-stable review patch. If anyone has any objections, please let us know.
------------------
From: Gregory Haskins <[email protected]>
patch 3aa416b07f0adf01c090baab26fb70c35ec17623 in mainline.
It is possible for the current->curr_chain_key to become inconsistent
with the current index if the chain fails to validate. The end result
is that future lock_acquire() operations may inadvertently fail to find
a hit in the cache resulting in a new node being added to the graph for
every acquire.
Signed-off-by: Gregory Haskins <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Chuck Ebbert <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
kernel/lockdep.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1521,7 +1521,7 @@ cache_hit:
}
static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
- struct held_lock *hlock, int chain_head)
+ struct held_lock *hlock, int chain_head, u64 chain_key)
{
/*
* Trylock needs to maintain the stack of held locks, but it
@@ -1534,7 +1534,7 @@ static int validate_chain(struct task_st
* graph_lock for us)
*/
if (!hlock->trylock && (hlock->check == 2) &&
- lookup_chain_cache(curr->curr_chain_key, hlock->class)) {
+ lookup_chain_cache(chain_key, hlock->class)) {
/*
* Check whether last held lock:
*
@@ -1576,7 +1576,7 @@ static int validate_chain(struct task_st
#else
static inline int validate_chain(struct task_struct *curr,
struct lockdep_map *lock, struct held_lock *hlock,
- int chain_head)
+ int chain_head, u64 chain_key)
{
return 1;
}
@@ -2450,11 +2450,11 @@ static int __lock_acquire(struct lockdep
chain_head = 1;
}
chain_key = iterate_chain_key(chain_key, id);
- curr->curr_chain_key = chain_key;
- if (!validate_chain(curr, lock, hlock, chain_head))
+ if (!validate_chain(curr, lock, hlock, chain_head, chain_key))
return 0;
+ curr->curr_chain_key = chain_key;
curr->lockdep_depth++;
check_chain_key(curr);
#ifdef CONFIG_DEBUG_LOCKDEP
--
-
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