diff options
| -rw-r--r-- | kernel/posix-cpu-timers.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 71a07699a36b..9641958ddb3e 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -377,27 +377,32 @@ static int posix_cpu_timer_create(struct k_itimer *new_timer) */ static int posix_cpu_timer_del(struct k_itimer *timer) { - struct task_struct *p = timer->it.cpu.task; int ret = 0; + unsigned long flags; + struct sighand_struct *sighand; + struct task_struct *p = timer->it.cpu.task; WARN_ON_ONCE(p == NULL); - read_lock(&tasklist_lock); - if (unlikely(p->sighand == NULL)) { + /* + * Protect against sighand release/switch in exit/exec and process/ + * thread timer list entry concurrent read/writes. + */ + sighand = lock_task_sighand(p, &flags); + if (unlikely(sighand == NULL)) { /* * We raced with the reaping of the task. * The deletion should have cleared us off the list. */ BUG_ON(!list_empty(&timer->it.cpu.entry)); } else { - spin_lock(&p->sighand->siglock); if (timer->it.cpu.firing) ret = TIMER_RETRY; else list_del(&timer->it.cpu.entry); - spin_unlock(&p->sighand->siglock); + + unlock_task_sighand(p, &flags); } - read_unlock(&tasklist_lock); if (!ret) put_task_struct(p); |