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Diffstat (limited to 'include/linux/ww_mutex.h')
-rw-r--r--include/linux/ww_mutex.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h
index bb763085479a..a401a2f31a77 100644
--- a/include/linux/ww_mutex.h
+++ b/include/linux/ww_mutex.h
@@ -65,6 +65,16 @@ struct ww_acquire_ctx {
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
+ /**
+ * @first_lock_dep_map: fake lockdep_map for first locked ww_mutex.
+ *
+ * lockdep requires the lockdep_map for the first locked ww_mutex
+ * in a ww transaction to remain in memory until all ww_mutexes of
+ * the transaction have been unlocked. Ensure this by keeping a
+ * fake locked ww_mutex lockdep map between ww_acquire_init() and
+ * ww_acquire_fini().
+ */
+ struct lockdep_map first_lock_dep_map;
#endif
#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
unsigned int deadlock_inject_interval;
@@ -146,7 +156,10 @@ 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);
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
#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
ctx->deadlock_inject_interval = 1;
@@ -185,6 +198,7 @@ static inline void ww_acquire_done(struct ww_acquire_ctx *ctx)
static inline void ww_acquire_fini(struct ww_acquire_ctx *ctx)
{
#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ mutex_release(&ctx->first_lock_dep_map, _THIS_IP_);
mutex_release(&ctx->dep_map, _THIS_IP_);
#endif
#ifdef DEBUG_WW_MUTEXES