Commit-ID: fe63b94a430c0c8058de317f0a8ce921c69dbee4 Gitweb: http://git.kernel.org/tip/fe63b94a430c0c8058de317f0a8ce921c69dbee4 Author: Carsten Emde <Carsten.Emde@xxxxxxxxx> AuthorDate: Sat, 12 Sep 2009 00:05:37 +0200 Committer: Steven Rostedt <rostedt@xxxxxxxxxxx> CommitDate: Sat, 12 Sep 2009 21:31:19 -0400 tracing: prevent NULL pointer dereference in ftrace_raw_event_block_bio_bounce Booting 2.6.31 and executing echo 1 >/sys/kernel/debug/tracing/events/enable leads to BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<c032a583>] ftrace_raw_event_block_bio_bounce+0x4b/0xb9 Apparently, bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask); is called in block/blk-map.c:58 where bio->bi_bdev in set to NULL and still is NULL when an attempt is made to evaluate bio->bi_bdev->bd_dev in include/trace/events/block.h:189. The tracepoint should ensure bio->bi_bdev is not dereferenced, if NULL. Signed-off-by: Carsten Emde <C.Emde@xxxxxxxxx> LKML-Reference: <4AAAC9B1.9060505@xxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- include/trace/events/block.h | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/include/trace/events/block.h b/include/trace/events/block.h index 9a74b46..d86af94 100644 --- a/include/trace/events/block.h +++ b/include/trace/events/block.h @@ -171,6 +171,7 @@ TRACE_EVENT(block_rq_complete, (unsigned long long)__entry->sector, __entry->nr_sector, __entry->errors) ); + TRACE_EVENT(block_bio_bounce, TP_PROTO(struct request_queue *q, struct bio *bio), @@ -186,7 +187,8 @@ TRACE_EVENT(block_bio_bounce, ), TP_fast_assign( - __entry->dev = bio->bi_bdev->bd_dev; + __entry->dev = bio->bi_bdev ? + bio->bi_bdev->bd_dev : 0; __entry->sector = bio->bi_sector; __entry->nr_sector = bio->bi_size >> 9; blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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