From: Yuyang Du Date: Mon, 6 May 2019 08:19:39 +0000 (+0800) Subject: locking/lockdep: Remove !dir in lock irq usage check X-Git-Tag: v5.3-rc1~203^2~57 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=bf998b98f5bce4ebc97b3980016f54fabb7a4958;p=linux.git locking/lockdep: Remove !dir in lock irq usage check In mark_lock_irq(), the following checks are performed: ---------------------------------- | -> | unsafe | read unsafe | |----------------------------------| | safe | F B | F* B* | |----------------------------------| | read safe | F? B* | - | ---------------------------------- Where: F: check_usage_forwards B: check_usage_backwards *: check enabled by STRICT_READ_CHECKS ?: check enabled by the !dir condition From checking point of view, the special F? case does not make sense, whereas it perhaps is made for peroformance concern. As later patch will address this issue, remove this exception, which makes the checks consistent later. With STRICT_READ_CHECKS = 1 which is default, there is no functional change. Signed-off-by: Yuyang Du Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bvanassche@acm.org Cc: frederic@kernel.org Cc: ming.lei@redhat.com Cc: will.deacon@arm.com Link: https://lkml.kernel.org/r/20190506081939.74287-24-duyuyang@gmail.com Signed-off-by: Ingo Molnar --- diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 9c4e2a7547d3..2168e94715b9 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -3235,7 +3235,7 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, * Validate that the lock dependencies don't have conflicting usage * states. */ - if ((!read || !dir || STRICT_READ_CHECKS) && + if ((!read || STRICT_READ_CHECKS) && !usage(curr, this, excl_bit, state_name(new_bit & ~LOCK_USAGE_READ_MASK))) return 0;