From: George Stark <gnstark@salutedevices.com>
To: <andy.shevchenko@gmail.com>, <pavel@ucw.cz>, <lee@kernel.org>,
<vadimp@nvidia.com>, <mpe@ellerman.id.au>, <npiggin@gmail.com>,
<christophe.leroy@csgroup.eu>, <hdegoede@redhat.com>,
<mazziesaccount@gmail.com>, <peterz@infradead.org>,
<mingo@redhat.com>, <will@kernel.org>, <longman@redhat.com>,
<boqun.feng@gmail.com>, <nikitos.tr@gmail.com>,
<kabel@kernel.org>
Cc: <linux-leds@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linuxppc-dev@lists.ozlabs.org>, <kernel@salutedevices.com>,
George Stark <gnstark@salutedevices.com>
Subject: [PATCH v5 02/10] locking/mutex: introduce devm_mutex_init
Date: Thu, 7 Mar 2024 05:40:26 +0300 [thread overview]
Message-ID: <20240307024034.1548605-3-gnstark@salutedevices.com> (raw)
In-Reply-To: <20240307024034.1548605-1-gnstark@salutedevices.com>
Using of devm API leads to a certain order of releasing resources.
So all dependent resources which are not devm-wrapped should be deleted
with respect to devm-release order. Mutex is one of such objects that
often is bound to other resources and has no own devm wrapping.
Since mutex_destroy() actually does nothing in non-debug builds
frequently calling mutex_destroy() is just ignored which is safe for now
but wrong formally and can lead to a problem if mutex_destroy() will be
extended so introduce devm_mutex_init()
Signed-off-by: George Stark <gnstark@salutedevices.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
Hello Christophe. Hope you don't mind I put you SoB tag because you helped alot
to make this patch happen.
include/linux/mutex.h | 13 +++++++++++++
kernel/locking/mutex-debug.c | 22 ++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index f7611c092db7..9bcf72cb941a 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -22,6 +22,8 @@
#include <linux/cleanup.h>
#include <linux/mutex_types.h>
+struct device;
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
, .dep_map = { \
@@ -115,10 +117,21 @@ do { \
#ifdef CONFIG_DEBUG_MUTEXES
+int devm_mutex_init(struct device *dev, struct mutex *lock);
void mutex_destroy(struct mutex *lock);
#else
+static inline int devm_mutex_init(struct device *dev, struct mutex *lock)
+{
+ /*
+ * since mutex_destroy is nop actually there's no need to register it
+ * in devm subsystem.
+ */
+ mutex_init(lock);
+ return 0;
+}
+
static inline void mutex_destroy(struct mutex *lock) {}
#endif
diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c
index bc8abb8549d2..c9efab1a8026 100644
--- a/kernel/locking/mutex-debug.c
+++ b/kernel/locking/mutex-debug.c
@@ -19,6 +19,7 @@
#include <linux/kallsyms.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
+#include <linux/device.h>
#include "mutex.h"
@@ -104,3 +105,24 @@ void mutex_destroy(struct mutex *lock)
}
EXPORT_SYMBOL_GPL(mutex_destroy);
+
+static void devm_mutex_release(void *res)
+{
+ mutex_destroy(res);
+}
+
+/**
+ * devm_mutex_init - Resource-managed mutex initialization
+ * @dev: Device which lifetime mutex is bound to
+ * @lock: Pointer to a mutex
+ *
+ * Initialize mutex which is automatically destroyed when the driver is detached.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int devm_mutex_init(struct device *dev, struct mutex *lock)
+{
+ mutex_init(lock);
+ return devm_add_action_or_reset(dev, devm_mutex_release, lock);
+}
+EXPORT_SYMBOL_GPL(devm_mutex_init);
--
2.25.1
next prev parent reply other threads:[~2024-03-07 2:40 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-07 2:40 [PATCH v5 00/10] devm_led_classdev_register() usage problem George Stark
2024-03-07 2:40 ` [PATCH v5 01/10] locking/mutex: move mutex_destroy() definition lower George Stark
2024-03-07 2:40 ` George Stark [this message]
2024-03-07 9:56 ` [PATCH v5 02/10] locking/mutex: introduce devm_mutex_init Marek Behún
2024-03-07 13:39 ` Waiman Long
2024-03-07 16:44 ` Marek Behún
2024-03-11 23:47 ` George Stark
2024-03-12 1:10 ` Waiman Long
2024-03-12 5:44 ` Christophe Leroy
2024-03-12 6:04 ` Christophe Leroy
2024-03-12 11:39 ` George Stark
2024-03-12 11:51 ` Christophe Leroy
2024-03-12 15:30 ` George Stark
2024-03-12 18:17 ` Christophe Leroy
2024-03-07 10:34 ` Andy Shevchenko
2024-03-12 0:01 ` George Stark
2024-03-12 5:41 ` Christophe Leroy
2024-03-12 8:58 ` Andy Shevchenko
2024-03-07 13:50 ` Christophe Leroy
2024-03-11 23:31 ` George Stark
2024-03-07 2:40 ` [PATCH v5 03/10] leds: aw2013: use devm API to cleanup module's resources George Stark
2024-03-07 2:40 ` [PATCH v5 04/10] leds: aw200xx: " George Stark
2024-03-07 2:40 ` [PATCH v5 05/10] leds: lp3952: " George Stark
2024-03-07 2:40 ` [PATCH v5 06/10] leds: lm3532: " George Stark
2024-03-07 2:40 ` [PATCH v5 07/10] leds: nic78bx: " George Stark
2024-03-07 2:40 ` [PATCH v5 08/10] leds: mlxreg: use devm_mutex_init for mutex initializtion George Stark
2024-03-07 2:40 ` [PATCH v5 09/10] leds: an30259a: use devm_mutext_init for mutext initialization George Stark
2024-03-07 2:40 ` [PATCH v5 10/10] leds: powernv: use LED_RETAIN_AT_SHUTDOWN flag for leds George Stark
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