| Message ID | 20200916184528.498184-8-kuba@kernel.org |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
| Series | rcu: prevent RCU_LOCKDEP_WARN() from swallowing the condition | expand |
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 53f9648cb982..50d45781fa99 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -321,7 +321,7 @@ static inline void rcu_preempt_sleep_check(void) { } #else /* #ifdef CONFIG_PROVE_RCU */ -#define RCU_LOCKDEP_WARN(c, s) do { } while (0) +#define RCU_LOCKDEP_WARN(c, s) do { } while (0 && (c)) #define rcu_sleep_check() do { } while (0) #endif /* #else #ifdef CONFIG_PROVE_RCU */
We run into a unused variable warning in bridge code when variable is only used inside the condition of rcu_dereference_protected(). #define mlock_dereference(X, br) \ rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock)) Since on builds with CONFIG_PROVE_RCU=n rcu_dereference_protected() compiles to nothing the compiler doesn't see the variable use. Prevent the warning by adding the condition as dead code. Signed-off-by: Jakub Kicinski <kuba@kernel.org> -- CC: paulmck@kernel.org CC: josh@joshtriplett.org CC: rostedt@goodmis.org CC: mathieu.desnoyers@efficios.com CC: joel@joelfernandes.org CC: jiangshanlai@gmail.com --- include/linux/rcupdate.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)