From: Davidlohr Bueso <dave@stgolabs.net>
To: mingo@kernel.org
Cc: peterz@infradead.org, dave@stgolabs.net,
linux-kernel@vger.kernel.org, Davidlohr Bueso <dbueso@suse.de>
Subject: [PATCH -tip] locking/mutex: Complain upon api misuse wrt interrupt context
Date: Thu, 24 Oct 2019 20:36:34 -0700 [thread overview]
Message-ID: <20191025033634.3330-1-dave@stgolabs.net> (raw)
Sprinkle warning checks, under CONFIG_DEBUG_MUTEXES. While the mutex
rules and semantics are explicitly documented, this allows to expose
any abusers and robustifies the whole thing. While trylock and unlock
are non-blocking, calling from irq context is still forbidden (lock
must be within the same context as unlock).
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
kernel/locking/mutex.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 468a9b8422e3..7e9c316c646c 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -733,6 +733,9 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
*/
void __sched mutex_unlock(struct mutex *lock)
{
+#ifdef CONFIG_DEBUG_MUTEXES
+ WARN_ON(in_interrupt());
+#endif
#ifndef CONFIG_DEBUG_LOCK_ALLOC
if (__mutex_unlock_fast(lock))
return;
@@ -1413,6 +1416,7 @@ int __sched mutex_trylock(struct mutex *lock)
#ifdef CONFIG_DEBUG_MUTEXES
DEBUG_LOCKS_WARN_ON(lock->magic != lock);
+ WARN_ON(in_interrupt());
#endif
locked = __mutex_trylock(lock);
--
2.16.4
next reply other threads:[~2019-10-25 3:39 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-25 3:36 Davidlohr Bueso [this message]
2019-10-25 8:10 ` [PATCH -tip] locking/mutex: Complain upon api misuse wrt interrupt context Peter Zijlstra
2019-10-25 17:27 ` Davidlohr Bueso
2019-10-30 10:03 ` [tip: locking/core] locking/mutex: Complain upon mutex API misuse in IRQ contexts tip-bot2 for Davidlohr Bueso
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