[PATCH 09/11] net: Clean up sk_wait_event() vs might_sleep()

Peter Zijlstra
2014-09-24T08:29:57Z

[-- Attachment #1: peterz-sleep-net-sk_stream_wait_memory.patch --]
[-- Type: text/plain, Size: 1093 bytes --]

WARNING: CPU: 1 PID: 1744 at kernel/sched/core.c:7104 __might_sleep+0x58/0x90()
do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff81070e10>] prepare_to_wait+0x50 /0xa0

[<ffffffff8105bc38>] __might_sleep+0x58/0x90
[<ffffffff8148c671>] lock_sock_nested+0x31/0xb0
[<ffffffff81498aaa>] sk_stream_wait_memory+0x18a/0x2d0

Which is a false positive because sk_wait_event() will already have
TASK_RUNNING at that point if it would've gone through
schedule_timeout().

So annotate with fixup_sleep(); which goes away on !DEBUG builds.

Cc: netdev@vger.kernel.org
Cc: David Miller <davem@davemloft.net>
Reported-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
include/net/sock.h | 1 +
1 file changed, 1 insertion(+)

--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -902,6 +902,7 @@ static inline void sock_rps_reset_rxhash
if (!__rc) { \
*(__timeo) = schedule_timeout(*(__timeo)); \
} \
+ fixup_sleep(); \
lock_sock(__sk); \
__rc = __condition; \
__rc; \