[PATCH 3/7 linux-next] powerpc/pmac: replace current->state by set_current_state()

Fabian Frederick fabf at skynet.be
Sat Feb 21 05:12:53 AEDT 2015


Use helper functions to access current->state.
Direct assignments are prone to races and therefore buggy.

current->state = TASK_RUNNING can be replaced by __set_current_state()

Thanks to Peter Zijlstra for the exact definition of the problem.

Suggested-By: Peter Zijlstra <peterz at infradead.org>
Signed-off-by: Fabian Frederick <fabf at skynet.be>
---
 drivers/macintosh/via-pmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/macintosh/via-pmu.c b/drivers/macintosh/via-pmu.c
index dee88e5..3c608d4 100644
--- a/drivers/macintosh/via-pmu.c
+++ b/drivers/macintosh/via-pmu.c
@@ -2109,7 +2109,7 @@ pmu_read(struct file *file, char __user *buf,
 
 	spin_lock_irqsave(&pp->lock, flags);
 	add_wait_queue(&pp->wait, &wait);
-	current->state = TASK_INTERRUPTIBLE;
+	set_current_state(TASK_INTERRUPTIBLE);
 
 	for (;;) {
 		ret = -EAGAIN;
@@ -2138,7 +2138,7 @@ pmu_read(struct file *file, char __user *buf,
 		schedule();
 		spin_lock_irqsave(&pp->lock, flags);
 	}
-	current->state = TASK_RUNNING;
+	__set_current_state(TASK_RUNNING);
 	remove_wait_queue(&pp->wait, &wait);
 	spin_unlock_irqrestore(&pp->lock, flags);
 	
-- 
2.1.0



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