Commit 0302d2fd authored by Thomas Hellström's avatar Thomas Hellström Committed by Peter Zijlstra
Browse files

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: 823a5662 ("locking/ww_mutex: Adjust to lockdep nest_lock requirements")
Reported-by: default avatarBoqun Feng <boqun.feng@gmail.com>
Suggested-by: default avatarBoqun Feng <boqun.feng@gmail.com>
Signed-off-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20241127085430.3045-1-thomas.hellstrom@linux.intel.com
parent 40384c84

include/linux/ww_mutex.h

+2 −2
Original line number Diff line number Diff line
@@ -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

+2 −2
Original line number Diff line number Diff line
@@ -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);