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| author | Thomas Gleixner <tglx@linutronix.de> | 2016-07-04 09:50:25 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-07-07 10:35:07 +0200 |
| commit | 2b1ecc3d1a6b10f8fbac7f83d80db30b5a2c2791 (patch) | |
| tree | a315e58fe3cf5a94f6ca990fb65d2a57834a7fc7 /kernel/signal.c | |
| parent | 177ec0a0a531695210b277d734b2f92ee5796303 (diff) | |
| download | lwn-2b1ecc3d1a6b10f8fbac7f83d80db30b5a2c2791.tar.gz lwn-2b1ecc3d1a6b10f8fbac7f83d80db30b5a2c2791.zip | |
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: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic 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: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 96e9bc40667f..af21afc00d08 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2751,23 +2751,18 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from) * @ts: upper bound on process time suspension */ int do_sigtimedwait(const sigset_t *which, siginfo_t *info, - const struct timespec *ts) + 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; } /** |