diff options
| author | Ming Lei <ming.lei@canonical.com> | 2015-01-29 20:17:27 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-01-29 08:30:51 -0800 |
| commit | e09aae7edec1d20824c60a6f0ca4589f99ada17b (patch) | |
| tree | 1cf7f6b2434f356f9dab4104bd5ecbfa85228799 /block | |
| parent | 74170118b26e55b611de5210f47657118a03a0e1 (diff) | |
| download | linux-e09aae7edec1d20824c60a6f0ca4589f99ada17b.tar.gz linux-e09aae7edec1d20824c60a6f0ca4589f99ada17b.tar.bz2 linux-e09aae7edec1d20824c60a6f0ca4589f99ada17b.zip | |
blk-mq: release mq's kobjects in blk_release_queue()
The kobject memory inside blk-mq hctx/ctx shouldn't have been freed
before the kobject is released because driver core can access it freely
before its release.
We can't do that in all ctx/hctx/mq_kobj's release handler because
it can be run before blk_cleanup_queue().
Given mq_kobj shouldn't have been introduced, this patch simply moves
mq's release into blk_release_queue().
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 29 | ||||
| -rw-r--r-- | block/blk-mq.h | 2 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 2 |
3 files changed, 26 insertions, 7 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 2f95747c287e..2390c5541e71 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1641,10 +1641,8 @@ static void blk_mq_free_hw_queues(struct request_queue *q, struct blk_mq_hw_ctx *hctx; unsigned int i; - queue_for_each_hw_ctx(q, hctx, i) { + queue_for_each_hw_ctx(q, hctx, i) free_cpumask_var(hctx->cpumask); - kfree(hctx); - } } static int blk_mq_init_hctx(struct request_queue *q, @@ -1869,6 +1867,27 @@ static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, mutex_unlock(&set->tag_list_lock); } +/* + * It is the actual release handler for mq, but we do it from + * request queue's release handler for avoiding use-after-free + * and headache because q->mq_kobj shouldn't have been introduced, + * but we can't group ctx/kctx kobj without it. + */ +void blk_mq_release(struct request_queue *q) +{ + struct blk_mq_hw_ctx *hctx; + unsigned int i; + + /* hctx kobj stays in hctx */ + queue_for_each_hw_ctx(q, hctx, i) + kfree(hctx); + + kfree(q->queue_hw_ctx); + + /* ctx kobj stays in queue_ctx */ + free_percpu(q->queue_ctx); +} + struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) { struct blk_mq_hw_ctx **hctxs; @@ -2002,12 +2021,8 @@ void blk_mq_free_queue(struct request_queue *q) percpu_ref_exit(&q->mq_usage_counter); - free_percpu(q->queue_ctx); - kfree(q->queue_hw_ctx); kfree(q->mq_map); - q->queue_ctx = NULL; - q->queue_hw_ctx = NULL; q->mq_map = NULL; mutex_lock(&all_q_mutex); diff --git a/block/blk-mq.h b/block/blk-mq.h index 4f4f943c22c3..6a48c4c0d8a2 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -62,6 +62,8 @@ extern void blk_mq_sysfs_unregister(struct request_queue *q); extern void blk_mq_rq_timed_out(struct request *req, bool reserved); +void blk_mq_release(struct request_queue *q); + /* * Basic implementation of sparser bitmap, allowing the user to spread * the bits over more cachelines. diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 935ea2aa0730..faaf36ade7eb 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -517,6 +517,8 @@ static void blk_release_queue(struct kobject *kobj) if (!q->mq_ops) blk_free_flush_queue(q->fq); + else + blk_mq_release(q); blk_trace_shutdown(q); |