[patch V5 13/26] signal: Provide posixtimer_sigqueue_init()
From: Thomas Gleixner
Date: Tue Oct 01 2024 - 04:44:50 EST
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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 <tglx@xxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
include/linux/posix-timers.h | 2 ++
kernel/signal.c | 11 +++++++++++
2 files changed, 13 insertions(+)
---
--- 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_wa
}
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);
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1907,6 +1907,17 @@ 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);