Like the previous change, the function lookup_chain_cache_add() returns the pointer of the lock chain if the chain is new.
No functional change. Signed-off-by: Yuyang Du <[email protected]> --- kernel/locking/lockdep.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 3546894..d545b6c 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2796,13 +2796,13 @@ static inline struct lock_chain *lookup_chain_cache(u64 chain_key) /* * If the key is not present yet in dependency chain cache then - * add it and return 1 - in this case the new dependency chain is - * validated. If the key is already hashed, return 0. - * (On return with 1 graph_lock is held.) + * add it and return the chain - in this case the new dependency + * chain will be validated. If the key is already hashed, return + * NULL. (On return with the new chain graph_lock is held.) */ -static inline int lookup_chain_cache_add(struct task_struct *curr, - struct held_lock *hlock, - u64 chain_key) +static inline struct lock_chain * +lookup_chain_cache_add(struct task_struct *curr, struct held_lock *hlock, + u64 chain_key) { struct lock_class *class = hlock_class(hlock); struct lock_chain *chain = lookup_chain_cache(chain_key); @@ -2810,7 +2810,7 @@ static inline int lookup_chain_cache_add(struct task_struct *curr, if (chain) { cache_hit: if (!check_no_collision(curr, hlock, chain)) - return 0; + return NULL; if (very_verbose(class)) { printk("\nhash chain already cached, key: " @@ -2819,7 +2819,7 @@ static inline int lookup_chain_cache_add(struct task_struct *curr, class->key, class->name); } - return 0; + return NULL; } if (very_verbose(class)) { @@ -2828,7 +2828,7 @@ static inline int lookup_chain_cache_add(struct task_struct *curr, } if (!graph_lock()) - return 0; + return NULL; /* * We have to walk the chain again locked - to avoid duplicates: @@ -2839,10 +2839,7 @@ static inline int lookup_chain_cache_add(struct task_struct *curr, goto cache_hit; } - if (!add_chain_cache(curr, hlock, chain_key)) - return 0; - - return 1; + return add_chain_cache(curr, hlock, chain_key); } static int validate_chain(struct task_struct *curr, -- 1.8.3.1
