[PATCH] Rework hrtimer_nanosleep to make sys_compat_nanosleep easier

Anton Blanchard
2007-10-15T06:43:18Z

Hi Thomas,

Thanks for the review, updates to follow.

Anton

--

Pull the copy_to_user out of hrtimer_nanosleep and into the callers
(common_nsleep, sys_nanosleep) in preparation for converting
compat_sys_nanosleep to use hrtimers.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 540799b..7a9398e 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -300,7 +300,7 @@ hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);

/* Precise sleep: */
extern long hrtimer_nanosleep(struct timespec *rqtp,
- struct timespec __user *rmtp,
+ struct timespec *rmtp,
const enum hrtimer_mode mode,
const clockid_t clockid);
extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index dc8a445..129fead 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1286,8 +1286,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
{
struct hrtimer_sleeper t;
- struct timespec __user *rmtp;
- struct timespec tu;
+ struct timespec *rmtp;
ktime_t time;

restart->fn = do_no_restart_syscall;
@@ -1298,14 +1297,12 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
if (do_nanosleep(&t, HRTIMER_MODE_ABS))
return 0;

- rmtp = (struct timespec __user *) restart->arg1;
+ rmtp = (struct timespec *)restart->arg1;
if (rmtp) {
time = ktime_sub(t.timer.expires, t.timer.base->get_time());
if (time.tv64 <= 0)
return 0;
- tu = ktime_to_timespec(time);
- if (copy_to_user(rmtp, &tu, sizeof(tu)))
- return -EFAULT;
+ *rmtp = ktime_to_timespec(time);
}

restart->fn = hrtimer_nanosleep_restart;
@@ -1314,12 +1311,11 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
return -ERESTART_RESTARTBLOCK;
}

-long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
+long hrtimer_nanosleep(struct timespec *rqtp, struct timespec *rmtp,
const enum hrtimer_mode mode, const clockid_t clockid)
{
struct restart_block *restart;
struct hrtimer_sleeper t;
- struct timespec tu;
ktime_t rem;

hrtimer_init(&t.timer, clockid, mode);
@@ -1335,9 +1331,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
rem = ktime_sub(t.timer.expires, t.timer.base->get_time());
if (rem.tv64 <= 0)
return 0;
- tu = ktime_to_timespec(rem);
- if (copy_to_user(rmtp, &tu, sizeof(tu)))
- return -EFAULT;
+ *rmtp = ktime_to_timespec(rem);
}

restart = &current_thread_info()->restart_block;
@@ -1353,7 +1347,8 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
asmlinkage long
sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
{
- struct timespec tu;
+ struct timespec tu, rmt;
+ int ret;

if (copy_from_user(&tu, rqtp, sizeof(tu)))
return -EFAULT;
@@ -1361,7 +1356,14 @@ sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
if (!timespec_valid(&tu))
return -EINVAL;

- return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+ ret = hrtimer_nanosleep(&tu, &rmt, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+
+ if (ret && rmtp) {
+ if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
+ return -EFAULT;
+ }
+
+ return ret;
}

/*
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 57efe04..cce8c75 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -980,9 +980,19 @@ sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp)
static int common_nsleep(const clockid_t which_clock, int flags,
struct timespec *tsave, struct timespec __user *rmtp)
{
- return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
+ struct timespec rmt;
+ int ret;
+
+ ret = hrtimer_nanosleep(tsave, &rmt, flags & TIMER_ABSTIME ?
HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
which_clock);
+
+ if (ret && rmtp) {
+ if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
+ return -EFAULT;
+ }
+
+ return ret;
}

asmlinkage long