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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-03-04 13:51:13 +0100
committerIngo Molnar <mingo@elte.hu>2009-03-04 18:38:33 +0100
commit1c21f14ec48a2256fb03682b24dddd23eacdc96f (patch)
tree03b6ecf8d87074d1f154ff8ac794e9084e00d7cd /kernel/lockdep.c
parent6700ec65c207068a81a535e9dca616fefac21671 (diff)
downloadlinux-1c21f14ec48a2256fb03682b24dddd23eacdc96f.tar.gz
lockdep: fix incorrect state name
In the recent mark_lock_irq() rework a bug snuck in that would report the
state of write locks causing irq inversion under a read lock as a read
lock.

Fix this by masking the read bit of the state when validating write
dependencies.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1236172646.5330.7450.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/lockdep.c')
-rw-r--r--kernel/lockdep.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 022d2ed7fd8b..ef6584fd9fe5 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -2015,7 +2015,8 @@ typedef int (*check_usage_f)(struct task_struct *, struct held_lock *,
 			     enum lock_usage_bit bit, const char *name);
 
 static int
-mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit)
+mark_lock_irq(struct task_struct *curr, struct held_lock *this,
+		enum lock_usage_bit new_bit)
 {
 	int excl_bit = exclusive_bit(new_bit);
 	int read = new_bit & 1;
@@ -2043,7 +2044,7 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit)
 	 * states.
 	 */
 	if ((!read || !dir || STRICT_READ_CHECKS) &&
-			!usage(curr, this, excl_bit, state_name(new_bit)))
+			!usage(curr, this, excl_bit, state_name(new_bit & ~1)))
 		return 0;
 
 	/*