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From:   Yuyang Du <duyuyang@gmail.com>
To:     peterz@infradead.org, will.deacon@arm.com, mingo@kernel.org
Cc:     cai@lca.pw, linux-kernel@vger.kernel.org,
        Yuyang Du <duyuyang@gmail.com>
Subject: [PATCH] locking/lockdep: Fix lock IRQ usage initialization bug
Date:   Mon, 10 Jun 2019 13:52:58 +0800
Message-Id: <20190610055258.6424-1-duyuyang@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The commit:

  091806515124b20 ("locking/lockdep: Consolidate lock usage bit initialization")

misses marking LOCK_USED flag at IRQ usage initialization when CONFIG_TRACE_IRQFLAGS
or CONFIG_PROVE_LOCKING is not defined. Fix it.

Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
 kernel/locking/lockdep.c | 110 +++++++++++++++++++++++------------------------
 1 file changed, 53 insertions(+), 57 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 48a840a..c3db987 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3460,9 +3460,61 @@ void trace_softirqs_off(unsigned long ip)
 		debug_atomic_inc(redundant_softirqs_off);
 }
 
+static inline unsigned int task_irq_context(struct task_struct *task)
+{
+	return 2 * !!task->hardirq_context + !!task->softirq_context;
+}
+
+static int separate_irq_context(struct task_struct *curr,
+		struct held_lock *hlock)
+{
+	unsigned int depth = curr->lockdep_depth;
+
+	/*
+	 * Keep track of points where we cross into an interrupt context:
+	 */
+	if (depth) {
+		struct held_lock *prev_hlock;
+
+		prev_hlock = curr->held_locks + depth-1;
+		/*
+		 * If we cross into another context, reset the
+		 * hash key (this also prevents the checking and the
+		 * adding of the dependency to 'prev'):
+		 */
+		if (prev_hlock->irq_context != hlock->irq_context)
+			return 1;
+	}
+	return 0;
+}
+
+#else /* defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) */
+
+static inline
+int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
+		enum lock_usage_bit new_bit)
+{
+	WARN_ON(1); /* Impossible innit? when we don't have TRACE_IRQFLAG */
+	return 1;
+}
+
+static inline unsigned int task_irq_context(struct task_struct *task)
+{
+	return 0;
+}
+
+static inline int separate_irq_context(struct task_struct *curr,
+		struct held_lock *hlock)
+{
+	return 0;
+}
+
+#endif /* defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) */
+
 static int
 mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
 {
+#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
 	if (!check)
 		goto lock_used;
 
@@ -3510,6 +3562,7 @@ void trace_softirqs_off(unsigned long ip)
 	}
 
 lock_used:
+#endif
 	/* mark it as used: */
 	if (!mark_lock(curr, hlock, LOCK_USED))
 		return 0;
@@ -3517,63 +3570,6 @@ void trace_softirqs_off(unsigned long ip)
 	return 1;
 }
 
-static inline unsigned int task_irq_context(struct task_struct *task)
-{
-	return 2 * !!task->hardirq_context + !!task->softirq_context;
-}
-
-static int separate_irq_context(struct task_struct *curr,
-		struct held_lock *hlock)
-{
-	unsigned int depth = curr->lockdep_depth;
-
-	/*
-	 * Keep track of points where we cross into an interrupt context:
-	 */
-	if (depth) {
-		struct held_lock *prev_hlock;
-
-		prev_hlock = curr->held_locks + depth-1;
-		/*
-		 * If we cross into another context, reset the
-		 * hash key (this also prevents the checking and the
-		 * adding of the dependency to 'prev'):
-		 */
-		if (prev_hlock->irq_context != hlock->irq_context)
-			return 1;
-	}
-	return 0;
-}
-
-#else /* defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) */
-
-static inline
-int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
-		enum lock_usage_bit new_bit)
-{
-	WARN_ON(1); /* Impossible innit? when we don't have TRACE_IRQFLAG */
-	return 1;
-}
-
-static inline int
-mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
-{
-	return 1;
-}
-
-static inline unsigned int task_irq_context(struct task_struct *task)
-{
-	return 0;
-}
-
-static inline int separate_irq_context(struct task_struct *curr,
-		struct held_lock *hlock)
-{
-	return 0;
-}
-
-#endif /* defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) */
-
 /*
  * Mark a lock with a usage bit, and validate the state transition:
  */
-- 
1.8.3.1