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Commit 26c4eb19 authored by Will Deacon's avatar Will Deacon Committed by Ingo Molnar
Browse files

locking/rwsem, security/apparmor: Replace homebrew use of write_can_lock() with lockdep 



The lockdep subsystem provides a robust way to assert that a lock is
held, so use that instead of write_can_lock, which can give incorrect
results for qrwlocks.

Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarJohn Johansen <john.johansen@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1507055129-12300-1-git-send-email-will.deacon@arm.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 0dc208b5

security/apparmor/include/lib.h

+0 −11
Original line number Diff line number Diff line
@@ -19,17 +19,6 @@ 


#include "match.h"



/* Provide our own test for whether a write lock is held for asserts

 * this is because on none SMP systems write_can_lock will always

 * resolve to true, which is what you want for code making decisions

 * based on it, but wrong for asserts checking that the lock is held

 */

#ifdef CONFIG_SMP

#define write_is_locked(X) !write_can_lock(X)

#else

#define write_is_locked(X) (1)

#endif /* CONFIG_SMP */



/*

 * DEBUG remains global (no per profile flag) since it is mostly used in sysctl

 * which is not related to profile accesses.

security/apparmor/label.c

+4 −4
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new) 


	AA_BUG(!orig);

	AA_BUG(!new);

	AA_BUG(!write_is_locked(&labels_set(orig)->lock));

	lockdep_assert_held_exclusive(&labels_set(orig)->lock);



	tmp = rcu_dereference_protected(orig->proxy->label,

					&labels_ns(orig)->lock);
@@ -571,7 +571,7 @@ static bool __label_remove(struct aa_label *label, struct aa_label *new) 


	AA_BUG(!ls);

	AA_BUG(!label);

	AA_BUG(!write_is_locked(&ls->lock));

	lockdep_assert_held_exclusive(&ls->lock);



	if (new)

		__aa_proxy_redirect(label, new);
@@ -608,7 +608,7 @@ static bool __label_replace(struct aa_label *old, struct aa_label *new) 
	AA_BUG(!ls);

	AA_BUG(!old);

	AA_BUG(!new);

	AA_BUG(!write_is_locked(&ls->lock));

	lockdep_assert_held_exclusive(&ls->lock);

	AA_BUG(new->flags & FLAG_IN_TREE);



	if (!label_is_stale(old))
@@ -645,7 +645,7 @@ static struct aa_label *__label_insert(struct aa_labelset *ls, 
	AA_BUG(!ls);

	AA_BUG(!label);

	AA_BUG(labels_set(label) != ls);

	AA_BUG(!write_is_locked(&ls->lock));

	lockdep_assert_held_exclusive(&ls->lock);

	AA_BUG(label->flags & FLAG_IN_TREE);



	/* Figure out where to put new node */