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authorMauro Carvalho Chehab <mchehab@redhat.com>2012-03-23 08:06:43 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-03-23 08:06:43 -0300
commit7483d45f0aee3afc0646d185cabd4af9f6cab58c (patch)
treea312f7d77c34748bec62f0431df33007b10e4e7f /kernel/fork.c
parent[media] tda10071: fix the delivery system (diff)
parent[media] update CARDLIST.em28xx (diff)
downloadwireguard-linux-7483d45f0aee3afc0646d185cabd4af9f6cab58c.tar.xz
wireguard-linux-7483d45f0aee3afc0646d185cabd4af9f6cab58c.zip
Merge branch 'staging/for_v3.4' into v4l_for_linus
* staging/for_v3.4: (10117 commits) [media] update CARDLIST.em28xx [media] partially reverts changeset fa5527c [media] stb0899: fix the limits for signal strength values [media] em28xx: support for 2304:0242 PCTV QuatroStick (510e) [media] em28xx: support for 2013:0251 PCTV QuatroStick nano (520e) [media] -EINVAL -> -ENOTTY [media] gspca - sn9c20x: Cleanup source [media] gspca - sn9c20x: Simplify register write for capture start/stop [media] gspca - sn9c20x: Add automatic JPEG compression mechanism [media] gspca - sn9c20x: Greater delay in case of sensor no response [media] gspca - sn9c20x: Optimize the code of write sequences [media] gspca - sn9c20x: Add the JPEG compression quality control [media] gspca - sn9c20x: Add a delay after Omnivision sensor reset [media] gspca - sn9c20x: Propagate USB errors to higher level [media] gspca - sn9c20x: Use the new video control mechanism [media] gspca - sn9c20x: Fix loss of frame start [media] gspca - zc3xx: Lack of register 08 value for sensor cs2102k [media] gspca - ov534_9: Add brightness to OmniVision 5621 sensor [media] gspca - zc3xx: Add V4L2_CID_JPEG_COMPRESSION_QUALITY control support [media] pvrusb2: fix 7MHz & 8MHz DVB-T tuner support for HVR1900 rev D1F5 ...
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c125
1 files changed, 84 insertions, 41 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index da4a6a10d088..26a7a6707fa7 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -66,6 +66,7 @@
#include <linux/user-return-notifier.h>
#include <linux/oom.h>
#include <linux/khugepaged.h>
+#include <linux/signalfd.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -76,6 +77,9 @@
#include <trace/events/sched.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/task.h>
+
/*
* Protected counters by write_lock_irq(&tasklist_lock)
*/
@@ -644,6 +648,58 @@ struct mm_struct *get_task_mm(struct task_struct *task)
}
EXPORT_SYMBOL_GPL(get_task_mm);
+struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
+{
+ struct mm_struct *mm;
+ int err;
+
+ err = mutex_lock_killable(&task->signal->cred_guard_mutex);
+ if (err)
+ return ERR_PTR(err);
+
+ mm = get_task_mm(task);
+ if (mm && mm != current->mm &&
+ !ptrace_may_access(task, mode)) {
+ mmput(mm);
+ mm = ERR_PTR(-EACCES);
+ }
+ mutex_unlock(&task->signal->cred_guard_mutex);
+
+ 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.
@@ -659,8 +715,6 @@ EXPORT_SYMBOL_GPL(get_task_mm);
*/
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)) {
@@ -680,17 +734,15 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
/* 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 (tsk->vfork_done)
+ complete_vfork_done(tsk);
/*
* 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) &&
@@ -870,6 +922,7 @@ static int copy_io(unsigned long clone_flags, struct task_struct *tsk)
{
#ifdef CONFIG_BLOCK
struct io_context *ioc = current->io_context;
+ struct io_context *new_ioc;
if (!ioc)
return 0;
@@ -881,11 +934,12 @@ static int copy_io(unsigned long clone_flags, struct task_struct *tsk)
if (unlikely(!tsk->io_context))
return -ENOMEM;
} else if (ioprio_valid(ioc->ioprio)) {
- tsk->io_context = alloc_io_context(GFP_KERNEL, -1);
- if (unlikely(!tsk->io_context))
+ new_ioc = get_task_io_context(tsk, GFP_KERNEL, NUMA_NO_NODE);
+ if (unlikely(!new_ioc))
return -ENOMEM;
- tsk->io_context->ioprio = ioc->ioprio;
+ new_ioc->ioprio = ioc->ioprio;
+ put_io_context(new_ioc);
}
#endif
return 0;
@@ -910,8 +964,10 @@ 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);
+ }
}
@@ -972,7 +1028,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
sched_autogroup_fork(sig);
#ifdef CONFIG_CGROUPS
- init_rwsem(&sig->threadgroup_fork_lock);
+ init_rwsem(&sig->group_rwsem);
#endif
sig->oom_adj = current->signal->oom_adj;
@@ -990,9 +1046,7 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
new_flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER);
new_flags |= PF_FORKNOEXEC;
- new_flags |= PF_STARTING;
p->flags = new_flags;
- clear_freeze_flag(p);
}
SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
@@ -1023,8 +1077,8 @@ void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
*/
static void posix_cpu_timers_init(struct task_struct *tsk)
{
- tsk->cputime_expires.prof_exp = cputime_zero;
- tsk->cputime_expires.virt_exp = cputime_zero;
+ tsk->cputime_expires.prof_exp = 0;
+ tsk->cputime_expires.virt_exp = 0;
tsk->cputime_expires.sched_exp = 0;
INIT_LIST_HEAD(&tsk->cpu_timers[0]);
INIT_LIST_HEAD(&tsk->cpu_timers[1]);
@@ -1132,14 +1186,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
init_sigpending(&p->pending);
- p->utime = cputime_zero;
- p->stime = cputime_zero;
- p->gtime = cputime_zero;
- p->utimescaled = cputime_zero;
- p->stimescaled = cputime_zero;
+ p->utime = p->stime = p->gtime = 0;
+ p->utimescaled = p->stimescaled = 0;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
- p->prev_utime = cputime_zero;
- p->prev_stime = cputime_zero;
+ p->prev_utime = p->prev_stime = 0;
#endif
#if defined(SPLIT_RSS_COUNTING)
memset(&p->rss_stat, 0, sizeof(p->rss_stat));
@@ -1158,7 +1208,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->io_context = NULL;
p->audit_context = NULL;
if (clone_flags & CLONE_THREAD)
- threadgroup_fork_read_lock(current);
+ threadgroup_change_begin(current);
cgroup_fork(p);
#ifdef CONFIG_NUMA
p->mempolicy = mpol_dup(p->mempolicy);
@@ -1296,6 +1346,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
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.
@@ -1373,8 +1424,11 @@ static struct task_struct *copy_process(unsigned long clone_flags,
proc_fork_connector(p);
cgroup_post_fork(p);
if (clone_flags & CLONE_THREAD)
- threadgroup_fork_read_unlock(current);
+ threadgroup_change_end(current);
perf_event_fork(p);
+
+ trace_task_newtask(p, clone_flags);
+
return p;
bad_fork_free_pid:
@@ -1408,7 +1462,7 @@ bad_fork_cleanup_policy:
bad_fork_cleanup_cgroup:
#endif
if (clone_flags & CLONE_THREAD)
- threadgroup_fork_read_unlock(current);
+ threadgroup_change_end(current);
cgroup_exit(p, cgroup_callbacks_done);
delayacct_tsk_free(p);
module_put(task_thread_info(p)->exec_domain->module);
@@ -1521,18 +1575,9 @@ long do_fork(unsigned long clone_flags,
if (clone_flags & CLONE_VFORK) {
p->vfork_done = &vfork;
init_completion(&vfork);
+ get_task_struct(p);
}
- audit_finish_fork(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 */
@@ -1540,10 +1585,8 @@ long do_fork(unsigned long clone_flags,
ptrace_event(trace, nr);
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(PTRACE_EVENT_VFORK_DONE, nr);
}
} else {
nr = PTR_ERR(p);