Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
signal: Split up __sigqueue_alloc()
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.
Reorganize __sigqueue_alloc() so the ucounts retrieval and the
initialization can be used independently.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20241105064213.371410037@linutronix.de
+35
-17
+35
-17
kernel/signal.c
+35
-17
kernel/signal.c
···
396
396
task_set_jobctl_pending(task, mask | JOBCTL_STOP_PENDING);
397
397
}
398
398
399
-
/*
400
-
* allocate a new signal queue record
401
-
* - this may be called without locks if and only if t == current, otherwise an
402
-
* appropriate lock must be held to stop the target task from exiting
403
-
*/
404
-
static struct sigqueue *
405
-
__sigqueue_alloc(int sig, struct task_struct *t, gfp_t gfp_flags,
406
-
int override_rlimit, const unsigned int sigqueue_flags)
399
+
static struct ucounts *sig_get_ucounts(struct task_struct *t, int sig,
400
+
int override_rlimit)
407
401
{
408
-
struct sigqueue *q = NULL;
409
402
struct ucounts *ucounts;
410
403
long sigpending;
411
404
···
417
424
if (!sigpending)
418
425
return NULL;
419
426
420
-
if (override_rlimit || likely(sigpending <= task_rlimit(t, RLIMIT_SIGPENDING))) {
421
-
q = kmem_cache_alloc(sigqueue_cachep, gfp_flags);
422
-
} else {
427
+
if (unlikely(!override_rlimit && sigpending > task_rlimit(t, RLIMIT_SIGPENDING))) {
428
+
dec_rlimit_put_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING);
423
429
print_dropped_signal(sig);
430
+
return NULL;
424
431
}
425
432
426
-
if (unlikely(q == NULL)) {
433
+
return ucounts;
434
+
}
435
+
436
+
static void __sigqueue_init(struct sigqueue *q, struct ucounts *ucounts,
437
+
const unsigned int sigqueue_flags)
438
+
{
439
+
INIT_LIST_HEAD(&q->list);
440
+
q->flags = sigqueue_flags;
441
+
q->ucounts = ucounts;
442
+
}
443
+
444
+
/*
445
+
* allocate a new signal queue record
446
+
* - this may be called without locks if and only if t == current, otherwise an
447
+
* appropriate lock must be held to stop the target task from exiting
448
+
*/
449
+
static struct sigqueue *__sigqueue_alloc(int sig, struct task_struct *t, gfp_t gfp_flags,
450
+
int override_rlimit, const unsigned int sigqueue_flags)
451
+
{
452
+
struct ucounts *ucounts = sig_get_ucounts(t, sig, override_rlimit);
453
+
struct sigqueue *q;
454
+
455
+
if (!ucounts)
456
+
return NULL;
457
+
458
+
q = kmem_cache_alloc(sigqueue_cachep, gfp_flags);
459
+
if (!q) {
427
460
dec_rlimit_put_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING);
428
-
} else {
429
-
INIT_LIST_HEAD(&q->list);
430
-
q->flags = sigqueue_flags;
431
-
q->ucounts = ucounts;
461
+
return NULL;
432
462
}
463
+
464
+
__sigqueue_init(q, ucounts, sigqueue_flags);
433
465
return q;
434
466
}
435
467