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From: Bart Van Assche <bvanassche@acm.org>
To: peterz@infradead.org
Cc: mingo@redhat.com, tj@kernel.org, longman@redhat.com,
	johannes.berg@intel.com, linux-kernel@vger.kernel.org,
	Bart Van Assche <bvanassche@acm.org>,
	Johannes Berg <johannes@sipsolutions.net>
Subject: [PATCH v6 02/16] locking/lockdep: Avoid that add_chain_cache() adds an invalid chain to the cache
Date: Wed,  9 Jan 2019 13:01:50 -0800	[thread overview]
Message-ID: <20190109210204.192109-3-bvanassche@acm.org> (raw)
In-Reply-To: <20190109210204.192109-1-bvanassche@acm.org>

Make sure that add_chain_cache() returns 0 and does not modify the
chain hash if nr_chain_hlocks == MAX_LOCKDEP_CHAIN_HLOCKS before this
function is called.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 kernel/locking/lockdep.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index cb3fa7042886..7a7c2d7b01c2 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2206,16 +2206,8 @@ static inline int add_chain_cache(struct task_struct *curr,
 			chain_hlocks[chain->base + j] = lock_id;
 		}
 		chain_hlocks[chain->base + j] = class - lock_classes;
-	}
-
-	if (nr_chain_hlocks < MAX_LOCKDEP_CHAIN_HLOCKS)
 		nr_chain_hlocks += chain->depth;
-
-#ifdef CONFIG_DEBUG_LOCKDEP
-	/*
-	 * Important for check_no_collision().
-	 */
-	if (unlikely(nr_chain_hlocks > MAX_LOCKDEP_CHAIN_HLOCKS)) {
+	} else {
 		if (!debug_locks_off_graph_unlock())
 			return 0;
 
@@ -2223,7 +2215,6 @@ static inline int add_chain_cache(struct task_struct *curr,
 		dump_stack();
 		return 0;
 	}
-#endif
 
 	hlist_add_head_rcu(&chain->entry, hash_head);
 	debug_atomic_inc(chain_lookup_misses);
-- 
2.20.1.97.g81188d93c3-goog


  parent reply	other threads:[~2019-01-09 21:03 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-09 21:01 [PATCH v6 00/16] locking/lockdep: Add support for dynamic keys Bart Van Assche
2019-01-09 21:01 ` [PATCH v6 01/16] locking/lockdep: Fix reported required memory size Bart Van Assche
2019-01-09 21:01 ` Bart Van Assche [this message]
2019-01-09 21:01 ` [PATCH v6 03/16] locking/lockdep: Make zap_class() remove all matching lock order entries Bart Van Assche
2019-01-09 21:01 ` [PATCH v6 04/16] locking/lockdep: Reorder struct lock_class members Bart Van Assche
2019-01-09 21:01 ` [PATCH v6 05/16] locking/lockdep: Initialize the locks_before and locks_after lists earlier Bart Van Assche
2019-01-09 21:01 ` [PATCH v6 06/16] locking/lockdep: Split lockdep_free_key_range() and lockdep_reset_lock() Bart Van Assche
2019-01-09 21:01 ` [PATCH v6 07/16] locking/lockdep: Make it easy to detect whether or not inside a selftest Bart Van Assche
2019-01-09 21:01 ` [PATCH v6 08/16] locking/lockdep: Free lock classes that are no longer in use Bart Van Assche
2019-01-09 21:01 ` [PATCH v6 09/16] locking/lockdep: Reuse list entries " Bart Van Assche
2019-01-09 21:01 ` [PATCH v6 10/16] locking/lockdep: Introduce lockdep_next_lockchain() and lock_chain_count() Bart Van Assche
2019-01-09 21:01 ` [PATCH v6 11/16] locking/lockdep: Reuse lock chains that have been freed Bart Van Assche
2019-01-09 21:02 ` [PATCH v6 12/16] locking/lockdep: Check data structure consistency Bart Van Assche
2019-01-09 21:02 ` [PATCH v6 13/16] locking/lockdep: Verify whether lock objects are small enough to be used as class keys Bart Van Assche
2019-01-09 21:02 ` [PATCH v6 14/16] locking/lockdep: Add support for dynamic keys Bart Van Assche
2019-01-09 21:02 ` [PATCH v6 15/16] kernel/workqueue: Use dynamic lockdep keys for workqueues Bart Van Assche
2019-01-09 21:02 ` [PATCH v6 16/16] lockdep tests: Test dynamic key registration Bart Van Assche
2019-01-11 12:48 ` [PATCH v6 00/16] locking/lockdep: Add support for dynamic keys Peter Zijlstra
2019-01-11 15:55   ` Bart Van Assche
2019-01-11 16:55     ` Peter Zijlstra
2019-01-11 17:01       ` Bart Van Assche
2019-01-14 12:52         ` Peter Zijlstra
2019-01-14 16:52           ` Bart Van Assche
2019-01-18  9:48             ` Peter Zijlstra
2019-01-19  2:34               ` Bart Van Assche
2019-02-01 12:15                 ` Peter Zijlstra
2019-02-03 17:36                   ` Bart Van Assche
2019-02-08 11:43                     ` Will Deacon
2019-02-08 16:31                       ` Bart Van Assche
2019-02-13 22:32                       ` Bart Van Assche

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