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authorThomas Gleixner <tglx@linutronix.de>2009-12-09 11:32:03 +0300
committerIngo Molnar <mingo@elte.hu>2009-12-09 12:01:07 +0300
commitdba091b9e3522b9d32fc9975e48d3b69633b45f0 (patch)
tree91549e3921971b6d0074fd34c29223b593381c8a /kernel/sched_fair.c
parent3160568371da441b7f2fb57f2f1225404207e8f2 (diff)
downloadlinux-dba091b9e3522b9d32fc9975e48d3b69633b45f0.tar.xz
sched: Protect sched_rr_get_param() access to task->sched_class
sched_rr_get_param calls task->sched_class->get_rr_interval(task) without protection against a concurrent sched_setscheduler() call which modifies task->sched_class. Serialize the access with task_rq_lock(task) and hand the rq pointer into get_rr_interval() as it's needed at least in the sched_fair implementation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <alpine.LFD.2.00.0912090930120.3089@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r--kernel/sched_fair.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index f61837ad336d..613c1c749677 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -2014,21 +2014,17 @@ static void moved_group_fair(struct task_struct *p)
}
#endif
-unsigned int get_rr_interval_fair(struct task_struct *task)
+unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task)
{
struct sched_entity *se = &task->se;
- unsigned long flags;
- struct rq *rq;
unsigned int rr_interval = 0;
/*
* Time slice is 0 for SCHED_OTHER tasks that are on an otherwise
* idle runqueue:
*/
- rq = task_rq_lock(task, &flags);
if (rq->cfs.load.weight)
rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
- task_rq_unlock(rq, &flags);
return rr_interval;
}