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From: Christoph Hellwig <hch@lst.de>
To: tglx@linutronix.de
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH for-4.8] irq/affinity: use get/put_online_cpus
Date: Thu, 11 Aug 2016 07:06:45 -0700
Message-ID: <1470924405-25728-1-git-send-email-hch@lst.de> (raw)

Without locking out CPU mask operations we might end up with an inconsistent
view of the cpumask in the function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 kernel/irq/affinity.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index f689593..32f6cfc 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -39,6 +39,7 @@ struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
 		return NULL;
 	}
 
+	get_online_cpus();
 	if (max_vecs >= num_online_cpus()) {
 		cpumask_copy(affinity_mask, cpu_online_mask);
 		*nr_vecs = num_online_cpus();
@@ -56,6 +57,7 @@ struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
 		}
 		*nr_vecs = vecs;
 	}
+	put_online_cpus();
 
 	return affinity_mask;
 }
-- 
2.1.4

             reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-11 14:06 Christoph Hellwig [this message]
2016-08-14 16:00 ` Christoph Hellwig
2016-08-22  9:01   ` Thomas Gleixner
2016-08-22  9:28 ` [tip:irq/urgent] genirq/affinity: Use get/put_online_cpus around cpumask operations tip-bot for Christoph Hellwig

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