Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2b1ecc3d authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

signals: Use hrtimer for sigtimedwait() 



We've converted most timeout related syscalls to hrtimers, but
sigtimedwait() did not get this treatment.

Convert it so we get a reasonable accuracy and remove the
user space exposure to the timer wheel properties.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Cyril Hrubis <chrubis@suse.cz>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094341.787164909@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 177ec0a0

kernel/signal.c

+10 −14
Original line number Diff line number Diff line
@@ -2753,21 +2753,16 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from) 
int do_sigtimedwait(const sigset_t *which, siginfo_t *info,

		    const struct timespec *ts)

{

	ktime_t *to = NULL, timeout = { .tv64 = KTIME_MAX };

	struct task_struct *tsk = current;

	long timeout = MAX_SCHEDULE_TIMEOUT;

	sigset_t mask = *which;

	int sig;

	int sig, ret = 0;



	if (ts) {

		if (!timespec_valid(ts))

			return -EINVAL;

		timeout = timespec_to_jiffies(ts);

		/*

		 * We can be close to the next tick, add another one

		 * to ensure we will wait at least the time asked for.

		 */

		if (ts->tv_sec || ts->tv_nsec)

			timeout++;

		timeout = timespec_to_ktime(*ts);

		to = &timeout;

	}



	/*
@@ -2778,7 +2773,7 @@ int do_sigtimedwait(const sigset_t *which, siginfo_t *info, 


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

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

	if (!sig && timeout) {

	if (!sig && timeout.tv64) {

		/*

		 * None ready, temporarily unblock those we're interested

		 * while we are sleeping in so that we'll be awakened when
@@ -2790,8 +2785,9 @@ int do_sigtimedwait(const sigset_t *which, siginfo_t *info, 
		recalc_sigpending();

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



		timeout = freezable_schedule_timeout_interruptible(timeout);



		__set_current_state(TASK_INTERRUPTIBLE);

		ret = freezable_schedule_hrtimeout_range(to, tsk->timer_slack_ns,

							 HRTIMER_MODE_REL);

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

		__set_task_blocked(tsk, &tsk->real_blocked);

		sigemptyset(&tsk->real_blocked);
@@ -2801,7 +2797,7 @@ int do_sigtimedwait(const sigset_t *which, siginfo_t *info, 


	if (sig)

		return sig;

	return timeout ? -EINTR : -EAGAIN;

	return ret ? -EINTR : -EAGAIN;

}



/**