mmc: core: Fix null pointer dereference due to race conditions
Fix race condition between mmcqd thread and the mmc_queue_suspend
updating a shared variable mq->flags, which can lead to potential
null pointer dereference as following-
Unable to handle kernel NULL pointer dereference at
virtual address 00000020
pgd = c0004000
[00000020] *pgd=00000000
mmcqd/0: 186] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
CPU: 0 Tainted: G W (3.4.0-1251694-eng #1)
PC is at mmc_blk_err_check+0x20c/0x3b8
LR is at mmc_start_req+0x198/0x718
cpu0 | cpu1
x |= 1 | x |= 2
final value of x can be x = 1 or x = 2
Change-Id: Ie0fff6d6dba5aebb3584cba9fb98de24515c4cd8
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
[merez@codeaurora.org: fix conflicts due to missing stop transmission
and changes in new request implementation in 3.14]
Signed-off-by: Maya Erez <merez@codeaurora.org>
[venkatg@codeaurora.org: Fix conflicts due to changes in 3.14 kernel]
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
[subhashj@codeaurora.org: fixed trivial merge conflicts]
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
[xiaonian@codeaurora.org: fixed trivial merge conflicts]
Signed-off-by: Xiaonian Wang <xiaonian@codeaurora.org>
3 files changed