Commit 1711ef38 authored by Toyo Abe's avatar Toyo Abe Committed by Linus Torvalds
Browse files

[PATCH] posix-timers: Fix clock_nanosleep() doesn't return the remaining time in compatibility mode 



The clock_nanosleep() function does not return the time remaining when the
sleep is interrupted by a signal.

This patch creates a new call out, compat_clock_nanosleep_restart(), which
handles returning the remaining time after a sleep is interrupted.  This
patch revives clock_nanosleep_restart().  It is now accessed via the new
call out.  The compat_clock_nanosleep_restart() is used for compatibility
access.

Since this is implemented in compatibility mode the normal path is
virtually unaffected - no real performance impact.

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 9c4751fd

include/linux/hrtimer.h

+1 −0
Original line number Diff line number Diff line
@@ -138,6 +138,7 @@ extern long hrtimer_nanosleep(struct timespec *rqtp, 
			      struct timespec __user *rmtp,

			      const enum hrtimer_mode mode,

			      const clockid_t clockid);

extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);



extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,

				 struct task_struct *tsk);

include/linux/posix-timers.h

+4 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ struct k_clock { 
	int (*timer_create) (struct k_itimer *timer);

	int (*nsleep) (const clockid_t which_clock, int flags,

		       struct timespec *, struct timespec __user *);

	long (*nsleep_restart) (struct restart_block *restart_block);

	int (*timer_set) (struct k_itimer * timr, int flags,

			  struct itimerspec * new_setting,

			  struct itimerspec * old_setting);
@@ -97,6 +98,7 @@ int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *ts); 
int posix_cpu_timer_create(struct k_itimer *timer);

int posix_cpu_nsleep(const clockid_t which_clock, int flags,

		     struct timespec *rqtp, struct timespec __user *rmtp);

long posix_cpu_nsleep_restart(struct restart_block *restart_block);

int posix_cpu_timer_set(struct k_itimer *timer, int flags,

			struct itimerspec *new, struct itimerspec *old);

int posix_cpu_timer_del(struct k_itimer *timer);
@@ -111,4 +113,6 @@ void posix_cpu_timers_exit_group(struct task_struct *task); 
void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,

			   cputime_t *newval, cputime_t *oldval);



long clock_nanosleep_restart(struct restart_block *restart_block);



#endif

kernel/compat.c

+33 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <linux/security.h>

#include <linux/timex.h>

#include <linux/migrate.h>

#include <linux/posix-timers.h>



#include <asm/uaccess.h>
@@ -601,6 +602,30 @@ long compat_sys_clock_getres(clockid_t which_clock, 
	return err;

} 



static long compat_clock_nanosleep_restart(struct restart_block *restart)

{

	long err;

	mm_segment_t oldfs;

	struct timespec tu;

	struct compat_timespec *rmtp = (struct compat_timespec *)(restart->arg1);



	restart->arg1 = (unsigned long) &tu;

	oldfs = get_fs();

	set_fs(KERNEL_DS);

	err = clock_nanosleep_restart(restart);

	set_fs(oldfs);



	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&

	    put_compat_timespec(&tu, rmtp))

		return -EFAULT;



	if (err == -ERESTART_RESTARTBLOCK) {

		restart->fn = compat_clock_nanosleep_restart;

		restart->arg1 = (unsigned long) rmtp;

	}

	return err;

}



long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,

			    struct compat_timespec __user *rqtp,

			    struct compat_timespec __user *rmtp)
@@ -608,6 +633,7 @@ long compat_sys_clock_nanosleep(clockid_t which_clock, int flags, 
	long err;

	mm_segment_t oldfs;

	struct timespec in, out; 

	struct restart_block *restart;



	if (get_compat_timespec(&in, rqtp)) 

		return -EFAULT;
@@ -618,9 +644,16 @@ long compat_sys_clock_nanosleep(clockid_t which_clock, int flags, 
				  (struct timespec __user *) &in,

				  (struct timespec __user *) &out);

	set_fs(oldfs);



	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&

	    put_compat_timespec(&out, rmtp))

		return -EFAULT;



	if (err == -ERESTART_RESTARTBLOCK) {

		restart = &current_thread_info()->restart_block;

		restart->fn = compat_clock_nanosleep_restart;

		restart->arg1 = (unsigned long) rmtp;

	}

	return err;	

}

kernel/hrtimer.c

+10 −10
Original line number Diff line number Diff line
@@ -693,7 +693,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod 
	return t->task == NULL;

}



static long __sched nanosleep_restart(struct restart_block *restart)

long __sched hrtimer_nanosleep_restart(struct restart_block *restart)

{

	struct hrtimer_sleeper t;

	struct timespec __user *rmtp;
@@ -702,13 +702,13 @@ static long __sched nanosleep_restart(struct restart_block *restart) 


	restart->fn = do_no_restart_syscall;



	hrtimer_init(&t.timer, restart->arg3, HRTIMER_ABS);

	t.timer.expires.tv64 = ((u64)restart->arg1 << 32) | (u64) restart->arg0;

	hrtimer_init(&t.timer, restart->arg0, HRTIMER_ABS);

	t.timer.expires.tv64 = ((u64)restart->arg3 << 32) | (u64) restart->arg2;



	if (do_nanosleep(&t, HRTIMER_ABS))

		return 0;



	rmtp = (struct timespec __user *) restart->arg2;

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

	if (rmtp) {

		time = ktime_sub(t.timer.expires, t.timer.base->get_time());

		if (time.tv64 <= 0)
@@ -718,7 +718,7 @@ static long __sched nanosleep_restart(struct restart_block *restart) 
			return -EFAULT;

	}



	restart->fn = nanosleep_restart;

	restart->fn = hrtimer_nanosleep_restart;



	/* The other values in restart are already filled in */

	return -ERESTART_RESTARTBLOCK;
@@ -751,11 +751,11 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, 
	}



	restart = &current_thread_info()->restart_block;

	restart->fn = nanosleep_restart;

	restart->arg0 = t.timer.expires.tv64 & 0xFFFFFFFF;

	restart->arg1 = t.timer.expires.tv64 >> 32;

	restart->arg2 = (unsigned long) rmtp;

	restart->arg3 = (unsigned long) t.timer.base->index;

	restart->fn = hrtimer_nanosleep_restart;

	restart->arg0 = (unsigned long) t.timer.base->index;

	restart->arg1 = (unsigned long) rmtp;

	restart->arg2 = t.timer.expires.tv64 & 0xFFFFFFFF;

	restart->arg3 = t.timer.expires.tv64 >> 32;



	return -ERESTART_RESTARTBLOCK;

}

kernel/posix-cpu-timers.c

+12 −5
Original line number Diff line number Diff line
@@ -1393,8 +1393,6 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, 
	}

}



static long posix_cpu_clock_nanosleep_restart(struct restart_block *);



int posix_cpu_nsleep(const clockid_t which_clock, int flags,

		     struct timespec *rqtp, struct timespec __user *rmtp)

{
@@ -1471,7 +1469,7 @@ int posix_cpu_nsleep(const clockid_t which_clock, int flags, 
		    copy_to_user(rmtp, &it.it_value, sizeof *rmtp))

			return -EFAULT;



		restart_block->fn = posix_cpu_clock_nanosleep_restart;

		restart_block->fn = posix_cpu_nsleep_restart;

		/* Caller already set restart_block->arg1 */

		restart_block->arg0 = which_clock;

		restart_block->arg1 = (unsigned long) rmtp;
@@ -1484,8 +1482,7 @@ int posix_cpu_nsleep(const clockid_t which_clock, int flags, 
	return error;

}



static long

posix_cpu_clock_nanosleep_restart(struct restart_block *restart_block)

long posix_cpu_nsleep_restart(struct restart_block *restart_block)

{

	clockid_t which_clock = restart_block->arg0;

	struct timespec __user *rmtp;
@@ -1524,6 +1521,10 @@ static int process_cpu_nsleep(const clockid_t which_clock, int flags, 
{

	return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp);

}

static long process_cpu_nsleep_restart(struct restart_block *restart_block)

{

	return -EINVAL;

}

static int thread_cpu_clock_getres(const clockid_t which_clock,

				   struct timespec *tp)

{
@@ -1544,6 +1545,10 @@ static int thread_cpu_nsleep(const clockid_t which_clock, int flags, 
{

	return -EINVAL;

}

static long thread_cpu_nsleep_restart(struct restart_block *restart_block)

{

	return -EINVAL;

}



static __init int init_posix_cpu_timers(void)

{
@@ -1553,6 +1558,7 @@ static __init int init_posix_cpu_timers(void) 
		.clock_set = do_posix_clock_nosettime,

		.timer_create = process_cpu_timer_create,

		.nsleep = process_cpu_nsleep,

		.nsleep_restart = process_cpu_nsleep_restart,

	};

	struct k_clock thread = {

		.clock_getres = thread_cpu_clock_getres,
@@ -1560,6 +1566,7 @@ static __init int init_posix_cpu_timers(void) 
		.clock_set = do_posix_clock_nosettime,

		.timer_create = thread_cpu_timer_create,

		.nsleep = thread_cpu_nsleep,

		.nsleep_restart = thread_cpu_nsleep_restart,

	};



	register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process);

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