[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: Toyo 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: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 12 insertions, 5 deletions

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index d38d9ec3276c..5667fef89dd1 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -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);