diff options
Diffstat (limited to 'kernel/exit.c')
-rw-r--r-- | kernel/exit.c | 42 |
1 files changed, 17 insertions, 25 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index eabca5a73a85..ceffc67b564a 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -58,11 +58,11 @@ static void exit_mm(struct task_struct * tsk); -static void __unhash_process(struct task_struct *p) +static void __unhash_process(struct task_struct *p, bool group_dead) { nr_threads--; detach_pid(p, PIDTYPE_PID); - if (thread_group_leader(p)) { + if (group_dead) { detach_pid(p, PIDTYPE_PGID); detach_pid(p, PIDTYPE_SID); @@ -79,10 +79,9 @@ static void __unhash_process(struct task_struct *p) static void __exit_signal(struct task_struct *tsk) { struct signal_struct *sig = tsk->signal; + bool group_dead = thread_group_leader(tsk); struct sighand_struct *sighand; - - BUG_ON(!sig); - BUG_ON(!atomic_read(&sig->count)); + struct tty_struct *uninitialized_var(tty); sighand = rcu_dereference_check(tsk->sighand, rcu_read_lock_held() || @@ -90,14 +89,16 @@ static void __exit_signal(struct task_struct *tsk) spin_lock(&sighand->siglock); posix_cpu_timers_exit(tsk); - if (atomic_dec_and_test(&sig->count)) + if (group_dead) { posix_cpu_timers_exit_group(tsk); - else { + tty = sig->tty; + sig->tty = NULL; + } else { /* * If there is any task waiting for the group exit * then notify it: */ - if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) + if (sig->notify_count > 0 && !--sig->notify_count) wake_up_process(sig->group_exit_task); if (tsk == sig->curr_target) @@ -123,32 +124,24 @@ static void __exit_signal(struct task_struct *tsk) sig->oublock += task_io_get_oublock(tsk); task_io_accounting_add(&sig->ioac, &tsk->ioac); sig->sum_sched_runtime += tsk->se.sum_exec_runtime; - sig = NULL; /* Marker for below. */ } - __unhash_process(tsk); + sig->nr_threads--; + __unhash_process(tsk, group_dead); /* * Do this under ->siglock, we can race with another thread * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals. */ flush_sigqueue(&tsk->pending); - - tsk->signal = NULL; tsk->sighand = NULL; spin_unlock(&sighand->siglock); __cleanup_sighand(sighand); clear_tsk_thread_flag(tsk,TIF_SIGPENDING); - if (sig) { + if (group_dead) { flush_sigqueue(&sig->shared_pending); - taskstats_tgid_free(sig); - /* - * Make sure ->signal can't go away under rq->lock, - * see account_group_exec_runtime(). - */ - task_rq_unlock_wait(tsk); - __cleanup_signal(sig); + tty_kref_put(tty); } } @@ -856,12 +849,9 @@ static void exit_notify(struct task_struct *tsk, int group_dead) tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE; - /* mt-exec, de_thread() is waiting for us */ - if (thread_group_leader(tsk) && - tsk->signal->group_exit_task && - tsk->signal->notify_count < 0) + /* mt-exec, de_thread() is waiting for group leader */ + if (unlikely(tsk->signal->notify_count < 0)) wake_up_process(tsk->signal->group_exit_task); - write_unlock_irq(&tasklist_lock); tracehook_report_death(tsk, signal, cookie, group_dead); @@ -1002,8 +992,10 @@ NORET_TYPE void do_exit(long code) exit_notify(tsk, group_dead); #ifdef CONFIG_NUMA + task_lock(tsk); mpol_put(tsk->mempolicy); tsk->mempolicy = NULL; + task_unlock(tsk); #endif #ifdef CONFIG_FUTEX if (unlikely(current->pi_state_cache)) |