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Message-Id: <200608092309.k79N93m7028316@dhcp119.mvista.com>
Date: Wed, 9 Aug 2006 16:09:03 -0700
From: toyoa@...sta.com
To: george@...dturkeyranch.net
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] posix-timers: Fix the flags handling in posix_cpu_nsleep().
When a posix_cpu_nsleep() sleep is interrupted by a signal more than twice,
it incorrectly reports the sleep time remaining to the user.
Because posix_cpu_nsleep() doesn't report back to the user when it's called
from restart function due to the wrong flags handling.
This patch, which applies after previous one, moves the nanosleep() function
from posix_cpu_nsleep() to do_cpu_nanosleep() and cleans up the flags handling
appropriately.
Signed-off-by: Toyo Abe <toyoa@...sta.com>
---
--- linux-2.6.18-rc4.org/kernel/posix-cpu-timers.c 2006-08-09 11:01:38.000000000 -0700
+++ linux-2.6.18-rc4/kernel/posix-cpu-timers.c 2006-08-09 11:00:40.000000000 -0700
@@ -1393,23 +1393,13 @@ void set_process_cpu_timer(struct task_s
}
}
-int posix_cpu_nsleep(const clockid_t which_clock, int flags,
- struct timespec *rqtp, struct timespec __user *rmtp)
+static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp, struct itimerspec *it)
{
- struct restart_block *restart_block =
- ¤t_thread_info()->restart_block;
struct k_itimer timer;
int error;
/*
- * Diagnose required errors first.
- */
- if (CPUCLOCK_PERTHREAD(which_clock) &&
- (CPUCLOCK_PID(which_clock) == 0 ||
- CPUCLOCK_PID(which_clock) == current->pid))
- return -EINVAL;
-
- /*
* Set up a temporary timer and then wait for it to go off.
*/
memset(&timer, 0, sizeof timer);
@@ -1420,11 +1410,12 @@ int posix_cpu_nsleep(const clockid_t whi
timer.it_process = current;
if (!error) {
static struct itimerspec zero_it;
- struct itimerspec it = { .it_value = *rqtp,
- .it_interval = {} };
+
+ memset(it, 0, sizeof *it);
+ it->it_value = *rqtp;
spin_lock_irq(&timer.it_lock);
- error = posix_cpu_timer_set(&timer, flags, &it, NULL);
+ error = posix_cpu_timer_set(&timer, flags, it, NULL);
if (error) {
spin_unlock_irq(&timer.it_lock);
return error;
@@ -1452,33 +1443,56 @@ int posix_cpu_nsleep(const clockid_t whi
* We were interrupted by a signal.
*/
sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
- posix_cpu_timer_set(&timer, 0, &zero_it, &it);
+ posix_cpu_timer_set(&timer, 0, &zero_it, it);
spin_unlock_irq(&timer.it_lock);
- if ((it.it_value.tv_sec | it.it_value.tv_nsec) == 0) {
+ if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
/*
* It actually did fire already.
*/
return 0;
}
+ error = -ERESTART_RESTARTBLOCK;
+ }
+
+ return error;
+}
+
+int posix_cpu_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp, struct timespec __user *rmtp)
+{
+ struct restart_block *restart_block =
+ ¤t_thread_info()->restart_block;
+ struct itimerspec it;
+ int error;
+
+ /*
+ * Diagnose required errors first.
+ */
+ if (CPUCLOCK_PERTHREAD(which_clock) &&
+ (CPUCLOCK_PID(which_clock) == 0 ||
+ CPUCLOCK_PID(which_clock) == current->pid))
+ return -EINVAL;
+
+ error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
+
+ if (error = -ERESTART_RESTARTBLOCK) {
+
+ if (flags & TIMER_ABSTIME)
+ return -ERESTARTNOHAND;
/*
- * Report back to the user the time still remaining.
- */
- if (rmtp != NULL && !(flags & TIMER_ABSTIME) &&
- copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
+ * Report back to the user the time still remaining.
+ */
+ if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
return -EFAULT;
restart_block->fn = posix_cpu_nsleep_restart;
- /* Caller already set restart_block->arg1 */
restart_block->arg0 = which_clock;
restart_block->arg1 = (unsigned long) rmtp;
restart_block->arg2 = rqtp->tv_sec;
restart_block->arg3 = rqtp->tv_nsec;
-
- error = -ERESTART_RESTARTBLOCK;
}
-
return error;
}
@@ -1487,13 +1501,31 @@ long posix_cpu_nsleep_restart(struct res
clockid_t which_clock = restart_block->arg0;
struct timespec __user *rmtp;
struct timespec t;
+ struct itimerspec it;
+ int error;
rmtp = (struct timespec __user *) restart_block->arg1;
t.tv_sec = restart_block->arg2;
t.tv_nsec = restart_block->arg3;
restart_block->fn = do_no_restart_syscall;
- return posix_cpu_nsleep(which_clock, TIMER_ABSTIME, &t, rmtp);
+ error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
+
+ if (error = -ERESTART_RESTARTBLOCK) {
+ /*
+ * Report back to the user the time still remaining.
+ */
+ if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
+ return -EFAULT;
+
+ restart_block->fn = posix_cpu_nsleep_restart;
+ restart_block->arg0 = which_clock;
+ restart_block->arg1 = (unsigned long) rmtp;
+ restart_block->arg2 = t.tv_sec;
+ restart_block->arg3 = t.tv_nsec;
+ }
+ return error;
+
}
-
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