dma-debug: fix locking bug in check_unmap()
authorAlexander Duyck <alexander.h.duyck@intel.com>
Fri, 22 Mar 2013 22:04:48 +0000 (15:04 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 22 Mar 2013 23:41:20 +0000 (16:41 -0700)
commit8d640a51ec9e9cdefa680b67ad55f933eefc5923
treec8e8964a54f42a529fceb6ef80590592d13bf68d
parent0ef1594c017521ea89278e80fe3f80dafb17abde
dma-debug: fix locking bug in check_unmap()

In check_unmap() it is possible to get into a dead-locked state if
dma_mapping_error is called.  The problem is that the bucket is locked in
check_unmap, and locked again by debug_dma_mapping_error which is called
by dma_mapping_error.  To resolve that we must release the lock on the
bucket before making the call to dma_mapping_error.

[akpm@linux-foundation.org: restore 80-col trickery to be consistent with the rest of the file]
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Reviewed-by: Shuah Khan <shuah.khan@hp.com>
Tested-by: Shuah Khan <shuah.khan@hp.com>
Cc: Jakub Kicinski <kubakici@wp.pl>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib/dma-debug.c