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authorJan Höppner <hoeppner@linux.ibm.com>2023-06-09 17:37:50 +0200
committerJens Axboe <axboe@kernel.dk>2023-06-09 11:35:52 -0600
commitccc45cb4e7271c74dbb27776ae8f73d84557f5c6 (patch)
treec1589e0c5688f2736b64158c2d131087803b1fc6
parent8cfb98196cceec35416041c6b91212d2b99392e4 (diff)
downloadperf-tools-ccc45cb4e7271c74dbb27776ae8f73d84557f5c6.tar.gz
s390/dasd: Use correct lock while counting channel queue length
The lock around counting the channel queue length in the BIODASDINFO ioctl was incorrectly changed to the dasd_block->queue_lock with commit 583d6535cb9d ("dasd: remove dead code"). This can lead to endless list iterations and a subsequent crash. The queue_lock is supposed to be used only for queue lists belonging to dasd_block. For dasd_device related queue lists the ccwdev lock must be used. Fix the mentioned issues by correctly using the ccwdev lock instead of the queue lock. Fixes: 583d6535cb9d ("dasd: remove dead code") Cc: stable@vger.kernel.org # v5.0+ Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com> Reviewed-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Link: https://lore.kernel.org/r/20230609153750.1258763-2-sth@linux.ibm.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--drivers/s390/block/dasd_ioctl.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index 9327dcdd6e5e4..8fca725b3daec 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -552,10 +552,10 @@ static int __dasd_ioctl_information(struct dasd_block *block,
memcpy(dasd_info->type, base->discipline->name, 4);
- spin_lock_irqsave(&block->queue_lock, flags);
+ spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
list_for_each(l, &base->ccw_queue)
dasd_info->chanq_len++;
- spin_unlock_irqrestore(&block->queue_lock, flags);
+ spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
return 0;
}