[PATCH] locking/lockdep: Fix lockdep_init_map_*() confusion

From: Peter Zijlstra
Date: Fri Jun 17 2022 - 09:39:36 EST



Commit dfd5e3f5fe27 ("locking/lockdep: Mark local_lock_t") added yet
another lockdep_init_map_*() variant, but forgot to update all the
existing users of the most complicated version.

This could lead to a loss of lock_type and hence an incorrect report.
Given the relative rarity of both local_lock and these annotations,
this is unlikely to happen in practise, still, best fix things.

Fixes: dfd5e3f5fe27 ("locking/lockdep: Mark local_lock_t")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
include/linux/lockdep.h | 30 +++++++++++++++++-------------
kernel/locking/lockdep.c | 7 ++++---
2 files changed, 21 insertions(+), 16 deletions(-)

--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -188,7 +188,7 @@ static inline void
lockdep_init_map_waits(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass, u8 inner, u8 outer)
{
- lockdep_init_map_type(lock, name, key, subclass, inner, LD_WAIT_INV, LD_LOCK_NORMAL);
+ lockdep_init_map_type(lock, name, key, subclass, inner, outer, LD_LOCK_NORMAL);
}

static inline void
@@ -211,24 +211,28 @@ static inline void lockdep_init_map(stru
* or they are too narrow (they suffer from a false class-split):
*/
#define lockdep_set_class(lock, key) \
- lockdep_init_map_waits(&(lock)->dep_map, #key, key, 0, \
- (lock)->dep_map.wait_type_inner, \
- (lock)->dep_map.wait_type_outer)
+ lockdep_init_map_type(&(lock)->dep_map, #key, key, 0, \
+ (lock)->dep_map.wait_type_inner, \
+ (lock)->dep_map.wait_type_outer, \
+ (lock)->dep_map.lock_type)

#define lockdep_set_class_and_name(lock, key, name) \
- lockdep_init_map_waits(&(lock)->dep_map, name, key, 0, \
- (lock)->dep_map.wait_type_inner, \
- (lock)->dep_map.wait_type_outer)
+ lockdep_init_map_type(&(lock)->dep_map, name, key, 0, \
+ (lock)->dep_map.wait_type_inner, \
+ (lock)->dep_map.wait_type_outer, \
+ (lock)->dep_map.lock_type)

#define lockdep_set_class_and_subclass(lock, key, sub) \
- lockdep_init_map_waits(&(lock)->dep_map, #key, key, sub,\
- (lock)->dep_map.wait_type_inner, \
- (lock)->dep_map.wait_type_outer)
+ lockdep_init_map_type(&(lock)->dep_map, #key, key, sub, \
+ (lock)->dep_map.wait_type_inner, \
+ (lock)->dep_map.wait_type_outer, \
+ (lock)->dep_map.lock_type)

#define lockdep_set_subclass(lock, sub) \
- lockdep_init_map_waits(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
- (lock)->dep_map.wait_type_inner, \
- (lock)->dep_map.wait_type_outer)
+ lockdep_init_map_type(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
+ (lock)->dep_map.wait_type_inner, \
+ (lock)->dep_map.wait_type_outer, \
+ (lock)->dep_map.lock_type)

#define lockdep_set_novalidate_class(lock) \
lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -5238,9 +5238,10 @@ __lock_set_class(struct lockdep_map *loc
return 0;
}

- lockdep_init_map_waits(lock, name, key, 0,
- lock->wait_type_inner,
- lock->wait_type_outer);
+ lockdep_init_map_type(lock, name, key, 0,
+ lock->wait_type_inner,
+ lock->wait_type_outer,
+ lock->lock_type);
class = register_lock_class(lock, subclass, 0);
hlock->class_idx = class - lock_classes;