diff options
| -rw-r--r-- | kernel/signal.c | 53 |
1 files changed, 52 insertions, 1 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index d2734dc4d74f..908b49c594e4 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2002,7 +2002,54 @@ out: unlock_task_sighand(t, &flags); return ret; } -#endif /* CONFIG_POSIX_TIMERS */ + +static void posixtimer_sig_unignore(struct task_struct *tsk, int sig) +{ + struct hlist_head *head = &tsk->signal->ignored_posix_timers; + struct hlist_node *tmp; + struct k_itimer *tmr; + + if (likely(hlist_empty(head))) + return; + + /* + * Rearming a timer with sighand lock held is not possible due to + * lock ordering vs. tmr::it_lock. Just stick the sigqueue back and + * let the signal delivery path deal with it whether it needs to be + * rearmed or not. This cannot be decided here w/o dropping sighand + * lock and creating a loop retry horror show. + */ + hlist_for_each_entry_safe(tmr, tmp , head, ignored_list) { + struct task_struct *target; + + /* + * tmr::sigq.info.si_signo is immutable, so accessing it + * without holding tmr::it_lock is safe. + */ + if (tmr->sigq.info.si_signo != sig) + continue; + + hlist_del_init(&tmr->ignored_list); + + /* This should never happen and leaks a reference count */ + if (WARN_ON_ONCE(!list_empty(&tmr->sigq.list))) + continue; + + /* + * Get the target for the signal. If target is a thread and + * has exited by now, drop the reference count. + */ + guard(rcu)(); + target = posixtimer_get_target(tmr); + if (target) + posixtimer_queue_sigqueue(&tmr->sigq, target, tmr->it_pid_type); + else + posixtimer_putref(tmr); + } +} +#else /* CONFIG_POSIX_TIMERS */ +static inline void posixtimer_sig_unignore(struct task_struct *tsk, int sig) { } +#endif /* !CONFIG_POSIX_TIMERS */ void do_notify_pidfd(struct task_struct *task) { @@ -4180,6 +4227,8 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) sigaction_compat_abi(act, oact); if (act) { + bool was_ignored = k->sa.sa_handler == SIG_IGN; + sigdelsetmask(&act->sa.sa_mask, sigmask(SIGKILL) | sigmask(SIGSTOP)); *k = *act; @@ -4200,6 +4249,8 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) flush_sigqueue_mask(p, &mask, &p->signal->shared_pending); for_each_thread(p, t) flush_sigqueue_mask(p, &mask, &t->pending); + } else if (was_ignored) { + posixtimer_sig_unignore(p, sig); } } |