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authorOleg Nesterov <oleg@tv-sign.ru>2008-02-01 20:35:31 +0300
committerThomas Gleixner <tglx@linutronix.de>2008-02-10 10:48:03 +0100
commit416529374b4793ba2d2e97e736d108a2e0f3ef07 (patch)
tree2523182bf1dd501aeef28a2c578d86b95cd90683 /kernel/compat.c
parent080344b98805553f9b01de0f59a41b1533036d8d (diff)
downloadlinux-sh-416529374b4793ba2d2e97e736d108a2e0f3ef07.tar.gz
hrtimer: fix *rmtp/restarts handling in compat_sys_nanosleep()
Spotted by Pavel Emelyanov and Alexey Dobriyan. compat_sys_nanosleep() implicitly uses hrtimer_nanosleep_restart(), this can't work. Make a suitable compat_nanosleep_restart() helper. Introduced by commit c70878b4e0b6cf8d2f1e46319e48e821ef4a8aba hrtimer: hook compat_sys_nanosleep up to high res timer code Also, set ->addr_limit = KERNEL_DS before doing hrtimer_nanosleep(), this func was changed by the previous patch and now takes the "__user *" parameter. Thanks to Ingo Molnar for fixing the bug in this patch. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Pavel Emelyanov <xemul@sw.ru> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Toyo Abe <toyoa@mvista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/compat.c')
-rw-r--r--kernel/compat.c44
1 files changed, 40 insertions, 4 deletions
diff --git a/kernel/compat.c b/kernel/compat.c
index 42a1ed4b61b1..f2a297504287 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -40,10 +40,36 @@ int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user
__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}
+static long compat_nanosleep_restart(struct restart_block *restart)
+{
+ struct compat_timespec __user *rmtp;
+ struct timespec rmt;
+ mm_segment_t oldfs;
+ long ret;
+
+ rmtp = (struct compat_timespec __user *)(restart->arg1);
+ restart->arg1 = (unsigned long)&rmt;
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ ret = hrtimer_nanosleep_restart(restart);
+ set_fs(oldfs);
+
+ if (ret) {
+ restart->fn = compat_nanosleep_restart;
+ restart->arg1 = (unsigned long)rmtp;
+
+ if (rmtp && put_compat_timespec(&rmt, rmtp))
+ return -EFAULT;
+ }
+
+ return ret;
+}
+
asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
struct compat_timespec __user *rmtp)
{
struct timespec tu, rmt;
+ mm_segment_t oldfs;
long ret;
if (get_compat_timespec(&tu, rqtp))
@@ -52,11 +78,21 @@ asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
if (!timespec_valid(&tu))
return -EINVAL;
- ret = hrtimer_nanosleep(&tu, rmtp ? &rmt : NULL, HRTIMER_MODE_REL,
- CLOCK_MONOTONIC);
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ ret = hrtimer_nanosleep(&tu,
+ rmtp ? (struct timespec __user *)&rmt : NULL,
+ HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+ set_fs(oldfs);
+
+ if (ret) {
+ struct restart_block *restart
+ = &current_thread_info()->restart_block;
+
+ restart->fn = compat_nanosleep_restart;
+ restart->arg1 = (unsigned long)rmtp;
- if (ret && rmtp) {
- if (put_compat_timespec(&rmt, rmtp))
+ if (rmtp && put_compat_timespec(&rmt, rmtp))
return -EFAULT;
}