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| author | Thomas Gleixner <tglx@linutronix.de> | 2016-03-19 11:30:33 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-03-20 09:34:02 -0600 |
| commit | 897bb0c7f1ea82d7cc882b19790b5e1df00ffc29 (patch) | |
| tree | 97b9ef1ba99b9c0f76ca57e398a55fa124ec3f7e /include/linux/blk-mq.h | |
| parent | 5173cb814b36439a9d9537016965e75798b9f130 (diff) | |
| download | lwn-897bb0c7f1ea82d7cc882b19790b5e1df00ffc29.tar.gz lwn-897bb0c7f1ea82d7cc882b19790b5e1df00ffc29.zip | |
blk-mq: Use proper cpumask iterator
queue_for_each_ctx() iterates over per_cpu variables under the assumption that
the possible cpu mask cannot have holes. That's wrong as all cpumasks can have
holes. In case there are holes the iteration ends up accessing uninitialized
memory and crashing as a result.
Replace the macro by a proper for_each_possible_cpu() loop and drop the unused
macro blk_ctx_sum() which references queue_for_each_ctx().
Reported-by: Xiong Zhou <jencce.kernel@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux/blk-mq.h')
| -rw-r--r-- | include/linux/blk-mq.h | 14 |
1 files changed, 0 insertions, 14 deletions
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 15a73d49fd1d..9ac9799b702b 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -263,22 +263,8 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq) for ((i) = 0; (i) < (q)->nr_hw_queues && \ ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++) -#define queue_for_each_ctx(q, ctx, i) \ - for ((i) = 0; (i) < (q)->nr_queues && \ - ({ ctx = per_cpu_ptr((q)->queue_ctx, (i)); 1; }); (i)++) - #define hctx_for_each_ctx(hctx, ctx, i) \ for ((i) = 0; (i) < (hctx)->nr_ctx && \ ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++) -#define blk_ctx_sum(q, sum) \ -({ \ - struct blk_mq_ctx *__x; \ - unsigned int __ret = 0, __i; \ - \ - queue_for_each_ctx((q), __x, __i) \ - __ret += sum; \ - __ret; \ -}) - #endif |