From: Yiyuan GUO <yguoaz@gmail.com>
To: hare@suse.de
Cc: axboe@kernel.dk, linux-block@vger.kernel.org, yguoaz@gmail.com,
Yiyuan GUO <yguoaz@cse.ust.hk>
Subject: [PATCH] block: add protection for divide by zero in blk_mq_map_queues
Date: Fri, 14 May 2021 17:16:09 +0800 [thread overview]
Message-ID: <20210514091609.66252-1-yguoaz@cse.ust.hk> (raw)
In-Reply-To: <21cb65d1-b91a-2627-3824-292de3a7553a@suse.de>
In function blk_mq_map_queues, qmap->nr_queues may equal zero
and thus it needs to be checked before we pass it to function
queue_index.
Signed-off-by: Yiyuan GUO <yguoaz@cse.ust.hk>
---
block/blk-mq-cpumap.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
index 3db84d319..dc440870e 100644
--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -65,7 +65,8 @@ int blk_mq_map_queues(struct blk_mq_queue_map *qmap)
} else {
first_sibling = get_first_sibling(cpu);
if (first_sibling == cpu)
- map[cpu] = queue_index(qmap, nr_queues, q++);
+ if (nr_queues)
+ map[cpu] = queue_index(qmap, nr_queues, q++);
else
map[cpu] = map[first_sibling];
}
--
2.25.1
next prev parent reply other threads:[~2021-05-14 9:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-14 8:28 A possible divide by zero bug in blk_mq_map_queues Yiyuan guo
2021-05-14 8:34 ` Hannes Reinecke
2021-05-14 9:16 ` Yiyuan GUO [this message]
2021-05-14 9:24 ` [PATCH] block: add protection for divide by zero " Hannes Reinecke
2021-05-14 9:38 ` [PATCH v2] " Yiyuan GUO
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