From: Yiyuan GUO <yguoaz@gmail.com>
To: hare@suse.de
Cc: axboe@kernel.dk, linux-block@vger.kernel.org, yguoaz@cse.ust.hk,
yguoaz@gmail.com
Subject: [PATCH v2] block: add protection for divide by zero in blk_mq_map_queues
Date: Fri, 14 May 2021 17:38:16 +0800 [thread overview]
Message-ID: <20210514093816.66612-1-yguoaz@cse.ust.hk> (raw)
In-Reply-To: <274501fd-3115-3015-3577-3ed64e4038a0@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 | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
index 3db84d319..c2163658e 100644
--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -64,7 +64,7 @@ int blk_mq_map_queues(struct blk_mq_queue_map *qmap)
map[cpu] = queue_index(qmap, nr_queues, q++);
} else {
first_sibling = get_first_sibling(cpu);
- if (first_sibling == cpu)
+ if ((first_sibling == cpu) && nr_queues)
map[cpu] = queue_index(qmap, nr_queues, q++);
else
map[cpu] = map[first_sibling];
--
2.25.1
prev parent reply other threads:[~2021-05-14 9:38 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 ` [PATCH] block: add protection for divide by zero " Yiyuan GUO
2021-05-14 9:24 ` Hannes Reinecke
2021-05-14 9:38 ` Yiyuan GUO [this message]
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