Module: xenomai-forge
Branch: master
Commit: 618228db04cc6842845d88602777b202a1a28a6d
URL:
http://git.xenomai.org/?p=xenomai-forge.git;a=commit;h=618228db04cc6842845d88602777b202a1a28a6d
Author: Philippe Gerum <r...@xenomai.org>
Date: Tue Sep 10 17:31:17 2013 +0200
cobalt/posix/sem: fix timeout handling in sem_timedwait()
Do not check validity of the timeout argument if the semaphore can be
locked immediately.
---
kernel/cobalt/posix/sem.c | 78 ++++++++++++++++++++++++---------------------
1 files changed, 42 insertions(+), 36 deletions(-)
diff --git a/kernel/cobalt/posix/sem.c b/kernel/cobalt/posix/sem.c
index f3a5d1c..076f2d2 100644
--- a/kernel/cobalt/posix/sem.c
+++ b/kernel/cobalt/posix/sem.c
@@ -540,32 +540,58 @@ static int sem_trywait(struct cobalt_sem *sem)
}
static inline int
-sem_timedwait_internal(struct cobalt_sem *sem, int timed, xnticks_t to)
+sem_timedwait_internal(struct cobalt_sem *sem, int timed,
+ const struct timespec __user *u_ts)
{
+ struct timespec ts;
xntmode_t tmode;
int ret, info;
+ spl_t s;
+
+ xnlock_get_irqsave(&nklock, s);
ret = sem_trywait_internal(sem);
- if (ret != -EAGAIN)
+ if (ret != -EAGAIN) {
+ xnlock_put_irqrestore(&nklock, s);
return ret;
-
- sem->nwaiters++;
+ }
if (timed) {
+ xnlock_put_irqrestore(&nklock, s);
+
+ if (u_ts == NULL ||
+ __xn_safe_copy_from_user(&ts, u_ts, sizeof(ts)))
+ return -EFAULT;
+
+ if (ts.tv_nsec >= ONE_BILLION)
+ return -EINVAL;
+
+ xnlock_get_irqsave(&nklock, s);
+
+ if (sem->value > 0) {
+ ret = 0;
+ --sem->value;
+ goto out;
+ }
+ sem->nwaiters++;
tmode = sem->flags & SEM_RAWCLOCK ? XN_ABSOLUTE : XN_REALTIME;
- info = xnsynch_sleep_on(&sem->synchbase, to, tmode);
- } else
+ info = xnsynch_sleep_on(&sem->synchbase, ts2ns(&ts) + 1, tmode);
+ } else {
+ sem->nwaiters++;
info = xnsynch_sleep_on(&sem->synchbase, XN_INFINITE,
XN_RELATIVE);
+ }
+ ret = 0;
if (info & XNRMID)
- return -EINVAL;
-
- if (info & (XNBREAK|XNTIMEO)) {
+ ret = -EINVAL;
+ else if (info & (XNBREAK|XNTIMEO)) {
sem->nwaiters--;
- return (info & XNBREAK) ? -EINTR : -ETIMEDOUT;
+ ret = (info & XNBREAK) ? -EINTR : -ETIMEDOUT;
}
+out:
+ xnlock_put_irqrestore(&nklock, s);
- return 0;
+ return ret;
}
/**
@@ -603,14 +629,7 @@ sem_timedwait_internal(struct cobalt_sem *sem, int timed,
xnticks_t to)
*/
static int sem_wait(struct cobalt_sem *sem)
{
- spl_t s;
- int err;
-
- xnlock_get_irqsave(&nklock, s);
- err = sem_timedwait_internal(sem, 0, XN_INFINITE);
- xnlock_put_irqrestore(&nklock, s);
-
- return err;
+ return sem_timedwait_internal(sem, 0, NULL);
}
/**
@@ -647,19 +666,10 @@ static int sem_wait(struct cobalt_sem *sem)
* Specification.</a>
*
*/
-static int sem_timedwait(struct cobalt_sem *sem, const struct timespec
*abs_timeout)
+static int sem_timedwait(struct cobalt_sem *sem,
+ const struct timespec __user *abs_timeout)
{
- spl_t s;
- int err;
-
- if (abs_timeout->tv_nsec > ONE_BILLION)
- return -EINVAL;
-
- xnlock_get_irqsave(&nklock, s);
- err = sem_timedwait_internal(sem, 1, ts2ns(abs_timeout) + 1);
- xnlock_put_irqrestore(&nklock, s);
-
- return err;
+ return sem_timedwait_internal(sem, 1, abs_timeout);
}
int sem_post_inner(struct cobalt_sem *sem, struct cobalt_kqueues *ownq, int
bcast)
@@ -818,15 +828,11 @@ int cobalt_sem_wait(struct __shadow_sem __user *u_sem)
int cobalt_sem_timedwait(struct __shadow_sem __user *u_sem,
struct timespec __user *u_ts)
{
- struct timespec ts;
struct cobalt_sem *sm;
__xn_get_user(sm, &u_sem->sem);
- if (__xn_safe_copy_from_user(&ts, u_ts, sizeof(ts)))
- return -EFAULT;
-
- return sem_timedwait(sm, &ts);
+ return sem_timedwait(sm, u_ts);
}
int cobalt_sem_trywait(struct __shadow_sem __user *u_sem)
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