[PATCH] lockdep: show more details about self-test failures

Make the locking self-test failures (of 'FAILURE' type) easier to debug by
printing more information.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h
index 952bee7..a1c10b0 100644 (file)
--- a/include/linux/debug_locks.h
+++ b/include/linux/debug_locks.h
@@ -24,7 +24,7 @@ extern int debug_locks_off(void);
        int __ret = 0;                                                  \
                                                                        \
        if (unlikely(c)) {                                              \
-               if (debug_locks_off())                                  \
+               if (debug_locks_silent || debug_locks_off())            \
                        WARN_ON(1);                                     \
                __ret = 1;                                              \
        }                                                               \

diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
index 1865164..841539d 100644 (file)
--- a/kernel/mutex-debug.c
+++ b/kernel/mutex-debug.c
@@ -77,6 +77,9 @@ void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 
 void debug_mutex_unlock(struct mutex *lock)
 {
+       if (unlikely(!debug_locks))
+               return;
+
        DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
        DEBUG_LOCKS_WARN_ON(lock->magic != lock);
        DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);

diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 7945787..280332c 100644 (file)
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -963,7 +963,9 @@ static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask)
                        printk("failed|");
                } else {
                        unexpected_testcase_failures++;
+
                        printk("FAILED|");
+                       dump_stack();
                }
        } else {
                testcase_successes++;