diff options
| -rw-r--r-- | include/linux/lockdep.h | 23 | ||||
| -rw-r--r-- | kernel/locking/lockdep.c | 14 | ||||
| -rw-r--r-- | lib/locking-selftest.c | 11 |
3 files changed, 47 insertions, 1 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 6a584b3e5c74..7cae5ea00d59 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -469,6 +469,20 @@ static inline void print_irqtrace_events(struct task_struct *curr) } #endif +/* Variable used to make lockdep treat read_lock() as recursive in selftests */ +#ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS +extern unsigned int force_read_lock_recursive; +#else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */ +#define force_read_lock_recursive 0 +#endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */ + +#ifdef CONFIG_LOCKDEP +extern bool read_lock_is_recursive(void); +#else /* CONFIG_LOCKDEP */ +/* If !LOCKDEP, the value is meaningless */ +#define read_lock_is_recursive() 0 +#endif + /* * For trivial one-depth nesting of a lock-class, the following * global define can be used. (Subsystems with multiple levels @@ -490,7 +504,14 @@ static inline void print_irqtrace_events(struct task_struct *curr) #define spin_release(l, i) lock_release(l, i) #define rwlock_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) -#define rwlock_acquire_read(l, s, t, i) lock_acquire_shared_recursive(l, s, t, NULL, i) +#define rwlock_acquire_read(l, s, t, i) \ +do { \ + if (read_lock_is_recursive()) \ + lock_acquire_shared_recursive(l, s, t, NULL, i); \ + else \ + lock_acquire_shared(l, s, t, NULL, i); \ +} while (0) + #define rwlock_release(l, i) lock_release(l, i) #define seqcount_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 54b74fabf40c..77cd9e6520c4 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -4968,6 +4968,20 @@ static bool lockdep_nmi(void) } /* + * read_lock() is recursive if: + * 1. We force lockdep think this way in selftests or + * 2. The implementation is not queued read/write lock or + * 3. The locker is at an in_interrupt() context. + */ +bool read_lock_is_recursive(void) +{ + return force_read_lock_recursive || + !IS_ENABLED(CONFIG_QUEUED_RWLOCKS) || + in_interrupt(); +} +EXPORT_SYMBOL_GPL(read_lock_is_recursive); + +/* * We are not always called with irqs disabled - do that here, * and also avoid lockdep recursion: */ diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 14f44f59e733..caadc4dd3368 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -28,6 +28,7 @@ * Change this to 1 if you want to see the failure printouts: */ static unsigned int debug_locks_verbose; +unsigned int force_read_lock_recursive; static DEFINE_WD_CLASS(ww_lockdep); @@ -1979,6 +1980,11 @@ void locking_selftest(void) } /* + * treats read_lock() as recursive read locks for testing purpose + */ + force_read_lock_recursive = 1; + + /* * Run the testsuite: */ printk("------------------------\n"); @@ -2073,6 +2079,11 @@ void locking_selftest(void) ww_tests(); + force_read_lock_recursive = 0; + /* + * queued_read_lock() specific test cases can be put here + */ + if (unexpected_testcase_failures) { printk("-----------------------------------------------------------------\n"); debug_locks = 0; |