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Commit e4b76555 authored by Toyo Abe's avatar Toyo Abe Committed by Linus Torvalds
Browse files

[PATCH] posix-timers: Fix the flags handling in posix_cpu_nsleep() 



When a posix_cpu_nsleep() sleep is interrupted by a signal more than twice, it
incorrectly reports the sleep time remaining to the user.  Because
posix_cpu_nsleep() doesn't report back to the user when it's called from
restart function due to the wrong flags handling.

This patch, which applies after previous one, moves the nanosleep() function
from posix_cpu_nsleep() to do_cpu_nanosleep() and cleans up the flags handling
appropriately.

Signed-off-by: default avatarToyo Abe <toyoa@mvista.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 1711ef38

kernel/posix-cpu-timers.c

+58 −26
Original line number Diff line number Diff line
@@ -1393,22 +1393,12 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, 
	}

}



int posix_cpu_nsleep(const clockid_t which_clock, int flags,

		     struct timespec *rqtp, struct timespec __user *rmtp)

static int do_cpu_nanosleep(const clockid_t which_clock, int flags,

			    struct timespec *rqtp, struct itimerspec *it)

{

	struct restart_block *restart_block =

	    &current_thread_info()->restart_block;

	struct k_itimer timer;

	int error;



	/*

	 * Diagnose required errors first.

	 */

	if (CPUCLOCK_PERTHREAD(which_clock) &&

	    (CPUCLOCK_PID(which_clock) == 0 ||

	     CPUCLOCK_PID(which_clock) == current->pid))

		return -EINVAL;



	/*

	 * Set up a temporary timer and then wait for it to go off.

	 */
@@ -1420,11 +1410,12 @@ int posix_cpu_nsleep(const clockid_t which_clock, int flags, 
	timer.it_process = current;

	if (!error) {

		static struct itimerspec zero_it;

		struct itimerspec it = { .it_value = *rqtp,

					 .it_interval = {} };



		memset(it, 0, sizeof *it);

		it->it_value = *rqtp;



		spin_lock_irq(&timer.it_lock);

		error = posix_cpu_timer_set(&timer, flags, &it, NULL);

		error = posix_cpu_timer_set(&timer, flags, it, NULL);

		if (error) {

			spin_unlock_irq(&timer.it_lock);

			return error;
@@ -1452,33 +1443,56 @@ int posix_cpu_nsleep(const clockid_t which_clock, int flags, 
		 * We were interrupted by a signal.

		 */

		sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);

		posix_cpu_timer_set(&timer, 0, &zero_it, &it);

		posix_cpu_timer_set(&timer, 0, &zero_it, it);

		spin_unlock_irq(&timer.it_lock);



		if ((it.it_value.tv_sec | it.it_value.tv_nsec) == 0) {

		if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {

			/*

			 * It actually did fire already.

			 */

			return 0;

		}



		error = -ERESTART_RESTARTBLOCK;

	}



	return error;

}



int posix_cpu_nsleep(const clockid_t which_clock, int flags,

		     struct timespec *rqtp, struct timespec __user *rmtp)

{

	struct restart_block *restart_block =

	    &current_thread_info()->restart_block;

	struct itimerspec it;

	int error;



	/*

	 * Diagnose required errors first.

	 */

	if (CPUCLOCK_PERTHREAD(which_clock) &&

	    (CPUCLOCK_PID(which_clock) == 0 ||

	     CPUCLOCK_PID(which_clock) == current->pid))

		return -EINVAL;



	error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);



	if (error == -ERESTART_RESTARTBLOCK) {



	       	if (flags & TIMER_ABSTIME)

			return -ERESTARTNOHAND;

		/*

	 	 * Report back to the user the time still remaining.

	 	 */

		if (rmtp != NULL && !(flags & TIMER_ABSTIME) &&

		    copy_to_user(rmtp, &it.it_value, sizeof *rmtp))

		if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))

			return -EFAULT;



		restart_block->fn = posix_cpu_nsleep_restart;

		/* Caller already set restart_block->arg1 */

		restart_block->arg0 = which_clock;

		restart_block->arg1 = (unsigned long) rmtp;

		restart_block->arg2 = rqtp->tv_sec;

		restart_block->arg3 = rqtp->tv_nsec;



		error = -ERESTART_RESTARTBLOCK;

	}



	return error;

}
@@ -1487,13 +1501,31 @@ long posix_cpu_nsleep_restart(struct restart_block *restart_block) 
	clockid_t which_clock = restart_block->arg0;

	struct timespec __user *rmtp;

	struct timespec t;

	struct itimerspec it;

	int error;



	rmtp = (struct timespec __user *) restart_block->arg1;

	t.tv_sec = restart_block->arg2;

	t.tv_nsec = restart_block->arg3;



	restart_block->fn = do_no_restart_syscall;

	return posix_cpu_nsleep(which_clock, TIMER_ABSTIME, &t, rmtp);

	error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);



	if (error == -ERESTART_RESTARTBLOCK) {

		/*

	 	 * Report back to the user the time still remaining.

	 	 */

		if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))

			return -EFAULT;



		restart_block->fn = posix_cpu_nsleep_restart;

		restart_block->arg0 = which_clock;

		restart_block->arg1 = (unsigned long) rmtp;

		restart_block->arg2 = t.tv_sec;

		restart_block->arg3 = t.tv_nsec;

	}

	return error;



}