aboutsummaryrefslogtreecommitdiff
path: root/kernel/fork.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c615
1 files changed, 383 insertions, 232 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index b77fd559c78..6a13c46cd87 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -28,12 +28,15 @@
#include <linux/mman.h>
#include <linux/mmu_notifier.h>
#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/vmacache.h>
#include <linux/nsproxy.h>
#include <linux/capability.h>
#include <linux/cpu.h>
#include <linux/cgroup.h>
#include <linux/security.h>
#include <linux/hugetlb.h>
+#include <linux/seccomp.h>
#include <linux/swap.h>
#include <linux/syscalls.h>
#include <linux/jiffies.h>
@@ -47,6 +50,7 @@
#include <linux/audit.h>
#include <linux/memcontrol.h>
#include <linux/ftrace.h>
+#include <linux/proc_fs.h>
#include <linux/profile.h>
#include <linux/rmap.h>
#include <linux/ksm.h>
@@ -66,6 +70,10 @@
#include <linux/user-return-notifier.h>
#include <linux/oom.h>
#include <linux/khugepaged.h>
+#include <linux/signalfd.h>
+#include <linux/uprobes.h>
+#include <linux/aio.h>
+#include <linux/compiler.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -110,32 +118,69 @@ int nr_processes(void)
return total;
}
-#ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
-# define alloc_task_struct_node(node) \
- kmem_cache_alloc_node(task_struct_cachep, GFP_KERNEL, node)
-# define free_task_struct(tsk) \
- kmem_cache_free(task_struct_cachep, (tsk))
+void __weak arch_release_task_struct(struct task_struct *tsk)
+{
+}
+
+#ifndef CONFIG_ARCH_TASK_STRUCT_ALLOCATOR
static struct kmem_cache *task_struct_cachep;
+
+static inline struct task_struct *alloc_task_struct_node(int node)
+{
+ return kmem_cache_alloc_node(task_struct_cachep, GFP_KERNEL, node);
+}
+
+static inline void free_task_struct(struct task_struct *tsk)
+{
+ kmem_cache_free(task_struct_cachep, tsk);
+}
#endif
-#ifndef __HAVE_ARCH_THREAD_INFO_ALLOCATOR
+void __weak arch_release_thread_info(struct thread_info *ti)
+{
+}
+
+#ifndef CONFIG_ARCH_THREAD_INFO_ALLOCATOR
+
+/*
+ * Allocate pages if THREAD_SIZE is >= PAGE_SIZE, otherwise use a
+ * kmemcache based allocator.
+ */
+# if THREAD_SIZE >= PAGE_SIZE
static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
int node)
{
-#ifdef CONFIG_DEBUG_STACK_USAGE
- gfp_t mask = GFP_KERNEL | __GFP_ZERO;
-#else
- gfp_t mask = GFP_KERNEL;
-#endif
- struct page *page = alloc_pages_node(node, mask, THREAD_SIZE_ORDER);
+ struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP,
+ THREAD_SIZE_ORDER);
return page ? page_address(page) : NULL;
}
static inline void free_thread_info(struct thread_info *ti)
{
- free_pages((unsigned long)ti, THREAD_SIZE_ORDER);
+ free_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER);
+}
+# else
+static struct kmem_cache *thread_info_cache;
+
+static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
+ int node)
+{
+ return kmem_cache_alloc_node(thread_info_cache, THREADINFO_GFP, node);
+}
+
+static void free_thread_info(struct thread_info *ti)
+{
+ kmem_cache_free(thread_info_cache, ti);
}
+
+void thread_info_cache_init(void)
+{
+ thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
+ THREAD_SIZE, 0, NULL);
+ BUG_ON(thread_info_cache == NULL);
+}
+# endif
#endif
/* SLAB cache for signal_struct structures (tsk->signal) */
@@ -166,9 +211,12 @@ static void account_kernel_stack(struct thread_info *ti, int account)
void free_task(struct task_struct *tsk)
{
account_kernel_stack(tsk->stack, -1);
+ arch_release_thread_info(tsk->stack);
free_thread_info(tsk->stack);
rt_mutex_debug_task_free(tsk);
ftrace_graph_exit_task(tsk);
+ put_seccomp_filter(tsk);
+ arch_release_task_struct(tsk);
free_task_struct(tsk);
}
EXPORT_SYMBOL(free_task);
@@ -192,6 +240,8 @@ void __put_task_struct(struct task_struct *tsk)
WARN_ON(atomic_read(&tsk->usage));
WARN_ON(tsk == current);
+ task_numa_free(tsk);
+ security_task_free(tsk);
exit_creds(tsk);
delayacct_tsk_free(tsk);
put_signal_struct(tsk->signal);
@@ -201,17 +251,11 @@ void __put_task_struct(struct task_struct *tsk)
}
EXPORT_SYMBOL_GPL(__put_task_struct);
-/*
- * macro override instead of weak attribute alias, to workaround
- * gcc 4.1.0 and 4.1.1 bugs with weak attribute and empty functions.
- */
-#ifndef arch_task_cache_init
-#define arch_task_cache_init()
-#endif
+void __init __weak arch_task_cache_init(void) { }
void __init fork_init(unsigned long mempages)
{
-#ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
+#ifndef CONFIG_ARCH_TASK_STRUCT_ALLOCATOR
#ifndef ARCH_MIN_TASKALIGN
#define ARCH_MIN_TASKALIGN L1_CACHE_BYTES
#endif
@@ -243,7 +287,7 @@ void __init fork_init(unsigned long mempages)
init_task.signal->rlim[RLIMIT_NPROC];
}
-int __attribute__((weak)) arch_dup_task_struct(struct task_struct *dst,
+int __weak arch_dup_task_struct(struct task_struct *dst,
struct task_struct *src)
{
*dst = *src;
@@ -258,21 +302,17 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
int node = tsk_fork_get_node(orig);
int err;
- prepare_to_copy(orig);
-
tsk = alloc_task_struct_node(node);
if (!tsk)
return NULL;
ti = alloc_thread_info_node(tsk, node);
- if (!ti) {
- free_task_struct(tsk);
- return NULL;
- }
+ if (!ti)
+ goto free_tsk;
err = arch_dup_task_struct(tsk, orig);
if (err)
- goto out;
+ goto free_ti;
tsk->stack = ti;
@@ -295,13 +335,15 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
tsk->btrace_seq = 0;
#endif
tsk->splice_pipe = NULL;
+ tsk->task_frag.page = NULL;
account_kernel_stack(ti, 1);
return tsk;
-out:
+free_ti:
free_thread_info(ti);
+free_tsk:
free_task_struct(tsk);
return NULL;
}
@@ -313,10 +355,11 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
struct rb_node **rb_link, *rb_parent;
int retval;
unsigned long charge;
- struct mempolicy *pol;
+ uprobe_start_dup_mmap();
down_write(&oldmm->mmap_sem);
flush_cache_dup_mm(oldmm);
+ uprobe_dup_mmap(oldmm, mm);
/*
* Not linked in yet - no deadlock potential:
*/
@@ -324,9 +367,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
mm->locked_vm = 0;
mm->mmap = NULL;
- mm->mmap_cache = NULL;
- mm->free_area_cache = oldmm->mmap_base;
- mm->cached_hole_size = ~0UL;
+ mm->vmacache_seqnum = 0;
mm->map_count = 0;
cpumask_clear(mm_cpumask(mm));
mm->mm_rb = RB_ROOT;
@@ -345,16 +386,15 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
struct file *file;
if (mpnt->vm_flags & VM_DONTCOPY) {
- long pages = vma_pages(mpnt);
- mm->total_vm -= pages;
vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file,
- -pages);
+ -vma_pages(mpnt));
continue;
}
charge = 0;
if (mpnt->vm_flags & VM_ACCOUNT) {
- unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
- if (security_vm_enough_memory(len))
+ unsigned long len = vma_pages(mpnt);
+
+ if (security_vm_enough_memory_mm(oldmm, len)) /* sic */
goto fail_nomem;
charge = len;
}
@@ -363,11 +403,9 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
goto fail_nomem;
*tmp = *mpnt;
INIT_LIST_HEAD(&tmp->anon_vma_chain);
- pol = mpol_dup(vma_policy(mpnt));
- retval = PTR_ERR(pol);
- if (IS_ERR(pol))
+ retval = vma_dup_policy(mpnt, tmp);
+ if (retval)
goto fail_nomem_policy;
- vma_set_policy(tmp, pol);
tmp->vm_mm = mm;
if (anon_vma_fork(tmp, mpnt))
goto fail_nomem_anon_vma_fork;
@@ -375,7 +413,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
tmp->vm_next = tmp->vm_prev = NULL;
file = tmp->vm_file;
if (file) {
- struct inode *inode = file->f_path.dentry->d_inode;
+ struct inode *inode = file_inode(file);
struct address_space *mapping = file->f_mapping;
get_file(file);
@@ -386,7 +424,12 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
mapping->i_mmap_writable++;
flush_dcache_mmap_lock(mapping);
/* insert tmp into the share list, just after mpnt */
- vma_prio_tree_add(tmp, mpnt);
+ if (unlikely(tmp->vm_flags & VM_NONLINEAR))
+ vma_nonlinear_insert(tmp,
+ &mapping->i_mmap_nonlinear);
+ else
+ vma_interval_tree_insert_after(tmp, mpnt,
+ &mapping->i_mmap);
flush_dcache_mmap_unlock(mapping);
mutex_unlock(&mapping->i_mmap_mutex);
}
@@ -427,9 +470,10 @@ out:
up_write(&mm->mmap_sem);
flush_tlb_mm(oldmm);
up_write(&oldmm->mmap_sem);
+ uprobe_end_dup_mmap();
return retval;
fail_nomem_anon_vma_fork:
- mpol_put(pol);
+ mpol_put(vma_policy(tmp));
fail_nomem_policy:
kmem_cache_free(vm_area_cachep, tmp);
fail_nomem:
@@ -479,7 +523,7 @@ static void mm_init_aio(struct mm_struct *mm)
{
#ifdef CONFIG_AIO
spin_lock_init(&mm->ioctx_lock);
- INIT_HLIST_HEAD(&mm->ioctx_list);
+ mm->ioctx_table = NULL;
#endif
}
@@ -489,19 +533,23 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
atomic_set(&mm->mm_count, 1);
init_rwsem(&mm->mmap_sem);
INIT_LIST_HEAD(&mm->mmlist);
- mm->flags = (current->mm) ?
- (current->mm->flags & MMF_INIT_MASK) : default_dump_filter;
mm->core_state = NULL;
- mm->nr_ptes = 0;
+ atomic_long_set(&mm->nr_ptes, 0);
memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
spin_lock_init(&mm->page_table_lock);
- mm->free_area_cache = TASK_UNMAPPED_BASE;
- mm->cached_hole_size = ~0UL;
mm_init_aio(mm);
mm_init_owner(mm, p);
+ clear_tlb_flush_pending(mm);
- if (likely(!mm_alloc_pgd(mm))) {
+ if (current->mm) {
+ mm->flags = current->mm->flags & MMF_INIT_MASK;
+ mm->def_flags = current->mm->def_flags & VM_INIT_DEF_MASK;
+ } else {
+ mm->flags = default_dump_filter;
mm->def_flags = 0;
+ }
+
+ if (likely(!mm_alloc_pgd(mm))) {
mmu_notifier_mm_init(mm);
return mm;
}
@@ -510,6 +558,23 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
return NULL;
}
+static void check_mm(struct mm_struct *mm)
+{
+ int i;
+
+ for (i = 0; i < NR_MM_COUNTERS; i++) {
+ long x = atomic_long_read(&mm->rss_stat.count[i]);
+
+ if (unlikely(x))
+ printk(KERN_ALERT "BUG: Bad rss-counter state "
+ "mm:%p idx:%d val:%ld\n", mm, i, x);
+ }
+
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
+ VM_BUG_ON(mm->pmd_huge_pte);
+#endif
+}
+
/*
* Allocate and initialize an mm_struct.
*/
@@ -537,9 +602,7 @@ void __mmdrop(struct mm_struct *mm)
mm_free_pgd(mm);
destroy_context(mm);
mmu_notifier_mm_destroy(mm);
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- VM_BUG_ON(mm->pmd_huge_pte);
-#endif
+ check_mm(mm);
free_mm(mm);
}
EXPORT_SYMBOL_GPL(__mmdrop);
@@ -552,6 +615,7 @@ void mmput(struct mm_struct *mm)
might_sleep();
if (atomic_dec_and_test(&mm->mm_users)) {
+ uprobe_clear_state(mm);
exit_aio(mm);
ksm_exit(mm);
khugepaged_exit(mm); /* must run before exit_mmap */
@@ -562,7 +626,6 @@ void mmput(struct mm_struct *mm)
list_del(&mm->mmlist);
spin_unlock(&mmlist_lock);
}
- put_swap_token(mm);
if (mm->binfmt)
module_put(mm->binfmt->module);
mmdrop(mm);
@@ -570,26 +633,6 @@ void mmput(struct mm_struct *mm)
}
EXPORT_SYMBOL_GPL(mmput);
-/*
- * We added or removed a vma mapping the executable. The vmas are only mapped
- * during exec and are not mapped with the mmap system call.
- * Callers must hold down_write() on the mm's mmap_sem for these
- */
-void added_exe_file_vma(struct mm_struct *mm)
-{
- mm->num_exe_file_vmas++;
-}
-
-void removed_exe_file_vma(struct mm_struct *mm)
-{
- mm->num_exe_file_vmas--;
- if ((mm->num_exe_file_vmas == 0) && mm->exe_file) {
- fput(mm->exe_file);
- mm->exe_file = NULL;
- }
-
-}
-
void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
{
if (new_exe_file)
@@ -597,15 +640,13 @@ void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
if (mm->exe_file)
fput(mm->exe_file);
mm->exe_file = new_exe_file;
- mm->num_exe_file_vmas = 0;
}
struct file *get_mm_exe_file(struct mm_struct *mm)
{
struct file *exe_file;
- /* We need mmap_sem to protect against races with removal of
- * VM_EXECUTABLE vmas */
+ /* We need mmap_sem to protect against races with removal of exe_file */
down_read(&mm->mmap_sem);
exe_file = mm->exe_file;
if (exe_file)
@@ -667,6 +708,38 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
return mm;
}
+static void complete_vfork_done(struct task_struct *tsk)
+{
+ struct completion *vfork;
+
+ task_lock(tsk);
+ vfork = tsk->vfork_done;
+ if (likely(vfork)) {
+ tsk->vfork_done = NULL;
+ complete(vfork);
+ }
+ task_unlock(tsk);
+}
+
+static int wait_for_vfork_done(struct task_struct *child,
+ struct completion *vfork)
+{
+ int killed;
+
+ freezer_do_not_count();
+ killed = wait_for_completion_killable(vfork);
+ freezer_count();
+
+ if (killed) {
+ task_lock(child);
+ child->vfork_done = NULL;
+ task_unlock(child);
+ }
+
+ put_task_struct(child);
+ return killed;
+}
+
/* Please note the differences between mmput and mm_release.
* mmput is called whenever we stop holding onto a mm_struct,
* error success whatever.
@@ -682,8 +755,6 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
*/
void mm_release(struct task_struct *tsk, struct mm_struct *mm)
{
- struct completion *vfork_done = tsk->vfork_done;
-
/* Get rid of any futexes when releasing the mm */
#ifdef CONFIG_FUTEX
if (unlikely(tsk->robust_list)) {
@@ -700,20 +771,17 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
exit_pi_state_list(tsk);
#endif
+ uprobe_free_utask(tsk);
+
/* Get rid of any cached register state */
deactivate_mm(tsk, mm);
- /* notify parent sleeping on vfork() */
- if (vfork_done) {
- tsk->vfork_done = NULL;
- complete(vfork_done);
- }
-
/*
* If we're exiting normally, clear a user-space tid field if
* requested. We leave this alone when dying by signal, to leave
* the value intact in a core dump, and to save the unnecessary
- * trouble otherwise. Userland only wants this done for a sys_exit.
+ * trouble, say, a killed vfork parent shouldn't touch this mm.
+ * Userland only wants this done for a sys_exit.
*/
if (tsk->clear_child_tid) {
if (!(tsk->flags & PF_SIGNALED) &&
@@ -728,20 +796,24 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
}
tsk->clear_child_tid = NULL;
}
+
+ /*
+ * All done, finally we can wake up parent and return this mm to him.
+ * Also kthread_stop() uses this completion for synchronization.
+ */
+ if (tsk->vfork_done)
+ complete_vfork_done(tsk);
}
/*
* Allocate a new mm structure and copy contents from the
* mm structure of the passed in task structure.
*/
-struct mm_struct *dup_mm(struct task_struct *tsk)
+static struct mm_struct *dup_mm(struct task_struct *tsk)
{
struct mm_struct *mm, *oldmm = current->mm;
int err;
- if (!oldmm)
- return NULL;
-
mm = allocate_mm();
if (!mm)
goto fail_nomem;
@@ -749,14 +821,9 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
memcpy(mm, oldmm, sizeof(*mm));
mm_init_cpumask(mm);
- /* Initializing for Swap token stuff */
- mm->token_priority = 0;
- mm->last_interval = 0;
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
mm->pmd_huge_pte = NULL;
#endif
-
if (!mm_init(mm, tsk))
goto fail_nomem;
@@ -818,6 +885,9 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
if (!oldmm)
return 0;
+ /* initialize the new vmacache entries */
+ vmacache_flush(tsk);
+
if (clone_flags & CLONE_VM) {
atomic_inc(&oldmm->mm_users);
mm = oldmm;
@@ -830,10 +900,6 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
goto fail_nomem;
good_mm:
- /* Initializing for Swap token stuff */
- mm->token_priority = 0;
- mm->last_interval = 0;
-
tsk->mm = mm;
tsk->active_mm = mm;
return 0;
@@ -901,9 +967,8 @@ static int copy_io(unsigned long clone_flags, struct task_struct *tsk)
* Share io context with parent, if CLONE_IO is set
*/
if (clone_flags & CLONE_IO) {
- tsk->io_context = ioc_task_link(ioc);
- if (unlikely(!tsk->io_context))
- return -ENOMEM;
+ ioc_task_link(ioc);
+ tsk->io_context = ioc;
} else if (ioprio_valid(ioc->ioprio)) {
new_ioc = get_task_io_context(tsk, GFP_KERNEL, NUMA_NO_NODE);
if (unlikely(!new_ioc))
@@ -935,8 +1000,10 @@ static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)
void __cleanup_sighand(struct sighand_struct *sighand)
{
- if (atomic_dec_and_test(&sighand->count))
+ if (atomic_dec_and_test(&sighand->count)) {
+ signalfd_cleanup(sighand);
kmem_cache_free(sighand_cachep, sighand);
+ }
}
@@ -977,9 +1044,12 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
sig->nr_threads = 1;
atomic_set(&sig->live, 1);
atomic_set(&sig->sigcnt, 1);
+
+ /* list_add(thread_node, thread_head) without INIT_LIST_HEAD() */
+ sig->thread_head = (struct list_head)LIST_HEAD_INIT(tsk->thread_node);
+ tsk->thread_node = (struct list_head)LIST_HEAD_INIT(sig->thread_head);
+
init_waitqueue_head(&sig->wait_chldexit);
- if (clone_flags & CLONE_NEWPID)
- sig->flags |= SIGNAL_UNKILLABLE;
sig->curr_target = tsk;
init_sigpending(&sig->shared_pending);
INIT_LIST_HEAD(&sig->posix_timers);
@@ -1000,25 +1070,17 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
init_rwsem(&sig->group_rwsem);
#endif
- sig->oom_adj = current->signal->oom_adj;
sig->oom_score_adj = current->signal->oom_score_adj;
sig->oom_score_adj_min = current->signal->oom_score_adj_min;
+ sig->has_child_subreaper = current->signal->has_child_subreaper ||
+ current->signal->is_child_subreaper;
+
mutex_init(&sig->cred_guard_mutex);
return 0;
}
-static void copy_flags(unsigned long clone_flags, struct task_struct *p)
-{
- unsigned long new_flags = p->flags;
-
- new_flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER);
- new_flags |= PF_FORKNOEXEC;
- new_flags |= PF_STARTING;
- p->flags = new_flags;
-}
-
SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
{
current->clear_child_tid = tidptr;
@@ -1030,17 +1092,19 @@ static void rt_mutex_init_task(struct task_struct *p)
{
raw_spin_lock_init(&p->pi_lock);
#ifdef CONFIG_RT_MUTEXES
- plist_head_init(&p->pi_waiters);
+ p->pi_waiters = RB_ROOT;
+ p->pi_waiters_leftmost = NULL;
p->pi_blocked_on = NULL;
+ p->pi_top_task = NULL;
#endif
}
-#ifdef CONFIG_MM_OWNER
+#ifdef CONFIG_MEMCG
void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
{
mm->owner = p;
}
-#endif /* CONFIG_MM_OWNER */
+#endif /* CONFIG_MEMCG */
/*
* Initialize POSIX timer handling for a single task.
@@ -1055,6 +1119,12 @@ static void posix_cpu_timers_init(struct task_struct *tsk)
INIT_LIST_HEAD(&tsk->cpu_timers[2]);
}
+static inline void
+init_task_pid(struct task_struct *task, enum pid_type type, struct pid *pid)
+{
+ task->pids[type].pid = pid;
+}
+
/*
* This creates a new process as a copy of the old one,
* but does not actually start it yet.
@@ -1065,7 +1135,6 @@ static void posix_cpu_timers_init(struct task_struct *tsk)
*/
static struct task_struct *copy_process(unsigned long clone_flags,
unsigned long stack_start,
- struct pt_regs *regs,
unsigned long stack_size,
int __user *child_tidptr,
struct pid *pid,
@@ -1073,11 +1142,13 @@ static struct task_struct *copy_process(unsigned long clone_flags,
{
int retval;
struct task_struct *p;
- int cgroup_callbacks_done = 0;
if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
return ERR_PTR(-EINVAL);
+ if ((clone_flags & (CLONE_NEWUSER|CLONE_FS)) == (CLONE_NEWUSER|CLONE_FS))
+ return ERR_PTR(-EINVAL);
+
/*
* Thread groups must share signals as well, and detached threads
* can only be started up within the thread group.
@@ -1103,6 +1174,18 @@ static struct task_struct *copy_process(unsigned long clone_flags,
current->signal->flags & SIGNAL_UNKILLABLE)
return ERR_PTR(-EINVAL);
+ /*
+ * If the new process will be in a different pid or user namespace
+ * do not allow it to share a thread group or signal handlers or
+ * parent with the forking task.
+ */
+ if (clone_flags & CLONE_SIGHAND) {
+ if ((clone_flags & (CLONE_NEWUSER | CLONE_NEWPID)) ||
+ (task_active_pid_ns(current) !=
+ current->nsproxy->pid_ns_for_children))
+ return ERR_PTR(-EINVAL);
+ }
+
retval = security_task_create(clone_flags);
if (retval)
goto fork_out;
@@ -1113,6 +1196,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto fork_out;
ftrace_graph_init_task(p);
+ get_seccomp_filter(p);
rt_mutex_init_task(p);
@@ -1123,8 +1207,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
retval = -EAGAIN;
if (atomic_read(&p->real_cred->user->processes) >=
task_rlimit(p, RLIMIT_NPROC)) {
- if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
- p->real_cred->user != INIT_USER)
+ if (p->real_cred->user != INIT_USER &&
+ !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN))
goto bad_fork_free;
}
current->flags &= ~PF_NPROC_EXCEEDED;
@@ -1145,9 +1229,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (!try_module_get(task_thread_info(p)->exec_domain->module))
goto bad_fork_cleanup_count;
- p->did_exec = 0;
delayacct_tsk_init(p); /* Must remain after dup_task_struct() */
- copy_flags(clone_flags, p);
+ p->flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER);
+ p->flags |= PF_FORKNOEXEC;
INIT_LIST_HEAD(&p->children);
INIT_LIST_HEAD(&p->sibling);
rcu_copy_process(p);
@@ -1158,9 +1242,15 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->utime = p->stime = p->gtime = 0;
p->utimescaled = p->stimescaled = 0;
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
- p->prev_utime = p->prev_stime = 0;
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ p->prev_cputime.utime = p->prev_cputime.stime = 0;
#endif
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+ seqlock_init(&p->vtime_seqlock);
+ p->vtime_snap = 0;
+ p->vtime_snap_whence = VTIME_SLEEPING;
+#endif
+
#if defined(SPLIT_RSS_COUNTING)
memset(&p->rss_stat, 0, sizeof(p->rss_stat));
#endif
@@ -1185,21 +1275,17 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (IS_ERR(p->mempolicy)) {
retval = PTR_ERR(p->mempolicy);
p->mempolicy = NULL;
- goto bad_fork_cleanup_cgroup;
+ goto bad_fork_cleanup_threadgroup_lock;
}
- mpol_fix_fork_child_flag(p);
#endif
#ifdef CONFIG_CPUSETS
p->cpuset_mem_spread_rotor = NUMA_NO_NODE;
p->cpuset_slab_spread_rotor = NUMA_NO_NODE;
+ seqcount_init(&p->mems_allowed_seq);
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
p->irq_events = 0;
-#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- p->hardirqs_enabled = 1;
-#else
p->hardirqs_enabled = 0;
-#endif
p->hardirq_enable_ip = 0;
p->hardirq_enable_event = 0;
p->hardirq_disable_ip = _THIS_IP_;
@@ -1221,13 +1307,19 @@ static struct task_struct *copy_process(unsigned long clone_flags,
#ifdef CONFIG_DEBUG_MUTEXES
p->blocked_on = NULL; /* not blocked yet */
#endif
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+#ifdef CONFIG_MEMCG
p->memcg_batch.do_batch = 0;
p->memcg_batch.memcg = NULL;
#endif
+#ifdef CONFIG_BCACHE
+ p->sequential_io = 0;
+ p->sequential_io_avg = 0;
+#endif
/* Perform scheduler related setup. Assign this task to a CPU. */
- sched_fork(p);
+ retval = sched_fork(clone_flags, p);
+ if (retval)
+ goto bad_fork_cleanup_policy;
retval = perf_event_init_task(p);
if (retval)
@@ -1260,22 +1352,17 @@ static struct task_struct *copy_process(unsigned long clone_flags,
retval = copy_io(clone_flags, p);
if (retval)
goto bad_fork_cleanup_namespaces;
- retval = copy_thread(clone_flags, stack_start, stack_size, p, regs);
+ retval = copy_thread(clone_flags, stack_start, stack_size, p);
if (retval)
goto bad_fork_cleanup_io;
if (pid != &init_struct_pid) {
retval = -ENOMEM;
- pid = alloc_pid(p->nsproxy->pid_ns);
+ pid = alloc_pid(p->nsproxy->pid_ns_for_children);
if (!pid)
goto bad_fork_cleanup_io;
}
- p->pid = pid_nr(pid);
- p->tgid = p->pid;
- if (clone_flags & CLONE_THREAD)
- p->tgid = current->tgid;
-
p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
/*
* Clear TID on mm_release()?
@@ -1310,28 +1397,32 @@ static struct task_struct *copy_process(unsigned long clone_flags,
clear_all_latency_tracing(p);
/* ok, now we should be set up.. */
- p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
- p->pdeath_signal = 0;
- p->exit_state = 0;
+ p->pid = pid_nr(pid);
+ if (clone_flags & CLONE_THREAD) {
+ p->exit_signal = -1;
+ p->group_leader = current->group_leader;
+ p->tgid = current->tgid;
+ } else {
+ if (clone_flags & CLONE_PARENT)
+ p->exit_signal = current->group_leader->exit_signal;
+ else
+ p->exit_signal = (clone_flags & CSIGNAL);
+ p->group_leader = p;
+ p->tgid = p->pid;
+ }
p->nr_dirtied = 0;
p->nr_dirtied_pause = 128 >> (PAGE_SHIFT - 10);
p->dirty_paused_when = 0;
- /*
- * Ok, make it visible to the rest of the system.
- * We dont wake it up yet.
- */
- p->group_leader = p;
+ p->pdeath_signal = 0;
INIT_LIST_HEAD(&p->thread_group);
+ p->task_works = NULL;
- /* Now that the task is set up, run cgroup callbacks if
- * necessary. We need to run them before the task is visible
- * on the tasklist. */
- cgroup_fork_callbacks(p);
- cgroup_callbacks_done = 1;
-
- /* Need tasklist lock for parent etc handling! */
+ /*
+ * Make it visible to the rest of the system, but dont wake it up yet.
+ * Need tasklist lock for parent etc handling!
+ */
write_lock_irq(&tasklist_lock);
/* CLONE_PARENT re-uses the old parent */
@@ -1361,36 +1452,44 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto bad_fork_free_pid;
}
- if (clone_flags & CLONE_THREAD) {
- current->signal->nr_threads++;
- atomic_inc(&current->signal->live);
- atomic_inc(&current->signal->sigcnt);
- p->group_leader = current->group_leader;
- list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
- }
-
if (likely(p->pid)) {
ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
+ init_task_pid(p, PIDTYPE_PID, pid);
if (thread_group_leader(p)) {
- if (is_child_reaper(pid))
- p->nsproxy->pid_ns->child_reaper = p;
+ init_task_pid(p, PIDTYPE_PGID, task_pgrp(current));
+ init_task_pid(p, PIDTYPE_SID, task_session(current));
+
+ if (is_child_reaper(pid)) {
+ ns_of_pid(pid)->child_reaper = p;
+ p->signal->flags |= SIGNAL_UNKILLABLE;
+ }
p->signal->leader_pid = pid;
p->signal->tty = tty_kref_get(current->signal->tty);
- attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
- attach_pid(p, PIDTYPE_SID, task_session(current));
list_add_tail(&p->sibling, &p->real_parent->children);
list_add_tail_rcu(&p->tasks, &init_task.tasks);
+ attach_pid(p, PIDTYPE_PGID);
+ attach_pid(p, PIDTYPE_SID);
__this_cpu_inc(process_counts);
+ } else {
+ current->signal->nr_threads++;
+ atomic_inc(&current->signal->live);
+ atomic_inc(&current->signal->sigcnt);
+ list_add_tail_rcu(&p->thread_group,
+ &p->group_leader->thread_group);
+ list_add_tail_rcu(&p->thread_node,
+ &p->signal->thread_head);
}
- attach_pid(p, PIDTYPE_PID, pid);
+ attach_pid(p, PIDTYPE_PID);
nr_threads++;
}
total_forks++;
spin_unlock(&current->sighand->siglock);
+ syscall_tracepoint_update(p);
write_unlock_irq(&tasklist_lock);
+
proc_fork_connector(p);
cgroup_post_fork(p);
if (clone_flags & CLONE_THREAD)
@@ -1398,6 +1497,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
perf_event_fork(p);
trace_task_newtask(p, clone_flags);
+ uprobe_copy_process(p, clone_flags);
return p;
@@ -1429,11 +1529,10 @@ bad_fork_cleanup_policy:
perf_event_free_task(p);
#ifdef CONFIG_NUMA
mpol_put(p->mempolicy);
-bad_fork_cleanup_cgroup:
+bad_fork_cleanup_threadgroup_lock:
#endif
if (clone_flags & CLONE_THREAD)
threadgroup_change_end(current);
- cgroup_exit(p, cgroup_callbacks_done);
delayacct_tsk_free(p);
module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
@@ -1445,12 +1544,6 @@ fork_out:
return ERR_PTR(retval);
}
-noinline struct pt_regs * __cpuinit __attribute__((weak)) idle_regs(struct pt_regs *regs)
-{
- memset(regs, 0, sizeof(struct pt_regs));
- return regs;
-}
-
static inline void init_idle_pids(struct pid_link *links)
{
enum pid_type type;
@@ -1461,13 +1554,10 @@ static inline void init_idle_pids(struct pid_link *links)
}
}
-struct task_struct * __cpuinit fork_idle(int cpu)
+struct task_struct *fork_idle(int cpu)
{
struct task_struct *task;
- struct pt_regs regs;
-
- task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL,
- &init_struct_pid, 0);
+ task = copy_process(CLONE_VM, 0, 0, NULL, &init_struct_pid, 0);
if (!IS_ERR(task)) {
init_idle_pids(task->pids);
init_idle(task, cpu);
@@ -1484,7 +1574,6 @@ struct task_struct * __cpuinit fork_idle(int cpu)
*/
long do_fork(unsigned long clone_flags,
unsigned long stack_start,
- struct pt_regs *regs,
unsigned long stack_size,
int __user *parent_tidptr,
int __user *child_tidptr)
@@ -1494,27 +1583,12 @@ long do_fork(unsigned long clone_flags,
long nr;
/*
- * Do some preliminary argument and permissions checking before we
- * actually start allocating stuff
- */
- if (clone_flags & CLONE_NEWUSER) {
- if (clone_flags & CLONE_THREAD)
- return -EINVAL;
- /* hopefully this check will go away when userns support is
- * complete
- */
- if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SETUID) ||
- !capable(CAP_SETGID))
- return -EPERM;
- }
-
- /*
* Determine whether and which event to report to ptracer. When
* called from kernel_thread or CLONE_UNTRACED is explicitly
* requested, no event is reported; otherwise, report if the event
* for the type of forking is enabled.
*/
- if (likely(user_mode(regs)) && !(clone_flags & CLONE_UNTRACED)) {
+ if (!(clone_flags & CLONE_UNTRACED)) {
if (clone_flags & CLONE_VFORK)
trace = PTRACE_EVENT_VFORK;
else if ((clone_flags & CSIGNAL) != SIGCHLD)
@@ -1526,7 +1600,7 @@ long do_fork(unsigned long clone_flags,
trace = 0;
}
- p = copy_process(clone_flags, stack_start, regs, stack_size,
+ p = copy_process(clone_flags, stack_start, stack_size,
child_tidptr, NULL, trace);
/*
* Do this prior waking up the new thread - the thread pointer
@@ -1534,10 +1608,12 @@ long do_fork(unsigned long clone_flags,
*/
if (!IS_ERR(p)) {
struct completion vfork;
+ struct pid *pid;
trace_sched_process_fork(current, p);
- nr = task_pid_vnr(p);
+ pid = get_task_pid(p, PIDTYPE_PID);
+ nr = pid_vnr(pid);
if (clone_flags & CLONE_PARENT_SETTID)
put_user(nr, parent_tidptr);
@@ -1545,34 +1621,84 @@ long do_fork(unsigned long clone_flags,
if (clone_flags & CLONE_VFORK) {
p->vfork_done = &vfork;
init_completion(&vfork);
+ get_task_struct(p);
}
- /*
- * We set PF_STARTING at creation in case tracing wants to
- * use this to distinguish a fully live task from one that
- * hasn't finished SIGSTOP raising yet. Now we clear it
- * and set the child going.
- */
- p->flags &= ~PF_STARTING;
-
wake_up_new_task(p);
/* forking complete and child started to run, tell ptracer */
if (unlikely(trace))
- ptrace_event(trace, nr);
+ ptrace_event_pid(trace, pid);
if (clone_flags & CLONE_VFORK) {
- freezer_do_not_count();
- wait_for_completion(&vfork);
- freezer_count();
- ptrace_event(PTRACE_EVENT_VFORK_DONE, nr);
+ if (!wait_for_vfork_done(p, &vfork))
+ ptrace_event_pid(PTRACE_EVENT_VFORK_DONE, pid);
}
+
+ put_pid(pid);
} else {
nr = PTR_ERR(p);
}
return nr;
}
+/*
+ * Create a kernel thread.
+ */
+pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
+{
+ return do_fork(flags|CLONE_VM|CLONE_UNTRACED, (unsigned long)fn,
+ (unsigned long)arg, NULL, NULL);
+}
+
+#ifdef __ARCH_WANT_SYS_FORK
+SYSCALL_DEFINE0(fork)
+{
+#ifdef CONFIG_MMU
+ return do_fork(SIGCHLD, 0, 0, NULL, NULL);
+#else
+ /* can not support in nommu mode */
+ return -EINVAL;
+#endif
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_VFORK
+SYSCALL_DEFINE0(vfork)
+{
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
+ 0, NULL, NULL);
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_CLONE
+#ifdef CONFIG_CLONE_BACKWARDS
+SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
+ int __user *, parent_tidptr,
+ int, tls_val,
+ int __user *, child_tidptr)
+#elif defined(CONFIG_CLONE_BACKWARDS2)
+SYSCALL_DEFINE5(clone, unsigned long, newsp, unsigned long, clone_flags,
+ int __user *, parent_tidptr,
+ int __user *, child_tidptr,
+ int, tls_val)
+#elif defined(CONFIG_CLONE_BACKWARDS3)
+SYSCALL_DEFINE6(clone, unsigned long, clone_flags, unsigned long, newsp,
+ int, stack_size,
+ int __user *, parent_tidptr,
+ int __user *, child_tidptr,
+ int, tls_val)
+#else
+SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
+ int __user *, parent_tidptr,
+ int __user *, child_tidptr,
+ int, tls_val)
+#endif
+{
+ return do_fork(clone_flags, newsp, 0, parent_tidptr, child_tidptr);
+}
+#endif
+
#ifndef ARCH_MIN_MMSTRUCT_ALIGN
#define ARCH_MIN_MMSTRUCT_ALIGN 0
#endif
@@ -1622,7 +1748,8 @@ static int check_unshare_flags(unsigned long unshare_flags)
{
if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
- CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET))
+ CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET|
+ CLONE_NEWUSER|CLONE_NEWPID))
return -EINVAL;
/*
* Not implemented, but pretend it works if there is nothing to
@@ -1689,19 +1816,35 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
{
struct fs_struct *fs, *new_fs = NULL;
struct files_struct *fd, *new_fd = NULL;
+ struct cred *new_cred = NULL;
struct nsproxy *new_nsproxy = NULL;
int do_sysvsem = 0;
int err;
- err = check_unshare_flags(unshare_flags);
- if (err)
- goto bad_unshare_out;
-
+ /*
+ * If unsharing a user namespace must also unshare the thread.
+ */
+ if (unshare_flags & CLONE_NEWUSER)
+ unshare_flags |= CLONE_THREAD | CLONE_FS;
+ /*
+ * If unsharing a thread from a thread group, must also unshare vm.
+ */
+ if (unshare_flags & CLONE_THREAD)
+ unshare_flags |= CLONE_VM;
+ /*
+ * If unsharing vm, must also unshare signal handlers.
+ */
+ if (unshare_flags & CLONE_VM)
+ unshare_flags |= CLONE_SIGHAND;
/*
* If unsharing namespace, must also unshare filesystem information.
*/
if (unshare_flags & CLONE_NEWNS)
unshare_flags |= CLONE_FS;
+
+ err = check_unshare_flags(unshare_flags);
+ if (err)
+ goto bad_unshare_out;
/*
* CLONE_NEWIPC must also detach from the undolist: after switching
* to a new ipc namespace, the semaphore arrays from the old
@@ -1715,11 +1858,15 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
err = unshare_fd(unshare_flags, &new_fd);
if (err)
goto bad_unshare_cleanup_fs;
- err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy, new_fs);
+ err = unshare_userns(unshare_flags, &new_cred);
if (err)
goto bad_unshare_cleanup_fd;
+ err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy,
+ new_cred, new_fs);
+ if (err)
+ goto bad_unshare_cleanup_cred;
- if (new_fs || new_fd || do_sysvsem || new_nsproxy) {
+ if (new_fs || new_fd || do_sysvsem || new_cred || new_nsproxy) {
if (do_sysvsem) {
/*
* CLONE_SYSVSEM is equivalent to sys_exit().
@@ -1727,10 +1874,8 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
exit_sem(current);
}
- if (new_nsproxy) {
+ if (new_nsproxy)
switch_task_namespaces(current, new_nsproxy);
- new_nsproxy = NULL;
- }
task_lock(current);
@@ -1752,11 +1897,17 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
}
task_unlock(current);
- }
- if (new_nsproxy)
- put_nsproxy(new_nsproxy);
+ if (new_cred) {
+ /* Install the new user namespace */
+ commit_creds(new_cred);
+ new_cred = NULL;
+ }
+ }
+bad_unshare_cleanup_cred:
+ if (new_cred)
+ put_cred(new_cred);
bad_unshare_cleanup_fd:
if (new_fd)
put_files_struct(new_fd);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 20:40:23 +0000