Amol Grover 4dfd5cd83d 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>

2020-02-20 15:58:23 -08:00

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