The patch titled
lockdep: add novalidate class for dev->mutex conversion
has been added to the -mm tree. Its filename is
lockdep-add-novalidate-class-for-dev-mutex-conversion.patch
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------------------------------------------------------
Subject: lockdep: add novalidate class for dev->mutex conversion
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
The conversion of device->sem to device->mutex resulted in lockdep
warnings. Create a novalidate class for now until the driver folks come
up with separate classes. That way we have at least the basic mutex
debugging coverage.
Add a checkpatch error so the usage is reserved for device->mutex.
[tglx@xxxxxxxxxxxxx: checkpatch and compile fix for LOCKDEP=n]
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Valdis Kletnieks <Valdis.Kletnieks@xxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/base/core.c | 1 +
include/linux/lockdep.h | 8 ++++++++
kernel/lockdep.c | 5 +++++
scripts/checkpatch.pl | 11 +++++++++++
4 files changed, 25 insertions(+)
diff -puN drivers/base/core.c~lockdep-add-novalidate-class-for-dev-mutex-conversion drivers/base/core.c
--- a/drivers/base/core.c~lockdep-add-novalidate-class-for-dev-mutex-conversion
+++ a/drivers/base/core.c
@@ -559,6 +559,7 @@ void device_initialize(struct device *de
kobject_init(&dev->kobj, &device_ktype);
INIT_LIST_HEAD(&dev->dma_pools);
mutex_init(&dev->mutex);
+ lockdep_set_novalidate_class(&dev->mutex);
spin_lock_init(&dev->devres_lock);
INIT_LIST_HEAD(&dev->devres_head);
device_pm_init(dev);
diff -puN include/linux/lockdep.h~lockdep-add-novalidate-class-for-dev-mutex-conversion include/linux/lockdep.h
--- a/include/linux/lockdep.h~lockdep-add-novalidate-class-for-dev-mutex-conversion
+++ a/include/linux/lockdep.h
@@ -44,6 +44,8 @@ struct lock_class_key {
struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
};
+extern struct lock_class_key __lockdep_no_validate__;
+
#define LOCKSTAT_POINTS 4
/*
@@ -270,6 +272,9 @@ extern void lockdep_init_map(struct lock
#define lockdep_set_subclass(lock, sub) \
lockdep_init_map(&(lock)->dep_map, #lock, \
(lock)->dep_map.key, sub)
+
+#define lockdep_set_novalidate_class(lock) \
+ lockdep_set_class(lock, &__lockdep_no_validate__)
/*
* Compare locking classes
*/
@@ -354,6 +359,9 @@ static inline void lockdep_on(void)
#define lockdep_set_class_and_subclass(lock, key, sub) \
do { (void)(key); } while (0)
#define lockdep_set_subclass(lock, sub) do { } while (0)
+
+#define lockdep_set_novalidate_class(lock) do { } while (0)
+
/*
* We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
* case since the result is not well defined and the caller should rather
diff -puN kernel/lockdep.c~lockdep-add-novalidate-class-for-dev-mutex-conversion kernel/lockdep.c
--- a/kernel/lockdep.c~lockdep-add-novalidate-class-for-dev-mutex-conversion
+++ a/kernel/lockdep.c
@@ -2716,6 +2716,8 @@ void lockdep_init_map(struct lockdep_map
}
EXPORT_SYMBOL_GPL(lockdep_init_map);
+struct lock_class_key __lockdep_no_validate__;
+
/*
* This gets called for every mutex_lock*()/spin_lock*() operation.
* We maintain the dependency maps and validate the locking attempt:
@@ -2750,6 +2752,9 @@ static int __lock_acquire(struct lockdep
return 0;
}
+ if (lock->key == &__lockdep_no_validate__)
+ check = 1;
+
if (!subclass)
class = lock->class_cache;
/*
diff -puN scripts/checkpatch.pl~lockdep-add-novalidate-class-for-dev-mutex-conversion scripts/checkpatch.pl
--- a/scripts/checkpatch.pl~lockdep-add-novalidate-class-for-dev-mutex-conversion
+++ a/scripts/checkpatch.pl
@@ -2656,6 +2656,7 @@ sub process {
# check for semaphores used as mutexes
if ($line =~ /^.\s*init_MUTEX_LOCKED\s*\(/) {
WARN("consider using a completion\n" . $herecurr);
+
}
# recommend strict_strto* over simple_strto*
if ($line =~ /\bsimple_(strto.*?)\s*\(/) {
@@ -2740,6 +2741,16 @@ sub process {
WARN("use of in_atomic() is incorrect outside core kernel code\n" . $herecurr);
}
}
+
+# check for lockdep_set_novalidate_class
+ if ($line =~ /^.\s*lockdep_set_novalidate_class\s*\(/ ||
+ $line =~ /__lockdep_no_validate__\s*\)/ ) {
+ if ($realfile !~ m@^kernel/lockdep@ &&
+ $realfile !~ m@^include/linux/lockdep@ &&
+ $realfile !~ m@^drivers/base/core@) {
+ ERROR("lockdep_no_validate class is reserved for device->mutex.\n" . $herecurr);
+ }
+ }
}
# If we have no input at all, then there is nothing to report on
_
Patches currently in -mm which might be from peterz@xxxxxxxxxxxxx are
origin.patch
linux-next.patch
posix-cpu-timers-reset-expire-cache-when-no-timer-is-running.patch
lockdep-add-novalidate-class-for-dev-mutex-conversion.patch
tracehooks-kill-some-pt_ptraced-checks.patch
tracehooks-check-pt_ptraced-before-reporting-the-single-step.patch
ptrace_signal-check-pt_ptraced-before-reporting-a-signal.patch
export-__ptrace_detach-and-do_notify_parent_cldstop.patch
reorder-the-code-in-kernel-ptracec.patch
implement-utrace-ptrace.patch
utrace-core.patch
--
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