Merge tag 'tomoyo-pr-20200128' of git://git.osdn.net/gitroot/tomoyo/tomoyo-test1
[linux-2.6-microblaze.git] / crypto / algapi.c
index b052f38..69605e2 100644 (file)
@@ -65,11 +65,6 @@ static int crypto_check_alg(struct crypto_alg *alg)
 
 static void crypto_free_instance(struct crypto_instance *inst)
 {
-       if (!inst->alg.cra_type->free) {
-               inst->tmpl->free(inst);
-               return;
-       }
-
        inst->alg.cra_type->free(inst);
 }
 
@@ -82,6 +77,15 @@ static void crypto_destroy_instance(struct crypto_alg *alg)
        crypto_tmpl_put(tmpl);
 }
 
+/*
+ * This function adds a spawn to the list secondary_spawns which
+ * will be used at the end of crypto_remove_spawns to unregister
+ * instances, unless the spawn happens to be one that is depended
+ * on by the new algorithm (nalg in crypto_remove_spawns).
+ *
+ * This function is also responsible for resurrecting any algorithms
+ * in the dependency chain of nalg by unsetting n->dead.
+ */
 static struct list_head *crypto_more_spawns(struct crypto_alg *alg,
                                            struct list_head *stack,
                                            struct list_head *top,
@@ -93,15 +97,17 @@ static struct list_head *crypto_more_spawns(struct crypto_alg *alg,
        if (!spawn)
                return NULL;
 
-       n = list_next_entry(spawn, list);
+       n = list_prev_entry(spawn, list);
+       list_move(&spawn->list, secondary_spawns);
 
-       if (spawn->alg && &n->list != stack && !n->alg)
-               n->alg = (n->list.next == stack) ? alg :
-                        &list_next_entry(n, list)->inst->alg;
+       if (list_is_last(&n->list, stack))
+               return top;
 
-       list_move(&spawn->list, secondary_spawns);
+       n = list_next_entry(n, list);
+       if (!spawn->dead)
+               n->dead = false;
 
-       return &n->list == stack ? top : &n->inst->alg.cra_users;
+       return &n->inst->alg.cra_users;
 }
 
 static void crypto_remove_instance(struct crypto_instance *inst,
@@ -113,8 +119,6 @@ static void crypto_remove_instance(struct crypto_instance *inst,
                return;
 
        inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
-       if (hlist_unhashed(&inst->list))
-               return;
 
        if (!tmpl || !crypto_tmpl_get(tmpl))
                return;
@@ -126,6 +130,12 @@ static void crypto_remove_instance(struct crypto_instance *inst,
        BUG_ON(!list_empty(&inst->alg.cra_users));
 }
 
+/*
+ * Given an algorithm alg, remove all algorithms that depend on it
+ * through spawns.  If nalg is not null, then exempt any algorithms
+ * that is depended on by nalg.  This is useful when nalg itself
+ * depends on alg.
+ */
 void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
                          struct crypto_alg *nalg)
 {
@@ -144,6 +154,11 @@ void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
                list_move(&spawn->list, &top);
        }
 
+       /*
+        * Perform a depth-first walk starting from alg through
+        * the cra_users tree.  The list stack records the path
+        * from alg to the current spawn.
+        */
        spawns = ⊤
        do {
                while (!list_empty(spawns)) {
@@ -153,17 +168,26 @@ void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
                                                 list);
                        inst = spawn->inst;
 
-                       BUG_ON(&inst->alg == alg);
-
                        list_move(&spawn->list, &stack);
+                       spawn->dead = !spawn->registered || &inst->alg != nalg;
+
+                       if (!spawn->registered)
+                               break;
+
+                       BUG_ON(&inst->alg == alg);
 
                        if (&inst->alg == nalg)
                                break;
 
-                       spawn->alg = NULL;
                        spawns = &inst->alg.cra_users;
 
                        /*
+                        * Even if spawn->registered is true, the
+                        * instance itself may still be unregistered.
+                        * This is because it may have failed during
+                        * registration.  Therefore we still need to
+                        * make the following test.
+                        *
                         * We may encounter an unregistered instance here, since
                         * an instance's spawns are set up prior to the instance
                         * being registered.  An unregistered instance will have
@@ -178,10 +202,15 @@ void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
        } while ((spawns = crypto_more_spawns(alg, &stack, &top,
                                              &secondary_spawns)));
 
+       /*
+        * Remove all instances that are marked as dead.  Also
+        * complete the resurrection of the others by moving them
+        * back to the cra_users list.
+        */
        list_for_each_entry_safe(spawn, n, &secondary_spawns, list) {
-               if (spawn->alg)
+               if (!spawn->dead)
                        list_move(&spawn->list, &spawn->alg->cra_users);
-               else
+               else if (spawn->registered)
                        crypto_remove_instance(spawn->inst, list);
        }
 }
@@ -257,6 +286,7 @@ void crypto_alg_tested(const char *name, int err)
        struct crypto_alg *alg;
        struct crypto_alg *q;
        LIST_HEAD(list);
+       bool best;
 
        down_write(&crypto_alg_sem);
        list_for_each_entry(q, &crypto_alg_list, cra_list) {
@@ -280,6 +310,21 @@ found:
 
        alg->cra_flags |= CRYPTO_ALG_TESTED;
 
+       /* Only satisfy larval waiters if we are the best. */
+       best = true;
+       list_for_each_entry(q, &crypto_alg_list, cra_list) {
+               if (crypto_is_moribund(q) || !crypto_is_larval(q))
+                       continue;
+
+               if (strcmp(alg->cra_name, q->cra_name))
+                       continue;
+
+               if (q->cra_priority > alg->cra_priority) {
+                       best = false;
+                       break;
+               }
+       }
+
        list_for_each_entry(q, &crypto_alg_list, cra_list) {
                if (q == alg)
                        continue;
@@ -303,10 +348,12 @@ found:
                                continue;
                        if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
                                continue;
-                       if (!crypto_mod_get(alg))
-                               continue;
 
-                       larval->adult = alg;
+                       if (best && crypto_mod_get(alg))
+                               larval->adult = alg;
+                       else
+                               larval->adult = ERR_PTR(-EAGAIN);
+
                        continue;
                }
 
@@ -397,7 +444,7 @@ static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
        return 0;
 }
 
-int crypto_unregister_alg(struct crypto_alg *alg)
+void crypto_unregister_alg(struct crypto_alg *alg)
 {
        int ret;
        LIST_HEAD(list);
@@ -406,15 +453,14 @@ int crypto_unregister_alg(struct crypto_alg *alg)
        ret = crypto_remove_alg(alg, &list);
        up_write(&crypto_alg_sem);
 
-       if (ret)
-               return ret;
+       if (WARN(ret, "Algorithm %s is not registered", alg->cra_driver_name))
+               return;
 
        BUG_ON(refcount_read(&alg->cra_refcnt) != 1);
        if (alg->cra_destroy)
                alg->cra_destroy(alg);
 
        crypto_remove_final(&list);
-       return 0;
 }
 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
 
@@ -438,18 +484,12 @@ err:
 }
 EXPORT_SYMBOL_GPL(crypto_register_algs);
 
-int crypto_unregister_algs(struct crypto_alg *algs, int count)
+void crypto_unregister_algs(struct crypto_alg *algs, int count)
 {
-       int i, ret;
-
-       for (i = 0; i < count; i++) {
-               ret = crypto_unregister_alg(&algs[i]);
-               if (ret)
-                       pr_err("Failed to unregister %s %s: %d\n",
-                              algs[i].cra_driver_name, algs[i].cra_name, ret);
-       }
+       int i;
 
-       return 0;
+       for (i = 0; i < count; i++)
+               crypto_unregister_alg(&algs[i]);
 }
 EXPORT_SYMBOL_GPL(crypto_unregister_algs);
 
@@ -561,6 +601,7 @@ int crypto_register_instance(struct crypto_template *tmpl,
                             struct crypto_instance *inst)
 {
        struct crypto_larval *larval;
+       struct crypto_spawn *spawn;
        int err;
 
        err = crypto_check_alg(&inst->alg);
@@ -572,6 +613,22 @@ int crypto_register_instance(struct crypto_template *tmpl,
 
        down_write(&crypto_alg_sem);
 
+       larval = ERR_PTR(-EAGAIN);
+       for (spawn = inst->spawns; spawn;) {
+               struct crypto_spawn *next;
+
+               if (spawn->dead)
+                       goto unlock;
+
+               next = spawn->next;
+               spawn->inst = inst;
+               spawn->registered = true;
+
+               crypto_mod_put(spawn->alg);
+
+               spawn = next;
+       }
+
        larval = __crypto_register_alg(&inst->alg);
        if (IS_ERR(larval))
                goto unlock;
@@ -594,7 +651,7 @@ err:
 }
 EXPORT_SYMBOL_GPL(crypto_register_instance);
 
-int crypto_unregister_instance(struct crypto_instance *inst)
+void crypto_unregister_instance(struct crypto_instance *inst)
 {
        LIST_HEAD(list);
 
@@ -606,97 +663,70 @@ int crypto_unregister_instance(struct crypto_instance *inst)
        up_write(&crypto_alg_sem);
 
        crypto_remove_final(&list);
-
-       return 0;
 }
 EXPORT_SYMBOL_GPL(crypto_unregister_instance);
 
-int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
-                     struct crypto_instance *inst, u32 mask)
+int crypto_grab_spawn(struct crypto_spawn *spawn, struct crypto_instance *inst,
+                     const char *name, u32 type, u32 mask)
 {
+       struct crypto_alg *alg;
        int err = -EAGAIN;
 
        if (WARN_ON_ONCE(inst == NULL))
                return -EINVAL;
 
-       spawn->inst = inst;
-       spawn->mask = mask;
+       /* Allow the result of crypto_attr_alg_name() to be passed directly */
+       if (IS_ERR(name))
+               return PTR_ERR(name);
+
+       alg = crypto_find_alg(name, spawn->frontend, type, mask);
+       if (IS_ERR(alg))
+               return PTR_ERR(alg);
 
        down_write(&crypto_alg_sem);
        if (!crypto_is_moribund(alg)) {
                list_add(&spawn->list, &alg->cra_users);
                spawn->alg = alg;
+               spawn->mask = mask;
+               spawn->next = inst->spawns;
+               inst->spawns = spawn;
                err = 0;
        }
        up_write(&crypto_alg_sem);
-
-       return err;
-}
-EXPORT_SYMBOL_GPL(crypto_init_spawn);
-
-int crypto_init_spawn2(struct crypto_spawn *spawn, struct crypto_alg *alg,
-                      struct crypto_instance *inst,
-                      const struct crypto_type *frontend)
-{
-       int err = -EINVAL;
-
-       if ((alg->cra_flags ^ frontend->type) & frontend->maskset)
-               goto out;
-
-       spawn->frontend = frontend;
-       err = crypto_init_spawn(spawn, alg, inst, frontend->maskset);
-
-out:
-       return err;
-}
-EXPORT_SYMBOL_GPL(crypto_init_spawn2);
-
-int crypto_grab_spawn(struct crypto_spawn *spawn, const char *name,
-                     u32 type, u32 mask)
-{
-       struct crypto_alg *alg;
-       int err;
-
-       alg = crypto_find_alg(name, spawn->frontend, type, mask);
-       if (IS_ERR(alg))
-               return PTR_ERR(alg);
-
-       err = crypto_init_spawn(spawn, alg, spawn->inst, mask);
-       crypto_mod_put(alg);
+       if (err)
+               crypto_mod_put(alg);
        return err;
 }
 EXPORT_SYMBOL_GPL(crypto_grab_spawn);
 
 void crypto_drop_spawn(struct crypto_spawn *spawn)
 {
-       if (!spawn->alg)
+       if (!spawn->alg) /* not yet initialized? */
                return;
 
        down_write(&crypto_alg_sem);
-       list_del(&spawn->list);
+       if (!spawn->dead)
+               list_del(&spawn->list);
        up_write(&crypto_alg_sem);
+
+       if (!spawn->registered)
+               crypto_mod_put(spawn->alg);
 }
 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
 
 static struct crypto_alg *crypto_spawn_alg(struct crypto_spawn *spawn)
 {
        struct crypto_alg *alg;
-       struct crypto_alg *alg2;
 
        down_read(&crypto_alg_sem);
        alg = spawn->alg;
-       alg2 = alg;
-       if (alg2)
-               alg2 = crypto_mod_get(alg2);
-       up_read(&crypto_alg_sem);
-
-       if (!alg2) {
-               if (alg)
-                       crypto_shoot_alg(alg);
-               return ERR_PTR(-EAGAIN);
+       if (!spawn->dead && !crypto_mod_get(alg)) {
+               alg->cra_flags |= CRYPTO_ALG_DYING;
+               alg = NULL;
        }
+       up_read(&crypto_alg_sem);
 
-       return alg;
+       return alg ?: ERR_PTR(-EAGAIN);
 }
 
 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
@@ -809,20 +839,6 @@ const char *crypto_attr_alg_name(struct rtattr *rta)
 }
 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
 
-struct crypto_alg *crypto_attr_alg2(struct rtattr *rta,
-                                   const struct crypto_type *frontend,
-                                   u32 type, u32 mask)
-{
-       const char *name;
-
-       name = crypto_attr_alg_name(rta);
-       if (IS_ERR(name))
-               return ERR_CAST(name);
-
-       return crypto_find_alg(name, frontend, type, mask);
-}
-EXPORT_SYMBOL_GPL(crypto_attr_alg2);
-
 int crypto_attr_u32(struct rtattr *rta, u32 *num)
 {
        struct crypto_attr_u32 *nu32;
@@ -856,32 +872,6 @@ int crypto_inst_setname(struct crypto_instance *inst, const char *name,
 }
 EXPORT_SYMBOL_GPL(crypto_inst_setname);
 
-void *crypto_alloc_instance(const char *name, struct crypto_alg *alg,
-                           unsigned int head)
-{
-       struct crypto_instance *inst;
-       char *p;
-       int err;
-
-       p = kzalloc(head + sizeof(*inst) + sizeof(struct crypto_spawn),
-                   GFP_KERNEL);
-       if (!p)
-               return ERR_PTR(-ENOMEM);
-
-       inst = (void *)(p + head);
-
-       err = crypto_inst_setname(inst, name, alg);
-       if (err)
-               goto err_free_inst;
-
-       return p;
-
-err_free_inst:
-       kfree(p);
-       return ERR_PTR(err);
-}
-EXPORT_SYMBOL_GPL(crypto_alloc_instance);
-
 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
 {
        INIT_LIST_HEAD(&queue->list);