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authorMing Lei <ming.lei@redhat.com>2022-03-08 15:32:18 +0800
committerJens Axboe <axboe@kernel.dk>2022-03-08 17:57:19 -0700
commit4f481208749a22d3570073e629dbc27d7d27c8da (patch)
tree8df524f2cca05a364031383731151d6b9b8775cc /block/blk-mq-sysfs.c
parentde0328d3a253a339be14a80fe2a0256ec26867da (diff)
blk-mq: prepare for implementing hctx table via xarray
It is inevitable to cause use-after-free on q->queue_hw_ctx between queue_for_each_hw_ctx() and blk_mq_update_nr_hw_queues(). And converting to xarray can fix the uaf, meantime code gets cleaner. Prepare for converting q->queue_hctx_ctx into xarray, one thing is that xa_for_each() can only accept 'unsigned long' as index, so changes type of hctx index of queue_for_each_hw_ctx() into 'unsigned long'. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220308073219.91173-6-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq-sysfs.c')
-rw-r--r--block/blk-mq-sysfs.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 674786574075..c08426975856 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -206,7 +206,7 @@ static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
{
struct blk_mq_hw_ctx *hctx;
- int i;
+ unsigned long i;
lockdep_assert_held(&q->sysfs_dir_lock);
@@ -255,7 +255,8 @@ void blk_mq_sysfs_init(struct request_queue *q)
int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
{
struct blk_mq_hw_ctx *hctx;
- int ret, i;
+ unsigned long i, j;
+ int ret;
WARN_ON_ONCE(!q->kobj.parent);
lockdep_assert_held(&q->sysfs_dir_lock);
@@ -278,8 +279,10 @@ out:
return ret;
unreg:
- while (--i >= 0)
- blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
+ queue_for_each_hw_ctx(q, hctx, j) {
+ if (j < i)
+ blk_mq_unregister_hctx(hctx);
+ }
kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
kobject_del(q->mq_kobj);
@@ -290,7 +293,7 @@ unreg:
void blk_mq_sysfs_unregister(struct request_queue *q)
{
struct blk_mq_hw_ctx *hctx;
- int i;
+ unsigned long i;
mutex_lock(&q->sysfs_dir_lock);
if (!q->mq_sysfs_init_done)
@@ -306,7 +309,8 @@ unlock:
int blk_mq_sysfs_register(struct request_queue *q)
{
struct blk_mq_hw_ctx *hctx;
- int i, ret = 0;
+ unsigned long i;
+ int ret = 0;
mutex_lock(&q->sysfs_dir_lock);
if (!q->mq_sysfs_init_done)