1 files changed, 63 insertions, 14 deletions

diff --git a/crypto/algapi.c b/crypto/algapi.c
index 6a98076d9d2a..feb77e4bbb48 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -81,16 +81,35 @@ static void crypto_destroy_instance(struct crypto_alg *alg)
 	crypto_tmpl_put(tmpl);
 }
 
+static struct list_head *crypto_more_spawns(struct crypto_alg *alg,
+					    struct list_head *stack,
+					    struct list_head *top,
+					    struct list_head *secondary_spawns)
+{
+	struct crypto_spawn *spawn, *n;
+
+	if (list_empty(stack))
+		return NULL;
+
+	spawn = list_first_entry(stack, struct crypto_spawn, list);
+	n = list_entry(spawn->list.next, struct crypto_spawn, list);
+
+	if (spawn->alg && &n->list != stack && !n->alg)
+		n->alg = (n->list.next == stack) ? alg :
+			 &list_entry(n->list.next, struct crypto_spawn,
+				     list)->inst->alg;
+
+	list_move(&spawn->list, secondary_spawns);
+
+	return &n->list == stack ? top : &n->inst->alg.cra_users;
+}
+
 static void crypto_remove_spawn(struct crypto_spawn *spawn,
-				struct list_head *list,
-				struct list_head *secondary_spawns)
+				struct list_head *list)
 {
 	struct crypto_instance *inst = spawn->inst;
 	struct crypto_template *tmpl = inst->tmpl;
 
-	list_del_init(&spawn->list);
-	spawn->alg = NULL;
-
 	if (crypto_is_dead(&inst->alg))
 		return;
 
@@ -106,25 +125,55 @@ static void crypto_remove_spawn(struct crypto_spawn *spawn,
 	hlist_del(&inst->list);
 	inst->alg.cra_destroy = crypto_destroy_instance;
 
-	list_splice(&inst->alg.cra_users, secondary_spawns);
+	BUG_ON(!list_empty(&inst->alg.cra_users));
 }
 
-static void crypto_remove_spawns(struct list_head *spawns,
-				 struct list_head *list, u32 new_type)
+static void crypto_remove_spawns(struct crypto_alg *alg,
+				 struct list_head *list,
+				 struct crypto_alg *nalg)
 {
+	u32 new_type = (nalg ?: alg)->cra_flags;
 	struct crypto_spawn *spawn, *n;
 	LIST_HEAD(secondary_spawns);
+	struct list_head *spawns;
+	LIST_HEAD(stack);
+	LIST_HEAD(top);
 
+	spawns = &alg->cra_users;
 	list_for_each_entry_safe(spawn, n, spawns, list) {
 		if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
 			continue;
 
-		crypto_remove_spawn(spawn, list, &secondary_spawns);
+		list_move(&spawn->list, &top);
 	}
 
-	while (!list_empty(&secondary_spawns)) {
-		list_for_each_entry_safe(spawn, n, &secondary_spawns, list)
-			crypto_remove_spawn(spawn, list, &secondary_spawns);
+	spawns = ⊤
+	do {
+		while (!list_empty(spawns)) {
+			struct crypto_instance *inst;
+
+			spawn = list_first_entry(spawns, struct crypto_spawn,
+						 list);
+			inst = spawn->inst;
+
+			BUG_ON(&inst->alg == alg);
+
+			list_move(&spawn->list, &stack);
+
+			if (&inst->alg == nalg)
+				break;
+
+			spawn->alg = NULL;
+			spawns = &inst->alg.cra_users;
+		}
+	} while ((spawns = crypto_more_spawns(alg, &stack, &top,
+					      &secondary_spawns)));
+
+	list_for_each_entry_safe(spawn, n, &secondary_spawns, list) {
+		if (spawn->alg)
+			list_move(&spawn->list, &spawn->alg->cra_users);
+		else
+			crypto_remove_spawn(spawn, list);
 	}
 }
 
@@ -258,7 +307,7 @@ found:
 		    q->cra_priority > alg->cra_priority)
 			continue;
 
-		crypto_remove_spawns(&q->cra_users, &list, alg->cra_flags);
+		crypto_remove_spawns(q, &list, alg);
 	}
 
 complete:
@@ -330,7 +379,7 @@ static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
 
 	crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
 	list_del_init(&alg->cra_list);
-	crypto_remove_spawns(&alg->cra_users, list, alg->cra_flags);
+	crypto_remove_spawns(alg, list, NULL);
 
 	return 0;
 }