[tip:core/locking] lockdep: Print lock name in lockdep_init_error()

From: tip-bot for Ming Lei
Date: Tue Dec 06 2011 - 04:41:29 EST


Commit-ID: 81140acc66322dcde8346dabdf1ab4c229fce8d4
Gitweb: http://git.kernel.org/tip/81140acc66322dcde8346dabdf1ab4c229fce8d4
Author: Ming Lei <tom.leiming@xxxxxxxxx>
AuthorDate: Thu, 17 Nov 2011 13:34:32 +0800
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 6 Dec 2011 08:16:55 +0100

lockdep: Print lock name in lockdep_init_error()

This patch prints the name of the lock which is acquired
before lockdep_init() is called, so that users can easily
find which lock triggered the lockdep init error warning.

This patch also removes the lockdep_init_error() message
of "Arch code didn't call lockdep_init() early enough?"
since lockdep_init() is called in arch independent code now.

Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1321508072-23853-2-git-send-email-tom.leiming@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/lockdep.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 54cc0dc..e69d633 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -431,6 +431,7 @@ unsigned int max_lockdep_depth;
* about it later on, in lockdep_info().
*/
static int lockdep_init_error;
+static const char *lock_init_error;
static unsigned long lockdep_init_trace_data[20];
static struct stack_trace lockdep_init_trace = {
.max_entries = ARRAY_SIZE(lockdep_init_trace_data),
@@ -657,6 +658,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
if (unlikely(!lockdep_initialized)) {
lockdep_init();
lockdep_init_error = 1;
+ lock_init_error = lock->name;
save_stack_trace(&lockdep_init_trace);
}
#endif
@@ -3978,7 +3980,8 @@ void __init lockdep_info(void)

#ifdef CONFIG_DEBUG_LOCKDEP
if (lockdep_init_error) {
- printk("WARNING: lockdep init error! Arch code didn't call lockdep_init() early enough?\n");
+ printk("WARNING: lockdep init error! lock-%s was acquired"
+ "before lockdep_init\n", lock_init_error);
printk("Call stack leading to lockdep invocation was:\n");
print_stack_trace(&lockdep_init_trace, 0);
}
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