From: Rabin Vincent <rabin@rab.in>
Date: Mon, 11 Aug 2008 07:30:26 +0000 (+0200)
Subject: lockdep: handle chains involving classes defined in modules
X-Git-Tag: v2.6.27-rc3~50^2^2~4
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8bfe0298f7a04952d19f4a2cf510d7a6311eeed0;p=linux-2.6

lockdep: handle chains involving classes defined in modules

Solve this by marking the classes as unused and not printing information
about the unused classes.

Reported-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 410c3365ad..ab933fecd2 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3176,6 +3176,7 @@ static void zap_class(struct lock_class *class)
 	list_del_rcu(&class->hash_entry);
 	list_del_rcu(&class->lock_entry);
 
+	class->key = NULL;
 }
 
 static inline int within(const void *addr, void *start, unsigned long size)
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 6252ff799d..fa19aee604 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -201,6 +201,9 @@ static int lc_show(struct seq_file *m, void *v)
 
 	for (i = 0; i < chain->depth; i++) {
 		class = lock_chain_get_class(chain, i);
+		if (!class->key)
+			continue;
+
 		seq_printf(m, "[%p] ", class->key);
 		print_name(m, class);
 		seq_puts(m, "\n");