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Commit 1c21f14e authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1236172646.5330.7450.camel@laptop>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 6700ec65

kernel/lockdep.c

+3 −2
Original line number Diff line number Diff line
@@ -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;



	/*