On 3/11/24 19:47, George Stark wrote:
Hello Waiman, Marek
Thanks for the review.
I've never used lockdep for debug but it seems preferable to
keep that feature working. It could be look like this:
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index f7611c092db7..574f6de6084d 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 +117,31 @@ do { \
#ifdef CONFIG_DEBUG_MUTEXES
+int debug_devm_mutex_init(struct device *dev, struct mutex *lock);
+
+#define devm_mutex_init(dev, mutex) \
+({ \
+ int ret; \
+ mutex_init(mutex); \
+ ret = debug_devm_mutex_init(dev, mutex); \
+ ret; \
+})
The int ret variable is not needed. The macro can just end with
debug_devm_mutex_init().
+
void mutex_destroy(struct mutex *lock);
#else
+/*
+* When CONFIG_DEBUG_MUTEXES is off mutex_destroy is just a nop so
+* there's no really need to register it in devm subsystem.
"no really need"?
+*/
+#define devm_mutex_init(dev, mutex) \
+({ \
+ typecheck(struct device *, dev); \
+ mutex_init(mutex); \
+ 0; \
+})
Do we need a typecheck() here? Compilation will fail with
CONFIG_DEBUG_MUTEXES if dev is not a device pointer.
+
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..967a5367c79a 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"
@@ -89,6 +90,16 @@ void debug_mutex_init(struct mutex *lock, const
char *name,
lock->magic = lock;
}
+static void devm_mutex_release(void *res)
+{
+ mutex_destroy(res);
+}
+
+int debug_devm_mutex_init(struct device *dev, struct mutex *lock)
+{
+ return devm_add_action_or_reset(dev, devm_mutex_release, lock);
+}
+
/***
* mutex_destroy - mark a mutex unusable
* @lock: the mutex to be destroyed
