From 54f1dd642fd088ba969206f09e7afffad7d9db2c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 5 Nov 2024 09:14:39 +0100 Subject: [PATCH] signal: Provide posixtimer_sigqueue_init() To cure the SIG_IGN handling for posix interval timers, the preallocated sigqueue needs to be embedded into struct k_itimer to prevent life time races of all sorts. Provide a new function to initialize the embedded sigqueue to prepare for that. Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/all/20241105064213.450427515@linutronix.de --- include/linux/posix-timers.h | 2 ++ kernel/signal.c | 11 +++++++++++ 2 files changed, 13 insertions(+) diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h index 9740fd0c2933f..200098d27cc04 100644 --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -12,6 +12,7 @@ struct kernel_siginfo; struct task_struct; +struct sigqueue; struct k_itimer; static inline clockid_t make_process_cpuclock(const unsigned int pid, @@ -106,6 +107,7 @@ static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct, } void posixtimer_rearm_itimer(struct task_struct *p); +bool posixtimer_init_sigqueue(struct sigqueue *q); bool posixtimer_deliver_signal(struct kernel_siginfo *info); void posixtimer_free_timer(struct k_itimer *timer); diff --git a/kernel/signal.c b/kernel/signal.c index dbd42471cf030..911ed3ab479e7 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1905,6 +1905,17 @@ void flush_itimer_signals(void) __flush_itimer_signals(&tsk->signal->shared_pending); } +bool posixtimer_init_sigqueue(struct sigqueue *q) +{ + struct ucounts *ucounts = sig_get_ucounts(current, -1, 0); + + if (!ucounts) + return false; + clear_siginfo(&q->info); + __sigqueue_init(q, ucounts, SIGQUEUE_PREALLOC); + return true; +} + struct sigqueue *sigqueue_alloc(void) { return __sigqueue_alloc(-1, current, GFP_KERNEL, 0, SIGQUEUE_PREALLOC); -- 2.39.5