Messages in this thread Patch in this message | | | Date | Mon, 3 Jun 2019 06:22:24 -0700 | From | tip-bot for Yuyang Du <> | Subject | [tip:locking/core] locking/lockdep: Remove !dir in lock irq usage check |
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Commit-ID: bf998b98f5bce4ebc97b3980016f54fabb7a4958 Gitweb: https://git.kernel.org/tip/bf998b98f5bce4ebc97b3980016f54fabb7a4958 Author: Yuyang Du <duyuyang@gmail.com> AuthorDate: Mon, 6 May 2019 16:19:39 +0800 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 3 Jun 2019 11:55:53 +0200
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 <duyuyang@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> 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 <mingo@kernel.org> --- kernel/locking/lockdep.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
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;
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