval;
}
id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni);
if (id < 0) {
- security_sem_free(sma);
- ipc_rcu_putref(sma);
+ ipc_rcu_putref(sma, sem_rcu_free);
return id;
}
ns->used_sems += nsems;
- sma->sem_perm.id = sem_buildid(id, sma->sem_perm.seq);
sma->sem_base = (struct sem *) &sma[1];
- /* sma->sem_pending = NULL; */
- sma->sem_pending_last = &sma->sem_pending;
- /* sma->undo = NULL; */
+
+ for (i = 0; i < nsems; i++) {
+ INIT_LIST_HEAD(&sma->sem_base[i].pending_alter);
+ INIT_LIST_HEAD(&sma->sem_base[i].pending_const);
+ spin_lock_init(&sma->sem_base[i].lock);
+ }
+
+ sma->complex_count = 0;
+ INIT_LIST_HEAD(&sma->pending_alter);
+ INIT_LIST_HEAD(&sma->pending_const);
+ INIT_LIST_HEAD(&sma->list_id);
sma->sem_nsems = nsems;
sma->sem_ctime = get_seconds();
- sem_unlock(sma);
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
return sma->sem_perm.id;
}
/*
- * Called with sem_ids.rw_mutex and ipcp locked.
+ * Called with sem_ids.rwsem and ipcp locked.
*/
static inline int sem_security(struct kern_ipc_perm *ipcp, int semflg)
{
@@ -293,7 +547,7 @@ static inline int sem_security(struct kern_ipc_perm *ipcp, int semflg)
}
/*
- * Called with sem_ids.rw_mutex and ipcp locked.
+ * Called with sem_ids.rwsem and ipcp locked.
*/
static inline int sem_more_checks(struct kern_ipc_perm *ipcp,
struct ipc_params *params)
@@ -307,10 +561,14 @@ static inline int sem_more_checks(struct kern_ipc_perm *ipcp,
return 0;
}
-asmlinkage long sys_semget(key_t key, int nsems, int semflg)
+SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
{
struct ipc_namespace *ns;
- struct ipc_ops sem_ops;
+ static const struct ipc_ops sem_ops = {
+ .getnew = newary,
+ .associate = sem_security,
+ .more_checks = sem_more_checks,
+ };
struct ipc_params sem_params;
ns = current->nsproxy->ipc_ns;
@@ -318,10 +576,6 @@ asmlinkage long sys_semget(key_t key, int nsems, int semflg)
if (nsems < 0 || nsems > ns->sc_semmsl)
return -EINVAL;
- sem_ops.getnew = newary;
- sem_ops.associate = sem_security;
- sem_ops.more_checks = sem_more_checks;
-
sem_params.key = key;
sem_params.flg = semflg;
sem_params.u.nsems = nsems;
@@ -329,55 +583,32 @@ asmlinkage long sys_semget(key_t key, int nsems, int semflg)
return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params);
}
-/* Manage the doubly linked list sma->sem_pending as a FIFO:
- * insert new queue elements at the tail sma->sem_pending_last.
- */
-static inline void append_to_queue (struct sem_array * sma,
- struct sem_queue * q)
-{
- *(q->prev = sma->sem_pending_last) = q;
- *(sma->sem_pending_last = &q->next) = NULL;
-}
-
-static inline void prepend_to_queue (struct sem_array * sma,
- struct sem_queue * q)
-{
- q->next = sma->sem_pending;
- *(q->prev = &sma->sem_pending) = q;
- if (q->next)
- q->next->prev = &q->next;
- else /* sma->sem_pending_last == &sma->sem_pending */
- sma->sem_pending_last = &q->next;
-}
-
-static inline void remove_from_queue (struct sem_array * sma,
- struct sem_queue * q)
-{
- *(q->prev) = q->next;
- if (q->next)
- q->next->prev = q->prev;
- else /* sma->sem_pending_last == &q->next */
- sma->sem_pending_last = q->prev;
- q->prev = NULL; /* mark as removed */
-}
-
-/*
- * Determine whether a sequence of semaphore operations would succeed
- * all at once. Return 0 if yes, 1 if need to sleep, else return error code.
+/**
+ * perform_atomic_semop - Perform (if possible) a semaphore operation
+ * @sma: semaphore array
+ * @q: struct sem_queue that describes the operation
+ *
+ * Returns 0 if the operation was possible.
+ * Returns 1 if the operation is impossible, the caller must sleep.
+ * Negative values are error codes.
*/
-
-static int try_atomic_semop (struct sem_array * sma, struct sembuf * sops,
- int nsops, struct sem_undo *un, int pid)
+static int perform_atomic_semop(struct sem_array *sma, struct sem_queue *q)
{
- int result, sem_op;
+ int result, sem_op, nsops, pid;
struct sembuf *sop;
- struct sem * curr;
+ struct sem *curr;
+ struct sembuf *sops;
+ struct sem_undo *un;
+
+ sops = q->sops;
+ nsops = q->nsops;
+ un = q->undo;
for (sop = sops; sop < sops + nsops; sop++) {
curr = sma->sem_base + sop->sem_num;
sem_op = sop->sem_op;
result = curr->semval;
-
+
if (!sem_op && result)
goto would_block;
@@ -386,26 +617,25 @@ static int try_atomic_semop (struct sem_array * sma, struct sembuf * sops,
goto would_block;
if (result > SEMVMX)
goto out_of_range;
+
if (sop->sem_flg & SEM_UNDO) {
int undo = un->semadj[sop->sem_num] - sem_op;
- /*
- * Exceeding the undo range is an error.
- */
+ /* Exceeding the undo range is an error. */
if (undo < (-SEMAEM - 1) || undo > SEMAEM)
goto out_of_range;
+ un->semadj[sop->sem_num] = undo;
}
+
curr->semval = result;
}
sop--;
+ pid = q->pid;
while (sop >= sops) {
sma->sem_base[sop->sem_num].sempid = pid;
- if (sop->sem_flg & SEM_UNDO)
- un->semadj[sop->sem_num] -= sop->sem_op;
sop--;
}
-
- sma->sem_otime = get_seconds();
+
return 0;
out_of_range:
@@ -413,6 +643,8 @@ out_of_range:
goto undo;
would_block:
+ q->blocking = sop;
+
if (sop->sem_flg & IPC_NOWAIT)
result = -EAGAIN;
else
@@ -421,154 +653,482 @@ would_block:
undo:
sop--;
while (sop >= sops) {
- sma->sem_base[sop->sem_num].semval -= sop->sem_op;
+ sem_op = sop->sem_op;
+ sma->sem_base[sop->sem_num].semval -= sem_op;
+ if (sop->sem_flg & SEM_UNDO)
+ un->semadj[sop->sem_num] += sem_op;
sop--;
}
return result;
}
-/* Go through the pending queue for the indicated semaphore
- * looking for tasks that can be completed.
+/** wake_up_sem_queue_prepare(q, error): Prepare wake-up
+ * @q: queue entry that must be signaled
+ * @error: Error value for the signal
+ *
+ * Prepare the wake-up of the queue entry q.
*/
-static void update_queue (struct sem_array * sma)
+static void wake_up_sem_queue_prepare(struct list_head *pt,
+ struct sem_queue *q, int error)
{
- int error;
- struct sem_queue * q;
+ if (list_empty(pt)) {
+ /*
+ * Hold preempt off so that we don't get preempted and have the
+ * wakee busy-wait until we're scheduled back on.
+ */
+ preempt_disable();
+ }
+ q->status = IN_WAKEUP;
+ q->pid = error;
- q = sma->sem_pending;
- while(q) {
- error = try_atomic_semop(sma, q->sops, q->nsops,
- q->undo, q->pid);
+ list_add_tail(&q->list, pt);
+}
+
+/**
+ * wake_up_sem_queue_do - do the actual wake-up
+ * @pt: list of tasks to be woken up
+ *
+ * Do the actual wake-up.
+ * The function is called without any locks held, thus the semaphore array
+ * could be destroyed already and the tasks can disappear as soon as the
+ * status is set to the actual return code.
+ */
+static void wake_up_sem_queue_do(struct list_head *pt)
+{
+ struct sem_queue *q, *t;
+ int did_something;
+
+ did_something = !list_empty(pt);
+ list_for_each_entry_safe(q, t, pt, list) {
+ wake_up_process(q->sleeper);
+ /* q can disappear immediately after writing q->status. */
+ smp_wmb();
+ q->status = q->pid;
+ }
+ if (did_something)
+ preempt_enable();
+}
+
+static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
+{
+ list_del(&q->list);
+ if (q->nsops > 1)
+ sma->complex_count--;
+}
+
+/** check_restart(sma, q)
+ * @sma: semaphore array
+ * @q: the operation that just completed
+ *
+ * update_queue is O(N^2) when it restarts scanning the whole queue of
+ * waiting operations. Therefore this function checks if the restart is
+ * really necessary. It is called after a previously waiting operation
+ * modified the array.
+ * Note that wait-for-zero operations are handled without restart.
+ */
+static int check_restart(struct sem_array *sma, struct sem_queue *q)
+{
+ /* pending complex alter operations are too difficult to analyse */
+ if (!list_empty(&sma->pending_alter))
+ return 1;
+
+ /* we were a sleeping complex operation. Too difficult */
+ if (q->nsops > 1)
+ return 1;
+
+ /* It is impossible that someone waits for the new value:
+ * - complex operations always restart.
+ * - wait-for-zero are handled seperately.
+ * - q is a previously sleeping simple operation that
+ * altered the array. It must be a decrement, because
+ * simple increments never sleep.
+ * - If there are older (higher priority) decrements
+ * in the queue, then they have observed the original
+ * semval value and couldn't proceed. The operation
+ * decremented to value - thus they won't proceed either.
+ */
+ return 0;
+}
+
+/**
+ * wake_const_ops - wake up non-alter tasks
+ * @sma: semaphore array.
+ * @semnum: semaphore that was modified.
+ * @pt: list head for the tasks that must be woken up.
+ *
+ * wake_const_ops must be called after a semaphore in a semaphore array
+ * was set to 0. If complex const operations are pending, wake_const_ops must
+ * be called with semnum = -1, as well as with the number of each modified
+ * semaphore.
+ * The tasks that must be woken up are added to @pt. The return code
+ * is stored in q->pid.
+ * The function returns 1 if at least one operation was completed successfully.
+ */
+static int wake_const_ops(struct sem_array *sma, int semnum,
+ struct list_head *pt)
+{
+ struct sem_queue *q;
+ struct list_head *walk;
+ struct list_head *pending_list;
+ int semop_completed = 0;
+
+ if (semnum == -1)
+ pending_list = &sma->pending_const;
+ else
+ pending_list = &sma->sem_base[semnum].pending_const;
+
+ walk = pending_list->next;
+ while (walk != pending_list) {
+ int error;
+
+ q = container_of(walk, struct sem_queue, list);
+ walk = walk->next;
+
+ error = perform_atomic_semop(sma, q);
- /* Does q->sleeper still need to sleep? */
if (error <= 0) {
- struct sem_queue *n;
- remove_from_queue(sma,q);
- q->status = IN_WAKEUP;
+ /* operation completed, remove from queue & wakeup */
+
+ unlink_queue(sma, q);
+
+ wake_up_sem_queue_prepare(pt, q, error);
+ if (error == 0)
+ semop_completed = 1;
+ }
+ }
+ return semop_completed;
+}
+
+/**
+ * do_smart_wakeup_zero - wakeup all wait for zero tasks
+ * @sma: semaphore array
+ * @sops: operations that were performed
+ * @nsops: number of operations
+ * @pt: list head of the tasks that must be woken up.
+ *
+ * Checks all required queue for wait-for-zero operations, based
+ * on the actual changes that were performed on the semaphore array.
+ * The function returns 1 if at least one operation was completed successfully.
+ */
+static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
+ int nsops, struct list_head *pt)
+{
+ int i;
+ int semop_completed = 0;
+ int got_zero = 0;
+
+ /* first: the per-semaphore queues, if known */
+ if (sops) {
+ for (i = 0; i < nsops; i++) {
+ int num = sops[i].sem_num;
+
+ if (sma->sem_base[num].semval == 0) {
+ got_zero = 1;
+ semop_completed |= wake_const_ops(sma, num, pt);
+ }
+ }
+ } else {
+ /*
+ * No sops means modified semaphores not known.
+ * Assume all were changed.
+ */
+ for (i = 0; i < sma->sem_nsems; i++) {
+ if (sma->sem_base[i].semval == 0) {
+ got_zero = 1;
+ semop_completed |= wake_const_ops(sma, i, pt);
+ }
+ }
+ }
+ /*
+ * If one of the modified semaphores got 0,
+ * then check the global queue, too.
+ */
+ if (got_zero)
+ semop_completed |= wake_const_ops(sma, -1, pt);
+
+ return semop_completed;
+}
+
+
+/**
+ * update_queue - look for tasks that can be completed.
+ * @sma: semaphore array.
+ * @semnum: semaphore that was modified.
+ * @pt: list head for the tasks that must be woken up.
+ *
+ * update_queue must be called after a semaphore in a semaphore array
+ * was modified. If multiple semaphores were modified, update_queue must
+ * be called with semnum = -1, as well as with the number of each modified
+ * semaphore.
+ * The tasks that must be woken up are added to @pt. The return code
+ * is stored in q->pid.
+ * The function internally checks if const operations can now succeed.
+ *
+ * The function return 1 if at least one semop was completed successfully.
+ */
+static int update_queue(struct sem_array *sma, int semnum, struct list_head *pt)
+{
+ struct sem_queue *q;
+ struct list_head *walk;
+ struct list_head *pending_list;
+ int semop_completed = 0;
+
+ if (semnum == -1)
+ pending_list = &sma->pending_alter;
+ else
+ pending_list = &sma->sem_base[semnum].pending_alter;
+
+again:
+ walk = pending_list->next;
+ while (walk != pending_list) {
+ int error, restart;
+
+ q = container_of(walk, struct sem_queue, list);
+ walk = walk->next;
+
+ /* If we are scanning the single sop, per-semaphore list of
+ * one semaphore and that semaphore is 0, then it is not
+ * necessary to scan further: simple increments
+ * that affect only one entry succeed immediately and cannot
+ * be in the per semaphore pending queue, and decrements
+ * cannot be successful if the value is already 0.
+ */
+ if (semnum != -1 && sma->sem_base[semnum].semval == 0)
+ break;
+
+ error = perform_atomic_semop(sma, q);
+
+ /* Does q->sleeper still need to sleep? */
+ if (error > 0)
+ continue;
+
+ unlink_queue(sma, q);
+
+ if (error) {
+ restart = 0;
+ } else {
+ semop_completed = 1;
+ do_smart_wakeup_zero(sma, q->sops, q->nsops, pt);
+ restart = check_restart(sma, q);
+ }
+
+ wake_up_sem_queue_prepare(pt, q, error);
+ if (restart)
+ goto again;
+ }
+ return semop_completed;
+}
+
+/**
+ * set_semotime - set sem_otime
+ * @sma: semaphore array
+ * @sops: operations that modified the array, may be NULL
+ *
+ * sem_otime is replicated to avoid cache line trashing.
+ * This function sets one instance to the current time.
+ */
+static void set_semotime(struct sem_array *sma, struct sembuf *sops)
+{
+ if (sops == NULL) {
+ sma->sem_base[0].sem_otime = get_seconds();
+ } else {
+ sma->sem_base[sops[0].sem_num].sem_otime =
+ get_seconds();
+ }
+}
+
+/**
+ * do_smart_update - optimized update_queue
+ * @sma: semaphore array
+ * @sops: operations that were performed
+ * @nsops: number of operations
+ * @otime: force setting otime
+ * @pt: list head of the tasks that must be woken up.
+ *
+ * do_smart_update() does the required calls to update_queue and wakeup_zero,
+ * based on the actual changes that were performed on the semaphore array.
+ * Note that the function does not do the actual wake-up: the caller is
+ * responsible for calling wake_up_sem_queue_do(@pt).
+ * It is safe to perform this call after dropping all locks.
+ */
+static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsops,
+ int otime, struct list_head *pt)
+{
+ int i;
+
+ otime |= do_smart_wakeup_zero(sma, sops, nsops, pt);
+
+ if (!list_empty(&sma->pending_alter)) {
+ /* semaphore array uses the global queue - just process it. */
+ otime |= update_queue(sma, -1, pt);
+ } else {
+ if (!sops) {
/*
- * Continue scanning. The next operation
- * that must be checked depends on the type of the
- * completed operation:
- * - if the operation modified the array, then
- * restart from the head of the queue and
- * check for threads that might be waiting
- * for semaphore values to become 0.
- * - if the operation didn't modify the array,
- * then just continue.
- */
- if (q->alter)
- n = sma->sem_pending;
- else
- n = q->next;
- wake_up_process(q->sleeper);
- /* hands-off: q will disappear immediately after
- * writing q->status.
+ * No sops, thus the modified semaphores are not
+ * known. Check all.
*/
- smp_wmb();
- q->status = error;
- q = n;
+ for (i = 0; i < sma->sem_nsems; i++)
+ otime |= update_queue(sma, i, pt);
} else {
- q = q->next;
+ /*
+ * Check the semaphores that were increased:
+ * - No complex ops, thus all sleeping ops are
+ * decrease.
+ * - if we decreased the value, then any sleeping
+ * semaphore ops wont be able to run: If the
+ * previous value was too small, then the new
+ * value will be too small, too.
+ */
+ for (i = 0; i < nsops; i++) {
+ if (sops[i].sem_op > 0) {
+ otime |= update_queue(sma,
+ sops[i].sem_num, pt);
+ }
+ }
}
}
+ if (otime)
+ set_semotime(sma, sops);
+}
+
+/*
+ * check_qop: Test if a queued operation sleeps on the semaphore semnum
+ */
+static int check_qop(struct sem_array *sma, int semnum, struct sem_queue *q,
+ bool count_zero)
+{
+ struct sembuf *sop = q->blocking;
+
+ /*
+ * Linux always (since 0.99.10) reported a task as sleeping on all
+ * semaphores. This violates SUS, therefore it was changed to the
+ * standard compliant behavior.
+ * Give the administrators a chance to notice that an application
+ * might misbehave because it relies on the Linux behavior.
+ */
+ pr_info_once("semctl(GETNCNT/GETZCNT) is since 3.16 Single Unix Specification compliant.\n"
+ "The task %s (%d) triggered the difference, watch for misbehavior.\n",
+ current->comm, task_pid_nr(current));
+
+ if (sop->sem_num != semnum)
+ return 0;
+
+ if (count_zero && sop->sem_op == 0)
+ return 1;
+ if (!count_zero && sop->sem_op < 0)
+ return 1;
+
+ return 0;
}
/* The following counts are associated to each semaphore:
* semncnt number of tasks waiting on semval being nonzero
* semzcnt number of tasks waiting on semval being zero
- * This model assumes that a task waits on exactly one semaphore.
- * Since semaphore operations are to be performed atomically, tasks actually
- * wait on a whole sequence of semaphores simultaneously.
- * The counts we return here are a rough approximation, but still
- * warrant that semncnt+semzcnt>0 if the task is on the pending queue.
+ *
+ * Per definition, a task waits only on the semaphore of the first semop
+ * that cannot proceed, even if additional operation would block, too.
*/
-static int count_semncnt (struct sem_array * sma, ushort semnum)
+static int count_semcnt(struct sem_array *sma, ushort semnum,
+ bool count_zero)
{
- int semncnt;
- struct sem_queue * q;
+ struct list_head *l;
+ struct sem_queue *q;
+ int semcnt;
- semncnt = 0;
- for (q = sma->sem_pending; q; q = q->next) {
- struct sembuf * sops = q->sops;
- int nsops = q->nsops;
- int i;
- for (i = 0; i < nsops; i++)
- if (sops[i].sem_num == semnum
- && (sops[i].sem_op < 0)
- && !(sops[i].sem_flg & IPC_NOWAIT))
- semncnt++;
+ semcnt = 0;
+ /* First: check the simple operations. They are easy to evaluate */
+ if (count_zero)
+ l = &sma->sem_base[semnum].pending_const;
+ else
+ l = &sma->sem_base[semnum].pending_alter;
+
+ list_for_each_entry(q, l, list) {
+ /* all task on a per-semaphore list sleep on exactly
+ * that semaphore
+ */
+ semcnt++;
}
- return semncnt;
-}
-static int count_semzcnt (struct sem_array * sma, ushort semnum)
-{
- int semzcnt;
- struct sem_queue * q;
- semzcnt = 0;
- for (q = sma->sem_pending; q; q = q->next) {
- struct sembuf * sops = q->sops;
- int nsops = q->nsops;
- int i;
- for (i = 0; i < nsops; i++)
- if (sops[i].sem_num == semnum
- && (sops[i].sem_op == 0)
- && !(sops[i].sem_flg & IPC_NOWAIT))
- semzcnt++;
+ /* Then: check the complex operations. */
+ list_for_each_entry(q, &sma->pending_alter, list) {
+ semcnt += check_qop(sma, semnum, q, count_zero);
}
- return semzcnt;
+ if (count_zero) {
+ list_for_each_entry(q, &sma->pending_const, list) {
+ semcnt += check_qop(sma, semnum, q, count_zero);
+ }
+ }
+ return semcnt;
}
-/* Free a semaphore set. freeary() is called with sem_ids.rw_mutex locked
- * as a writer and the spinlock for this semaphore set hold. sem_ids.rw_mutex
+/* Free a semaphore set. freeary() is called with sem_ids.rwsem locked
+ * as a writer and the spinlock for this semaphore set hold. sem_ids.rwsem
* remains locked on exit.
*/
static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
{
- struct sem_undo *un;
- struct sem_queue *q;
+ struct sem_undo *un, *tu;
+ struct sem_queue *q, *tq;
struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm);
-
- /* Invalidate the existing undo structures for this semaphore set.
- * (They will be freed without any further action in exit_sem()
- * or during the next semop.)
- */
- for (un = sma->undo; un; un = un->id_next)
+ struct list_head tasks;
+ int i;
+
+ /* Free the existing undo structures for this semaphore set. */
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_for_each_entry_safe(un, tu, &sma->list_id, list_id) {
+ list_del(&un->list_id);
+ spin_lock(&un->ulp->lock);
un->semid = -1;
+ list_del_rcu(&un->list_proc);
+ spin_unlock(&un->ulp->lock);
+ kfree_rcu(un, rcu);
+ }
/* Wake up all pending processes and let them fail with EIDRM. */
- q = sma->sem_pending;
- while(q) {
- struct sem_queue *n;
- /* lazy remove_from_queue: we are killing the whole queue */
- q->prev = NULL;
- n = q->next;
- q->status = IN_WAKEUP;
- wake_up_process(q->sleeper); /* doesn't sleep */
- smp_wmb();
- q->status = -EIDRM; /* hands-off q */
- q = n;
+ INIT_LIST_HEAD(&tasks);
+ list_for_each_entry_safe(q, tq, &sma->pending_const, list) {
+ unlink_queue(sma, q);
+ wake_up_sem_queue_prepare(&tasks, q, -EIDRM);
+ }
+
+ list_for_each_entry_safe(q, tq, &sma->pending_alter, list) {
+ unlink_queue(sma, q);
+ wake_up_sem_queue_prepare(&tasks, q, -EIDRM);
+ }
+ for (i = 0; i < sma->sem_nsems; i++) {
+ struct sem *sem = sma->sem_base + i;
+ list_for_each_entry_safe(q, tq, &sem->pending_const, list) {
+ unlink_queue(sma, q);
+ wake_up_sem_queue_prepare(&tasks, q, -EIDRM);
+ }
+ list_for_each_entry_safe(q, tq, &sem->pending_alter, list) {
+ unlink_queue(sma, q);
+ wake_up_sem_queue_prepare(&tasks, q, -EIDRM);
+ }
}
/* Remove the semaphore set from the IDR */
sem_rmid(ns, sma);
- sem_unlock(sma);
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ wake_up_sem_queue_do(&tasks);
ns->used_sems -= sma->sem_nsems;
- security_sem_free(sma);
- ipc_rcu_putref(sma);
+ ipc_rcu_putref(sma, sem_rcu_free);
}
static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
return copy_to_user(buf, in, sizeof(*in));
case IPC_OLD:
{
struct semid_ds out;
+ memset(&out, 0, sizeof(out));
+
ipc64_perm_to_ipc_perm(&in->sem_perm, &out.sem_perm);
out.sem_otime = in->sem_otime;
@@ -582,13 +1142,28 @@ static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in,
}
}
+static time_t get_semotime(struct sem_array *sma)
+{
+ int i;
+ time_t res;
+
+ res = sma->sem_base[0].sem_otime;
+ for (i = 1; i < sma->sem_nsems; i++) {
+ time_t to = sma->sem_base[i].sem_otime;
+
+ if (to > res)
+ res = to;
+ }
+ return res;
+}
+
static int semctl_nolock(struct ipc_namespace *ns, int semid,
- int cmd, int version, union semun arg)
+ int cmd, int version, void __user *p)
{
- int err = -EINVAL;
+ int err;
struct sem_array *sma;
- switch(cmd) {
+ switch (cmd) {
case IPC_INFO:
case SEM_INFO:
{
@@ -598,8 +1173,8 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
err = security_sem_semctl(NULL, cmd);
if (err)
return err;
-
- memset(&seminfo,0,sizeof(seminfo));
+
+ memset(&seminfo, 0, sizeof(seminfo));
seminfo.semmni = ns->sc_semmni;
seminfo.semmns = ns->sc_semmns;
seminfo.semmsl = ns->sc_semmsl;
@@ -608,7 +1183,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
seminfo.semmnu = SEMMNU;
seminfo.semmap = SEMMAP;
seminfo.semume = SEMUME;
- down_read(&sem_ids(ns).rw_mutex);
+ down_read(&sem_ids(ns).rwsem);
if (cmd == SEM_INFO) {
seminfo.semusz = sem_ids(ns).in_use;
seminfo.semaem = ns->used_sems;
@@ -617,114 +1192,198 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
seminfo.semaem = SEMAEM;
}
max_id = ipc_get_maxid(&sem_ids(ns));
- up_read(&sem_ids(ns).rw_mutex);
- if (copy_to_user (arg.__buf, &seminfo, sizeof(struct seminfo)))
+ up_read(&sem_ids(ns).rwsem);
+ if (copy_to_user(p, &seminfo, sizeof(struct seminfo)))
return -EFAULT;
- return (max_id < 0) ? 0: max_id;
+ return (max_id < 0) ? 0 : max_id;
}
case IPC_STAT:
case SEM_STAT:
{
struct semid64_ds tbuf;
- int id;
+ int id = 0;
+
+ memset(&tbuf, 0, sizeof(tbuf));
+ rcu_read_lock();
if (cmd == SEM_STAT) {
- sma = sem_lock(ns, semid);
- if (IS_ERR(sma))
- return PTR_ERR(sma);
+ sma = sem_obtain_object(ns, semid);
+ if (IS_ERR(sma)) {
+ err = PTR_ERR(sma);
+ goto out_unlock;
+ }
id = sma->sem_perm.id;
} else {
- sma = sem_lock_check(ns, semid);
- if (IS_ERR(sma))
- return PTR_ERR(sma);
- id = 0;
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ err = PTR_ERR(sma);
+ goto out_unlock;
+ }
}
err = -EACCES;
- if (ipcperms (&sma->sem_perm, S_IRUGO))
+ if (ipcperms(ns, &sma->sem_perm, S_IRUGO))
goto out_unlock;
err = security_sem_semctl(sma, cmd);
if (err)
goto out_unlock;
- memset(&tbuf, 0, sizeof(tbuf));
-
kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
- tbuf.sem_otime = sma->sem_otime;
- tbuf.sem_ctime = sma->sem_ctime;
- tbuf.sem_nsems = sma->sem_nsems;
- sem_unlock(sma);
- if (copy_semid_to_user (arg.buf, &tbuf, version))
+ tbuf.sem_otime = get_semotime(sma);
+ tbuf.sem_ctime = sma->sem_ctime;
+ tbuf.sem_nsems = sma->sem_nsems;
+ rcu_read_unlock();
+ if (copy_semid_to_user(p, &tbuf, version))
return -EFAULT;
return id;
}
default:
return -EINVAL;
}
- return err;
out_unlock:
- sem_unlock(sma);
+ rcu_read_unlock();
return err;
}
-static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
- int cmd, int version, union semun arg)
+static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
+ unsigned long arg)
{
+ struct sem_undo *un;
struct sem_array *sma;
- struct sem* curr;
+ struct sem *curr;
int err;
+ struct list_head tasks;
+ int val;
+#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
+ /* big-endian 64bit */
+ val = arg >> 32;
+#else
+ /* 32bit or little-endian 64bit */
+ val = arg;
+#endif
+
+ if (val > SEMVMX || val < 0)
+ return -ERANGE;
+
+ INIT_LIST_HEAD(&tasks);
+
+ rcu_read_lock();
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
+ return PTR_ERR(sma);
+ }
+
+ if (semnum < 0 || semnum >= sma->sem_nsems) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+
+
+ if (ipcperms(ns, &sma->sem_perm, S_IWUGO)) {
+ rcu_read_unlock();
+ return -EACCES;
+ }
+
+ err = security_sem_semctl(sma, SETVAL);
+ if (err) {
+ rcu_read_unlock();
+ return -EACCES;
+ }
+
+ sem_lock(sma, NULL, -1);
+
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ return -EIDRM;
+ }
+
+ curr = &sma->sem_base[semnum];
+
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_for_each_entry(un, &sma->list_id, list_id)
+ un->semadj[semnum] = 0;
+
+ curr->semval = val;
+ curr->sempid = task_tgid_vnr(current);
+ sma->sem_ctime = get_seconds();
+ /* maybe some queued-up processes were waiting for this */
+ do_smart_update(sma, NULL, 0, 0, &tasks);
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ wake_up_sem_queue_do(&tasks);
+ return 0;
+}
+
+static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
+ int cmd, void __user *p)
+{
+ struct sem_array *sma;
+ struct sem *curr;
+ int err, nsems;
ushort fast_sem_io[SEMMSL_FAST];
- ushort* sem_io = fast_sem_io;
- int nsems;
+ ushort *sem_io = fast_sem_io;
+ struct list_head tasks;
- sma = sem_lock_check(ns, semid);
- if (IS_ERR(sma))
+ INIT_LIST_HEAD(&tasks);
+
+ rcu_read_lock();
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
return PTR_ERR(sma);
+ }
nsems = sma->sem_nsems;
err = -EACCES;
- if (ipcperms (&sma->sem_perm, (cmd==SETVAL||cmd==SETALL)?S_IWUGO:S_IRUGO))
- goto out_unlock;
+ if (ipcperms(ns, &sma->sem_perm, cmd == SETALL ? S_IWUGO : S_IRUGO))
+ goto out_rcu_wakeup;
err = security_sem_semctl(sma, cmd);
if (err)
- goto out_unlock;
+ goto out_rcu_wakeup;
err = -EACCES;
switch (cmd) {
case GETALL:
{
- ushort __user *array = arg.array;
+ ushort __user *array = p;
int i;
- if(nsems > SEMMSL_FAST) {
- ipc_rcu_getref(sma);
- sem_unlock(sma);
-
+ sem_lock(sma, NULL, -1);
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ err = -EIDRM;
+ goto out_unlock;
+ }
+ if (nsems > SEMMSL_FAST) {
+ if (!ipc_rcu_getref(sma)) {
+ err = -EIDRM;
+ goto out_unlock;
+ }
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
sem_io = ipc_alloc(sizeof(ushort)*nsems);
- if(sem_io == NULL) {
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- sem_unlock(sma);
+ if (sem_io == NULL) {
+ ipc_rcu_putref(sma, ipc_rcu_free);
return -ENOMEM;
}
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- if (sma->sem_perm.deleted) {
- sem_unlock(sma);
+ rcu_read_lock();
+ sem_lock_and_putref(sma);
+ if (!ipc_valid_object(&sma->sem_perm)) {
err = -EIDRM;
- goto out_free;
+ goto out_unlock;
}
}
-
for (i = 0; i < sma->sem_nsems; i++)
sem_io[i] = sma->sem_base[i].semval;
- sem_unlock(sma);
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
err = 0;
- if(copy_to_user(array, sem_io, nsems*sizeof(ushort)))
+ if (copy_to_user(array, sem_io, nsems*sizeof(ushort)))
err = -EFAULT;
goto out_free;
}
@@ -733,61 +1392,65 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
int i;
struct sem_undo *un;
- ipc_rcu_getref(sma);
- sem_unlock(sma);
+ if (!ipc_rcu_getref(sma)) {
+ err = -EIDRM;
+ goto out_rcu_wakeup;
+ }
+ rcu_read_unlock();
- if(nsems > SEMMSL_FAST) {
+ if (nsems > SEMMSL_FAST) {
sem_io = ipc_alloc(sizeof(ushort)*nsems);
- if(sem_io == NULL) {
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- sem_unlock(sma);
+ if (sem_io == NULL) {
+ ipc_rcu_putref(sma, ipc_rcu_free);
return -ENOMEM;
}
}
- if (copy_from_user (sem_io, arg.array, nsems*sizeof(ushort))) {
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- sem_unlock(sma);
+ if (copy_from_user(sem_io, p, nsems*sizeof(ushort))) {
+ ipc_rcu_putref(sma, ipc_rcu_free);
err = -EFAULT;
goto out_free;
}
for (i = 0; i < nsems; i++) {
if (sem_io[i] > SEMVMX) {
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- sem_unlock(sma);
+ ipc_rcu_putref(sma, ipc_rcu_free);
err = -ERANGE;
goto out_free;
}
}
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- if (sma->sem_perm.deleted) {
- sem_unlock(sma);
+ rcu_read_lock();
+ sem_lock_and_putref(sma);
+ if (!ipc_valid_object(&sma->sem_perm)) {
err = -EIDRM;
- goto out_free;
+ goto out_unlock;
}
for (i = 0; i < nsems; i++)
sma->sem_base[i].semval = sem_io[i];
- for (un = sma->undo; un; un = un->id_next)
+
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_for_each_entry(un, &sma->list_id, list_id) {
for (i = 0; i < nsems; i++)
un->semadj[i] = 0;
+ }
sma->sem_ctime = get_seconds();
/* maybe some queued-up processes were waiting for this */
- update_queue(sma);
+ do_smart_update(sma, NULL, 0, 0, &tasks);
err = 0;
goto out_unlock;
}
- /* GETVAL, GETPID, GETNCTN, GETZCNT, SETVAL: fall-through */
+ /* GETVAL, GETPID, GETNCTN, GETZCNT: fall-through */
}
err = -EINVAL;
- if(semnum < 0 || semnum >= nsems)
- goto out_unlock;
+ if (semnum < 0 || semnum >= nsems)
+ goto out_rcu_wakeup;
+ sem_lock(sma, NULL, -1);
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ err = -EIDRM;
+ goto out_unlock;
+ }
curr = &sma->sem_base[semnum];
switch (cmd) {
@@ -798,70 +1461,42 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
err = curr->sempid;
goto out_unlock;
case GETNCNT:
- err = count_semncnt(sma,semnum);
+ err = count_semcnt(sma, semnum, 0);
goto out_unlock;
case GETZCNT:
- err = count_semzcnt(sma,semnum);
- goto out_unlock;
- case SETVAL:
- {
- int val = arg.val;
- struct sem_undo *un;
- err = -ERANGE;
- if (val > SEMVMX || val < 0)
- goto out_unlock;
-
- for (un = sma->undo; un; un = un->id_next)
- un->semadj[semnum] = 0;
- curr->semval = val;
- curr->sempid = task_tgid_vnr(current);
- sma->sem_ctime = get_seconds();
- /* maybe some queued-up processes were waiting for this */
- update_queue(sma);
- err = 0;
+ err = count_semcnt(sma, semnum, 1);
goto out_unlock;
}
- }
+
out_unlock:
- sem_unlock(sma);
+ sem_unlock(sma, -1);
+out_rcu_wakeup:
+ rcu_read_unlock();
+ wake_up_sem_queue_do(&tasks);
out_free:
- if(sem_io != fast_sem_io)
+ if (sem_io != fast_sem_io)
ipc_free(sem_io, sizeof(ushort)*nsems);
return err;
}
-struct sem_setbuf {
- uid_t uid;
- gid_t gid;
- mode_t mode;
-};
-
-static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __user *buf, int version)
+static inline unsigned long
+copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
- {
- struct semid64_ds tbuf;
-
- if(copy_from_user(&tbuf, buf, sizeof(tbuf)))
+ if (copy_from_user(out, buf, sizeof(*out)))
return -EFAULT;
-
- out->uid = tbuf.sem_perm.uid;
- out->gid = tbuf.sem_perm.gid;
- out->mode = tbuf.sem_perm.mode;
-
return 0;
- }
case IPC_OLD:
{
struct semid_ds tbuf_old;
- if(copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
+ if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
return -EFAULT;
- out->uid = tbuf_old.sem_perm.uid;
- out->gid = tbuf_old.sem_perm.gid;
- out->mode = tbuf_old.sem_perm.mode;
+ out->sem_perm.uid = tbuf_old.sem_perm.uid;
+ out->sem_perm.gid = tbuf_old.sem_perm.gid;
+ out->sem_perm.mode = tbuf_old.sem_perm.mode;
return 0;
}
@@ -870,74 +1505,72 @@ static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __
}
}
-static int semctl_down(struct ipc_namespace *ns, int semid, int semnum,
- int cmd, int version, union semun arg)
+/*
+ * This function handles some semctl commands which require the rwsem
+ * to be held in write mode.
+ * NOTE: no locks must be held, the rwsem is taken inside this function.
+ */
+static int semctl_down(struct ipc_namespace *ns, int semid,
+ int cmd, int version, void __user *p)
{
struct sem_array *sma;
int err;
- struct sem_setbuf uninitialized_var(setbuf);
+ struct semid64_ds semid64;
struct kern_ipc_perm *ipcp;
- if(cmd == IPC_SET) {
- if(copy_semid_from_user (&setbuf, arg.buf, version))
+ if (cmd == IPC_SET) {
+ if (copy_semid_from_user(&semid64, p, version))
return -EFAULT;
}
- sma = sem_lock_check_down(ns, semid);
- if (IS_ERR(sma))
- return PTR_ERR(sma);
- ipcp = &sma->sem_perm;
+ down_write(&sem_ids(ns).rwsem);
+ rcu_read_lock();
- err = audit_ipc_obj(ipcp);
- if (err)
- goto out_unlock;
-
- if (cmd == IPC_SET) {
- err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
- if (err)
- goto out_unlock;
- }
- if (current->euid != ipcp->cuid &&
- current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) {
- err=-EPERM;
- goto out_unlock;
+ ipcp = ipcctl_pre_down_nolock(ns, &sem_ids(ns), semid, cmd,
+ &semid64.sem_perm, 0);
+ if (IS_ERR(ipcp)) {
+ err = PTR_ERR(ipcp);
+ goto out_unlock1;
}
+ sma = container_of(ipcp, struct sem_array, sem_perm);
+
err = security_sem_semctl(sma, cmd);
if (err)
- goto out_unlock;
+ goto out_unlock1;
- switch(cmd){
+ switch (cmd) {
case IPC_RMID:
+ sem_lock(sma, NULL, -1);
+ /* freeary unlocks the ipc object and rcu */
freeary(ns, ipcp);
- err = 0;
- break;
+ goto out_up;
case IPC_SET:
- ipcp->uid = setbuf.uid;
- ipcp->gid = setbuf.gid;
- ipcp->mode = (ipcp->mode & ~S_IRWXUGO)
- | (setbuf.mode & S_IRWXUGO);
+ sem_lock(sma, NULL, -1);
+ err = ipc_update_perm(&semid64.sem_perm, ipcp);
+ if (err)
+ goto out_unlock0;
sma->sem_ctime = get_seconds();
- sem_unlock(sma);
- err = 0;
break;
default:
- sem_unlock(sma);
err = -EINVAL;
- break;
+ goto out_unlock1;
}
- return err;
-out_unlock:
- sem_unlock(sma);
+out_unlock0:
+ sem_unlock(sma, -1);
+out_unlock1:
+ rcu_read_unlock();
+out_up:
+ up_write(&sem_ids(ns).rwsem);
return err;
}
-asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg)
+SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
{
- int err = -EINVAL;
int version;
struct ipc_namespace *ns;
+ void __user *p = (void __user *)arg;
if (semid < 0)
return -EINVAL;
@@ -945,28 +1578,24 @@ asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg)
version = ipc_parse_version(&cmd);
ns = current->nsproxy->ipc_ns;
- switch(cmd) {
+ switch (cmd) {
case IPC_INFO:
case SEM_INFO:
case IPC_STAT:
case SEM_STAT:
- err = semctl_nolock(ns, semid, cmd, version, arg);
- return err;
+ return semctl_nolock(ns, semid, cmd, version, p);
case GETALL:
case GETVAL:
case GETPID:
case GETNCNT:
case GETZCNT:
- case SETVAL:
case SETALL:
- err = semctl_main(ns,semid,semnum,cmd,version,arg);
- return err;
+ return semctl_main(ns, semid, semnum, cmd, p);
+ case SETVAL:
+ return semctl_setval(ns, semid, semnum, arg);
case IPC_RMID:
case IPC_SET:
- down_write(&sem_ids(ns).rw_mutex);
- err = semctl_down(ns,semid,semnum,cmd,version,arg);
- up_write(&sem_ids(ns).rw_mutex);
- return err;
+ return semctl_down(ns, semid, cmd, version, p);
default:
return -EINVAL;
}
@@ -994,111 +1623,167 @@ static inline int get_undo_list(struct sem_undo_list **undo_listp)
return -ENOMEM;
spin_lock_init(&undo_list->lock);
atomic_set(&undo_list->refcnt, 1);
+ INIT_LIST_HEAD(&undo_list->list_proc);
+
current->sysvsem.undo_list = undo_list;
}
*undo_listp = undo_list;
return 0;
}
+static struct sem_undo *__lookup_undo(struct sem_undo_list *ulp, int semid)
+{
+ struct sem_undo *un;
+
+ list_for_each_entry_rcu(un, &ulp->list_proc, list_proc) {
+ if (un->semid == semid)
+ return un;
+ }
+ return NULL;
+}
+
static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
{
- struct sem_undo **last, *un;
+ struct sem_undo *un;
- last = &ulp->proc_list;
- un = *last;
- while(un != NULL) {
- if(un->semid==semid)
- break;
- if(un->semid==-1) {
- *last=un->proc_next;
- kfree(un);
- } else {
- last=&un->proc_next;
- }
- un=*last;
+ assert_spin_locked(&ulp->lock);
+
+ un = __lookup_undo(ulp, semid);
+ if (un) {
+ list_del_rcu(&un->list_proc);
+ list_add_rcu(&un->list_proc, &ulp->list_proc);
}
return un;
}
-static struct sem_undo *find_undo(struct ipc_namespace *ns, int semid)
+/**
+ * find_alloc_undo - lookup (and if not present create) undo array
+ * @ns: namespace
+ * @semid: semaphore array id
+ *
+ * The function looks up (and if not present creates) the undo structure.
+ * The size of the undo structure depends on the size of the semaphore
+ * array, thus the alloc path is not that straightforward.
+ * Lifetime-rules: sem_undo is rcu-protected, on success, the function
+ * performs a rcu_read_lock().
+ */
+static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
{
struct sem_array *sma;
struct sem_undo_list *ulp;
struct sem_undo *un, *new;
- int nsems;
- int error;
+ int nsems, error;
error = get_undo_list(&ulp);
if (error)
return ERR_PTR(error);
+ rcu_read_lock();
spin_lock(&ulp->lock);
un = lookup_undo(ulp, semid);
spin_unlock(&ulp->lock);
- if (likely(un!=NULL))
+ if (likely(un != NULL))
goto out;
/* no undo structure around - allocate one. */
- sma = sem_lock_check(ns, semid);
- if (IS_ERR(sma))
- return ERR_PTR(PTR_ERR(sma));
+ /* step 1: figure out the size of the semaphore array */
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
+ return ERR_CAST(sma);
+ }
nsems = sma->sem_nsems;
- ipc_rcu_getref(sma);
- sem_unlock(sma);
+ if (!ipc_rcu_getref(sma)) {
+ rcu_read_unlock();
+ un = ERR_PTR(-EIDRM);
+ goto out;
+ }
+ rcu_read_unlock();
+ /* step 2: allocate new undo structure */
new = kzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL);
if (!new) {
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- sem_unlock(sma);
+ ipc_rcu_putref(sma, ipc_rcu_free);
return ERR_PTR(-ENOMEM);
}
- new->semadj = (short *) &new[1];
- new->semid = semid;
- spin_lock(&ulp->lock);
- un = lookup_undo(ulp, semid);
- if (un) {
- spin_unlock(&ulp->lock);
+ /* step 3: Acquire the lock on semaphore array */
+ rcu_read_lock();
+ sem_lock_and_putref(sma);
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
kfree(new);
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- sem_unlock(sma);
+ un = ERR_PTR(-EIDRM);
goto out;
}
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- if (sma->sem_perm.deleted) {
- sem_unlock(sma);
- spin_unlock(&ulp->lock);
+ spin_lock(&ulp->lock);
+
+ /*
+ * step 4: check for races: did someone else allocate the undo struct?
+ */
+ un = lookup_undo(ulp, semid);
+ if (un) {
kfree(new);
- un = ERR_PTR(-EIDRM);
- goto out;
+ goto success;
}
- new->proc_next = ulp->proc_list;
- ulp->proc_list = new;
- new->id_next = sma->undo;
- sma->undo = new;
- sem_unlock(sma);
+ /* step 5: initialize & link new undo structure */
+ new->semadj = (short *) &new[1];
+ new->ulp = ulp;
+ new->semid = semid;
+ assert_spin_locked(&ulp->lock);
+ list_add_rcu(&new->list_proc, &ulp->list_proc);
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_add(&new->list_id, &sma->list_id);
un = new;
+
+success:
spin_unlock(&ulp->lock);
+ sem_unlock(sma, -1);
out:
return un;
}
-asmlinkage long sys_semtimedop(int semid, struct sembuf __user *tsops,
- unsigned nsops, const struct timespec __user *timeout)
+
+/**
+ * get_queue_result - retrieve the result code from sem_queue
+ * @q: Pointer to queue structure
+ *
+ * Retrieve the return code from the pending queue. If IN_WAKEUP is found in
+ * q->status, then we must loop until the value is replaced with the final
+ * value: This may happen if a task is woken up by an unrelated event (e.g.
+ * signal) and in parallel the task is woken up by another task because it got
+ * the requested semaphores.
+ *
+ * The function can be called with or without holding the semaphore spinlock.
+ */
+static int get_queue_result(struct sem_queue *q)
+{
+ int error;
+
+ error = q->status;
+ while (unlikely(error == IN_WAKEUP)) {
+ cpu_relax();
+ error = q->status;
+ }
+
+ return error;
+}
+
+SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
+ unsigned, nsops, const struct timespec __user *, timeout)
{
int error = -EINVAL;
struct sem_array *sma;
struct sembuf fast_sops[SEMOPM_FAST];
- struct sembuf* sops = fast_sops, *sop;
+ struct sembuf *sops = fast_sops, *sop;
struct sem_undo *un;
- int undos = 0, alter = 0, max;
+ int undos = 0, alter = 0, max, locknum;
struct sem_queue queue;
unsigned long jiffies_left = 0;
struct ipc_namespace *ns;
+ struct list_head tasks;
ns = current->nsproxy->ipc_ns;
@@ -1106,13 +1791,13 @@ asmlinkage long sys_semtimedop(int semid, struct sembuf __user *tsops,
return -EINVAL;
if (nsops > ns->sc_semopm)
return -E2BIG;
- if(nsops > SEMOPM_FAST) {
- sops = kmalloc(sizeof(*sops)*nsops,GFP_KERNEL);
- if(sops==NULL)
+ if (nsops > SEMOPM_FAST) {
+ sops = kmalloc(sizeof(*sops)*nsops, GFP_KERNEL);
+ if (sops == NULL)
return -ENOMEM;
}
- if (copy_from_user (sops, tsops, nsops * sizeof(*tsops))) {
- error=-EFAULT;
+ if (copy_from_user(sops, tsops, nsops * sizeof(*tsops))) {
+ error = -EFAULT;
goto out_free;
}
if (timeout) {
@@ -1138,120 +1823,191 @@ asmlinkage long sys_semtimedop(int semid, struct sembuf __user *tsops,
alter = 1;
}
-retry_undos:
+ INIT_LIST_HEAD(&tasks);
+
if (undos) {
- un = find_undo(ns, semid);
+ /* On success, find_alloc_undo takes the rcu_read_lock */
+ un = find_alloc_undo(ns, semid);
if (IS_ERR(un)) {
error = PTR_ERR(un);
goto out_free;
}
- } else
+ } else {
un = NULL;
+ rcu_read_lock();
+ }
- sma = sem_lock_check(ns, semid);
+ sma = sem_obtain_object_check(ns, semid);
if (IS_ERR(sma)) {
+ rcu_read_unlock();
error = PTR_ERR(sma);
goto out_free;
}
- /*
- * semid identifiers are not unique - find_undo may have
- * allocated an undo structure, it was invalidated by an RMID
- * and now a new array with received the same id. Check and retry.
- */
- if (un && un->semid == -1) {
- sem_unlock(sma);
- goto retry_undos;
- }
error = -EFBIG;
if (max >= sma->sem_nsems)
- goto out_unlock_free;
+ goto out_rcu_wakeup;
error = -EACCES;
- if (ipcperms(&sma->sem_perm, alter ? S_IWUGO : S_IRUGO))
- goto out_unlock_free;
+ if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO))
+ goto out_rcu_wakeup;
error = security_sem_semop(sma, sops, nsops, alter);
if (error)
- goto out_unlock_free;
+ goto out_rcu_wakeup;
- error = try_atomic_semop (sma, sops, nsops, un, task_tgid_vnr(current));
- if (error <= 0) {
- if (alter && error == 0)
- update_queue (sma);
+ error = -EIDRM;
+ locknum = sem_lock(sma, sops, nsops);
+ /*
+ * We eventually might perform the following check in a lockless
+ * fashion, considering ipc_valid_object() locking constraints.
+ * If nsops == 1 and there is no contention for sem_perm.lock, then
+ * only a per-semaphore lock is held and it's OK to proceed with the
+ * check below. More details on the fine grained locking scheme
+ * entangled here and why it's RMID race safe on comments at sem_lock()
+ */
+ if (!ipc_valid_object(&sma->sem_perm))
goto out_unlock_free;
- }
-
- /* We need to sleep on this operation, so we put the current
- * task into the pending queue and go to sleep.
+ /*
+ * semid identifiers are not unique - find_alloc_undo may have
+ * allocated an undo structure, it was invalidated by an RMID
+ * and now a new array with received the same id. Check and fail.
+ * This case can be detected checking un->semid. The existence of
+ * "un" itself is guaranteed by rcu.
*/
-
- queue.sma = sma;
+ if (un && un->semid == -1)
+ goto out_unlock_free;
+
queue.sops = sops;
queue.nsops = nsops;
queue.undo = un;
queue.pid = task_tgid_vnr(current);
- queue.id = semid;
queue.alter = alter;
- if (alter)
- append_to_queue(sma ,&queue);
- else
- prepend_to_queue(sma ,&queue);
+
+ error = perform_atomic_semop(sma, &queue);
+ if (error == 0) {
+ /* If the operation was successful, then do
+ * the required updates.
+ */
+ if (alter)
+ do_smart_update(sma, sops, nsops, 1, &tasks);
+ else
+ set_semotime(sma, sops);
+ }
+ if (error <= 0)
+ goto out_unlock_free;
+
+ /* We need to sleep on this operation, so we put the current
+ * task into the pending queue and go to sleep.
+ */
+
+ if (nsops == 1) {
+ struct sem *curr;
+ curr = &sma->sem_base[sops->sem_num];
+
+ if (alter) {
+ if (sma->complex_count) {
+ list_add_tail(&queue.list,
+ &sma->pending_alter);
+ } else {
+
+ list_add_tail(&queue.list,
+ &curr->pending_alter);
+ }
+ } else {
+ list_add_tail(&queue.list, &curr->pending_const);
+ }
+ } else {
+ if (!sma->complex_count)
+ merge_queues(sma);
+
+ if (alter)
+ list_add_tail(&queue.list, &sma->pending_alter);
+ else
+ list_add_tail(&queue.list, &sma->pending_const);
+
+ sma->complex_count++;
+ }
queue.status = -EINTR;
queue.sleeper = current;
+
+sleep_again:
current->state = TASK_INTERRUPTIBLE;
- sem_unlock(sma);
+ sem_unlock(sma, locknum);
+ rcu_read_unlock();
if (timeout)
jiffies_left = schedule_timeout(jiffies_left);
else
schedule();
- error = queue.status;
- while(unlikely(error == IN_WAKEUP)) {
- cpu_relax();
- error = queue.status;
- }
+ error = get_queue_result(&queue);
if (error != -EINTR) {
/* fast path: update_queue already obtained all requested
- * resources */
+ * resources.
+ * Perform a smp_mb(): User space could assume that semop()
+ * is a memory barrier: Without the mb(), the cpu could
+ * speculatively read in user space stale data that was
+ * overwritten by the previous owner of the semaphore.
+ */
+ smp_mb();
+
goto out_free;
}
- sma = sem_lock(ns, semid);
+ rcu_read_lock();
+ sma = sem_obtain_lock(ns, semid, sops, nsops, &locknum);
+
+ /*
+ * Wait until it's guaranteed that no wakeup_sem_queue_do() is ongoing.
+ */
+ error = get_queue_result(&queue);
+
+ /*
+ * Array removed? If yes, leave without sem_unlock().
+ */
if (IS_ERR(sma)) {
- BUG_ON(queue.prev != NULL);
- error = -EIDRM;
+ rcu_read_unlock();
goto out_free;
}
+
/*
- * If queue.status != -EINTR we are woken up by another process
+ * If queue.status != -EINTR we are woken up by another process.
+ * Leave without unlink_queue(), but with sem_unlock().
*/
- error = queue.status;
- if (error != -EINTR) {
+ if (error != -EINTR)
goto out_unlock_free;
- }
/*
* If an interrupt occurred we have to clean up the queue
*/
if (timeout && jiffies_left == 0)
error = -EAGAIN;
- remove_from_queue(sma,&queue);
- goto out_unlock_free;
+
+ /*
+ * If the wakeup was spurious, just retry
+ */
+ if (error == -EINTR && !signal_pending(current))
+ goto sleep_again;
+
+ unlink_queue(sma, &queue);
out_unlock_free:
- sem_unlock(sma);
+ sem_unlock(sma, locknum);
+out_rcu_wakeup:
+ rcu_read_unlock();
+ wake_up_sem_queue_do(&tasks);
out_free:
- if(sops != fast_sops)
+ if (sops != fast_sops)
kfree(sops);
return error;
}
-asmlinkage long sys_semop (int semid, struct sembuf __user *tsops, unsigned nsops)
+SYSCALL_DEFINE3(semop, int, semid, struct sembuf __user *, tsops,
+ unsigned, nsops)
{
return sys_semtimedop(semid, tsops, nsops, NULL);
}
@@ -1271,7 +2027,7 @@ int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
return error;
atomic_inc(&undo_list->refcnt);
tsk->sysvsem.undo_list = undo_list;
- } else
+ } else
tsk->sysvsem.undo_list = NULL;
return 0;
@@ -1291,55 +2047,72 @@ int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
*/
void exit_sem(struct task_struct *tsk)
{
- struct sem_undo_list *undo_list;
- struct sem_undo *u, **up;
- struct ipc_namespace *ns;
+ struct sem_undo_list *ulp;
- undo_list = tsk->sysvsem.undo_list;
- if (!undo_list)
+ ulp = tsk->sysvsem.undo_list;
+ if (!ulp)
return;
+ tsk->sysvsem.undo_list = NULL;
- if (!atomic_dec_and_test(&undo_list->refcnt))
+ if (!atomic_dec_and_test(&ulp->refcnt))
return;
- ns = tsk->nsproxy->ipc_ns;
- /* There's no need to hold the semundo list lock, as current
- * is the last task exiting for this undo list.
- */
- for (up = &undo_list->proc_list; (u = *up); *up = u->proc_next, kfree(u)) {
+ for (;;) {
struct sem_array *sma;
- int nsems, i;
- struct sem_undo *un, **unp;
- int semid;
-
- semid = u->semid;
+ struct sem_undo *un;
+ struct list_head tasks;
+ int semid, i;
+
+ rcu_read_lock();
+ un = list_entry_rcu(ulp->list_proc.next,
+ struct sem_undo, list_proc);
+ if (&un->list_proc == &ulp->list_proc)
+ semid = -1;
+ else
+ semid = un->semid;
+
+ if (semid == -1) {
+ rcu_read_unlock();
+ break;
+ }
+
+ sma = sem_obtain_object_check(tsk->nsproxy->ipc_ns, un->semid);
+ /* exit_sem raced with IPC_RMID, nothing to do */
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
+ continue;
+ }
- if(semid == -1)
+ sem_lock(sma, NULL, -1);
+ /* exit_sem raced with IPC_RMID, nothing to do */
+ if (!ipc_valid_object(&sma->sem_perm)) {
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
continue;
- sma = sem_lock(ns, semid);
- if (IS_ERR(sma))
+ }
+ un = __lookup_undo(ulp, semid);
+ if (un == NULL) {
+ /* exit_sem raced with IPC_RMID+semget() that created
+ * exactly the same semid. Nothing to do.
+ */
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
continue;
+ }
- if (u->semid == -1)
- goto next_entry;
+ /* remove un from the linked lists */
+ ipc_assert_locked_object(&sma->sem_perm);
+ list_del(&un->list_id);
- BUG_ON(sem_checkid(sma, u->semid));
+ spin_lock(&ulp->lock);
+ list_del_rcu(&un->list_proc);
+ spin_unlock(&ulp->lock);
- /* remove u from the sma->undo list */
- for (unp = &sma->undo; (un = *unp); unp = &un->id_next) {
- if (u == un)
- goto found;
- }
- printk ("exit_sem undo list error id=%d\n", u->semid);
- goto next_entry;
-found:
- *unp = un->id_next;
- /* perform adjustments registered in u */
- nsems = sma->sem_nsems;
- for (i = 0; i < nsems; i++) {
- struct sem * semaphore = &sma->sem_base[i];
- if (u->semadj[i]) {
- semaphore->semval += u->semadj[i];
+ /* perform adjustments registered in un */
+ for (i = 0; i < sma->sem_nsems; i++) {
+ struct sem *semaphore = &sma->sem_base[i];
+ if (un->semadj[i]) {
+ semaphore->semval += un->semadj[i];
/*
* Range checks of the new semaphore value,
* not defined by sus:
@@ -1351,7 +2124,7 @@ found:
* Linux caps the semaphore value, both at 0
* and at SEMVMX.
*
- * Manfred <manfred@colorfullife.com>
+ * Manfred <manfred@colorfullife.com>
*/
if (semaphore->semval < 0)
semaphore->semval = 0;
@@ -1360,31 +2133,46 @@ found:
semaphore->sempid = task_tgid_vnr(current);
}
}
- sma->sem_otime = get_seconds();
/* maybe some queued-up processes were waiting for this */
- update_queue(sma);
-next_entry:
- sem_unlock(sma);
+ INIT_LIST_HEAD(&tasks);
+ do_smart_update(sma, NULL, 0, 1, &tasks);
+ sem_unlock(sma, -1);
+ rcu_read_unlock();
+ wake_up_sem_queue_do(&tasks);
+
+ kfree_rcu(un, rcu);
}
- kfree(undo_list);
+ kfree(ulp);
}
#ifdef CONFIG_PROC_FS
static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
{
+ struct user_namespace *user_ns = seq_user_ns(s);
struct sem_array *sma = it;
+ time_t sem_otime;
+
+ /*
+ * The proc interface isn't aware of sem_lock(), it calls
+ * ipc_lock_object() directly (in sysvipc_find_ipc).
+ * In order to stay compatible with sem_lock(), we must wait until
+ * all simple semop() calls have left their critical regions.
+ */
+ sem_wait_array(sma);
+
+ sem_otime = get_semotime(sma);
return seq_printf(s,
- "%10d %10d %4o %10lu %5u %5u %5u %5u %10lu %10lu\n",
+ "%10d %10d %4o %10u %5u %5u %5u %5u %10lu %10lu\n",
sma->sem_perm.key,
sma->sem_perm.id,
sma->sem_perm.mode,
sma->sem_nsems,
- sma->sem_perm.uid,
- sma->sem_perm.gid,
- sma->sem_perm.cuid,
- sma->sem_perm.cgid,
- sma->sem_otime,
+ from_kuid_munged(user_ns, sma->sem_perm.uid),
+ from_kgid_munged(user_ns, sma->sem_perm.gid),
+ from_kuid_munged(user_ns, sma->sem_perm.cuid),
+ from_kgid_munged(user_ns, sma->sem_perm.cgid),
+ sem_otime,
sma->sem_ctime);
}
#endif
diff --git a/ipc/shm.c b/ipc/shm.c
index cc63fae02f0..89fc354156c 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -19,6 +19,9 @@
* namespaces support
* OpenVZ, SWsoft Inc.
* Pavel Emelianov <xemul@openvz.org>
+ *
+ * Better ipc lock (kern_ipc_perm.lock) handling
+ * Davidlohr Bueso <davidlohr.bueso@hp.com>, June 2013.
*/
#include <linux/slab.h>
@@ -40,7 +43,7 @@
#include <linux/mount.h>
#include <linux/ipc_namespace.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include "util.h"
@@ -54,18 +57,17 @@ struct shm_file_data {
#define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data))
static const struct file_operations shm_file_operations;
-static struct vm_operations_struct shm_vm_ops;
+static const struct vm_operations_struct shm_vm_ops;
#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS])
#define shm_unlock(shp) \
ipc_unlock(&(shp)->shm_perm)
-#define shm_buildid(id, seq) ipc_buildid(id, seq)
static int newseg(struct ipc_namespace *, struct ipc_params *);
static void shm_open(struct vm_area_struct *vma);
static void shm_close(struct vm_area_struct *vma);
-static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
+static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
#ifdef CONFIG_PROC_FS
static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
#endif
@@ -75,20 +77,21 @@ void shm_init_ns(struct ipc_namespace *ns)
ns->shm_ctlmax = SHMMAX;
ns->shm_ctlall = SHMALL;
ns->shm_ctlmni = SHMMNI;
+ ns->shm_rmid_forced = 0;
ns->shm_tot = 0;
- ipc_init_ids(&ns->ids[IPC_SHM_IDS]);
+ ipc_init_ids(&shm_ids(ns));
}
/*
- * Called with shm_ids.rw_mutex (writer) and the shp structure locked.
- * Only shm_ids.rw_mutex remains locked on exit.
+ * Called with shm_ids.rwsem (writer) and the shp structure locked.
+ * Only shm_ids.rwsem remains locked on exit.
*/
static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
{
struct shmid_kernel *shp;
shp = container_of(ipcp, struct shmid_kernel, shm_perm);
- if (shp->shm_nattch){
+ if (shp->shm_nattch) {
shp->shm_perm.mode |= SHM_DEST;
/* Do not find it any more */
shp->shm_perm.key = IPC_PRIVATE;
@@ -101,47 +104,52 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
void shm_exit_ns(struct ipc_namespace *ns)
{
free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
+ idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
}
#endif
-void __init shm_init (void)
+static int __init ipc_ns_init(void)
{
shm_init_ns(&init_ipc_ns);
+ return 0;
+}
+
+pure_initcall(ipc_ns_init);
+
+void __init shm_init(void)
+{
ipc_init_proc_interface("sysvipc/shm",
- " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n",
+#if BITS_PER_LONG <= 32
+ " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
+#else
+ " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
+#endif
IPC_SHM_IDS, sysvipc_shm_proc_show);
}
-/*
- * shm_lock_(check_)down routines are called in the paths where the rw_mutex
- * is held to protect access to the idr tree.
- */
-static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns,
- int id)
+static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id)
{
- struct kern_ipc_perm *ipcp = ipc_lock_down(&shm_ids(ns), id);
+ struct kern_ipc_perm *ipcp = ipc_obtain_object(&shm_ids(ns), id);
if (IS_ERR(ipcp))
- return (struct shmid_kernel *)ipcp;
+ return ERR_CAST(ipcp);
return container_of(ipcp, struct shmid_kernel, shm_perm);
}
-static inline struct shmid_kernel *shm_lock_check_down(
- struct ipc_namespace *ns,
- int id)
+static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace *ns, int id)
{
- struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id);
+ struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&shm_ids(ns), id);
if (IS_ERR(ipcp))
- return (struct shmid_kernel *)ipcp;
+ return ERR_CAST(ipcp);
return container_of(ipcp, struct shmid_kernel, shm_perm);
}
/*
- * shm_lock_(check_) routines are called in the paths where the rw_mutex
- * is not held.
+ * shm_lock_(check_) routines are called in the paths where the rwsem
+ * is not necessarily held.
*/
static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
{
@@ -153,15 +161,19 @@ static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
return container_of(ipcp, struct shmid_kernel, shm_perm);
}
-static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns,
- int id)
+static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
{
- struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id);
+ rcu_read_lock();
+ ipc_lock_object(&ipcp->shm_perm);
+}
- if (IS_ERR(ipcp))
- return (struct shmid_kernel *)ipcp;
+static void shm_rcu_free(struct rcu_head *head)
+{
+ struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
+ struct shmid_kernel *shp = ipc_rcu_to_struct(p);
- return container_of(ipcp, struct shmid_kernel, shm_perm);
+ security_shm_free(shp);
+ ipc_rcu_free(head);
}
static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
@@ -169,12 +181,6 @@ static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
ipc_rmid(&shm_ids(ns), &s->shm_perm);
}
-static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
-{
- return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
-}
-
-
/* This is called by fork, once for every shm attach. */
static void shm_open(struct vm_area_struct *vma)
@@ -197,22 +203,41 @@ static void shm_open(struct vm_area_struct *vma)
* @ns: namespace
* @shp: struct to free
*
- * It has to be called with shp and shm_ids.rw_mutex (writer) locked,
+ * It has to be called with shp and shm_ids.rwsem (writer) locked,
* but returns with shp unlocked and freed.
*/
static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
{
+ struct file *shm_file;
+
+ shm_file = shp->shm_file;
+ shp->shm_file = NULL;
ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
shm_rmid(ns, shp);
shm_unlock(shp);
- if (!is_file_hugepages(shp->shm_file))
- shmem_lock(shp->shm_file, 0, shp->mlock_user);
- else
- user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size,
- shp->mlock_user);
- fput (shp->shm_file);
- security_shm_free(shp);
- ipc_rcu_putref(shp);
+ if (!is_file_hugepages(shm_file))
+ shmem_lock(shm_file, 0, shp->mlock_user);
+ else if (shp->mlock_user)
+ user_shm_unlock(file_inode(shm_file)->i_size, shp->mlock_user);
+ fput(shm_file);
+ ipc_rcu_putref(shp, shm_rcu_free);
+}
+
+/*
+ * shm_may_destroy - identifies whether shm segment should be destroyed now
+ *
+ * Returns true if and only if there are no active users of the segment and
+ * one of the following is true:
+ *
+ * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
+ *
+ * 2) sysctl kernel.shm_rmid_forced is set to 1.
+ */
+static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
+{
+ return (shp->shm_nattch == 0) &&
+ (ns->shm_rmid_forced ||
+ (shp->shm_perm.mode & SHM_DEST));
}
/*
@@ -223,24 +248,100 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
*/
static void shm_close(struct vm_area_struct *vma)
{
- struct file * file = vma->vm_file;
+ struct file *file = vma->vm_file;
struct shm_file_data *sfd = shm_file_data(file);
struct shmid_kernel *shp;
struct ipc_namespace *ns = sfd->ns;
- down_write(&shm_ids(ns).rw_mutex);
+ down_write(&shm_ids(ns).rwsem);
/* remove from the list of attaches of the shm segment */
- shp = shm_lock_down(ns, sfd->id);
+ shp = shm_lock(ns, sfd->id);
BUG_ON(IS_ERR(shp));
shp->shm_lprid = task_tgid_vnr(current);
shp->shm_dtim = get_seconds();
shp->shm_nattch--;
- if(shp->shm_nattch == 0 &&
- shp->shm_perm.mode & SHM_DEST)
+ if (shm_may_destroy(ns, shp))
shm_destroy(ns, shp);
else
shm_unlock(shp);
- up_write(&shm_ids(ns).rw_mutex);
+ up_write(&shm_ids(ns).rwsem);
+}
+
+/* Called with ns->shm_ids(ns).rwsem locked */
+static int shm_try_destroy_current(int id, void *p, void *data)
+{
+ struct ipc_namespace *ns = data;
+ struct kern_ipc_perm *ipcp = p;
+ struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+ if (shp->shm_creator != current)
+ return 0;
+
+ /*
+ * Mark it as orphaned to destroy the segment when
+ * kernel.shm_rmid_forced is changed.
+ * It is noop if the following shm_may_destroy() returns true.
+ */
+ shp->shm_creator = NULL;
+
+ /*
+ * Don't even try to destroy it. If shm_rmid_forced=0 and IPC_RMID
+ * is not set, it shouldn't be deleted here.
+ */
+ if (!ns->shm_rmid_forced)
+ return 0;
+
+ if (shm_may_destroy(ns, shp)) {
+ shm_lock_by_ptr(shp);
+ shm_destroy(ns, shp);
+ }
+ return 0;
+}
+
+/* Called with ns->shm_ids(ns).rwsem locked */
+static int shm_try_destroy_orphaned(int id, void *p, void *data)
+{
+ struct ipc_namespace *ns = data;
+ struct kern_ipc_perm *ipcp = p;
+ struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+ /*
+ * We want to destroy segments without users and with already
+ * exit'ed originating process.
+ *
+ * As shp->* are changed under rwsem, it's safe to skip shp locking.
+ */
+ if (shp->shm_creator != NULL)
+ return 0;
+
+ if (shm_may_destroy(ns, shp)) {
+ shm_lock_by_ptr(shp);
+ shm_destroy(ns, shp);
+ }
+ return 0;
+}
+
+void shm_destroy_orphaned(struct ipc_namespace *ns)
+{
+ down_write(&shm_ids(ns).rwsem);
+ if (shm_ids(ns).in_use)
+ idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
+ up_write(&shm_ids(ns).rwsem);
+}
+
+
+void exit_shm(struct task_struct *task)
+{
+ struct ipc_namespace *ns = task->nsproxy->ipc_ns;
+
+ if (shm_ids(ns).in_use == 0)
+ return;
+
+ /* Destroy all already created segments, but not mapped yet */
+ down_write(&shm_ids(ns).rwsem);
+ if (shm_ids(ns).in_use)
+ idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_current, ns);
+ up_write(&shm_ids(ns).rwsem);
}
static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
@@ -271,16 +372,14 @@ static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
if (sfd->vm_ops->get_policy)
pol = sfd->vm_ops->get_policy(vma, addr);
- else if (vma->vm_policy) {
+ else if (vma->vm_policy)
pol = vma->vm_policy;
- mpol_get(pol); /* get_vma_policy() expects this */
- } else
- pol = current->mempolicy;
+
return pol;
}
#endif
-static int shm_mmap(struct file * file, struct vm_area_struct * vma)
+static int shm_mmap(struct file *file, struct vm_area_struct *vma)
{
struct shm_file_data *sfd = shm_file_data(file);
int ret;
@@ -308,46 +407,60 @@ static int shm_release(struct inode *ino, struct file *file)
return 0;
}
-static int shm_fsync(struct file *file, struct dentry *dentry, int datasync)
+static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
- int (*fsync) (struct file *, struct dentry *, int datasync);
struct shm_file_data *sfd = shm_file_data(file);
- int ret = -EINVAL;
- fsync = sfd->file->f_op->fsync;
- if (fsync)
- ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync);
- return ret;
+ if (!sfd->file->f_op->fsync)
+ return -EINVAL;
+ return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
}
-static unsigned long shm_get_unmapped_area(struct file *file,
- unsigned long addr, unsigned long len, unsigned long pgoff,
- unsigned long flags)
+static long shm_fallocate(struct file *file, int mode, loff_t offset,
+ loff_t len)
{
struct shm_file_data *sfd = shm_file_data(file);
- return get_unmapped_area(sfd->file, addr, len, pgoff, flags);
+
+ if (!sfd->file->f_op->fallocate)
+ return -EOPNOTSUPP;
+ return sfd->file->f_op->fallocate(file, mode, offset, len);
}
-int is_file_shm_hugepages(struct file *file)
+static unsigned long shm_get_unmapped_area(struct file *file,
+ unsigned long addr, unsigned long len, unsigned long pgoff,
+ unsigned long flags)
{
- int ret = 0;
-
- if (file->f_op == &shm_file_operations) {
- struct shm_file_data *sfd;
- sfd = shm_file_data(file);
- ret = is_file_hugepages(sfd->file);
- }
- return ret;
+ struct shm_file_data *sfd = shm_file_data(file);
+ return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
+ pgoff, flags);
}
static const struct file_operations shm_file_operations = {
.mmap = shm_mmap,
.fsync = shm_fsync,
.release = shm_release,
+#ifndef CONFIG_MMU
.get_unmapped_area = shm_get_unmapped_area,
+#endif
+ .llseek = noop_llseek,
+ .fallocate = shm_fallocate,
};
-static struct vm_operations_struct shm_vm_ops = {
+static const struct file_operations shm_file_operations_huge = {
+ .mmap = shm_mmap,
+ .fsync = shm_fsync,
+ .release = shm_release,
+ .get_unmapped_area = shm_get_unmapped_area,
+ .llseek = noop_llseek,
+ .fallocate = shm_fallocate,
+};
+
+int is_file_shm_hugepages(struct file *file)
+{
+ return file->f_op == &shm_file_operations_huge;
+}
+
+static const struct vm_operations_struct shm_vm_ops = {
.open = shm_open, /* callback for a new vm-area open */
.close = shm_close, /* callback for when the vm-area is released */
.fault = shm_fault,
@@ -362,9 +475,8 @@ static struct vm_operations_struct shm_vm_ops = {
* @ns: namespace
* @params: ptr to the structure that contains key, size and shmflg
*
- * Called with shm_ids.rw_mutex held as a writer.
+ * Called with shm_ids.rwsem held as a writer.
*/
-
static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
{
key_t key = params->key;
@@ -372,15 +484,20 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
size_t size = params->u.size;
int error;
struct shmid_kernel *shp;
- int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
- struct file * file;
+ size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ struct file *file;
char name[13];
int id;
+ vm_flags_t acctflag = 0;
if (size < SHMMIN || size > ns->shm_ctlmax)
return -EINVAL;
- if (ns->shm_tot + numpages > ns->shm_ctlall)
+ if (numpages << PAGE_SHIFT < size)
+ return -ENOSPC;
+
+ if (ns->shm_tot + numpages < ns->shm_tot ||
+ ns->shm_tot + numpages > ns->shm_ctlall)
return -ENOSPC;
shp = ipc_rcu_alloc(sizeof(*shp));
@@ -394,31 +511,43 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
shp->shm_perm.security = NULL;
error = security_shm_alloc(shp);
if (error) {
- ipc_rcu_putref(shp);
+ ipc_rcu_putref(shp, ipc_rcu_free);
return error;
}
- sprintf (name, "SYSV%08x", key);
+ sprintf(name, "SYSV%08x", key);
if (shmflg & SHM_HUGETLB) {
- /* hugetlb_file_setup takes care of mlock user accounting */
- file = hugetlb_file_setup(name, size);
- shp->mlock_user = current->user;
+ struct hstate *hs;
+ size_t hugesize;
+
+ hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
+ if (!hs) {
+ error = -EINVAL;
+ goto no_file;
+ }
+ hugesize = ALIGN(size, huge_page_size(hs));
+
+ /* hugetlb_file_setup applies strict accounting */
+ if (shmflg & SHM_NORESERVE)
+ acctflag = VM_NORESERVE;
+ file = hugetlb_file_setup(name, hugesize, acctflag,
+ &shp->mlock_user, HUGETLB_SHMFS_INODE,
+ (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
} else {
- int acctflag = VM_ACCOUNT;
/*
* Do not allow no accounting for OVERCOMMIT_NEVER, even
- * if it's asked for.
+ * if it's asked for.
*/
if ((shmflg & SHM_NORESERVE) &&
sysctl_overcommit_memory != OVERCOMMIT_NEVER)
- acctflag = 0;
+ acctflag = VM_NORESERVE;
file = shmem_file_setup(name, size, acctflag);
}
error = PTR_ERR(file);
if (IS_ERR(file))
goto no_file;
- id = shm_addid(ns, shp);
+ id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
if (id < 0) {
error = id;
goto no_id;
@@ -430,29 +559,33 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
shp->shm_ctim = get_seconds();
shp->shm_segsz = size;
shp->shm_nattch = 0;
- shp->shm_perm.id = shm_buildid(id, shp->shm_perm.seq);
shp->shm_file = file;
+ shp->shm_creator = current;
+
/*
* shmid gets reported as "inode#" in /proc/pid/maps.
* proc-ps tools use this. Changing this will break them.
*/
- file->f_dentry->d_inode->i_ino = shp->shm_perm.id;
+ file_inode(file)->i_ino = shp->shm_perm.id;
ns->shm_tot += numpages;
error = shp->shm_perm.id;
- shm_unlock(shp);
+
+ ipc_unlock_object(&shp->shm_perm);
+ rcu_read_unlock();
return error;
no_id:
+ if (is_file_hugepages(file) && shp->mlock_user)
+ user_shm_unlock(size, shp->mlock_user);
fput(file);
no_file:
- security_shm_free(shp);
- ipc_rcu_putref(shp);
+ ipc_rcu_putref(shp, shm_rcu_free);
return error;
}
/*
- * Called with shm_ids.rw_mutex and ipcp locked.
+ * Called with shm_ids.rwsem and ipcp locked.
*/
static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
{
@@ -463,7 +596,7 @@ static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
}
/*
- * Called with shm_ids.rw_mutex and ipcp locked.
+ * Called with shm_ids.rwsem and ipcp locked.
*/
static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
struct ipc_params *params)
@@ -477,18 +610,18 @@ static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
return 0;
}
-asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
+SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
{
struct ipc_namespace *ns;
- struct ipc_ops shm_ops;
+ static const struct ipc_ops shm_ops = {
+ .getnew = newseg,
+ .associate = shm_security,
+ .more_checks = shm_more_checks,
+ };
struct ipc_params shm_params;
ns = current->nsproxy->ipc_ns;
- shm_ops.getnew = newseg;
- shm_ops.associate = shm_security;
- shm_ops.more_checks = shm_more_checks;
-
shm_params.key = key;
shm_params.flg = shmflg;
shm_params.u.size = size;
@@ -498,13 +631,14 @@ asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
return copy_to_user(buf, in, sizeof(*in));
case IPC_OLD:
{
struct shmid_ds out;
+ memset(&out, 0, sizeof(out));
ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
out.shm_segsz = in->shm_segsz;
out.shm_atime = in->shm_atime;
@@ -521,28 +655,14 @@ static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_
}
}
-struct shm_setbuf {
- uid_t uid;
- gid_t gid;
- mode_t mode;
-};
-
-static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version)
+static inline unsigned long
+copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
- {
- struct shmid64_ds tbuf;
-
- if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
+ if (copy_from_user(out, buf, sizeof(*out)))
return -EFAULT;
-
- out->uid = tbuf.shm_perm.uid;
- out->gid = tbuf.shm_perm.gid;
- out->mode = tbuf.shm_perm.mode;
-
return 0;
- }
case IPC_OLD:
{
struct shmid_ds tbuf_old;
@@ -550,9 +670,9 @@ static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __
if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
return -EFAULT;
- out->uid = tbuf_old.shm_perm.uid;
- out->gid = tbuf_old.shm_perm.gid;
- out->mode = tbuf_old.shm_perm.mode;
+ out->shm_perm.uid = tbuf_old.shm_perm.uid;
+ out->shm_perm.gid = tbuf_old.shm_perm.gid;
+ out->shm_perm.mode = tbuf_old.shm_perm.mode;
return 0;
}
@@ -563,14 +683,14 @@ static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __
static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
return copy_to_user(buf, in, sizeof(*in));
case IPC_OLD:
{
struct shminfo out;
- if(in->shmmax > INT_MAX)
+ if (in->shmmax > INT_MAX)
out.shmmax = INT_MAX;
else
out.shmmax = (int)in->shmmax;
@@ -578,7 +698,7 @@ static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminf
out.shmmin = in->shmmin;
out.shmmni = in->shmmni;
out.shmseg = in->shmseg;
- out.shmall = in->shmall;
+ out.shmall = in->shmall;
return copy_to_user(buf, &out, sizeof(out));
}
@@ -588,7 +708,35 @@ static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminf
}
/*
- * Called with shm_ids.rw_mutex held as a reader
+ * Calculate and add used RSS and swap pages of a shm.
+ * Called with shm_ids.rwsem held as a reader
+ */
+static void shm_add_rss_swap(struct shmid_kernel *shp,
+ unsigned long *rss_add, unsigned long *swp_add)
+{
+ struct inode *inode;
+
+ inode = file_inode(shp->shm_file);
+
+ if (is_file_hugepages(shp->shm_file)) {
+ struct address_space *mapping = inode->i_mapping;
+ struct hstate *h = hstate_file(shp->shm_file);
+ *rss_add += pages_per_huge_page(h) * mapping->nrpages;
+ } else {
+#ifdef CONFIG_SHMEM
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ spin_lock(&info->lock);
+ *rss_add += inode->i_mapping->nrpages;
+ *swp_add += info->swapped;
+ spin_unlock(&info->lock);
+#else
+ *rss_add += inode->i_mapping->nrpages;
+#endif
+ }
+}
+
+/*
+ * Called with shm_ids.rwsem held as a reader
*/
static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
unsigned long *swp)
@@ -602,68 +750,113 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
in_use = shm_ids(ns).in_use;
for (total = 0, next_id = 0; total < in_use; next_id++) {
+ struct kern_ipc_perm *ipc;
struct shmid_kernel *shp;
- struct inode *inode;
- shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
- if (shp == NULL)
+ ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
+ if (ipc == NULL)
continue;
+ shp = container_of(ipc, struct shmid_kernel, shm_perm);
- inode = shp->shm_file->f_path.dentry->d_inode;
-
- if (is_file_hugepages(shp->shm_file)) {
- struct address_space *mapping = inode->i_mapping;
- *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages;
- } else {
- struct shmem_inode_info *info = SHMEM_I(inode);
- spin_lock(&info->lock);
- *rss += inode->i_mapping->nrpages;
- *swp += info->swapped;
- spin_unlock(&info->lock);
- }
+ shm_add_rss_swap(shp, rss, swp);
total++;
}
}
-asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
+/*
+ * This function handles some shmctl commands which require the rwsem
+ * to be held in write mode.
+ * NOTE: no locks must be held, the rwsem is taken inside this function.
+ */
+static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
+ struct shmid_ds __user *buf, int version)
{
- struct shm_setbuf setbuf;
+ struct kern_ipc_perm *ipcp;
+ struct shmid64_ds shmid64;
struct shmid_kernel *shp;
- int err, version;
- struct ipc_namespace *ns;
+ int err;
- if (cmd < 0 || shmid < 0) {
+ if (cmd == IPC_SET) {
+ if (copy_shmid_from_user(&shmid64, buf, version))
+ return -EFAULT;
+ }
+
+ down_write(&shm_ids(ns).rwsem);
+ rcu_read_lock();
+
+ ipcp = ipcctl_pre_down_nolock(ns, &shm_ids(ns), shmid, cmd,
+ &shmid64.shm_perm, 0);
+ if (IS_ERR(ipcp)) {
+ err = PTR_ERR(ipcp);
+ goto out_unlock1;
+ }
+
+ shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+ err = security_shm_shmctl(shp, cmd);
+ if (err)
+ goto out_unlock1;
+
+ switch (cmd) {
+ case IPC_RMID:
+ ipc_lock_object(&shp->shm_perm);
+ /* do_shm_rmid unlocks the ipc object and rcu */
+ do_shm_rmid(ns, ipcp);
+ goto out_up;
+ case IPC_SET:
+ ipc_lock_object(&shp->shm_perm);
+ err = ipc_update_perm(&shmid64.shm_perm, ipcp);
+ if (err)
+ goto out_unlock0;
+ shp->shm_ctim = get_seconds();
+ break;
+ default:
err = -EINVAL;
- goto out;
+ goto out_unlock1;
}
- version = ipc_parse_version(&cmd);
- ns = current->nsproxy->ipc_ns;
+out_unlock0:
+ ipc_unlock_object(&shp->shm_perm);
+out_unlock1:
+ rcu_read_unlock();
+out_up:
+ up_write(&shm_ids(ns).rwsem);
+ return err;
+}
- switch (cmd) { /* replace with proc interface ? */
- case IPC_INFO:
- {
- struct shminfo64 shminfo;
+static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
+ int cmd, int version, void __user *buf)
+{
+ int err;
+ struct shmid_kernel *shp;
+ /* preliminary security checks for *_INFO */
+ if (cmd == IPC_INFO || cmd == SHM_INFO) {
err = security_shm_shmctl(NULL, cmd);
if (err)
return err;
+ }
- memset(&shminfo,0,sizeof(shminfo));
+ switch (cmd) {
+ case IPC_INFO:
+ {
+ struct shminfo64 shminfo;
+
+ memset(&shminfo, 0, sizeof(shminfo));
shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
shminfo.shmmax = ns->shm_ctlmax;
shminfo.shmall = ns->shm_ctlall;
shminfo.shmmin = SHMMIN;
- if(copy_shminfo_to_user (buf, &shminfo, version))
+ if (copy_shminfo_to_user(buf, &shminfo, version))
return -EFAULT;
- down_read(&shm_ids(ns).rw_mutex);
+ down_read(&shm_ids(ns).rwsem);
err = ipc_get_maxid(&shm_ids(ns));
- up_read(&shm_ids(ns).rw_mutex);
+ up_read(&shm_ids(ns).rwsem);
- if(err<0)
+ if (err < 0)
err = 0;
goto out;
}
@@ -671,20 +864,16 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
{
struct shm_info shm_info;
- err = security_shm_shmctl(NULL, cmd);
- if (err)
- return err;
-
- memset(&shm_info,0,sizeof(shm_info));
- down_read(&shm_ids(ns).rw_mutex);
+ memset(&shm_info, 0, sizeof(shm_info));
+ down_read(&shm_ids(ns).rwsem);
shm_info.used_ids = shm_ids(ns).in_use;
- shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
+ shm_get_stat(ns, &shm_info.shm_rss, &shm_info.shm_swp);
shm_info.shm_tot = ns->shm_tot;
shm_info.swap_attempts = 0;
shm_info.swap_successes = 0;
err = ipc_get_maxid(&shm_ids(ns));
- up_read(&shm_ids(ns).rw_mutex);
- if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
+ up_read(&shm_ids(ns).rwsem);
+ if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
err = -EFAULT;
goto out;
}
@@ -698,32 +887,31 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
struct shmid64_ds tbuf;
int result;
- if (!buf) {
- err = -EFAULT;
- goto out;
- }
-
+ rcu_read_lock();
if (cmd == SHM_STAT) {
- shp = shm_lock(ns, shmid);
+ shp = shm_obtain_object(ns, shmid);
if (IS_ERR(shp)) {
err = PTR_ERR(shp);
- goto out;
+ goto out_unlock;
}
result = shp->shm_perm.id;
} else {
- shp = shm_lock_check(ns, shmid);
+ shp = shm_obtain_object_check(ns, shmid);
if (IS_ERR(shp)) {
err = PTR_ERR(shp);
- goto out;
+ goto out_unlock;
}
result = 0;
}
- err=-EACCES;
- if (ipcperms (&shp->shm_perm, S_IRUGO))
+
+ err = -EACCES;
+ if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
goto out_unlock;
+
err = security_shm_shmctl(shp, cmd);
if (err)
goto out_unlock;
+
memset(&tbuf, 0, sizeof(tbuf));
kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
tbuf.shm_segsz = shp->shm_segsz;
@@ -733,152 +921,119 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
tbuf.shm_cpid = shp->shm_cprid;
tbuf.shm_lpid = shp->shm_lprid;
tbuf.shm_nattch = shp->shm_nattch;
- shm_unlock(shp);
- if(copy_shmid_to_user (buf, &tbuf, version))
+ rcu_read_unlock();
+
+ if (copy_shmid_to_user(buf, &tbuf, version))
err = -EFAULT;
else
err = result;
goto out;
}
- case SHM_LOCK:
- case SHM_UNLOCK:
- {
- shp = shm_lock_check(ns, shmid);
- if (IS_ERR(shp)) {
- err = PTR_ERR(shp);
- goto out;
- }
+ default:
+ return -EINVAL;
+ }
- err = audit_ipc_obj(&(shp->shm_perm));
- if (err)
- goto out_unlock;
+out_unlock:
+ rcu_read_unlock();
+out:
+ return err;
+}
- if (!capable(CAP_IPC_LOCK)) {
- err = -EPERM;
- if (current->euid != shp->shm_perm.uid &&
- current->euid != shp->shm_perm.cuid)
- goto out_unlock;
- if (cmd == SHM_LOCK &&
- !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
- goto out_unlock;
- }
+SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
+{
+ struct shmid_kernel *shp;
+ int err, version;
+ struct ipc_namespace *ns;
- err = security_shm_shmctl(shp, cmd);
- if (err)
- goto out_unlock;
-
- if(cmd==SHM_LOCK) {
- struct user_struct * user = current->user;
- if (!is_file_hugepages(shp->shm_file)) {
- err = shmem_lock(shp->shm_file, 1, user);
- if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){
- shp->shm_perm.mode |= SHM_LOCKED;
- shp->mlock_user = user;
- }
- }
- } else if (!is_file_hugepages(shp->shm_file)) {
- shmem_lock(shp->shm_file, 0, shp->mlock_user);
- shp->shm_perm.mode &= ~SHM_LOCKED;
- shp->mlock_user = NULL;
- }
- shm_unlock(shp);
- goto out;
- }
+ if (cmd < 0 || shmid < 0)
+ return -EINVAL;
+
+ version = ipc_parse_version(&cmd);
+ ns = current->nsproxy->ipc_ns;
+
+ switch (cmd) {
+ case IPC_INFO:
+ case SHM_INFO:
+ case SHM_STAT:
+ case IPC_STAT:
+ return shmctl_nolock(ns, shmid, cmd, version, buf);
case IPC_RMID:
+ case IPC_SET:
+ return shmctl_down(ns, shmid, cmd, buf, version);
+ case SHM_LOCK:
+ case SHM_UNLOCK:
{
- /*
- * We cannot simply remove the file. The SVID states
- * that the block remains until the last person
- * detaches from it, then is deleted. A shmat() on
- * an RMID segment is legal in older Linux and if
- * we change it apps break...
- *
- * Instead we set a destroyed flag, and then blow
- * the name away when the usage hits zero.
- */
- down_write(&shm_ids(ns).rw_mutex);
- shp = shm_lock_check_down(ns, shmid);
+ struct file *shm_file;
+
+ rcu_read_lock();
+ shp = shm_obtain_object_check(ns, shmid);
if (IS_ERR(shp)) {
err = PTR_ERR(shp);
- goto out_up;
- }
-
- err = audit_ipc_obj(&(shp->shm_perm));
- if (err)
- goto out_unlock_up;
-
- if (current->euid != shp->shm_perm.uid &&
- current->euid != shp->shm_perm.cuid &&
- !capable(CAP_SYS_ADMIN)) {
- err=-EPERM;
- goto out_unlock_up;
+ goto out_unlock1;
}
+ audit_ipc_obj(&(shp->shm_perm));
err = security_shm_shmctl(shp, cmd);
if (err)
- goto out_unlock_up;
+ goto out_unlock1;
- do_shm_rmid(ns, &shp->shm_perm);
- up_write(&shm_ids(ns).rw_mutex);
- goto out;
- }
+ ipc_lock_object(&shp->shm_perm);
- case IPC_SET:
- {
- if (!buf) {
- err = -EFAULT;
- goto out;
+ /* check if shm_destroy() is tearing down shp */
+ if (!ipc_valid_object(&shp->shm_perm)) {
+ err = -EIDRM;
+ goto out_unlock0;
}
- if (copy_shmid_from_user (&setbuf, buf, version)) {
- err = -EFAULT;
- goto out;
- }
- down_write(&shm_ids(ns).rw_mutex);
- shp = shm_lock_check_down(ns, shmid);
- if (IS_ERR(shp)) {
- err = PTR_ERR(shp);
- goto out_up;
+ if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
+ kuid_t euid = current_euid();
+ if (!uid_eq(euid, shp->shm_perm.uid) &&
+ !uid_eq(euid, shp->shm_perm.cuid)) {
+ err = -EPERM;
+ goto out_unlock0;
+ }
+ if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) {
+ err = -EPERM;
+ goto out_unlock0;
+ }
}
- err = audit_ipc_obj(&(shp->shm_perm));
- if (err)
- goto out_unlock_up;
- err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
- if (err)
- goto out_unlock_up;
- err=-EPERM;
- if (current->euid != shp->shm_perm.uid &&
- current->euid != shp->shm_perm.cuid &&
- !capable(CAP_SYS_ADMIN)) {
- goto out_unlock_up;
+
+ shm_file = shp->shm_file;
+ if (is_file_hugepages(shm_file))
+ goto out_unlock0;
+
+ if (cmd == SHM_LOCK) {
+ struct user_struct *user = current_user();
+ err = shmem_lock(shm_file, 1, user);
+ if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
+ shp->shm_perm.mode |= SHM_LOCKED;
+ shp->mlock_user = user;
+ }
+ goto out_unlock0;
}
- err = security_shm_shmctl(shp, cmd);
- if (err)
- goto out_unlock_up;
-
- shp->shm_perm.uid = setbuf.uid;
- shp->shm_perm.gid = setbuf.gid;
- shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO)
- | (setbuf.mode & S_IRWXUGO);
- shp->shm_ctim = get_seconds();
- break;
+ /* SHM_UNLOCK */
+ if (!(shp->shm_perm.mode & SHM_LOCKED))
+ goto out_unlock0;
+ shmem_lock(shm_file, 0, shp->mlock_user);
+ shp->shm_perm.mode &= ~SHM_LOCKED;
+ shp->mlock_user = NULL;
+ get_file(shm_file);
+ ipc_unlock_object(&shp->shm_perm);
+ rcu_read_unlock();
+ shmem_unlock_mapping(shm_file->f_mapping);
+
+ fput(shm_file);
+ return err;
}
-
default:
- err = -EINVAL;
- goto out;
+ return -EINVAL;
}
- err = 0;
-out_unlock_up:
- shm_unlock(shp);
-out_up:
- up_write(&shm_ids(ns).rw_mutex);
- goto out;
-out_unlock:
- shm_unlock(shp);
-out:
+out_unlock0:
+ ipc_unlock_object(&shp->shm_perm);
+out_unlock1:
+ rcu_read_unlock();
return err;
}
@@ -889,29 +1044,30 @@ out:
* "raddr" thing points to kernel space, and there has to be a wrapper around
* this.
*/
-long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
+long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
+ unsigned long shmlba)
{
struct shmid_kernel *shp;
unsigned long addr;
unsigned long size;
- struct file * file;
+ struct file *file;
int err;
unsigned long flags;
unsigned long prot;
int acc_mode;
- unsigned long user_addr;
struct ipc_namespace *ns;
struct shm_file_data *sfd;
struct path path;
- mode_t f_mode;
+ fmode_t f_mode;
+ unsigned long populate = 0;
err = -EINVAL;
if (shmid < 0)
goto out;
else if ((addr = (ulong)shmaddr)) {
- if (addr & (SHMLBA-1)) {
+ if (addr & (shmlba - 1)) {
if (shmflg & SHM_RND)
- addr &= ~(SHMLBA-1); /* round down */
+ addr &= ~(shmlba - 1); /* round down */
else
#ifndef __ARCH_FORCE_SHMLBA
if (addr & ~PAGE_MASK)
@@ -945,36 +1101,54 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
* additional creator id...
*/
ns = current->nsproxy->ipc_ns;
- shp = shm_lock_check(ns, shmid);
+ rcu_read_lock();
+ shp = shm_obtain_object_check(ns, shmid);
if (IS_ERR(shp)) {
err = PTR_ERR(shp);
- goto out;
+ goto out_unlock;
}
err = -EACCES;
- if (ipcperms(&shp->shm_perm, acc_mode))
+ if (ipcperms(ns, &shp->shm_perm, acc_mode))
goto out_unlock;
err = security_shm_shmat(shp, shmaddr, shmflg);
if (err)
goto out_unlock;
- path.dentry = dget(shp->shm_file->f_path.dentry);
- path.mnt = shp->shm_file->f_path.mnt;
+ ipc_lock_object(&shp->shm_perm);
+
+ /* check if shm_destroy() is tearing down shp */
+ if (!ipc_valid_object(&shp->shm_perm)) {
+ ipc_unlock_object(&shp->shm_perm);
+ err = -EIDRM;
+ goto out_unlock;
+ }
+
+ path = shp->shm_file->f_path;
+ path_get(&path);
shp->shm_nattch++;
size = i_size_read(path.dentry->d_inode);
- shm_unlock(shp);
+ ipc_unlock_object(&shp->shm_perm);
+ rcu_read_unlock();
err = -ENOMEM;
sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
- if (!sfd)
- goto out_put_dentry;
-
- err = -ENOMEM;
+ if (!sfd) {
+ path_put(&path);
+ goto out_nattch;
+ }
- file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations);
- if (!file)
- goto out_free;
+ file = alloc_file(&path, f_mode,
+ is_file_hugepages(shp->shm_file) ?
+ &shm_file_operations_huge :
+ &shm_file_operations);
+ err = PTR_ERR(file);
+ if (IS_ERR(file)) {
+ kfree(sfd);
+ path_put(&path);
+ goto out_nattch;
+ }
file->private_data = sfd;
file->f_mapping = shp->shm_file->f_mapping;
@@ -983,9 +1157,16 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
sfd->file = shp->shm_file;
sfd->vm_ops = NULL;
+ err = security_mmap_file(file, prot, flags);
+ if (err)
+ goto out_fput;
+
down_write(&current->mm->mmap_sem);
if (addr && !(shmflg & SHM_REMAP)) {
err = -EINVAL;
+ if (addr + size < addr)
+ goto invalid;
+
if (find_vma_intersection(current->mm, addr, addr + size))
goto invalid;
/*
@@ -996,49 +1177,44 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
addr > current->mm->start_stack - size - PAGE_SIZE * 5)
goto invalid;
}
-
- user_addr = do_mmap (file, addr, size, prot, flags, 0);
- *raddr = user_addr;
+
+ addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate);
+ *raddr = addr;
err = 0;
- if (IS_ERR_VALUE(user_addr))
- err = (long)user_addr;
+ if (IS_ERR_VALUE(addr))
+ err = (long)addr;
invalid:
up_write(&current->mm->mmap_sem);
+ if (populate)
+ mm_populate(addr, populate);
+out_fput:
fput(file);
out_nattch:
- down_write(&shm_ids(ns).rw_mutex);
- shp = shm_lock_down(ns, shmid);
+ down_write(&shm_ids(ns).rwsem);
+ shp = shm_lock(ns, shmid);
BUG_ON(IS_ERR(shp));
shp->shm_nattch--;
- if(shp->shm_nattch == 0 &&
- shp->shm_perm.mode & SHM_DEST)
+ if (shm_may_destroy(ns, shp))
shm_destroy(ns, shp);
else
shm_unlock(shp);
- up_write(&shm_ids(ns).rw_mutex);
-
-out:
+ up_write(&shm_ids(ns).rwsem);
return err;
out_unlock:
- shm_unlock(shp);
- goto out;
-
-out_free:
- kfree(sfd);
-out_put_dentry:
- dput(path.dentry);
- goto out_nattch;
+ rcu_read_unlock();
+out:
+ return err;
}
-asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg)
+SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
{
unsigned long ret;
long err;
- err = do_shmat(shmid, shmaddr, shmflg, &ret);
+ err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
if (err)
return err;
force_successful_syscall_return();
@@ -1049,13 +1225,16 @@ asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg)
* detach and kill segment if marked destroyed.
* The work is done in shm_close.
*/
-asmlinkage long sys_shmdt(char __user *shmaddr)
+SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
{
struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma, *next;
+ struct vm_area_struct *vma;
unsigned long addr = (unsigned long)shmaddr;
- loff_t size = 0;
int retval = -EINVAL;
+#ifdef CONFIG_MMU
+ loff_t size = 0;
+ struct vm_area_struct *next;
+#endif
if (addr & ~PAGE_MASK)
return retval;
@@ -1084,6 +1263,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
*/
vma = find_vma(mm, addr);
+#ifdef CONFIG_MMU
while (vma) {
next = vma->vm_next;
@@ -1096,7 +1276,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
(vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
- size = vma->vm_file->f_path.dentry->d_inode->i_size;
+ size = file_inode(vma->vm_file)->i_size;
do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
/*
* We discovered the size of the shm segment, so
@@ -1114,7 +1294,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
/*
* We need look no further than the maximum address a fragment
* could possibly have landed at. Also cast things to loff_t to
- * prevent overflows and make comparisions vs. equal-width types.
+ * prevent overflows and make comparisons vs. equal-width types.
*/
size = PAGE_ALIGN(size);
while (vma && (loff_t)(vma->vm_end - addr) <= size) {
@@ -1128,6 +1308,16 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
vma = next;
}
+#else /* CONFIG_MMU */
+ /* under NOMMU conditions, the exact address to be destroyed must be
+ * given */
+ if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+ retval = 0;
+ }
+
+#endif
+
up_write(&mm->mmap_sem);
return retval;
}
@@ -1135,17 +1325,22 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
#ifdef CONFIG_PROC_FS
static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
{
+ struct user_namespace *user_ns = seq_user_ns(s);
struct shmid_kernel *shp = it;
- char *format;
+ unsigned long rss = 0, swp = 0;
-#define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
-#define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
+ shm_add_rss_swap(shp, &rss, &swp);
- if (sizeof(size_t) <= sizeof(int))
- format = SMALL_STRING;
- else
- format = BIG_STRING;
- return seq_printf(s, format,
+#if BITS_PER_LONG <= 32
+#define SIZE_SPEC "%10lu"
+#else
+#define SIZE_SPEC "%21lu"
+#endif
+
+ return seq_printf(s,
+ "%10d %10d %4o " SIZE_SPEC " %5u %5u "
+ "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
+ SIZE_SPEC " " SIZE_SPEC "\n",
shp->shm_perm.key,
shp->shm_perm.id,
shp->shm_perm.mode,
@@ -1153,12 +1348,14 @@ static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
shp->shm_cprid,
shp->shm_lprid,
shp->shm_nattch,
- shp->shm_perm.uid,
- shp->shm_perm.gid,
- shp->shm_perm.cuid,
- shp->shm_perm.cgid,
+ from_kuid_munged(user_ns, shp->shm_perm.uid),
+ from_kgid_munged(user_ns, shp->shm_perm.gid),
+ from_kuid_munged(user_ns, shp->shm_perm.cuid),
+ from_kgid_munged(user_ns, shp->shm_perm.cgid),
shp->shm_atim,
shp->shm_dtim,
- shp->shm_ctim);
+ shp->shm_ctim,
+ rss * PAGE_SIZE,
+ swp * PAGE_SIZE);
}
#endif
diff --git a/ipc/syscall.c b/ipc/syscall.c
new file mode 100644
index 00000000000..52429489cde
--- /dev/null
+++ b/ipc/syscall.c
@@ -0,0 +1,99 @@
+/*
+ * sys_ipc() is the old de-multiplexer for the SysV IPC calls.
+ *
+ * This is really horribly ugly, and new architectures should just wire up
+ * the individual syscalls instead.
+ */
+#include <linux/unistd.h>
+
+#ifdef __ARCH_WANT_SYS_IPC
+#include <linux/errno.h>
+#include <linux/ipc.h>
+#include <linux/shm.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+
+SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
+ unsigned long, third, void __user *, ptr, long, fifth)
+{
+ int version, ret;
+
+ version = call >> 16; /* hack for backward compatibility */
+ call &= 0xffff;
+
+ switch (call) {
+ case SEMOP:
+ return sys_semtimedop(first, (struct sembuf __user *)ptr,
+ second, NULL);
+ case SEMTIMEDOP:
+ return sys_semtimedop(first, (struct sembuf __user *)ptr,
+ second,
+ (const struct timespec __user *)fifth);
+
+ case SEMGET:
+ return sys_semget(first, second, third);
+ case SEMCTL: {
+ unsigned long arg;
+ if (!ptr)
+ return -EINVAL;
+ if (get_user(arg, (unsigned long __user *) ptr))
+ return -EFAULT;
+ return sys_semctl(first, second, third, arg);
+ }
+
+ case MSGSND:
+ return sys_msgsnd(first, (struct msgbuf __user *) ptr,
+ second, third);
+ case MSGRCV:
+ switch (version) {
+ case 0: {
+ struct ipc_kludge tmp;
+ if (!ptr)
+ return -EINVAL;
+
+ if (copy_from_user(&tmp,
+ (struct ipc_kludge __user *) ptr,
+ sizeof(tmp)))
+ return -EFAULT;
+ return sys_msgrcv(first, tmp.msgp, second,
+ tmp.msgtyp, third);
+ }
+ default:
+ return sys_msgrcv(first,
+ (struct msgbuf __user *) ptr,
+ second, fifth, third);
+ }
+ case MSGGET:
+ return sys_msgget((key_t) first, second);
+ case MSGCTL:
+ return sys_msgctl(first, second, (struct msqid_ds __user *)ptr);
+
+ case SHMAT:
+ switch (version) {
+ default: {
+ unsigned long raddr;
+ ret = do_shmat(first, (char __user *)ptr,
+ second, &raddr, SHMLBA);
+ if (ret)
+ return ret;
+ return put_user(raddr, (unsigned long __user *) third);
+ }
+ case 1:
+ /*
+ * This was the entry point for kernel-originating calls
+ * from iBCS2 in 2.2 days.
+ */
+ return -EINVAL;
+ }
+ case SHMDT:
+ return sys_shmdt((char __user *)ptr);
+ case SHMGET:
+ return sys_shmget(first, second, third);
+ case SHMCTL:
+ return sys_shmctl(first, second,
+ (struct shmid_ds __user *) ptr);
+ default:
+ return -ENOSYS;
+ }
+}
+#endif
diff --git a/ipc/util.c b/ipc/util.c
index fd1b50da9db..27d74e69fd5 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -15,6 +15,29 @@
* Jun 2006 - namespaces ssupport
* OpenVZ, SWsoft Inc.
* Pavel Emelianov <xemul@openvz.org>
+ *
+ * General sysv ipc locking scheme:
+ * rcu_read_lock()
+ * obtain the ipc object (kern_ipc_perm) by looking up the id in an idr
+ * tree.
+ * - perform initial checks (capabilities, auditing and permission,
+ * etc).
+ * - perform read-only operations, such as STAT, INFO commands.
+ * acquire the ipc lock (kern_ipc_perm.lock) through
+ * ipc_lock_object()
+ * - perform data updates, such as SET, RMID commands and
+ * mechanism-specific operations (semop/semtimedop,
+ * msgsnd/msgrcv, shmat/shmdt).
+ * drop the ipc lock, through ipc_unlock_object().
+ * rcu_read_unlock()
+ *
+ * The ids->rwsem must be taken when:
+ * - creating, removing and iterating the existing entries in ipc
+ * identifier sets.
+ * - iterating through files under /proc/sysvipc/
+ *
+ * Note that sems have a special fast path that avoids kern_ipc_perm.lock -
+ * see sem_lock().
*/
#include <linux/mm.h>
@@ -23,6 +46,7 @@
#include <linux/msg.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
+#include <linux/notifier.h>
#include <linux/capability.h>
#include <linux/highuid.h>
#include <linux/security.h>
@@ -33,6 +57,7 @@
#include <linux/audit.h>
#include <linux/nsproxy.h>
#include <linux/rwsem.h>
+#include <linux/memory.h>
#include <linux/ipc_namespace.h>
#include <asm/unistd.h>
@@ -46,61 +71,89 @@ struct ipc_proc_iface {
int (*show)(struct seq_file *, void *);
};
-struct ipc_namespace init_ipc_ns = {
- .kref = {
- .refcount = ATOMIC_INIT(2),
- },
+static void ipc_memory_notifier(struct work_struct *work)
+{
+ ipcns_notify(IPCNS_MEMCHANGED);
+}
+
+static int ipc_memory_callback(struct notifier_block *self,
+ unsigned long action, void *arg)
+{
+ static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
+
+ switch (action) {
+ case MEM_ONLINE: /* memory successfully brought online */
+ case MEM_OFFLINE: /* or offline: it's time to recompute msgmni */
+ /*
+ * This is done by invoking the ipcns notifier chain with the
+ * IPC_MEMCHANGED event.
+ * In order not to keep the lock on the hotplug memory chain
+ * for too long, queue a work item that will, when waken up,
+ * activate the ipcns notification chain.
+ */
+ schedule_work(&ipc_memory_wq);
+ break;
+ case MEM_GOING_ONLINE:
+ case MEM_GOING_OFFLINE:
+ case MEM_CANCEL_ONLINE:
+ case MEM_CANCEL_OFFLINE:
+ default:
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block ipc_memory_nb = {
+ .notifier_call = ipc_memory_callback,
+ .priority = IPC_CALLBACK_PRI,
};
/**
- * ipc_init - initialise IPC subsystem
+ * ipc_init - initialise ipc subsystem
+ *
+ * The various sysv ipc resources (semaphores, messages and shared
+ * memory) are initialised.
*
- * The various system5 IPC resources (semaphores, messages and shared
- * memory) are initialised
+ * A callback routine is registered into the memory hotplug notifier
+ * chain: since msgmni scales to lowmem this callback routine will be
+ * called upon successful memory add / remove to recompute msmgni.
*/
-
static int __init ipc_init(void)
{
sem_init();
msg_init();
shm_init();
+ register_hotmemory_notifier(&ipc_memory_nb);
+ register_ipcns_notifier(&init_ipc_ns);
return 0;
}
-__initcall(ipc_init);
+device_initcall(ipc_init);
/**
- * ipc_init_ids - initialise IPC identifiers
- * @ids: Identifier set
+ * ipc_init_ids - initialise ipc identifiers
+ * @ids: ipc identifier set
*
- * Set up the sequence range to use for the ipc identifier range (limited
- * below IPCMNI) then initialise the ids idr.
+ * Set up the sequence range to use for the ipc identifier range (limited
+ * below IPCMNI) then initialise the ids idr.
*/
-
void ipc_init_ids(struct ipc_ids *ids)
{
- init_rwsem(&ids->rw_mutex);
-
ids->in_use = 0;
ids->seq = 0;
- {
- int seq_limit = INT_MAX/SEQ_MULTIPLIER;
- if(seq_limit > USHRT_MAX)
- ids->seq_max = USHRT_MAX;
- else
- ids->seq_max = seq_limit;
- }
-
+ ids->next_id = -1;
+ init_rwsem(&ids->rwsem);
idr_init(&ids->ipcs_idr);
}
#ifdef CONFIG_PROC_FS
static const struct file_operations sysvipc_proc_fops;
/**
- * ipc_init_proc_interface - Create a proc interface for sysipc types using a seq_file interface.
- * @path: Path in procfs
- * @header: Banner to be printed at the beginning of the file.
- * @ids: ipc id table to iterate.
- * @show: show routine.
+ * ipc_init_proc_interface - create a proc interface for sysipc types using a seq_file interface.
+ * @path: Path in procfs
+ * @header: Banner to be printed at the beginning of the file.
+ * @ids: ipc id table to iterate.
+ * @show: show routine.
*/
void __init ipc_init_proc_interface(const char *path, const char *header,
int ids, int (*show)(struct seq_file *, void *))
@@ -116,29 +169,26 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
iface->ids = ids;
iface->show = show;
- pde = create_proc_entry(path,
- S_IRUGO, /* world readable */
- NULL /* parent dir */);
- if (pde) {
- pde->data = iface;
- pde->proc_fops = &sysvipc_proc_fops;
- } else {
+ pde = proc_create_data(path,
+ S_IRUGO, /* world readable */
+ NULL, /* parent dir */
+ &sysvipc_proc_fops,
+ iface);
+ if (!pde)
kfree(iface);
- }
}
#endif
/**
- * ipc_findkey - find a key in an ipc identifier set
- * @ids: Identifier set
- * @key: The key to find
- *
- * Requires ipc_ids.rw_mutex locked.
- * Returns the LOCKED pointer to the ipc structure if found or NULL
- * if not.
- * If key is found ipc points to the owning ipc structure
+ * ipc_findkey - find a key in an ipc identifier set
+ * @ids: ipc identifier set
+ * @key: key to find
+ *
+ * Returns the locked pointer to the ipc structure if found or NULL
+ * otherwise. If key is found ipc points to the owning ipc structure
+ *
+ * Called with ipc_ids.rwsem held.
*/
-
static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
{
struct kern_ipc_perm *ipc;
@@ -156,7 +206,8 @@ static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
continue;
}
- ipc_lock_by_ptr(ipc);
+ rcu_read_lock();
+ ipc_lock_object(ipc);
return ipc;
}
@@ -164,12 +215,11 @@ static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
}
/**
- * ipc_get_maxid - get the last assigned id
- * @ids: IPC identifier set
+ * ipc_get_maxid - get the last assigned id
+ * @ids: ipc identifier set
*
- * Called with ipc_ids.rw_mutex held.
+ * Called with ipc_ids.rwsem held.
*/
-
int ipc_get_maxid(struct ipc_ids *ids)
{
struct kern_ipc_perm *ipc;
@@ -195,22 +245,24 @@ int ipc_get_maxid(struct ipc_ids *ids)
}
/**
- * ipc_addid - add an IPC identifier
- * @ids: IPC identifier set
- * @new: new IPC permission set
- * @size: limit for the number of used ids
+ * ipc_addid - add an ipc identifier
+ * @ids: ipc identifier set
+ * @new: new ipc permission set
+ * @size: limit for the number of used ids
*
- * Add an entry 'new' to the IPC ids idr. The permissions object is
- * initialised and the first free entry is set up and the id assigned
- * is returned. The 'new' entry is returned in a locked state on success.
- * On failure the entry is not locked and a negative err-code is returned.
+ * Add an entry 'new' to the ipc ids idr. The permissions object is
+ * initialised and the first free entry is set up and the id assigned
+ * is returned. The 'new' entry is returned in a locked state on success.
+ * On failure the entry is not locked and a negative err-code is returned.
*
- * Called with ipc_ids.rw_mutex held as a writer.
+ * Called with writer ipc_ids.rwsem held.
*/
-
-int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
+int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size)
{
- int id, err;
+ kuid_t euid;
+ kgid_t egid;
+ int id;
+ int next_id = ids->next_id;
if (size > IPCMNI)
size = IPCMNI;
@@ -218,76 +270,86 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
if (ids->in_use >= size)
return -ENOSPC;
- err = idr_get_new(&ids->ipcs_idr, new, &id);
- if (err)
- return err;
+ idr_preload(GFP_KERNEL);
+
+ spin_lock_init(&new->lock);
+ new->deleted = false;
+ rcu_read_lock();
+ spin_lock(&new->lock);
+
+ id = idr_alloc(&ids->ipcs_idr, new,
+ (next_id < 0) ? 0 : ipcid_to_idx(next_id), 0,
+ GFP_NOWAIT);
+ idr_preload_end();
+ if (id < 0) {
+ spin_unlock(&new->lock);
+ rcu_read_unlock();
+ return id;
+ }
ids->in_use++;
- new->cuid = new->uid = current->euid;
- new->gid = new->cgid = current->egid;
+ current_euid_egid(&euid, &egid);
+ new->cuid = new->uid = euid;
+ new->gid = new->cgid = egid;
- new->seq = ids->seq++;
- if(ids->seq > ids->seq_max)
- ids->seq = 0;
+ if (next_id < 0) {
+ new->seq = ids->seq++;
+ if (ids->seq > IPCID_SEQ_MAX)
+ ids->seq = 0;
+ } else {
+ new->seq = ipcid_to_seqx(next_id);
+ ids->next_id = -1;
+ }
- spin_lock_init(&new->lock);
- new->deleted = 0;
- rcu_read_lock();
- spin_lock(&new->lock);
+ new->id = ipc_buildid(id, new->seq);
return id;
}
/**
- * ipcget_new - create a new ipc object
- * @ns: namespace
- * @ids: IPC identifer set
- * @ops: the actual creation routine to call
- * @params: its parameters
- *
- * This routine is called by sys_msgget, sys_semget() and sys_shmget()
- * when the key is IPC_PRIVATE.
+ * ipcget_new - create a new ipc object
+ * @ns: ipc namespace
+ * @ids: ipc identifer set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called by sys_msgget, sys_semget() and sys_shmget()
+ * when the key is IPC_PRIVATE.
*/
static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
- struct ipc_ops *ops, struct ipc_params *params)
+ const struct ipc_ops *ops, struct ipc_params *params)
{
int err;
-retry:
- err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
-
- if (!err)
- return -ENOMEM;
- down_write(&ids->rw_mutex);
+ down_write(&ids->rwsem);
err = ops->getnew(ns, params);
- up_write(&ids->rw_mutex);
-
- if (err == -EAGAIN)
- goto retry;
-
+ up_write(&ids->rwsem);
return err;
}
/**
- * ipc_check_perms - check security and permissions for an IPC
- * @ipcp: ipc permission set
- * @ops: the actual security routine to call
- * @params: its parameters
+ * ipc_check_perms - check security and permissions for an ipc object
+ * @ns: ipc namespace
+ * @ipcp: ipc permission set
+ * @ops: the actual security routine to call
+ * @params: its parameters
*
- * This routine is called by sys_msgget(), sys_semget() and sys_shmget()
- * when the key is not IPC_PRIVATE and that key already exists in the
- * ids IDR.
+ * This routine is called by sys_msgget(), sys_semget() and sys_shmget()
+ * when the key is not IPC_PRIVATE and that key already exists in the
+ * ds IDR.
*
- * On success, the IPC id is returned.
+ * On success, the ipc id is returned.
*
- * It is called with ipc_ids.rw_mutex and ipcp->lock held.
+ * It is called with ipc_ids.rwsem and ipcp->lock held.
*/
-static int ipc_check_perms(struct kern_ipc_perm *ipcp, struct ipc_ops *ops,
- struct ipc_params *params)
+static int ipc_check_perms(struct ipc_namespace *ns,
+ struct kern_ipc_perm *ipcp,
+ const struct ipc_ops *ops,
+ struct ipc_params *params)
{
int err;
- if (ipcperms(ipcp, params->flg))
+ if (ipcperms(ns, ipcp, params->flg))
err = -EACCES;
else {
err = ops->associate(ipcp, params->flg);
@@ -299,40 +361,36 @@ static int ipc_check_perms(struct kern_ipc_perm *ipcp, struct ipc_ops *ops,
}
/**
- * ipcget_public - get an ipc object or create a new one
- * @ns: namespace
- * @ids: IPC identifer set
- * @ops: the actual creation routine to call
- * @params: its parameters
- *
- * This routine is called by sys_msgget, sys_semget() and sys_shmget()
- * when the key is not IPC_PRIVATE.
- * It adds a new entry if the key is not found and does some permission
- * / security checkings if the key is found.
- *
- * On success, the ipc id is returned.
+ * ipcget_public - get an ipc object or create a new one
+ * @ns: ipc namespace
+ * @ids: ipc identifer set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called by sys_msgget, sys_semget() and sys_shmget()
+ * when the key is not IPC_PRIVATE.
+ * It adds a new entry if the key is not found and does some permission
+ * / security checkings if the key is found.
+ *
+ * On success, the ipc id is returned.
*/
static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
- struct ipc_ops *ops, struct ipc_params *params)
+ const struct ipc_ops *ops, struct ipc_params *params)
{
struct kern_ipc_perm *ipcp;
int flg = params->flg;
int err;
-retry:
- err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
/*
* Take the lock as a writer since we are potentially going to add
* a new entry + read locks are not "upgradable"
*/
- down_write(&ids->rw_mutex);
+ down_write(&ids->rwsem);
ipcp = ipc_findkey(ids, params->key);
if (ipcp == NULL) {
/* key not used */
if (!(flg & IPC_CREAT))
err = -ENOENT;
- else if (!err)
- err = -ENOMEM;
else
err = ops->getnew(ns, params);
} else {
@@ -349,53 +407,44 @@ retry:
* ipc_check_perms returns the IPC id on
* success
*/
- err = ipc_check_perms(ipcp, ops, params);
+ err = ipc_check_perms(ns, ipcp, ops, params);
}
ipc_unlock(ipcp);
}
- up_write(&ids->rw_mutex);
-
- if (err == -EAGAIN)
- goto retry;
+ up_write(&ids->rwsem);
return err;
}
/**
- * ipc_rmid - remove an IPC identifier
- * @ids: IPC identifier set
- * @ipcp: ipc perm structure containing the identifier to remove
+ * ipc_rmid - remove an ipc identifier
+ * @ids: ipc identifier set
+ * @ipcp: ipc perm structure containing the identifier to remove
*
- * ipc_ids.rw_mutex (as a writer) and the spinlock for this ID are held
- * before this function is called, and remain locked on the exit.
+ * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held
+ * before this function is called, and remain locked on the exit.
*/
-
void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
{
int lid = ipcid_to_idx(ipcp->id);
idr_remove(&ids->ipcs_idr, lid);
-
ids->in_use--;
-
- ipcp->deleted = 1;
-
- return;
+ ipcp->deleted = true;
}
/**
- * ipc_alloc - allocate ipc space
- * @size: size desired
+ * ipc_alloc - allocate ipc space
+ * @size: size desired
*
- * Allocate memory from the appropriate pools and return a pointer to it.
- * NULL is returned if the allocation fails
+ * Allocate memory from the appropriate pools and return a pointer to it.
+ * NULL is returned if the allocation fails
*/
-
-void* ipc_alloc(int size)
+void *ipc_alloc(int size)
{
- void* out;
- if(size > PAGE_SIZE)
+ void *out;
+ if (size > PAGE_SIZE)
out = vmalloc(size);
else
out = kmalloc(size, GFP_KERNEL);
@@ -403,183 +452,94 @@ void* ipc_alloc(int size)
}
/**
- * ipc_free - free ipc space
- * @ptr: pointer returned by ipc_alloc
- * @size: size of block
+ * ipc_free - free ipc space
+ * @ptr: pointer returned by ipc_alloc
+ * @size: size of block
*
- * Free a block created with ipc_alloc(). The caller must know the size
- * used in the allocation call.
+ * Free a block created with ipc_alloc(). The caller must know the size
+ * used in the allocation call.
*/
-
-void ipc_free(void* ptr, int size)
+void ipc_free(void *ptr, int size)
{
- if(size > PAGE_SIZE)
+ if (size > PAGE_SIZE)
vfree(ptr);
else
kfree(ptr);
}
-/*
- * rcu allocations:
- * There are three headers that are prepended to the actual allocation:
- * - during use: ipc_rcu_hdr.
- * - during the rcu grace period: ipc_rcu_grace.
- * - [only if vmalloc]: ipc_rcu_sched.
- * Their lifetime doesn't overlap, thus the headers share the same memory.
- * Unlike a normal union, they are right-aligned, thus some container_of
- * forward/backward casting is necessary:
- */
-struct ipc_rcu_hdr
-{
- int refcount;
- int is_vmalloc;
- void *data[0];
-};
-
-
-struct ipc_rcu_grace
-{
- struct rcu_head rcu;
- /* "void *" makes sure alignment of following data is sane. */
- void *data[0];
-};
-
-struct ipc_rcu_sched
-{
- struct work_struct work;
- /* "void *" makes sure alignment of following data is sane. */
- void *data[0];
-};
-
-#define HDRLEN_KMALLOC (sizeof(struct ipc_rcu_grace) > sizeof(struct ipc_rcu_hdr) ? \
- sizeof(struct ipc_rcu_grace) : sizeof(struct ipc_rcu_hdr))
-#define HDRLEN_VMALLOC (sizeof(struct ipc_rcu_sched) > HDRLEN_KMALLOC ? \
- sizeof(struct ipc_rcu_sched) : HDRLEN_KMALLOC)
-
-static inline int rcu_use_vmalloc(int size)
-{
- /* Too big for a single page? */
- if (HDRLEN_KMALLOC + size > PAGE_SIZE)
- return 1;
- return 0;
-}
-
/**
- * ipc_rcu_alloc - allocate ipc and rcu space
- * @size: size desired
+ * ipc_rcu_alloc - allocate ipc and rcu space
+ * @size: size desired
*
- * Allocate memory for the rcu header structure + the object.
- * Returns the pointer to the object.
- * NULL is returned if the allocation fails.
+ * Allocate memory for the rcu header structure + the object.
+ * Returns the pointer to the object or NULL upon failure.
*/
-
-void* ipc_rcu_alloc(int size)
+void *ipc_rcu_alloc(int size)
{
- void* out;
- /*
- * We prepend the allocation with the rcu struct, and
- * workqueue if necessary (for vmalloc).
+ /*
+ * We prepend the allocation with the rcu struct
*/
- if (rcu_use_vmalloc(size)) {
- out = vmalloc(HDRLEN_VMALLOC + size);
- if (out) {
- out += HDRLEN_VMALLOC;
- container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 1;
- container_of(out, struct ipc_rcu_hdr, data)->refcount = 1;
- }
- } else {
- out = kmalloc(HDRLEN_KMALLOC + size, GFP_KERNEL);
- if (out) {
- out += HDRLEN_KMALLOC;
- container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 0;
- container_of(out, struct ipc_rcu_hdr, data)->refcount = 1;
- }
- }
-
- return out;
+ struct ipc_rcu *out = ipc_alloc(sizeof(struct ipc_rcu) + size);
+ if (unlikely(!out))
+ return NULL;
+ atomic_set(&out->refcount, 1);
+ return out + 1;
}
-void ipc_rcu_getref(void *ptr)
+int ipc_rcu_getref(void *ptr)
{
- container_of(ptr, struct ipc_rcu_hdr, data)->refcount++;
-}
+ struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
-static void ipc_do_vfree(struct work_struct *work)
-{
- vfree(container_of(work, struct ipc_rcu_sched, work));
+ return atomic_inc_not_zero(&p->refcount);
}
-/**
- * ipc_schedule_free - free ipc + rcu space
- * @head: RCU callback structure for queued work
- *
- * Since RCU callback function is called in bh,
- * we need to defer the vfree to schedule_work().
- */
-static void ipc_schedule_free(struct rcu_head *head)
+void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head))
{
- struct ipc_rcu_grace *grace;
- struct ipc_rcu_sched *sched;
+ struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
- grace = container_of(head, struct ipc_rcu_grace, rcu);
- sched = container_of(&(grace->data[0]), struct ipc_rcu_sched,
- data[0]);
+ if (!atomic_dec_and_test(&p->refcount))
+ return;
- INIT_WORK(&sched->work, ipc_do_vfree);
- schedule_work(&sched->work);
+ call_rcu(&p->rcu, func);
}
-/**
- * ipc_immediate_free - free ipc + rcu space
- * @head: RCU callback structure that contains pointer to be freed
- *
- * Free from the RCU callback context.
- */
-static void ipc_immediate_free(struct rcu_head *head)
+void ipc_rcu_free(struct rcu_head *head)
{
- struct ipc_rcu_grace *free =
- container_of(head, struct ipc_rcu_grace, rcu);
- kfree(free);
-}
+ struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
-void ipc_rcu_putref(void *ptr)
-{
- if (--container_of(ptr, struct ipc_rcu_hdr, data)->refcount > 0)
- return;
-
- if (container_of(ptr, struct ipc_rcu_hdr, data)->is_vmalloc) {
- call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
- ipc_schedule_free);
- } else {
- call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
- ipc_immediate_free);
- }
+ if (is_vmalloc_addr(p))
+ vfree(p);
+ else
+ kfree(p);
}
/**
- * ipcperms - check IPC permissions
- * @ipcp: IPC permission set
- * @flag: desired permission set.
+ * ipcperms - check ipc permissions
+ * @ns: ipc namespace
+ * @ipcp: ipc permission set
+ * @flag: desired permission set
+ *
+ * Check user, group, other permissions for access
+ * to ipc resources. return 0 if allowed
*
- * Check user, group, other permissions for access
- * to ipc resources. return 0 if allowed
+ * @flag will most probably be 0 or S_...UGO from <linux/stat.h>
*/
-
-int ipcperms (struct kern_ipc_perm *ipcp, short flag)
-{ /* flag will most probably be 0 or S_...UGO from <linux/stat.h> */
- int requested_mode, granted_mode, err;
+int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
+{
+ kuid_t euid = current_euid();
+ int requested_mode, granted_mode;
- if (unlikely((err = audit_ipc_obj(ipcp))))
- return err;
+ audit_ipc_obj(ipcp);
requested_mode = (flag >> 6) | (flag >> 3) | flag;
granted_mode = ipcp->mode;
- if (current->euid == ipcp->cuid || current->euid == ipcp->uid)
+ if (uid_eq(euid, ipcp->cuid) ||
+ uid_eq(euid, ipcp->uid))
granted_mode >>= 6;
else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
granted_mode >>= 3;
/* is there some bit set in requested_mode but not in granted_mode? */
- if ((requested_mode & ~granted_mode & 0007) &&
- !capable(CAP_IPC_OWNER))
+ if ((requested_mode & ~granted_mode & 0007) &&
+ !ns_capable(ns->user_ns, CAP_IPC_OWNER))
return -1;
return security_ipc_permission(ipcp, flag);
@@ -591,36 +551,33 @@ int ipcperms (struct kern_ipc_perm *ipcp, short flag)
*/
/**
- * kernel_to_ipc64_perm - convert kernel ipc permissions to user
- * @in: kernel permissions
- * @out: new style IPC permissions
+ * kernel_to_ipc64_perm - convert kernel ipc permissions to user
+ * @in: kernel permissions
+ * @out: new style ipc permissions
*
- * Turn the kernel object @in into a set of permissions descriptions
- * for returning to userspace (@out).
+ * Turn the kernel object @in into a set of permissions descriptions
+ * for returning to userspace (@out).
*/
-
-
-void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
+void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
{
out->key = in->key;
- out->uid = in->uid;
- out->gid = in->gid;
- out->cuid = in->cuid;
- out->cgid = in->cgid;
+ out->uid = from_kuid_munged(current_user_ns(), in->uid);
+ out->gid = from_kgid_munged(current_user_ns(), in->gid);
+ out->cuid = from_kuid_munged(current_user_ns(), in->cuid);
+ out->cgid = from_kgid_munged(current_user_ns(), in->cgid);
out->mode = in->mode;
out->seq = in->seq;
}
/**
- * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
- * @in: new style IPC permissions
- * @out: old style IPC permissions
+ * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
+ * @in: new style ipc permissions
+ * @out: old style ipc permissions
*
- * Turn the new style permissions object @in into a compatibility
- * object and store it into the @out pointer.
+ * Turn the new style permissions object @in into a compatibility
+ * object and store it into the @out pointer.
*/
-
-void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
+void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
{
out->key = in->key;
SET_UID(out->uid, in->uid);
@@ -632,128 +589,96 @@ void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
}
/**
- * ipc_lock - Lock an ipc structure without rw_mutex held
- * @ids: IPC identifier set
+ * ipc_obtain_object
+ * @ids: ipc identifier set
* @id: ipc id to look for
*
- * Look for an id in the ipc ids idr and lock the associated ipc object.
- *
- * The ipc object is locked on exit.
+ * Look for an id in the ipc ids idr and return associated ipc object.
*
- * This is the routine that should be called when the rw_mutex is not already
- * held, i.e. idr tree not protected: it protects the idr tree in read mode
- * during the idr_find().
+ * Call inside the RCU critical section.
+ * The ipc object is *not* locked on exit.
*/
-
-struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
+struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id)
{
struct kern_ipc_perm *out;
int lid = ipcid_to_idx(id);
- down_read(&ids->rw_mutex);
-
- rcu_read_lock();
out = idr_find(&ids->ipcs_idr, lid);
- if (out == NULL) {
- rcu_read_unlock();
- up_read(&ids->rw_mutex);
+ if (!out)
return ERR_PTR(-EINVAL);
- }
-
- up_read(&ids->rw_mutex);
-
- spin_lock(&out->lock);
-
- /* ipc_rmid() may have already freed the ID while ipc_lock
- * was spinning: here verify that the structure is still valid
- */
- if (out->deleted) {
- spin_unlock(&out->lock);
- rcu_read_unlock();
- return ERR_PTR(-EINVAL);
- }
return out;
}
/**
- * ipc_lock_down - Lock an ipc structure with rw_sem held
- * @ids: IPC identifier set
+ * ipc_lock - lock an ipc structure without rwsem held
+ * @ids: ipc identifier set
* @id: ipc id to look for
*
* Look for an id in the ipc ids idr and lock the associated ipc object.
*
- * The ipc object is locked on exit.
- *
- * This is the routine that should be called when the rw_mutex is already
- * held, i.e. idr tree protected.
+ * The ipc object is locked on successful exit.
*/
-
-struct kern_ipc_perm *ipc_lock_down(struct ipc_ids *ids, int id)
+struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
{
struct kern_ipc_perm *out;
- int lid = ipcid_to_idx(id);
rcu_read_lock();
- out = idr_find(&ids->ipcs_idr, lid);
- if (out == NULL) {
- rcu_read_unlock();
- return ERR_PTR(-EINVAL);
- }
+ out = ipc_obtain_object(ids, id);
+ if (IS_ERR(out))
+ goto err1;
spin_lock(&out->lock);
- /*
- * No need to verify that the structure is still valid since the
- * rw_mutex is held.
+ /* ipc_rmid() may have already freed the ID while ipc_lock
+ * was spinning: here verify that the structure is still valid
*/
- return out;
-}
-
-struct kern_ipc_perm *ipc_lock_check_down(struct ipc_ids *ids, int id)
-{
- struct kern_ipc_perm *out;
-
- out = ipc_lock_down(ids, id);
- if (IS_ERR(out))
+ if (ipc_valid_object(out))
return out;
- if (ipc_checkid(out, id)) {
- ipc_unlock(out);
- return ERR_PTR(-EIDRM);
- }
-
+ spin_unlock(&out->lock);
+ out = ERR_PTR(-EINVAL);
+err1:
+ rcu_read_unlock();
return out;
}
-struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id)
+/**
+ * ipc_obtain_object_check
+ * @ids: ipc identifier set
+ * @id: ipc id to look for
+ *
+ * Similar to ipc_obtain_object() but also checks
+ * the ipc object reference counter.
+ *
+ * Call inside the RCU critical section.
+ * The ipc object is *not* locked on exit.
+ */
+struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
{
- struct kern_ipc_perm *out;
+ struct kern_ipc_perm *out = ipc_obtain_object(ids, id);
- out = ipc_lock(ids, id);
if (IS_ERR(out))
- return out;
+ goto out;
- if (ipc_checkid(out, id)) {
- ipc_unlock(out);
+ if (ipc_checkid(out, id))
return ERR_PTR(-EIDRM);
- }
-
+out:
return out;
}
/**
* ipcget - Common sys_*get() code
- * @ns : namsepace
- * @ids : IPC identifier set
- * @ops : operations to be called on ipc object creation, permission checks
- * and further checks
- * @params : the parameters needed by the previous operations.
+ * @ns: namsepace
+ * @ids: ipc identifier set
+ * @ops: operations to be called on ipc object creation, permission checks
+ * and further checks
+ * @params: the parameters needed by the previous operations.
*
* Common routine called by sys_msgget(), sys_semget() and sys_shmget().
*/
int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
- struct ipc_ops *ops, struct ipc_params *params)
+ const struct ipc_ops *ops, struct ipc_params *params)
{
if (params->key == IPC_PRIVATE)
return ipcget_new(ns, ids, ops, params);
@@ -761,19 +686,83 @@ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
return ipcget_public(ns, ids, ops, params);
}
-#ifdef __ARCH_WANT_IPC_PARSE_VERSION
+/**
+ * ipc_update_perm - update the permissions of an ipc object
+ * @in: the permission given as input.
+ * @out: the permission of the ipc to set.
+ */
+int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
+{
+ kuid_t uid = make_kuid(current_user_ns(), in->uid);
+ kgid_t gid = make_kgid(current_user_ns(), in->gid);
+ if (!uid_valid(uid) || !gid_valid(gid))
+ return -EINVAL;
+
+ out->uid = uid;
+ out->gid = gid;
+ out->mode = (out->mode & ~S_IRWXUGO)
+ | (in->mode & S_IRWXUGO);
+
+ return 0;
+}
+
+/**
+ * ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd
+ * @ns: ipc namespace
+ * @ids: the table of ids where to look for the ipc
+ * @id: the id of the ipc to retrieve
+ * @cmd: the cmd to check
+ * @perm: the permission to set
+ * @extra_perm: one extra permission parameter used by msq
+ *
+ * This function does some common audit and permissions check for some IPC_XXX
+ * cmd and is called from semctl_down, shmctl_down and msgctl_down.
+ * It must be called without any lock held and
+ * - retrieves the ipc with the given id in the given table.
+ * - performs some audit and permission check, depending on the given cmd
+ * - returns a pointer to the ipc object or otherwise, the corresponding error.
+ *
+ * Call holding the both the rwsem and the rcu read lock.
+ */
+struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
+ struct ipc_ids *ids, int id, int cmd,
+ struct ipc64_perm *perm, int extra_perm)
+{
+ kuid_t euid;
+ int err = -EPERM;
+ struct kern_ipc_perm *ipcp;
+
+ ipcp = ipc_obtain_object_check(ids, id);
+ if (IS_ERR(ipcp)) {
+ err = PTR_ERR(ipcp);
+ goto err;
+ }
+
+ audit_ipc_obj(ipcp);
+ if (cmd == IPC_SET)
+ audit_ipc_set_perm(extra_perm, perm->uid,
+ perm->gid, perm->mode);
+
+ euid = current_euid();
+ if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
+ ns_capable(ns->user_ns, CAP_SYS_ADMIN))
+ return ipcp; /* successful lookup */
+err:
+ return ERR_PTR(err);
+}
+
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
/**
- * ipc_parse_version - IPC call version
- * @cmd: pointer to command
+ * ipc_parse_version - ipc call version
+ * @cmd: pointer to command
*
- * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
- * The @cmd value is turned from an encoding command and version into
- * just the command code.
+ * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
+ * The @cmd value is turned from an encoding command and version into
+ * just the command code.
*/
-
-int ipc_parse_version (int *cmd)
+int ipc_parse_version(int *cmd)
{
if (*cmd & IPC_64) {
*cmd ^= IPC_64;
@@ -783,7 +772,7 @@ int ipc_parse_version (int *cmd)
}
}
-#endif /* __ARCH_WANT_IPC_PARSE_VERSION */
+#endif /* CONFIG_ARCH_WANT_IPC_PARSE_VERSION */
#ifdef CONFIG_PROC_FS
struct ipc_proc_iter {
@@ -810,11 +799,12 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
if (total >= ids->in_use)
return NULL;
- for ( ; pos < IPCMNI; pos++) {
+ for (; pos < IPCMNI; pos++) {
ipc = idr_find(&ids->ipcs_idr, pos);
if (ipc != NULL) {
*new_pos = pos + 1;
- ipc_lock_by_ptr(ipc);
+ rcu_read_lock();
+ ipc_lock_object(ipc);
return ipc;
}
}
@@ -852,7 +842,7 @@ static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
* Take the lock - this will be released by the corresponding
* call to stop().
*/
- down_read(&ids->rw_mutex);
+ down_read(&ids->rwsem);
/* pos < 0 is invalid */
if (*pos < 0)
@@ -879,7 +869,7 @@ static void sysvipc_proc_stop(struct seq_file *s, void *it)
ids = &iter->ns->ids[iface->ids];
/* Release the lock we took in start() */
- up_read(&ids->rw_mutex);
+ up_read(&ids->rwsem);
}
static int sysvipc_proc_show(struct seq_file *s, void *it)
@@ -893,7 +883,7 @@ static int sysvipc_proc_show(struct seq_file *s, void *it)
return iface->show(s, it);
}
-static struct seq_operations sysvipc_proc_seqops = {
+static const struct seq_operations sysvipc_proc_seqops = {
.start = sysvipc_proc_start,
.stop = sysvipc_proc_stop,
.next = sysvipc_proc_next,
@@ -912,19 +902,18 @@ static int sysvipc_proc_open(struct inode *inode, struct file *file)
goto out;
ret = seq_open(file, &sysvipc_proc_seqops);
- if (ret)
- goto out_kfree;
+ if (ret) {
+ kfree(iter);
+ goto out;
+ }
seq = file->private_data;
seq->private = iter;
- iter->iface = PDE(inode)->data;
+ iter->iface = PDE_DATA(inode);
iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
out:
return ret;
-out_kfree:
- kfree(iter);
- goto out;
}
static int sysvipc_proc_release(struct inode *inode, struct file *file)
diff --git a/ipc/util.h b/ipc/util.h
index f37d160c98f..1a5a0fcd099 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -10,17 +10,26 @@
#ifndef _IPC_UTIL_H
#define _IPC_UTIL_H
+#include <linux/unistd.h>
#include <linux/err.h>
-#define USHRT_MAX 0xffff
#define SEQ_MULTIPLIER (IPCMNI)
-void sem_init (void);
-void msg_init (void);
-void shm_init (void);
+void sem_init(void);
+void msg_init(void);
+void shm_init(void);
struct ipc_namespace;
+#ifdef CONFIG_POSIX_MQUEUE
+extern void mq_clear_sbinfo(struct ipc_namespace *ns);
+extern void mq_put_mnt(struct ipc_namespace *ns);
+#else
+static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { }
+static inline void mq_put_mnt(struct ipc_namespace *ns) { }
+#endif
+
+#ifdef CONFIG_SYSVIPC
void sem_init_ns(struct ipc_namespace *ns);
void msg_init_ns(struct ipc_namespace *ns);
void shm_init_ns(struct ipc_namespace *ns);
@@ -28,6 +37,22 @@ void shm_init_ns(struct ipc_namespace *ns);
void sem_exit_ns(struct ipc_namespace *ns);
void msg_exit_ns(struct ipc_namespace *ns);
void shm_exit_ns(struct ipc_namespace *ns);
+#else
+static inline void sem_init_ns(struct ipc_namespace *ns) { }
+static inline void msg_init_ns(struct ipc_namespace *ns) { }
+static inline void shm_init_ns(struct ipc_namespace *ns) { }
+
+static inline void sem_exit_ns(struct ipc_namespace *ns) { }
+static inline void msg_exit_ns(struct ipc_namespace *ns) { }
+static inline void shm_exit_ns(struct ipc_namespace *ns) { }
+#endif
+
+struct ipc_rcu {
+ struct rcu_head rcu;
+ atomic_t refcount;
+} ____cacheline_aligned_in_smp;
+
+#define ipc_rcu_to_struct(p) ((void *)(p+1))
/*
* Structure that holds the parameters needed by the ipc operations
@@ -53,9 +78,9 @@ struct ipc_params {
* . routine to call for an extra check if needed
*/
struct ipc_ops {
- int (*getnew) (struct ipc_namespace *, struct ipc_params *);
- int (*associate) (struct kern_ipc_perm *, int);
- int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *);
+ int (*getnew)(struct ipc_namespace *, struct ipc_params *);
+ int (*associate)(struct kern_ipc_perm *, int);
+ int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *);
};
struct seq_file;
@@ -74,24 +99,26 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
#define IPC_SHM_IDS 2
#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
+#define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
+#define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX)
-/* must be called with ids->rw_mutex acquired for writing */
+/* must be called with ids->rwsem acquired for writing */
int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
-/* must be called with ids->rw_mutex acquired for reading */
+/* must be called with ids->rwsem acquired for reading */
int ipc_get_maxid(struct ipc_ids *);
/* must be called with both locks acquired. */
void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
/* must be called with ipcp locked */
-int ipcperms(struct kern_ipc_perm *ipcp, short flg);
+int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
/* for rare, potentially huge allocations.
* both function can sleep
*/
-void* ipc_alloc(int size);
-void ipc_free(void* ptr, int size);
+void *ipc_alloc(int size);
+void ipc_free(void *ptr, int size);
/*
* For allocation that need to be freed by RCU.
@@ -99,61 +126,82 @@ void ipc_free(void* ptr, int size);
* getref increases the refcount, the putref call that reduces the recount
* to 0 schedules the rcu destruction. Caller must guarantee locking.
*/
-void* ipc_rcu_alloc(int size);
-void ipc_rcu_getref(void *ptr);
-void ipc_rcu_putref(void *ptr);
+void *ipc_rcu_alloc(int size);
+int ipc_rcu_getref(void *ptr);
+void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head));
+void ipc_rcu_free(struct rcu_head *head);
-/*
- * ipc_lock_down: called with rw_mutex held
- * ipc_lock: called without that lock held
- */
-struct kern_ipc_perm *ipc_lock_down(struct ipc_ids *, int);
struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
+struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id);
void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
+int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
+struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
+ struct ipc_ids *ids, int id, int cmd,
+ struct ipc64_perm *perm, int extra_perm);
-#if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
- /* On IA-64, we always use the "64-bit version" of the IPC structures. */
+#ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+/* On IA-64, we always use the "64-bit version" of the IPC structures. */
# define ipc_parse_version(cmd) IPC_64
#else
-int ipc_parse_version (int *cmd);
+int ipc_parse_version(int *cmd);
#endif
extern void free_msg(struct msg_msg *msg);
-extern struct msg_msg *load_msg(const void __user *src, int len);
-extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
+extern struct msg_msg *load_msg(const void __user *src, size_t len);
+extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst);
+extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len);
+
+extern void recompute_msgmni(struct ipc_namespace *);
static inline int ipc_buildid(int id, int seq)
{
return SEQ_MULTIPLIER * seq + id;
}
-/*
- * Must be called with ipcp locked
- */
static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid)
{
- if (uid / SEQ_MULTIPLIER != ipcp->seq)
- return 1;
- return 0;
+ return uid / SEQ_MULTIPLIER != ipcp->seq;
}
-static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm)
+static inline void ipc_lock_object(struct kern_ipc_perm *perm)
{
- rcu_read_lock();
spin_lock(&perm->lock);
}
-static inline void ipc_unlock(struct kern_ipc_perm *perm)
+static inline void ipc_unlock_object(struct kern_ipc_perm *perm)
{
spin_unlock(&perm->lock);
+}
+
+static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm)
+{
+ assert_spin_locked(&perm->lock);
+}
+
+static inline void ipc_unlock(struct kern_ipc_perm *perm)
+{
+ ipc_unlock_object(perm);
rcu_read_unlock();
}
-struct kern_ipc_perm *ipc_lock_check_down(struct ipc_ids *ids, int id);
-struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id);
-int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
- struct ipc_ops *ops, struct ipc_params *params);
+/*
+ * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths
+ * where the respective ipc_ids.rwsem is not being held down.
+ * Checks whether the ipc object is still around or if it's gone already, as
+ * ipc_rmid() may have already freed the ID while the ipc lock was spinning.
+ * Needs to be called with kern_ipc_perm.lock held -- exception made for one
+ * checkpoint case at sys_semtimedop() as noted in code commentary.
+ */
+static inline bool ipc_valid_object(struct kern_ipc_perm *perm)
+{
+ return !perm->deleted;
+}
+struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
+int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
+ const struct ipc_ops *ops, struct ipc_params *params);
+void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
+ void (*free)(struct ipc_namespace *, struct kern_ipc_perm *));
#endif
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 03:33:31 +0000