Messages in this thread Patch in this message | | | From | Yuyang Du <> | Subject | [PATCH v2 23/23] locking/lockdep: Remove !dir in lock irq usage check | Date | Mon, 6 May 2019 16:19:39 +0800 |
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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> --- 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 24e3bca..7275d6c 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -3234,7 +3234,7 @@ typedef int (*check_usage_f)(struct task_struct *, struct held_lock *, * 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; -- 1.8.3.1
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