From: Peter Zijlstra <peterz@infradead.org>
Date: Wed, 24 Sep 2014 08:18:54 +0000 (+0200)
Subject: sched, net: Clean up sk_wait_event() vs. might_sleep()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=26cabd31259ba43f68026ce3f62b78094124333f;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

sched, net: Clean up sk_wait_event() vs. might_sleep()

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 sched_annotate_sleep(); which goes away on !DEBUG builds.

Reported-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140924082242.524407432@infradead.org
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: netdev@vger.kernel.org
Cc: tglx@linutronix.de
Cc: ilya.dryomov@inktank.com
Cc: umgwanakikbuti@gmail.com
Cc: oleg@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/include/net/sock.h b/include/net/sock.h
index 7db3db112baa..e6f235ebf6c9 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -897,6 +897,7 @@ static inline void sock_rps_reset_rxhash(struct sock *sk)
 		if (!__rc) {						\
 			*(__timeo) = schedule_timeout(*(__timeo));	\
 		}							\
+		sched_annotate_sleep();						\
 		lock_sock(__sk);					\
 		__rc = __condition;					\
 		__rc;							\