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,
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,
return;
inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
- if (hlist_unhashed(&inst->list))
- return;
if (!tmpl || !crypto_tmpl_get(tmpl))
return;
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)
{
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)) {
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
} 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);
}
}
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) {
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;
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;
}
return 0;
}
-int crypto_unregister_alg(struct crypto_alg *alg)
+void crypto_unregister_alg(struct crypto_alg *alg)
{
int ret;
LIST_HEAD(list);
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);
}
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);
struct crypto_instance *inst)
{
struct crypto_larval *larval;
+ struct crypto_spawn *spawn;
int err;
err = crypto_check_alg(&inst->alg);
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;
+
+ if (spawn->dropref)
+ crypto_mod_put(spawn->alg);
+
+ spawn = next;
+ }
+
larval = __crypto_register_alg(&inst->alg);
if (IS_ERR(larval))
goto unlock;
}
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);
up_write(&crypto_alg_sem);
crypto_remove_final(&list);
-
- return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_instance);
if (WARN_ON_ONCE(inst == NULL))
return -EINVAL;
- spawn->inst = inst;
+ spawn->next = inst->spawns;
+ inst->spawns = spawn;
+
spawn->mask = mask;
down_write(&crypto_alg_sem);
if (IS_ERR(alg))
return PTR_ERR(alg);
+ spawn->dropref = true;
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)
- return;
-
down_write(&crypto_alg_sem);
- list_del(&spawn->list);
+ if (!spawn->dead)
+ list_del(&spawn->list);
up_write(&crypto_alg_sem);
+
+ if (spawn->dropref && !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,
projects / linux-block.git / blobdiff