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: 823a566221a5 ("locking/ww_mutex: Adjust to lockdep nest_lock requirements")
Reported-by: Boqun Feng <boqun.feng@gmail.com>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20241127085430.3045-1-thomas.hellstrom@linux.intel.com

diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h
index a401a2f31a775197a100b7168431337fe60d3a48..45ff6f7a872bb5abd517396243de4ab314af2371 100644 (file)
--- a/include/linux/ww_mutex.h
+++ b/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

diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 6e0c019f71b6891c660067ec79de4b817983e663..ed99344317f50d9d9d3e12b740e418cd94117709 100644 (file)
--- a/lib/locking-selftest.c
+++ b/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);