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| author | Ahmed Ehab <bottaawesome633@gmail.com> | 2024-08-25 01:10:30 +0300 |
|---|---|---|
| committer | Boqun Feng <boqun.feng@gmail.com> | 2024-10-17 20:07:23 -0700 |
| commit | d7fe143cb115076fed0126ad8cf5ba6c3e575e43 (patch) | |
| tree | 0d410064425a157c21079e06b2b6507dab7fdb65 | |
| parent | 0784181b44af831a3fa52e1e5ff77c388d699dba (diff) | |
| download | linux-d7fe143cb115076fed0126ad8cf5ba6c3e575e43.tar.gz linux-d7fe143cb115076fed0126ad8cf5ba6c3e575e43.tar.bz2 linux-d7fe143cb115076fed0126ad8cf5ba6c3e575e43.zip | |
locking/lockdep: Avoid creating new name string literals in lockdep_set_subclass()
Syzbot reports a problem that a warning will be triggered while
searching a lock class in look_up_lock_class().
The cause of the issue is that a new name is created and used by
lockdep_set_subclass() instead of using the existing one. This results
in a lock instance has a different name pointer than previous registered
one stored in lock class, and WARN_ONCE() is triggered because of that
in look_up_lock_class().
To fix this, change lockdep_set_subclass() to use the existing name
instead of a new one. Hence, no new name will be created by
lockdep_set_subclass(). Hence, the warning is avoided.
[boqun: Reword the commit log to state the correct issue]
Reported-by: <syzbot+7f4a6f7f7051474e40ad@syzkaller.appspotmail.com>
Fixes: de8f5e4f2dc1f ("lockdep: Introduce wait-type checks")
Cc: stable@vger.kernel.org
Signed-off-by: Ahmed Ehab <bottaawesome633@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/lkml/20240824221031.7751-1-bottaawesome633@gmail.com/
| -rw-r--r-- | include/linux/lockdep.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 217f7abf2cbf..67964dc4db95 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -173,7 +173,7 @@ static inline void lockdep_init_map(struct lockdep_map *lock, const char *name, (lock)->dep_map.lock_type) #define lockdep_set_subclass(lock, sub) \ - lockdep_init_map_type(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\ + lockdep_init_map_type(&(lock)->dep_map, (lock)->dep_map.name, (lock)->dep_map.key, sub,\ (lock)->dep_map.wait_type_inner, \ (lock)->dep_map.wait_type_outer, \ (lock)->dep_map.lock_type) |