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authorThomas Gleixner <tglx@linutronix.de>2024-11-05 09:14:31 +0100
committerThomas Gleixner <tglx@linutronix.de>2024-11-07 02:14:43 +0100
commit513793bc6ab331b947111e8efaf8fcef33fb83e5 (patch)
treef220c4840bee94120d29307d7acdbcb726e026b3 /kernel/signal.c
parent15cbfb92efee5c7f09e531a331e19759dbe0ac3c (diff)
posix-timers: Make signal delivery consistent
Signals of timers which are reprogammed, disarmed or deleted can deliver signals related to the past. The POSIX spec is blury about this: - "The effect of disarming or resetting a timer with pending expiration notifications is unspecified." - "The disposition of pending signals for the deleted timer is unspecified." In both cases it is reasonable to expect that pending signals are discarded. Especially in the reprogramming case it does not make sense to account for previous overruns or to deliver a signal for a timer which has been disarmed. This makes the behaviour consistent and understandable. Remove the si_sys_private check from the signal delivery code and invoke posix_timer_deliver_signal() unconditionally for posix timer related signals. Change posix_timer_deliver_signal() so it controls the actual signal delivery via the return value. It now instructs the signal code to drop the signal when: 1) The timer does not longer exist in the hash table 2) The timer signal_seq value is not the same as the si_sys_private value which was set when the signal was queued. This is also a preparatory change to embed the sigqueue into the k_itimer structure, which in turn allows to remove the si_sys_private magic. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20241105064213.040348644@linutronix.de
Diffstat (limited to 'kernel/signal.c')
-rw-r--r--kernel/signal.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index df34aa47181e..68e6bc70ccf2 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -550,10 +550,8 @@ still_pending:
list_del_init(&first->list);
copy_siginfo(info, &first->info);
- *resched_timer =
- (first->flags & SIGQUEUE_PREALLOC) &&
- (info->si_code == SI_TIMER) &&
- (info->si_sys_private);
+ *resched_timer = (first->flags & SIGQUEUE_PREALLOC) &&
+ (info->si_code == SI_TIMER);
__sigqueue_free(first);
} else {