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| author | Thomas Gleixner <tglx@linutronix.de> | 2009-12-09 10:15:11 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-12-14 17:11:35 +0100 |
| commit | 1a551ae715825bb2a2107a2dd68de024a1fa4e32 (patch) | |
| tree | 03f29f6a37be1eea125994aee5d34b4daf804a20 /kernel/sched.c | |
| parent | 23f5d142519621b16cf2b378cf8adf4dcf01a616 (diff) | |
| download | lwn-1a551ae715825bb2a2107a2dd68de024a1fa4e32.tar.gz lwn-1a551ae715825bb2a2107a2dd68de024a1fa4e32.zip | |
sched: Use rcu in sched_get_rr_param()
read_lock(&tasklist_lock) does not protect
sys_sched_get_rr_param() against a concurrent update of the
policy or scheduler parameters as do_sched_scheduler() does not
take the tasklist_lock.
The access to task->sched_class->get_rr_interval is protected by
task_rq_lock(task).
Use rcu_read_lock() to protect find_task_by_vpid() and prevent
the task struct from going away.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20091209100706.862897167@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 79893123325c..db5c26692dd5 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6873,7 +6873,7 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, return -EINVAL; retval = -ESRCH; - read_lock(&tasklist_lock); + rcu_read_lock(); p = find_process_by_pid(pid); if (!p) goto out_unlock; @@ -6886,13 +6886,13 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, time_slice = p->sched_class->get_rr_interval(rq, p); task_rq_unlock(rq, &flags); - read_unlock(&tasklist_lock); + rcu_read_unlock(); jiffies_to_timespec(time_slice, &t); retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; return retval; out_unlock: - read_unlock(&tasklist_lock); + rcu_read_unlock(); return retval; } |