signal: Cleanup unused posix-timer leftovers

Remove the leftovers of sigqueue preallocation as it's not longer used.

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/20241105064213.786506636@linutronix.de

Author: KAGA-KOKO

include/linux/sched/signal.h

@@ -338,8 +338,6 @@ extern void force_fatal_sig(int);
 extern void force_exit_sig(int);
 extern int send_sig(int, struct task_struct *, int);
 extern int zap_other_threads(struct task_struct *p);
-extern struct sigqueue *sigqueue_alloc(void);
-extern void sigqueue_free(struct sigqueue *);
 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
 
 static inline void clear_notify_signal(void)

kernel/signal.c

@@ -439,8 +439,8 @@ static void __sigqueue_init(struct sigqueue *q, struct ucounts *ucounts,
  * - this may be called without locks if and only if t == current, otherwise an
  *   appropriate lock must be held to stop the target task from exiting
  */
-static struct sigqueue *__sigqueue_alloc(int sig, struct task_struct *t, gfp_t gfp_flags,
-					 int override_rlimit, const unsigned int sigqueue_flags)
+static struct sigqueue *sigqueue_alloc(int sig, struct task_struct *t, gfp_t gfp_flags,
+				       int override_rlimit)
 {
 	struct ucounts *ucounts = sig_get_ucounts(t, sig, override_rlimit);
 	struct sigqueue *q;
@@ -454,7 +454,7 @@ static struct sigqueue *__sigqueue_alloc(int sig, struct task_struct *t, gfp_t g
 		return NULL;
 	}
 
-	__sigqueue_init(q, ucounts, sigqueue_flags);
+	__sigqueue_init(q, ucounts, 0);
 	return q;
 }
 
@@ -1070,7 +1070,7 @@ static int __send_signal_locked(int sig, struct kernel_siginfo *info,
 	else
 		override_rlimit = 0;
 
-	q = __sigqueue_alloc(sig, t, GFP_ATOMIC, override_rlimit, 0);
+	q = sigqueue_alloc(sig, t, GFP_ATOMIC, override_rlimit);
 
 	if (q) {
 		list_add_tail(&q->list, &pending->list);
@@ -1926,37 +1926,6 @@ bool posixtimer_init_sigqueue(struct sigqueue *q)
 	return true;
 }
 
-struct sigqueue *sigqueue_alloc(void)
-{
-	return __sigqueue_alloc(-1, current, GFP_KERNEL, 0, SIGQUEUE_PREALLOC);
-}
-
-void sigqueue_free(struct sigqueue *q)
-{
-	spinlock_t *lock = &current->sighand->siglock;
-	unsigned long flags;
-
-	if (WARN_ON_ONCE(!(q->flags & SIGQUEUE_PREALLOC)))
-		return;
-	/*
-	 * We must hold ->siglock while testing q->list
-	 * to serialize with collect_signal() or with
-	 * __exit_signal()->flush_sigqueue().
-	 */
-	spin_lock_irqsave(lock, flags);
-	q->flags &= ~SIGQUEUE_PREALLOC;
-	/*
-	 * If it is queued it will be freed when dequeued,
-	 * like the "regular" sigqueue.
-	 */
-	if (!list_empty(&q->list))
-		q = NULL;
-	spin_unlock_irqrestore(lock, flags);
-
-	if (q)
-		__sigqueue_free(q);
-}
-
 static void posixtimer_queue_sigqueue(struct sigqueue *q, struct task_struct *t, enum pid_type type)
 {
 	struct sigpending *pending;