locking/ww_mutex: Fix ww_mutex dummy lockdep map selftest warnings

The below commit introduces a dummy lockdep map, but didn't get
the initialization quite right (it should mimic the initialization
of the real ww_mutex lockdep maps). It also introduced a separate
locking api selftest failure. Fix these.

Closes: https://lore.kernel.org/lkml/Zw19sMtnKdyOVQoh@boqun-archlinux/
Fixes: 823a566 ("locking/ww_mutex: Adjust to lockdep nest_lock requirements")
Reported-by: Boqun Feng <[email protected]>
Suggested-by: Boqun Feng <[email protected]>
Signed-off-by: Thomas Hellström <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

Author: Thomas Hellström

include/linux/ww_mutex.h

@@ -156,8 +156,8 @@ static inline void ww_acquire_init(struct ww_acquire_ctx *ctx,
 	debug_check_no_locks_freed((void *)ctx, sizeof(*ctx));
 	lockdep_init_map(&ctx->dep_map, ww_class->acquire_name,
 			 &ww_class->acquire_key, 0);
-	lockdep_init_map(&ctx->first_lock_dep_map, ww_class->mutex_name,
-			 &ww_class->mutex_key, 0);
+	lockdep_init_map_wait(&ctx->first_lock_dep_map, ww_class->mutex_name,
+			      &ww_class->mutex_key, 0, LD_WAIT_SLEEP);
 	mutex_acquire(&ctx->dep_map, 0, 0, _RET_IP_);
 	mutex_acquire_nest(&ctx->first_lock_dep_map, 0, 0, &ctx->dep_map, _RET_IP_);
 #endif

lib/locking-selftest.c

@@ -1720,8 +1720,6 @@ static void ww_test_normal(void)
 {
 	int ret;
 
-	WWAI(&t);
-
 	/*
 	 * None of the ww_mutex codepaths should be taken in the 'normal'
 	 * mutex calls. The easiest way to verify this is by using the
@@ -1770,6 +1768,8 @@ static void ww_test_normal(void)
 	ww_mutex_base_unlock(&o.base);
 	WARN_ON(o.ctx != (void *)~0UL);
 
+	WWAI(&t);
+
 	/* nest_lock */
 	o.ctx = (void *)~0UL;
 	ww_mutex_base_lock_nest_lock(&o.base, &t);