diff options
| author | Ming Lei <ming.lei@redhat.com> | 2021-12-02 17:07:16 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-12-02 08:20:49 -0700 |
| commit | 18d78171c061889a9a43152f60d6a27a10fc7656 (patch) | |
| tree | 05c4db7fc4b7b64cdda8eaca0ecf447afe13e97d | |
| parent | 8a7518931baa8ea023700987f3db31cb0a80610b (diff) | |
blk-mq: check q->poll_stat in queue_poll_stat_show
Without checking q->poll_stat in queue_poll_stat_show(), kernel panic
may be caused if q->poll_stat isn't allocated.
Fixes: 48b5c1fbcd8c ("block: only allocate poll_stats if there's a user of them")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20211202090716.3292244-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-mq-debugfs.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 7f27dca3a45e..3a790eb4995c 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -30,6 +30,9 @@ static int queue_poll_stat_show(void *data, struct seq_file *m) struct request_queue *q = data; int bucket; + if (!q->poll_stat) + return 0; + for (bucket = 0; bucket < (BLK_MQ_POLL_STATS_BKTS / 2); bucket++) { seq_printf(m, "read (%d Bytes): ", 1 << (9 + bucket)); print_stat(m, &q->poll_stat[2 * bucket]); |