From a362f463a6d316d14daed0f817e151835ce97ff7 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 27 Oct 2005 09:07:33 -0700 Subject: [PATCH] Revert "remove false BUG_ON() from run_posix_cpu_timers()" This reverts commit 3de463c7d9d58f8cf3395268230cb20a4c15bffa. Roland has another patch that allows us to leave the BUG_ON() in place by just making sure that the condition it tests for really is always true. That goes in next. Signed-off-by: Linus Torvalds --- kernel/exit.c | 8 ++++++++ kernel/posix-cpu-timers.c | 36 ++++++++++++++++++------------------ 2 files changed, 26 insertions(+), 18 deletions(-) diff --git a/kernel/exit.c b/kernel/exit.c index 4897977a1f4b..3b25b182d2be 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -825,6 +825,14 @@ fastcall NORET_TYPE void do_exit(long code) tsk->flags |= PF_EXITING; + /* + * Make sure we don't try to process any timer firings + * while we are already exiting. + */ + tsk->it_virt_expires = cputime_zero; + tsk->it_prof_expires = cputime_zero; + tsk->it_sched_expires = 0; + if (unlikely(in_atomic())) printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", current->comm, current->pid, diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 383ba22f0b62..ea1aca5e7c2b 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1293,30 +1293,30 @@ void run_posix_cpu_timers(struct task_struct *tsk) #undef UNEXPIRED + BUG_ON(tsk->exit_state); + /* * Double-check with locks held. */ read_lock(&tasklist_lock); - if (likely(tsk->signal != NULL)) { - spin_lock(&tsk->sighand->siglock); + spin_lock(&tsk->sighand->siglock); - /* - * Here we take off tsk->cpu_timers[N] and tsk->signal->cpu_timers[N] - * all the timers that are firing, and put them on the firing list. - */ - check_thread_timers(tsk, &firing); - check_process_timers(tsk, &firing); + /* + * Here we take off tsk->cpu_timers[N] and tsk->signal->cpu_timers[N] + * all the timers that are firing, and put them on the firing list. + */ + check_thread_timers(tsk, &firing); + check_process_timers(tsk, &firing); - /* - * We must release these locks before taking any timer's lock. - * There is a potential race with timer deletion here, as the - * siglock now protects our private firing list. We have set - * the firing flag in each timer, so that a deletion attempt - * that gets the timer lock before we do will give it up and - * spin until we've taken care of that timer below. - */ - spin_unlock(&tsk->sighand->siglock); - } + /* + * We must release these locks before taking any timer's lock. + * There is a potential race with timer deletion here, as the + * siglock now protects our private firing list. We have set + * the firing flag in each timer, so that a deletion attempt + * that gets the timer lock before we do will give it up and + * spin until we've taken care of that timer below. + */ + spin_unlock(&tsk->sighand->siglock); read_unlock(&tasklist_lock); /* -- 2.20.1