Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
signal: Replace resched_timer logic
In preparation for handling ignored posix timer signals correctly and
embedding the sigqueue struct into struct k_itimer, hand down a pointer to
the sigqueue struct into posix_timer_deliver_signal() instead of just
having a boolean flag.
No functional change.
Suggested-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/all/20241105064213.652658158@linutronix.de
+24
-15
+3
-2
include/linux/posix-timers.h
+3
-2
include/linux/posix-timers.h
···
110
110
void posixtimer_rearm_itimer(struct task_struct *p);
111
111
bool posixtimer_init_sigqueue(struct sigqueue *q);
112
112
int posixtimer_send_sigqueue(struct k_itimer *tmr);
113
-
bool posixtimer_deliver_signal(struct kernel_siginfo *info);
113
+
bool posixtimer_deliver_signal(struct kernel_siginfo *info, struct sigqueue *timer_sigq);
114
114
void posixtimer_free_timer(struct k_itimer *timer);
115
115
116
116
/* Init task static initializer */
···
135
135
static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
136
136
u64 cpu_limit) { }
137
137
static inline void posixtimer_rearm_itimer(struct task_struct *p) { }
138
-
static inline bool posixtimer_deliver_signal(struct kernel_siginfo *info) { return false; }
138
+
static inline bool posixtimer_deliver_signal(struct kernel_siginfo *info,
139
+
struct sigqueue *timer_sigq) { return false; }
139
140
static inline void posixtimer_free_timer(struct k_itimer *timer) { }
140
141
#endif
141
142
+20
-12
kernel/signal.c
+20
-12
kernel/signal.c
···
545
545
}
546
546
547
547
static void collect_signal(int sig, struct sigpending *list, kernel_siginfo_t *info,
548
-
bool *resched_timer)
548
+
struct sigqueue **timer_sigq)
549
549
{
550
550
struct sigqueue *q, *first = NULL;
551
551
···
568
568
list_del_init(&first->list);
569
569
copy_siginfo(info, &first->info);
570
570
571
-
*resched_timer = (first->flags & SIGQUEUE_PREALLOC) &&
572
-
(info->si_code == SI_TIMER);
573
-
574
-
__sigqueue_free(first);
571
+
/*
572
+
* posix-timer signals are preallocated and freed when the
573
+
* timer goes away. Either directly or by clearing
574
+
* SIGQUEUE_PREALLOC so that the next delivery will free
575
+
* them. Spare the extra round through __sigqueue_free()
576
+
* which is ignoring preallocated signals.
577
+
*/
578
+
if (unlikely((first->flags & SIGQUEUE_PREALLOC) && (info->si_code == SI_TIMER)))
579
+
*timer_sigq = first;
580
+
else
581
+
__sigqueue_free(first);
575
582
} else {
576
583
/*
577
584
* Ok, it wasn't in the queue. This must be
···
595
588
}
596
589
597
590
static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
598
-
kernel_siginfo_t *info, bool *resched_timer)
591
+
kernel_siginfo_t *info, struct sigqueue **timer_sigq)
599
592
{
600
593
int sig = next_signal(pending, mask);
601
594
602
595
if (sig)
603
-
collect_signal(sig, pending, info, resched_timer);
596
+
collect_signal(sig, pending, info, timer_sigq);
604
597
return sig;
605
598
}
606
599
···
612
605
int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type)
613
606
{
614
607
struct task_struct *tsk = current;
615
-
bool resched_timer = false;
608
+
struct sigqueue *timer_sigq;
616
609
int signr;
617
610
618
611
lockdep_assert_held(&tsk->sighand->siglock);
619
612
620
613
again:
621
614
*type = PIDTYPE_PID;
622
-
signr = __dequeue_signal(&tsk->pending, mask, info, &resched_timer);
615
+
timer_sigq = NULL;
616
+
signr = __dequeue_signal(&tsk->pending, mask, info, &timer_sigq);
623
617
if (!signr) {
624
618
*type = PIDTYPE_TGID;
625
619
signr = __dequeue_signal(&tsk->signal->shared_pending,
626
-
mask, info, &resched_timer);
620
+
mask, info, &timer_sigq);
627
621
628
622
if (unlikely(signr == SIGALRM))
629
623
posixtimer_rearm_itimer(tsk);
···
650
642
current->jobctl |= JOBCTL_STOP_DEQUEUED;
651
643
}
652
644
653
-
if (IS_ENABLED(CONFIG_POSIX_TIMERS) && unlikely(resched_timer)) {
654
-
if (!posixtimer_deliver_signal(info))
645
+
if (IS_ENABLED(CONFIG_POSIX_TIMERS) && unlikely(timer_sigq)) {
646
+
if (!posixtimer_deliver_signal(info, timer_sigq))
655
647
goto again;
656
648
}
657
649
+1
-1
kernel/time/posix-timers.c
+1
-1
kernel/time/posix-timers.c
···
254
254
* This function is called from the signal delivery code. It decides
255
255
* whether the signal should be dropped and rearms interval timers.
256
256
*/
257
-
bool posixtimer_deliver_signal(struct kernel_siginfo *info)
257
+
bool posixtimer_deliver_signal(struct kernel_siginfo *info, struct sigqueue *timer_sigq)
258
258
{
259
259
struct k_itimer *timr;
260
260
unsigned long flags;