[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>
diff --git a/kernel/compat.c b/kernel/compat.c
index 126dee9..75573e5 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -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 @@
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 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 @@
(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 = ¤t_thread_info()->restart_block;
+ restart->fn = compat_clock_nanosleep_restart;
+ restart->arg1 = (unsigned long) rmtp;
+ }
return err;
}
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 21c38a7..d0ba190 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -693,7 +693,7 @@
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 @@
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 @@
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 @@
}
restart = ¤t_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;
}
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index d38d9ec..5667fef 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1393,8 +1393,6 @@
}
}
-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 @@
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 @@
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 @@
{
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 @@
{
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 @@
.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 @@
.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);
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index ac6dc87..e5ebcc1 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -973,3 +973,24 @@
return CLOCK_DISPATCH(which_clock, nsleep,
(which_clock, flags, &t, rmtp));
}
+
+/*
+ * nanosleep_restart for monotonic and realtime clocks
+ */
+static int common_nsleep_restart(struct restart_block *restart_block)
+{
+ return hrtimer_nanosleep_restart(restart_block);
+}
+
+/*
+ * This will restart clock_nanosleep. This is required only by
+ * compat_clock_nanosleep_restart for now.
+ */
+long
+clock_nanosleep_restart(struct restart_block *restart_block)
+{
+ clockid_t which_clock = restart_block->arg0;
+
+ return CLOCK_DISPATCH(which_clock, nsleep_restart,
+ (restart_block));
+}
