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-rw-r--r--fs/exec.c2
-rw-r--r--include/linux/sched/task.h2
-rw-r--r--kernel/exit.c2
-rw-r--r--kernel/time/posix-timers.c19
4 files changed, 17 insertions, 8 deletions
diff --git a/fs/exec.c b/fs/exec.c
index 0989fb8472a1..778123259e42 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1301,7 +1301,7 @@ int begin_new_exec(struct linux_binprm * bprm)
bprm->mm = NULL;
#ifdef CONFIG_POSIX_TIMERS
- exit_itimers(me->signal);
+ exit_itimers(me);
flush_itimer_signals();
#endif
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 505aaf9fe477..81cab4b01edc 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -85,7 +85,7 @@ static inline void exit_thread(struct task_struct *tsk)
extern __noreturn void do_group_exit(int);
extern void exit_files(struct task_struct *);
-extern void exit_itimers(struct signal_struct *);
+extern void exit_itimers(struct task_struct *);
extern pid_t kernel_clone(struct kernel_clone_args *kargs);
struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);
diff --git a/kernel/exit.c b/kernel/exit.c
index f072959fcab7..64c938ce36fe 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -766,7 +766,7 @@ void __noreturn do_exit(long code)
#ifdef CONFIG_POSIX_TIMERS
hrtimer_cancel(&tsk->signal->real_timer);
- exit_itimers(tsk->signal);
+ exit_itimers(tsk);
#endif
if (tsk->mm)
setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 1cd10b102c51..5dead89308b7 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -1051,15 +1051,24 @@ retry_delete:
}
/*
- * This is called by do_exit or de_thread, only when there are no more
- * references to the shared signal_struct.
+ * This is called by do_exit or de_thread, only when nobody else can
+ * modify the signal->posix_timers list. Yet we need sighand->siglock
+ * to prevent the race with /proc/pid/timers.
*/
-void exit_itimers(struct signal_struct *sig)
+void exit_itimers(struct task_struct *tsk)
{
+ struct list_head timers;
struct k_itimer *tmr;
- while (!list_empty(&sig->posix_timers)) {
- tmr = list_entry(sig->posix_timers.next, struct k_itimer, list);
+ if (list_empty(&tsk->signal->posix_timers))
+ return;
+
+ spin_lock_irq(&tsk->sighand->siglock);
+ list_replace_init(&tsk->signal->posix_timers, &timers);
+ spin_unlock_irq(&tsk->sighand->siglock);
+
+ while (!list_empty(&timers)) {
+ tmr = list_first_entry(&timers, struct k_itimer, list);
itimer_delete(tmr);
}
}