Merge tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull debugobjects fixes from Thomas Gleixner:
 "Two fixes for debugobjects:

   - Prevent the allocation path from waking up kswapd.

     That's a long standing issue due to the GFP_ATOMIC allocation flag.
     As debug objects can be invoked from pretty much any context waking
     kswapd can end up in arbitrary lock chains versus the waitqueue
     lock

   - Correct the explicit lockdep wait-type violation in
     debug_object_fill_pool()"

* tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  debugobjects: Don't wake up kswapd from fill_pool()
  debugobjects,locking: Annotate debug_object_fill_pool() wait type violation

2 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index b32256e9e944..74bd269a80a2 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -344,6 +344,16 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
 #define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
 #define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))
 
+/*
+ * Must use lock_map_aquire_try() with override maps to avoid
+ * lockdep thinking they participate in the block chain.
+ */
+#define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type)	\
+	struct lockdep_map _name = {			\
+		.name = #_name "-wait-type-override",	\
+		.wait_type_inner = _wait_type,		\
+		.lock_type = LD_LOCK_WAIT_OVERRIDE, }
+
 #else /* !CONFIG_LOCKDEP */
 
 static inline void lockdep_init_task(struct task_struct *task)
@@ -432,6 +442,9 @@ extern int lockdep_is_held(const void *);
 #define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
 #define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
 
+#define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type)	\
+	struct lockdep_map __maybe_unused _name = {}
+
 #endif /* !LOCKDEP */
 
 enum xhlock_context_t {
@@ -556,6 +569,7 @@ do {									\
 #define rwsem_release(l, i)			lock_release(l, i)
 
 #define lock_map_acquire(l)			lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
+#define lock_map_acquire_try(l)			lock_acquire_exclusive(l, 0, 1, NULL, _THIS_IP_)
 #define lock_map_acquire_read(l)		lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
 #define lock_map_acquire_tryread(l)		lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
 #define lock_map_release(l)			lock_release(l, _THIS_IP_)
diff --git a/include/linux/lockdep_types.h b/include/linux/lockdep_types.h
index d22430840b53..59f4fb1626ea 100644
--- a/include/linux/lockdep_types.h
+++ b/include/linux/lockdep_types.h
@@ -33,6 +33,7 @@ enum lockdep_wait_type {
 enum lockdep_lock_type {
 	LD_LOCK_NORMAL = 0,	/* normal, catch all */
 	LD_LOCK_PERCPU,		/* percpu */
+	LD_LOCK_WAIT_OVERRIDE,	/* annotation */
 	LD_LOCK_MAX,
 };