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-rw-r--r--include/linux/ipc_namespace.h2
-rw-r--r--ipc/msg.c124
-rw-r--r--ipc/msgutil.c110
-rw-r--r--ipc/sem.c474
-rw-r--r--ipc/shm.c2
-rw-r--r--ipc/util.c150
-rw-r--r--ipc/util.h19
7 files changed, 540 insertions, 341 deletions
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index ae221a7b509..c4d870b0d5e 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -43,8 +43,8 @@ struct ipc_namespace {
size_t shm_ctlmax;
size_t shm_ctlall;
+ unsigned long shm_tot;
int shm_ctlmni;
- int shm_tot;
/*
* Defines whether IPC_RMID is forced for _all_ shm segments regardless
* of shmctl()
diff --git a/ipc/msg.c b/ipc/msg.c
index fede1d06ef3..d0c6d967b39 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -66,6 +66,7 @@ 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])
@@ -237,14 +238,9 @@ 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);
@@ -253,14 +249,9 @@ 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;
+ list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
msr->r_msg = NULL;
wake_up_process(msr->r_tsk);
smp_mb();
@@ -278,7 +269,7 @@ static void expunge_all(struct msg_queue *msq, int res)
*/
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);
@@ -286,11 +277,7 @@ static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
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);
-
- tmp = tmp->next;
+ list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
atomic_dec(&ns->msg_hdrs);
free_msg(msg);
}
@@ -583,6 +570,7 @@ static int testmsg(struct msg_msg *msg, long type, int mode)
switch(mode)
{
case SEARCH_ANY:
+ case SEARCH_NUMBER:
return 1;
case SEARCH_LESSEQUAL:
if (msg->m_type <=type)
@@ -602,14 +590,9 @@ static int testmsg(struct msg_msg *msg, long type, int mode)
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)) {
@@ -685,7 +668,12 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
goto out_unlock_free;
}
ss_add(msq, &s);
- ipc_rcu_getref(msq);
+
+ if (!ipc_rcu_getref(msq)) {
+ err = -EIDRM;
+ goto out_unlock_free;
+ }
+
msg_unlock(msq);
schedule();
@@ -738,6 +726,8 @@ SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
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.
@@ -774,14 +764,10 @@ static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
* 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,
- int msgflg, long *msgtyp,
- unsigned long *copy_number)
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
{
struct msg_msg *copy;
- *copy_number = *msgtyp;
- *msgtyp = 0;
/*
* Create dummy message to copy real message to.
*/
@@ -797,9 +783,7 @@ static inline void free_copy(struct msg_msg *copy)
free_msg(copy);
}
#else
-static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz,
- int msgflg, long *msgtyp,
- unsigned long *copy_number)
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
{
return ERR_PTR(-ENOSYS);
}
@@ -809,6 +793,30 @@ 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;
+ 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;
+ } else if (mode == SEARCH_NUMBER) {
+ if (*msgtyp == count)
+ return msg;
+ } else
+ return msg;
+ count++;
+ }
+ }
+
+ return 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))
@@ -818,15 +826,13 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
int mode;
struct ipc_namespace *ns;
struct msg_msg *copy = NULL;
- unsigned long copy_number = 0;
ns = current->nsproxy->ipc_ns;
if (msqid < 0 || (long) bufsz < 0)
return -EINVAL;
if (msgflg & MSG_COPY) {
- copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax),
- msgflg, &msgtyp, &copy_number);
+ copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
if (IS_ERR(copy))
return PTR_ERR(copy);
}
@@ -840,45 +846,13 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
for (;;) {
struct msg_receiver msr_d;
- struct list_head *tmp;
- long msg_counter = 0;
msg = ERR_PTR(-EACCES);
if (ipcperms(ns, &msq->q_perm, S_IRUGO))
goto out_unlock;
- 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) {
- msgtyp = walk_msg->m_type - 1;
- } else if (msgflg & MSG_COPY) {
- if (copy_number == msg_counter) {
- /*
- * Found requested message.
- * Copy it.
- */
- msg = copy_msg(msg, copy);
- if (IS_ERR(msg))
- goto out_unlock;
- break;
- }
- msg = ERR_PTR(-EAGAIN);
- } else
- break;
- msg_counter++;
- }
- tmp = tmp->next;
- }
+ msg = find_msg(msq, &msgtyp, mode);
+
if (!IS_ERR(msg)) {
/*
* Found a suitable message.
@@ -892,8 +866,10 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
* If we are copying, then do not unlink message and do
* not update queue parameters.
*/
- if (msgflg & MSG_COPY)
+ if (msgflg & MSG_COPY) {
+ msg = copy_msg(msg, copy);
goto out_unlock;
+ }
list_del(&msg->m_list);
msq->q_qnum--;
msq->q_rtime = get_seconds();
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index 5df8e4bf1db..d43439e6eb4 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -17,7 +17,7 @@
#include <linux/ipc_namespace.h>
#include <linux/utsname.h>
#include <linux/proc_fs.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include "util.h"
@@ -37,59 +37,70 @@ struct ipc_namespace init_ipc_ns = {
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 (int)(PAGE_SIZE-sizeof(struct msg_msg))
+#define DATALEN_SEG (int)(PAGE_SIZE-sizeof(struct msg_msgseg))
-struct msg_msg *load_msg(const void __user *src, int len)
+
+static struct msg_msg *alloc_msg(int len)
{
struct msg_msg *msg;
struct msg_msgseg **pseg;
- int err;
int alen;
- alen = len;
- if (alen > DATALEN_MSG)
- alen = DATALEN_MSG;
-
+ 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, int len)
+{
+ struct msg_msg *msg;
+ struct msg_msgseg *seg;
+ int err = -EFAULT;
+ int 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);
@@ -113,23 +124,16 @@ struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
if (src->m_ts > dst->m_ts)
return ERR_PTR(-EINVAL);
- alen = len;
- if (alen > DATALEN_MSG)
- alen = DATALEN_MSG;
-
+ alen = min(len, DATALEN_MSG);
memcpy(dst + 1, src + 1, alen);
- len -= alen;
- dst_pseg = dst->next;
- src_pseg = src->next;
- while (len > 0) {
- alen = len;
- if (alen > DATALEN_SEG)
- alen = DATALEN_SEG;
- memcpy(dst_pseg + 1, src_pseg + 1, alen);
- dst_pseg = dst_pseg->next;
+ for (dst_pseg = dst->next, src_pseg = src->next;
+ src_pseg != NULL;
+ dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
+
len -= alen;
- src_pseg = src_pseg->next;
+ alen = min(len, DATALEN_SEG);
+ memcpy(dst_pseg + 1, src_pseg + 1, alen);
}
dst->m_type = src->m_type;
@@ -148,24 +152,16 @@ int store_msg(void __user *dest, struct msg_msg *msg, int len)
int 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/sem.c b/ipc/sem.c
index 5b167d00efa..e78ee3186d1 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -94,12 +94,12 @@
struct sem {
int semval; /* current value */
int sempid; /* pid of last operation */
+ spinlock_t lock; /* spinlock for fine-grained semtimedop */
struct list_head sem_pending; /* pending single-sop operations */
};
/* One queue for each sleeping process in the system. */
struct sem_queue {
- struct list_head simple_list; /* queue of pending operations */
struct list_head list; /* queue of pending operations */
struct task_struct *sleeper; /* this process */
struct sem_undo *undo; /* undo structure */
@@ -138,7 +138,6 @@ struct sem_undo_list {
#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)
static int newary(struct ipc_namespace *, struct ipc_params *);
@@ -191,47 +190,164 @@ void __init sem_init (void)
}
/*
+ * 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.
+ *
+ * Carefully guard against sma->complex_count changing between zero
+ * and non-zero while we are spinning for the lock. The value of
+ * sma->complex_count cannot change while we are holding the lock,
+ * so sem_unlock should be fine.
+ *
+ * The global lock path checks that all the local locks have been released,
+ * checking each local lock once. This means that the local lock paths
+ * cannot start their critical sections while the global lock is held.
+ */
+static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
+ int nsops)
+{
+ int locknum;
+ again:
+ if (nsops == 1 && !sma->complex_count) {
+ struct sem *sem = sma->sem_base + sops->sem_num;
+
+ /* Lock just the semaphore we are interested in. */
+ spin_lock(&sem->lock);
+
+ /*
+ * If sma->complex_count was set while we were spinning,
+ * we may need to look at things we did not lock here.
+ */
+ if (unlikely(sma->complex_count)) {
+ spin_unlock(&sem->lock);
+ goto lock_array;
+ }
+
+ /*
+ * Another process is holding the global lock on the
+ * sem_array; we cannot enter our critical section,
+ * but have to wait for the global lock to be released.
+ */
+ if (unlikely(spin_is_locked(&sma->sem_perm.lock))) {
+ spin_unlock(&sem->lock);
+ spin_unlock_wait(&sma->sem_perm.lock);
+ goto again;
+ }
+
+ locknum = sops->sem_num;
+ } else {
+ int i;
+ /*
+ * Lock the semaphore array, and wait for all of the
+ * individual semaphore locks to go away. The code
+ * above ensures no new single-lock holders will enter
+ * their critical section while the array lock is held.
+ */
+ lock_array:
+ spin_lock(&sma->sem_perm.lock);
+ for (i = 0; i < sma->sem_nsems; i++) {
+ struct sem *sem = sma->sem_base + i;
+ spin_unlock_wait(&sem->lock);
+ }
+ locknum = -1;
+ }
+ return locknum;
+}
+
+static inline void sem_unlock(struct sem_array *sma, int locknum)
+{
+ if (locknum == -1) {
+ spin_unlock(&sma->sem_perm.lock);
+ } else {
+ struct sem *sem = sma->sem_base + locknum;
+ spin_unlock(&sem->lock);
+ }
+ rcu_read_unlock();
+}
+
+/*
* sem_lock_(check_) routines are called in the paths where the rw_mutex
* is not held.
*/
-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;
+ struct sem_array *sma;
+
+ rcu_read_lock();
+ ipcp = ipc_obtain_object(&sem_ids(ns), id);
+ if (IS_ERR(ipcp)) {
+ sma = ERR_CAST(ipcp);
+ goto err;
+ }
+
+ 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 (!ipcp->deleted)
+ return container_of(ipcp, struct sem_array, sem_perm);
+
+ sem_unlock(sma, *locknum);
+ sma = ERR_PTR(-EINVAL);
+err:
+ rcu_read_unlock();
+ return sma;
+}
+
+static inline struct sem_array *sem_obtain_object(struct ipc_namespace *ns, int id)
{
- struct kern_ipc_perm *ipcp = ipc_lock(&sem_ids(ns), id);
+ struct kern_ipc_perm *ipcp = ipc_obtain_object(&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 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)
{
- ipc_lock_by_ptr(&sma->sem_perm);
+ rcu_read_lock();
+ sem_lock(sma, NULL, -1);
ipc_rcu_putref(sma);
}
static inline void sem_getref_and_unlock(struct sem_array *sma)
{
- ipc_rcu_getref(sma);
- ipc_unlock(&(sma)->sem_perm);
+ WARN_ON_ONCE(!ipc_rcu_getref(sma));
+ sem_unlock(sma, -1);
}
static inline void sem_putref(struct sem_array *sma)
{
- ipc_lock_by_ptr(&sma->sem_perm);
- ipc_rcu_putref(sma);
- ipc_unlock(&(sma)->sem_perm);
+ sem_lock_and_putref(sma);
+ sem_unlock(sma, -1);
+}
+
+/*
+ * Call inside the rcu read section.
+ */
+static inline void sem_getref(struct sem_array *sma)
+{
+ sem_lock(sma, NULL, -1);
+ WARN_ON_ONCE(!ipc_rcu_getref(sma));
+ sem_unlock(sma, -1);
}
static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
@@ -324,15 +440,17 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
sma->sem_base = (struct sem *) &sma[1];
- for (i = 0; i < nsems; i++)
+ for (i = 0; i < nsems; i++) {
INIT_LIST_HEAD(&sma->sem_base[i].sem_pending);
+ spin_lock_init(&sma->sem_base[i].lock);
+ }
sma->complex_count = 0;
INIT_LIST_HEAD(&sma->sem_pending);
INIT_LIST_HEAD(&sma->list_id);
sma->sem_nsems = nsems;
sma->sem_ctime = get_seconds();
- sem_unlock(sma);
+ sem_unlock(sma, -1);
return sma->sem_perm.id;
}
@@ -471,7 +589,7 @@ static void wake_up_sem_queue_prepare(struct list_head *pt,
q->status = IN_WAKEUP;
q->pid = error;
- list_add_tail(&q->simple_list, pt);
+ list_add_tail(&q->list, pt);
}
/**
@@ -489,7 +607,7 @@ static void wake_up_sem_queue_do(struct list_head *pt)
int did_something;
did_something = !list_empty(pt);
- list_for_each_entry_safe(q, t, pt, simple_list) {
+ list_for_each_entry_safe(q, t, pt, list) {
wake_up_process(q->sleeper);
/* q can disappear immediately after writing q->status. */
smp_wmb();
@@ -502,9 +620,7 @@ static void wake_up_sem_queue_do(struct list_head *pt)
static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
{
list_del(&q->list);
- if (q->nsops == 1)
- list_del(&q->simple_list);
- else
+ if (q->nsops > 1)
sma->complex_count--;
}
@@ -557,9 +673,9 @@ static int check_restart(struct sem_array *sma, struct sem_queue *q)
}
/*
* semval is 0. Check if there are wait-for-zero semops.
- * They must be the first entries in the per-semaphore simple queue
+ * They must be the first entries in the per-semaphore queue
*/
- h = list_first_entry(&curr->sem_pending, struct sem_queue, simple_list);
+ h = list_first_entry(&curr->sem_pending, struct sem_queue, list);
BUG_ON(h->nsops != 1);
BUG_ON(h->sops[0].sem_num != q->sops[0].sem_num);
@@ -579,8 +695,9 @@ static int check_restart(struct sem_array *sma, struct sem_queue *q)
* @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 semaphore were modified, then @semnum
- * must be set to -1.
+ * 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 return 1 if at least one semop was completed successfully.
@@ -590,30 +707,19 @@ 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 offset;
int semop_completed = 0;
- /* if there are complex operations around, then knowing the semaphore
- * that was modified doesn't help us. Assume that multiple semaphores
- * were modified.
- */
- if (sma->complex_count)
- semnum = -1;
-
- if (semnum == -1) {
+ if (semnum == -1)
pending_list = &sma->sem_pending;
- offset = offsetof(struct sem_queue, list);
- } else {
+ else
pending_list = &sma->sem_base[semnum].sem_pending;
- offset = offsetof(struct sem_queue, simple_list);
- }
again:
walk = pending_list->next;
while (walk != pending_list) {
int error, restart;
- q = (struct sem_queue *)((char *)walk - offset);
+ q = container_of(walk, struct sem_queue, list);
walk = walk->next;
/* If we are scanning the single sop, per-semaphore list of
@@ -672,9 +778,18 @@ static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsop
if (sma->complex_count || sops == NULL) {
if (update_queue(sma, -1, pt))
otime = 1;
+ }
+
+ if (!sops) {
+ /* No semops; something special is going on. */
+ for (i = 0; i < sma->sem_nsems; i++) {
+ if (update_queue(sma, i, pt))
+ otime = 1;
+ }
goto done;
}
+ /* Check the semaphores that were modified. */
for (i = 0; i < nsops; i++) {
if (sops[i].sem_op > 0 ||
(sops[i].sem_op < 0 &&
@@ -745,6 +860,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
struct sem_queue *q, *tq;
struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm);
struct list_head tasks;
+ int i;
/* Free the existing undo structures for this semaphore set. */
assert_spin_locked(&sma->sem_perm.lock);
@@ -763,10 +879,17 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
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->sem_pending, 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);
wake_up_sem_queue_do(&tasks);
ns->used_sems -= sma->sem_nsems;
@@ -842,18 +965,25 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
case SEM_STAT:
{
struct semid64_ds tbuf;
- int id;
+ int id = 0;
+
+ memset(&tbuf, 0, sizeof(tbuf));
if (cmd == SEM_STAT) {
- sma = sem_lock(ns, semid);
- if (IS_ERR(sma))
- return PTR_ERR(sma);
+ rcu_read_lock();
+ 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;
+ rcu_read_lock();
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ err = PTR_ERR(sma);
+ goto out_unlock;
+ }
}
err = -EACCES;
@@ -864,13 +994,11 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
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);
+ rcu_read_unlock();
if (copy_semid_to_user(p, &tbuf, version))
return -EFAULT;
return id;
@@ -879,7 +1007,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
return -EINVAL;
}
out_unlock:
- sem_unlock(sma);
+ rcu_read_unlock();
return err;
}
@@ -890,7 +1018,6 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
struct sem_array *sma;
struct sem* curr;
int err;
- int nsems;
struct list_head tasks;
int val;
#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
@@ -901,31 +1028,39 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
val = arg;
#endif
- sma = sem_lock_check(ns, semid);
- if (IS_ERR(sma))
- return PTR_ERR(sma);
+ if (val > SEMVMX || val < 0)
+ return -ERANGE;
INIT_LIST_HEAD(&tasks);
- nsems = sma->sem_nsems;
- err = -EACCES;
- if (ipcperms(ns, &sma->sem_perm, S_IWUGO))
- goto out_unlock;
+ 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)
- goto out_unlock;
+ if (err) {
+ rcu_read_unlock();
+ return -EACCES;
+ }
- err = -EINVAL;
- if(semnum < 0 || semnum >= nsems)
- goto out_unlock;
+ sem_lock(sma, NULL, -1);
curr = &sma->sem_base[semnum];
- err = -ERANGE;
- if (val > SEMVMX || val < 0)
- goto out_unlock;
-
assert_spin_locked(&sma->sem_perm.lock);
list_for_each_entry(un, &sma->list_id, list_id)
un->semadj[semnum] = 0;
@@ -935,11 +1070,9 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
sma->sem_ctime = get_seconds();
/* maybe some queued-up processes were waiting for this */
do_smart_update(sma, NULL, 0, 0, &tasks);
- err = 0;
-out_unlock:
- sem_unlock(sma);
+ sem_unlock(sma, -1);
wake_up_sem_queue_do(&tasks);
- return err;
+ return 0;
}
static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
@@ -947,27 +1080,34 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
{
struct sem_array *sma;
struct sem* curr;
- int err;
+ int err, nsems;
ushort fast_sem_io[SEMMSL_FAST];
ushort* sem_io = fast_sem_io;
- int nsems;
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);
+ }
- INIT_LIST_HEAD(&tasks);
nsems = sma->sem_nsems;
err = -EACCES;
if (ipcperms(ns, &sma->sem_perm,
- cmd == SETALL ? S_IWUGO : S_IRUGO))
- goto out_unlock;
+ cmd == SETALL ? S_IWUGO : S_IRUGO)) {
+ rcu_read_unlock();
+ goto out_wakeup;
+ }
err = security_sem_semctl(sma, cmd);
- if (err)
- goto out_unlock;
+ if (err) {
+ rcu_read_unlock();
+ goto out_wakeup;
+ }
err = -EACCES;
switch (cmd) {
@@ -977,7 +1117,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
int i;
if(nsems > SEMMSL_FAST) {
- sem_getref_and_unlock(sma);
+ sem_getref(sma);
sem_io = ipc_alloc(sizeof(ushort)*nsems);
if(sem_io == NULL) {
@@ -987,15 +1127,16 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
sem_lock_and_putref(sma);
if (sma->sem_perm.deleted) {
- sem_unlock(sma);
+ sem_unlock(sma, -1);
err = -EIDRM;
goto out_free;
}
- }
+ } else
+ sem_lock(sma, NULL, -1);
for (i = 0; i < sma->sem_nsems; i++)
sem_io[i] = sma->sem_base[i].semval;
- sem_unlock(sma);
+ sem_unlock(sma, -1);
err = 0;
if(copy_to_user(array, sem_io, nsems*sizeof(ushort)))
err = -EFAULT;
@@ -1006,7 +1147,11 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
int i;
struct sem_undo *un;
- sem_getref_and_unlock(sma);
+ if (!ipc_rcu_getref(sma)) {
+ rcu_read_unlock();
+ return -EIDRM;
+ }
+ rcu_read_unlock();
if(nsems > SEMMSL_FAST) {
sem_io = ipc_alloc(sizeof(ushort)*nsems);
@@ -1031,7 +1176,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
}
sem_lock_and_putref(sma);
if (sma->sem_perm.deleted) {
- sem_unlock(sma);
+ sem_unlock(sma, -1);
err = -EIDRM;
goto out_free;
}
@@ -1053,9 +1198,12 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
/* GETVAL, GETPID, GETNCTN, GETZCNT: fall-through */
}
err = -EINVAL;
- if(semnum < 0 || semnum >= nsems)
- goto out_unlock;
+ if (semnum < 0 || semnum >= nsems) {
+ rcu_read_unlock();
+ goto out_wakeup;
+ }
+ sem_lock(sma, NULL, -1);
curr = &sma->sem_base[semnum];
switch (cmd) {
@@ -1072,10 +1220,11 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
err = count_semzcnt(sma,semnum);
goto out_unlock;
}
+
out_unlock:
- sem_unlock(sma);
+ sem_unlock(sma, -1);
+out_wakeup:
wake_up_sem_queue_do(&tasks);
-
out_free:
if(sem_io != fast_sem_io)
ipc_free(sem_io, sizeof(ushort)*nsems);
@@ -1126,33 +1275,39 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
return -EFAULT;
}
- ipcp = ipcctl_pre_down(ns, &sem_ids(ns), semid, cmd,
- &semid64.sem_perm, 0);
+ ipcp = ipcctl_pre_down_nolock(ns, &sem_ids(ns), semid, cmd,
+ &semid64.sem_perm, 0);
if (IS_ERR(ipcp))
return PTR_ERR(ipcp);
sma = container_of(ipcp, struct sem_array, sem_perm);
err = security_sem_semctl(sma, cmd);
- if (err)
+ if (err) {
+ rcu_read_unlock();
goto out_unlock;
+ }
switch(cmd){
case IPC_RMID:
+ sem_lock(sma, NULL, -1);
freeary(ns, ipcp);
goto out_up;
case IPC_SET:
+ sem_lock(sma, NULL, -1);
err = ipc_update_perm(&semid64.sem_perm, ipcp);
if (err)
goto out_unlock;
sma->sem_ctime = get_seconds();
break;
default:
+ rcu_read_unlock();
err = -EINVAL;
+ goto out_up;
}
out_unlock:
- sem_unlock(sma);
+ sem_unlock(sma, -1);
out_up:
up_write(&sem_ids(ns).rw_mutex);
return err;
@@ -1264,8 +1419,7 @@ 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)
@@ -1277,16 +1431,22 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
spin_unlock(&ulp->lock);
if (likely(un!=NULL))
goto out;
- rcu_read_unlock();
/* no undo structure around - allocate one. */
/* step 1: figure out the size of the semaphore array */
- sma = sem_lock_check(ns, semid);
- if (IS_ERR(sma))
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ rcu_read_unlock();
return ERR_CAST(sma);
+ }
nsems = sma->sem_nsems;
- sem_getref_and_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);
@@ -1298,7 +1458,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
/* step 3: Acquire the lock on semaphore array */
sem_lock_and_putref(sma);
if (sma->sem_perm.deleted) {
- sem_unlock(sma);
+ sem_unlock(sma, -1);
kfree(new);
un = ERR_PTR(-EIDRM);
goto out;
@@ -1326,7 +1486,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
success:
spin_unlock(&ulp->lock);
rcu_read_lock();
- sem_unlock(sma);
+ sem_unlock(sma, -1);
out:
return un;
}
@@ -1366,7 +1526,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
struct sembuf fast_sops[SEMOPM_FAST];
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 l