From 26c4eb192c6224e5297496cead36404b62fb071b Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 3 Oct 2017 19:25:26 +0100 Subject: [PATCH] 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: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Acked-by: John Johansen Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner 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: Ingo Molnar --- security/apparmor/include/lib.h | 11 ----------- security/apparmor/label.c | 8 ++++---- 2 files changed, 4 insertions(+), 15 deletions(-) diff --git a/security/apparmor/include/lib.h b/security/apparmor/include/lib.h index 436b3a722357..f546707a2bbb 100644 --- a/security/apparmor/include/lib.h +++ b/security/apparmor/include/lib.h @@ -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. diff --git a/security/apparmor/label.c b/security/apparmor/label.c index c5b99b954580..ad28e03a6f30 100644 --- a/security/apparmor/label.c +++ b/security/apparmor/label.c @@ -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 */