From 37da5d0ffa7b61f79156fbbd3369f17b9a1638bd Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sat, 17 Aug 2024 14:57:40 +0800 Subject: [PATCH] crypto: api - Do not wait for tests during registration As registration is usually carried out during module init, this is a context where as little work as possible should be carried out. Testing may trigger module loads of underlying components, which could even lead back to the module that is registering at the moment. This may lead to dead-locks outside of the Crypto API. Avoid this by not waiting for the tests to complete. They will be scheduled but completion will be asynchronous. Any users will still wait for completion. Reported-by: Russell King Signed-off-by: Herbert Xu --- crypto/algapi.c | 23 ++++++++++++----------- crypto/api.c | 41 +++++++++++++++++++++-------------------- crypto/internal.h | 3 +-- 3 files changed, 34 insertions(+), 33 deletions(-) diff --git a/crypto/algapi.c b/crypto/algapi.c index d2ccc1289f92..74e2261c184c 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -366,7 +366,8 @@ void crypto_alg_tested(const char *name, int err) } pr_err("alg: Unexpected test result for %s: %d\n", name, err); - goto unlock; + up_write(&crypto_alg_sem); + return; found: q->cra_flags |= CRYPTO_ALG_DEAD; @@ -387,11 +388,12 @@ found: crypto_alg_finish_registration(alg, &list); complete: + list_del_init(&test->alg.cra_list); complete_all(&test->completion); -unlock: up_write(&crypto_alg_sem); + crypto_alg_put(&test->alg); crypto_remove_final(&list); } EXPORT_SYMBOL_GPL(crypto_alg_tested); @@ -412,7 +414,6 @@ int crypto_register_alg(struct crypto_alg *alg) { struct crypto_larval *larval; LIST_HEAD(algs_to_put); - bool test_started = false; int err; alg->cra_flags &= ~CRYPTO_ALG_DEAD; @@ -423,15 +424,16 @@ int crypto_register_alg(struct crypto_alg *alg) down_write(&crypto_alg_sem); larval = __crypto_register_alg(alg, &algs_to_put); if (!IS_ERR_OR_NULL(larval)) { - test_started = crypto_boot_test_finished(); + bool test_started = crypto_boot_test_finished(); + larval->test_started = test_started; + if (test_started) + crypto_schedule_test(larval); } up_write(&crypto_alg_sem); if (IS_ERR(larval)) return PTR_ERR(larval); - if (test_started) - crypto_wait_for_test(larval); crypto_remove_final(&algs_to_put); return 0; } @@ -646,8 +648,10 @@ int crypto_register_instance(struct crypto_template *tmpl, larval = __crypto_register_alg(&inst->alg, &algs_to_put); if (IS_ERR(larval)) goto unlock; - else if (larval) + else if (larval) { larval->test_started = true; + crypto_schedule_test(larval); + } hlist_add_head(&inst->list, &tmpl->instances); inst->tmpl = tmpl; @@ -657,8 +661,6 @@ unlock: if (IS_ERR(larval)) return PTR_ERR(larval); - if (larval) - crypto_wait_for_test(larval); crypto_remove_final(&algs_to_put); return 0; } @@ -1042,6 +1044,7 @@ static void __init crypto_start_tests(void) l->test_started = true; larval = l; + crypto_schedule_test(larval); break; } @@ -1049,8 +1052,6 @@ static void __init crypto_start_tests(void) if (!larval) break; - - crypto_wait_for_test(larval); } set_crypto_boot_test_finished(); diff --git a/crypto/api.c b/crypto/api.c index ffb81aa32725..bbe29d438815 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -154,32 +154,31 @@ static struct crypto_alg *crypto_larval_add(const char *name, u32 type, return alg; } -void crypto_larval_kill(struct crypto_alg *alg) +static void crypto_larval_kill(struct crypto_larval *larval) { - struct crypto_larval *larval = (void *)alg; + bool unlinked; down_write(&crypto_alg_sem); - list_del(&alg->cra_list); + unlinked = list_empty(&larval->alg.cra_list); + if (!unlinked) + list_del_init(&larval->alg.cra_list); up_write(&crypto_alg_sem); - complete_all(&larval->completion); - crypto_alg_put(alg); -} -EXPORT_SYMBOL_GPL(crypto_larval_kill); -void crypto_wait_for_test(struct crypto_larval *larval) + if (unlinked) + return; + + complete_all(&larval->completion); + crypto_alg_put(&larval->alg); +} + +void crypto_schedule_test(struct crypto_larval *larval) { int err; err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult); - if (WARN_ON_ONCE(err != NOTIFY_STOP)) - goto out; - - err = wait_for_completion_killable(&larval->completion); - WARN_ON(err); -out: - crypto_larval_kill(&larval->alg); + WARN_ON_ONCE(err != NOTIFY_STOP); } -EXPORT_SYMBOL_GPL(crypto_wait_for_test); +EXPORT_SYMBOL_GPL(crypto_schedule_test); static void crypto_start_test(struct crypto_larval *larval) { @@ -198,7 +197,7 @@ static void crypto_start_test(struct crypto_larval *larval) larval->test_started = true; up_write(&crypto_alg_sem); - crypto_wait_for_test(larval); + crypto_schedule_test(larval); } static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg) @@ -218,9 +217,11 @@ again: alg = larval->adult; if (time_left < 0) alg = ERR_PTR(-EINTR); - else if (!time_left) + else if (!time_left) { + if (crypto_is_test_larval(larval)) + crypto_larval_kill(larval); alg = ERR_PTR(-ETIMEDOUT); - else if (!alg) { + } else if (!alg) { u32 type; u32 mask; @@ -355,7 +356,7 @@ struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask) crypto_mod_put(larval); alg = ERR_PTR(-ENOENT); } - crypto_larval_kill(larval); + crypto_larval_kill(container_of(larval, struct crypto_larval, alg)); return alg; } EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup); diff --git a/crypto/internal.h b/crypto/internal.h index aee31319be2e..711a6a5bfa2b 100644 --- a/crypto/internal.h +++ b/crypto/internal.h @@ -113,8 +113,7 @@ struct crypto_alg *crypto_mod_get(struct crypto_alg *alg); struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask); struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask); -void crypto_larval_kill(struct crypto_alg *alg); -void crypto_wait_for_test(struct crypto_larval *larval); +void crypto_schedule_test(struct crypto_larval *larval); void crypto_alg_tested(const char *name, int err); void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,