[PATCH v18 24/42] locking/lockdep: prevent various lockdep assertions when lockdep_off()'ed
From: Byungchul Park <byungchul@sk.com>
Date: 2025-12-05 07:20:37
Also in:
dri-devel, linux-arch, linux-block, linux-doc, linux-ext4, linux-fsdevel, linux-i2c, linux-ide, linux-media, linux-mm, linux-modules, linux-nfs, linux-rt-devel, lkml, rcu, rust-for-linux
Subsystem:
locking primitives, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, Linus Torvalds
lockdep provides APIs for assertion only if lockdep is enabled at the
moment asserting to avoid unnecessary confusion, using the following
condition, debug_locks && !this_cpu_read(lockdep_recursion).
However, lockdep_{off,on}() are also used for disabling and enabling
lockdep for a simular purpose. Add !lockdep_recursing(current) that is
updated by lockdep_{off,on}() to the condition so that the assertions
are aware of !__lockdep_enabled if lockdep_off()'ed.
Signed-off-by: Byungchul Park <byungchul@sk.com>
---
include/linux/lockdep.h | 3 ++-
kernel/locking/lockdep.c | 10 ++++++++++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index ebfc781c3095..9389fc859129 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h@@ -303,6 +303,7 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); lockdep_assert_once(!current->lockdep_depth) #define lockdep_recursing(tsk) ((tsk)->lockdep_recursion) +extern bool lockdep_recursing_current(void); #define lockdep_pin_lock(l) lock_pin_lock(&(l)->dep_map) #define lockdep_repin_lock(l,c) lock_repin_lock(&(l)->dep_map, (c))
@@ -630,7 +631,7 @@ DECLARE_PER_CPU(int, hardirqs_enabled); DECLARE_PER_CPU(int, hardirq_context); DECLARE_PER_CPU(unsigned int, lockdep_recursion); -#define __lockdep_enabled (debug_locks && !this_cpu_read(lockdep_recursion)) +#define __lockdep_enabled (debug_locks && !this_cpu_read(lockdep_recursion) && !lockdep_recursing_current()) #define lockdep_assert_irqs_enabled() \ do { \
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index dc97f2753ef8..39b9e3e27c0b 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c@@ -6900,3 +6900,13 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) warn_rcu_exit(rcu); } EXPORT_SYMBOL_GPL(lockdep_rcu_suspicious); + +/* + * For avoiding header dependency when using (struct task_struct *)current + * and lockdep_recursing() at the same time. + */ +noinstr bool lockdep_recursing_current(void) +{ + return lockdep_recursing(current); +} +EXPORT_SYMBOL_GPL(lockdep_recursing_current);
--
2.17.1