Commit a2b80ce8 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Frederic Weisbecker
Browse files

signal: Remove task argument from dequeue_signal() 



The task pointer which is handed to dequeue_signal() is always current. The
argument along with the first comment about signalfd in that function is
confusing at best. Remove it and use current internally.

Update the stale comment for dequeue_signal() while at it.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Reviewed-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
parent 566e2d82

fs/signalfd.c

+2 −2
Original line number Diff line number Diff line
@@ -159,7 +159,7 @@ static ssize_t signalfd_dequeue(struct signalfd_ctx *ctx, kernel_siginfo_t *info 
	DECLARE_WAITQUEUE(wait, current);



	spin_lock_irq(&current->sighand->siglock);

	ret = dequeue_signal(current, &ctx->sigmask, info, &type);

	ret = dequeue_signal(&ctx->sigmask, info, &type);

	switch (ret) {

	case 0:

		if (!nonblock)
@@ -174,7 +174,7 @@ static ssize_t signalfd_dequeue(struct signalfd_ctx *ctx, kernel_siginfo_t *info 
	add_wait_queue(&current->sighand->signalfd_wqh, &wait);

	for (;;) {

		set_current_state(TASK_INTERRUPTIBLE);

		ret = dequeue_signal(current, &ctx->sigmask, info, &type);

		ret = dequeue_signal(&ctx->sigmask, info, &type);

		if (ret != 0)

			break;

		if (signal_pending(current)) {

include/linux/sched/signal.h

+2 −3
Original line number Diff line number Diff line
@@ -276,8 +276,7 @@ static inline void signal_set_stop_flags(struct signal_struct *sig, 
extern void flush_signals(struct task_struct *);

extern void ignore_signals(struct task_struct *);

extern void flush_signal_handlers(struct task_struct *, int force_default);

extern int dequeue_signal(struct task_struct *task, sigset_t *mask,

			  kernel_siginfo_t *info, enum pid_type *type);

extern int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type);



static inline int kernel_dequeue_signal(void)

{
@@ -287,7 +286,7 @@ static inline int kernel_dequeue_signal(void) 
	int ret;



	spin_lock_irq(&task->sighand->siglock);

	ret = dequeue_signal(task, &task->blocked, &__info, &__type);

	ret = dequeue_signal(&task->blocked, &__info, &__type);

	spin_unlock_irq(&task->sighand->siglock);



	return ret;

kernel/signal.c

+10 −13
Original line number Diff line number Diff line
@@ -618,20 +618,18 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, 
}



/*

 * Dequeue a signal and return the element to the caller, which is

 * expected to free it.

 *

 * All callers have to hold the siglock.

 * Try to dequeue a signal. If a deliverable signal is found fill in the

 * caller provided siginfo and return the signal number. Otherwise return

 * 0.

 */

int dequeue_signal(struct task_struct *tsk, sigset_t *mask,

		   kernel_siginfo_t *info, enum pid_type *type)

int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type)

{

	struct task_struct *tsk = current;

	bool resched_timer = false;

	int signr;



	/* We only dequeue private signals from ourselves, we don't let

	 * signalfd steal them

	 */

	lockdep_assert_held(&tsk->sighand->siglock);



	*type = PIDTYPE_PID;

	signr = __dequeue_signal(&tsk->pending, mask, info, &resched_timer);

	if (!signr) {
@@ -2793,8 +2791,7 @@ bool get_signal(struct ksignal *ksig) 
		type = PIDTYPE_PID;

		signr = dequeue_synchronous_signal(&ksig->info);

		if (!signr)

			signr = dequeue_signal(current, &current->blocked,

					       &ksig->info, &type);

			signr = dequeue_signal(&current->blocked, &ksig->info, &type);



		if (!signr)

			break; /* will return 0 */
@@ -3648,7 +3645,7 @@ static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info, 
	signotset(&mask);



	spin_lock_irq(&tsk->sighand->siglock);

	sig = dequeue_signal(tsk, &mask, info, &type);

	sig = dequeue_signal(&mask, info, &type);

	if (!sig && timeout) {

		/*

		 * None ready, temporarily unblock those we're interested
@@ -3667,7 +3664,7 @@ static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info, 
		spin_lock_irq(&tsk->sighand->siglock);

		__set_task_blocked(tsk, &tsk->real_blocked);

		sigemptyset(&tsk->real_blocked);

		sig = dequeue_signal(tsk, &mask, info, &type);

		sig = dequeue_signal(&mask, info, &type);

	}

	spin_unlock_irq(&tsk->sighand->siglock);