diff options
| author | Kent Overstreet <kent.overstreet@linux.dev> | 2022-09-24 00:13:05 -0400 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2022-10-03 23:54:30 -0400 |
| commit | e1e9d7a1a81d7e464bf79878412450b77d2690c5 (patch) | |
| tree | 4ee933c559a6ac8a0a68dcc506266c1237c3ccd7 | |
| parent | ab140ac5142494649f0b022d49b44077f7b93a34 (diff) | |
locking/lockdep: lockdep_set_no_check_recursion()
This adds a method to tell lockdep not to check lock ordering within a
lock class - but to still check lock ordering w.r.t. other lock types.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
| -rw-r--r-- | include/linux/lockdep.h | 6 | ||||
| -rw-r--r-- | include/linux/lockdep_types.h | 2 | ||||
| -rw-r--r-- | kernel/locking/lockdep.c | 25 |
3 files changed, 32 insertions, 1 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index e027c504b7d3..66f28553c694 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -666,4 +666,10 @@ lockdep_rcu_suspicious(const char *file, const int line, const char *s) } #endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void lockdep_set_no_check_recursion(struct lockdep_map *map); +#else +static inline void lockdep_set_no_check_recursion(struct lockdep_map *map) {} +#endif + #endif /* __LINUX_LOCKDEP_H */ diff --git a/include/linux/lockdep_types.h b/include/linux/lockdep_types.h index d22430840b53..506e769b4a95 100644 --- a/include/linux/lockdep_types.h +++ b/include/linux/lockdep_types.h @@ -128,7 +128,7 @@ struct lock_class { u8 wait_type_inner; u8 wait_type_outer; u8 lock_type; - /* u8 hole; */ + u8 no_check_recursion; #ifdef CONFIG_LOCK_STAT unsigned long contention_point[LOCKSTAT_POINTS]; diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index fe2cebd7651e..0e83dfd9c20b 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -3021,6 +3021,9 @@ check_deadlock(struct task_struct *curr, struct held_lock *next) if ((next->read == 2) && prev->read) continue; + if (hlock_class(next)->no_check_recursion) + continue; + /* * We're holding the nest_lock, which serializes this lock's * nesting behaviour. @@ -3082,6 +3085,10 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, return 2; } + if (hlock_class(prev) == hlock_class(next) && + hlock_class(prev)->no_check_recursion) + return 2; + /* * Prove that the new <prev> -> <next> dependency would not * create a circular dependency in the graph. (We do this by @@ -6615,3 +6622,21 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) dump_stack(); } EXPORT_SYMBOL_GPL(lockdep_rcu_suspicious); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void lockdep_set_no_check_recursion(struct lockdep_map *lock) +{ + struct lock_class *class = lock->class_cache[0]; + unsigned long flags; + + raw_local_irq_save(flags); + lockdep_recursion_inc(); + + if (!class) + class = register_lock_class(lock, 0, 0); + + class->no_check_recursion = true; + lockdep_recursion_finish(); + raw_local_irq_restore(flags); +} +#endif |