3.16.55-rc1 review patch. If anyone has any objections, please let me know.
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From: Jens Axboe axboe@kernel.dk
commit 2967acbb257a6a9bf912f4778b727e00972eac9b upstream.
A previous commit changed the locking around registration/cleanup, but direct callers of blk_trace_remove() were missed. This means that if we hit the error path in setup, we will deadlock on attempting to re-acquire the queue trace mutex.
Fixes: 1f2cac107c59 ("blktrace: fix unlocked access to init/start-stop/teardown") Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Ben Hutchings ben@decadent.org.uk --- kernel/trace/blktrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -562,7 +562,7 @@ static int __blk_trace_setup(struct requ return ret;
if (copy_to_user(arg, &buts, sizeof(buts))) { - blk_trace_remove(q); + __blk_trace_remove(q); return -EFAULT; } return 0; @@ -608,7 +608,7 @@ static int compat_blk_trace_setup(struct return ret;
if (copy_to_user(arg, &buts.name, ARRAY_SIZE(buts.name))) { - blk_trace_remove(q); + __blk_trace_remove(q); return -EFAULT; }