From: "tip-bot2 for Davidlohr Bueso" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Davidlohr Bueso <dbueso@suse.de>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
dave@stgolabs.net, Ingo Molnar <mingo@kernel.org>,
Borislav Petkov <bp@alien8.de>,
linux-kernel@vger.kernel.org
Subject: [tip: locking/core] locking/mutex: Complain upon mutex API misuse in IRQ contexts
Date: Wed, 30 Oct 2019 10:03:59 -0000 [thread overview]
Message-ID: <157242983900.29376.2332769194381838907.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20191025033634.3330-1-dave@stgolabs.net>
The following commit has been merged into the locking/core branch of tip:
Commit-ID: a0855d24fc22d49cdc25664fb224caee16998683
Gitweb: https://git.kernel.org/tip/a0855d24fc22d49cdc25664fb224caee16998683
Author: Davidlohr Bueso <dave@stgolabs.net>
AuthorDate: Thu, 24 Oct 2019 20:36:34 -07:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Tue, 29 Oct 2019 12:22:52 +01:00
locking/mutex: Complain upon mutex API misuse in IRQ contexts
Add warning checks if mutex_trylock() or mutex_unlock() are used in
IRQ contexts, under CONFIG_DEBUG_MUTEXES=y.
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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Link: https://lkml.kernel.org/r/20191025033634.3330-1-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/locking/mutex.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 5352ce5..54cc5f9 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);
prev parent reply other threads:[~2019-10-30 10:04 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-25 3:36 [PATCH -tip] locking/mutex: Complain upon api misuse wrt interrupt context Davidlohr Bueso
2019-10-25 8:10 ` Peter Zijlstra
2019-10-25 17:27 ` Davidlohr Bueso
2019-10-30 10:03 ` tip-bot2 for Davidlohr Bueso [this message]
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