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| author | Jose Alonso <joalonsof@gmail.com> | 2014-01-28 08:09:46 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2014-01-28 08:09:46 -0700 |
| commit | 0d0b7d427987f6e98b6f32e84ee071f36f85c3d4 (patch) | |
| tree | 49e20246644048c004f1b1d3c95440538465a12b /include | |
| parent | 17a05cca99d952f5b4766fa48a2703548966636a (diff) | |
| download | linux-0d0b7d427987f6e98b6f32e84ee071f36f85c3d4.tar.gz linux-0d0b7d427987f6e98b6f32e84ee071f36f85c3d4.tar.bz2 linux-0d0b7d427987f6e98b6f32e84ee071f36f85c3d4.zip | |
blk-mq: for_each_* macro correctness
I observed that there are for_each macros that do an extra memory access
beyond the defined area.
Normally this does not cause problems.
But, this can cause exceptions. For example: if the area is allocated at
the end of a page and the next page is not accessible.
For correctness, I suggest changing the arguments of the 'for loop' like
others 'for_each' do in the kernel.
Signed-off-by: Jose Alonso <joalonsof@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/blk-mq.h | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 851d34b7ac26..161b23105b1e 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -158,16 +158,16 @@ static inline struct request *blk_mq_tag_to_rq(struct blk_mq_hw_ctx *hctx, } #define queue_for_each_hw_ctx(q, hctx, i) \ - for ((i) = 0, hctx = (q)->queue_hw_ctx[0]; \ - (i) < (q)->nr_hw_queues; (i)++, hctx = (q)->queue_hw_ctx[i]) + 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, ctx = per_cpu_ptr((q)->queue_ctx, 0); \ - (i) < (q)->nr_queues; (i)++, ctx = per_cpu_ptr(q->queue_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, ctx = (hctx)->ctxs[0]; \ - (i) < (hctx)->nr_ctx; (i)++, ctx = (hctx)->ctxs[(i)]) + for ((i) = 0; (i) < (hctx)->nr_ctx && \ + ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++) #define blk_ctx_sum(q, sum) \ ({ \ |