Commit-ID: 523b113bace5e64e860d8c61d7aa25057d274753 Gitweb: https://git.kernel.org/tip/523b113bace5e64e860d8c61d7aa25057d274753 Author: Bart Van Assche <[email protected]> AuthorDate: Thu, 14 Feb 2019 15:00:39 -0800 Committer: Ingo Molnar <[email protected]> CommitDate: Thu, 28 Feb 2019 07:55:40 +0100
locking/lockdep: Avoid that add_chain_cache() adds an invalid chain to the cache 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. Signed-off-by: Bart Van Assche <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- 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 ec6f6aff4d8d..21d84510e28f 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2195,16 +2195,8 @@ 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; @@ -2212,7 +2204,6 @@ 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);
