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| author | Amol Grover <frextrite@gmail.com> | 2020-01-18 19:54:18 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-02-21 02:58:23 +0300 |
| commit | 4dfd5cd83dc4458049c7f6eb9c4f361acc4239ea (patch) | |
| tree | 77997758f8b5f1d2a6615c69428ab57d74738040 /include/linux/rculist.h | |
| parent | aa24f93753e256c4b14fe46f7261f150cff2a50c (diff) | |
| download | linux-4dfd5cd83dc4458049c7f6eb9c4f361acc4239ea.tar.xz | |
rculist: Add brackets around cond argument in __list_check_rcu macro
Passing a complex lockdep condition to __list_check_rcu results
in false positive lockdep splat due to incorrect expression
evaluation.
For example, a lockdep check condition `cond1 || cond2` is
evaluated as `!cond1 || cond2 && !rcu_read_lock_any_held()`
which, according to operator precedence, evaluates to
`!cond1 || (cond2 && !rcu_read_lock_any_held())`.
This would result in a lockdep splat when cond1 is false
and cond2 is true which is logically incorrect.
Signed-off-by: Amol Grover <frextrite@gmail.com>
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'include/linux/rculist.h')
| -rw-r--r-- | include/linux/rculist.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 9f313e4999fe..8214cdc715f2 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -60,9 +60,9 @@ static inline void INIT_LIST_HEAD_RCU(struct list_head *list) #define __list_check_rcu(dummy, cond, extra...) \ ({ \ check_arg_count_one(extra); \ - RCU_LOCKDEP_WARN(!cond && !rcu_read_lock_any_held(), \ + RCU_LOCKDEP_WARN(!(cond) && !rcu_read_lock_any_held(), \ "RCU-list traversed in non-reader section!"); \ - }) + }) #else #define __list_check_rcu(dummy, cond, extra...) \ ({ check_arg_count_one(extra); }) |