From f342a2c7512ff8fa72443ae29ab2541b298a2183 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sun, 13 Nov 2022 16:12:33 -0800 Subject: [PATCH] BACKPORT: crypto: api - optimize algorithm registration when self-tests disabled Currently, registering an algorithm with the crypto API always causes a notification to be posted to the "cryptomgr", which then creates a kthread to self-test the algorithm. However, if self-tests are disabled in the kconfig (as is the default option), then this kthread just notifies waiters that the algorithm has been tested, then exits. This causes a significant amount of overhead, especially in the kthread creation and destruction, which is not necessary at all. For example, in a quick test I found that booting a "minimum" x86_64 kernel with all the crypto options enabled (except for the self-tests) takes about 400ms until PID 1 can start. Of that, a full 13ms is spent just doing this pointless dance, involving a kthread being created, run, and destroyed over 200 times. That's over 3% of the entire kernel start time. Fix this by just skipping the creation of the test larval and the posting of the registration notification entirely, when self-tests are disabled. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Bug: 256875295 (cherry picked from commit a7008584ab19d2df05caa95634cd72bc41f4cad3) (Resolved trivial conflict due to missing upstream commit d6097b8d5d55) Change-Id: Ia6be068618e9286c1be01415a6766ba2fa94fc0d Signed-off-by: Eric Biggers --- crypto/algapi.c | 156 +++++++++++++++++++++++++++--------------------- crypto/api.c | 3 - 2 files changed, 87 insertions(+), 72 deletions(-) diff --git a/crypto/algapi.c b/crypto/algapi.c index 76fdaa16bd4a..0da0d16065e6 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -216,12 +216,64 @@ void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list, } EXPORT_SYMBOL_GPL(crypto_remove_spawns); +static void crypto_alg_finish_registration(struct crypto_alg *alg, + bool fulfill_requests, + struct list_head *algs_to_put) +{ + struct crypto_alg *q; + + list_for_each_entry(q, &crypto_alg_list, cra_list) { + if (q == alg) + continue; + + if (crypto_is_moribund(q)) + continue; + + if (crypto_is_larval(q)) { + struct crypto_larval *larval = (void *)q; + + /* + * Check to see if either our generic name or + * specific name can satisfy the name requested + * by the larval entry q. + */ + if (strcmp(alg->cra_name, q->cra_name) && + strcmp(alg->cra_driver_name, q->cra_name)) + continue; + + if (larval->adult) + continue; + if ((q->cra_flags ^ alg->cra_flags) & larval->mask) + continue; + + if (fulfill_requests && crypto_mod_get(alg)) + larval->adult = alg; + else + larval->adult = ERR_PTR(-EAGAIN); + + continue; + } + + if (strcmp(alg->cra_name, q->cra_name)) + continue; + + if (strcmp(alg->cra_driver_name, q->cra_driver_name) && + q->cra_priority > alg->cra_priority) + continue; + + crypto_remove_spawns(q, algs_to_put, alg); + } + + crypto_notify(CRYPTO_MSG_ALG_LOADED, alg); +} + static struct crypto_larval *crypto_alloc_test_larval(struct crypto_alg *alg) { struct crypto_larval *larval; - if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER)) - return NULL; + if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER) || + IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS)) + return NULL; /* No self-test needed */ larval = crypto_larval_alloc(alg->cra_name, alg->cra_flags | CRYPTO_ALG_TESTED, 0); @@ -242,7 +294,8 @@ static struct crypto_larval *crypto_alloc_test_larval(struct crypto_alg *alg) return larval; } -static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg) +static struct crypto_larval * +__crypto_register_alg(struct crypto_alg *alg, struct list_head *algs_to_put) { struct crypto_alg *q; struct crypto_larval *larval; @@ -253,9 +306,6 @@ static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg) INIT_LIST_HEAD(&alg->cra_users); - /* No cheating! */ - alg->cra_flags &= ~CRYPTO_ALG_TESTED; - ret = -EEXIST; list_for_each_entry(q, &crypto_alg_list, cra_list) { @@ -282,13 +332,18 @@ static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg) list_add(&alg->cra_list, &crypto_alg_list); - if (larval) - list_add(&larval->alg.cra_list, &crypto_alg_list); - else - alg->cra_flags |= CRYPTO_ALG_TESTED; - crypto_stats_init(alg); + if (larval) { + /* No cheating! */ + alg->cra_flags &= ~CRYPTO_ALG_TESTED; + + list_add(&larval->alg.cra_list, &crypto_alg_list); + } else { + alg->cra_flags |= CRYPTO_ALG_TESTED; + crypto_alg_finish_registration(alg, true, algs_to_put); + } + out: return larval; @@ -327,7 +382,10 @@ found: alg->cra_flags |= CRYPTO_ALG_TESTED; - /* Only satisfy larval waiters if we are the best. */ + /* + * If a higher-priority implementation of the same algorithm is + * currently being tested, then don't fulfill request larvals. + */ best = true; list_for_each_entry(q, &crypto_alg_list, cra_list) { if (crypto_is_moribund(q) || !crypto_is_larval(q)) @@ -342,47 +400,7 @@ found: } } - list_for_each_entry(q, &crypto_alg_list, cra_list) { - if (q == alg) - continue; - - if (crypto_is_moribund(q)) - continue; - - if (crypto_is_larval(q)) { - struct crypto_larval *larval = (void *)q; - - /* - * Check to see if either our generic name or - * specific name can satisfy the name requested - * by the larval entry q. - */ - if (strcmp(alg->cra_name, q->cra_name) && - strcmp(alg->cra_driver_name, q->cra_name)) - continue; - - if (larval->adult) - continue; - if ((q->cra_flags ^ alg->cra_flags) & larval->mask) - continue; - - if (best && crypto_mod_get(alg)) - larval->adult = alg; - else - larval->adult = ERR_PTR(-EAGAIN); - - continue; - } - - if (strcmp(alg->cra_name, q->cra_name)) - continue; - - if (strcmp(alg->cra_driver_name, q->cra_driver_name) && - q->cra_priority > alg->cra_priority) - continue; - - crypto_remove_spawns(q, &list, alg); - } + crypto_alg_finish_registration(alg, best, &list); complete: complete_all(&test->completion); @@ -409,7 +427,8 @@ EXPORT_SYMBOL_GPL(crypto_remove_final); int crypto_register_alg(struct crypto_alg *alg) { struct crypto_larval *larval; - bool test_started; + LIST_HEAD(algs_to_put); + bool test_started = false; int err; alg->cra_flags &= ~CRYPTO_ALG_DEAD; @@ -418,17 +437,18 @@ int crypto_register_alg(struct crypto_alg *alg) return err; down_write(&crypto_alg_sem); - larval = __crypto_register_alg(alg); - test_started = static_key_enabled(&crypto_boot_test_finished); - if (!IS_ERR_OR_NULL(larval)) + larval = __crypto_register_alg(alg, &algs_to_put); + if (!IS_ERR_OR_NULL(larval)) { + test_started = static_key_enabled(&crypto_boot_test_finished); larval->test_started = test_started; + } up_write(&crypto_alg_sem); - if (IS_ERR_OR_NULL(larval)) + if (IS_ERR(larval)) return PTR_ERR(larval); - if (test_started) crypto_wait_for_test(larval); + crypto_remove_final(&algs_to_put); return 0; } EXPORT_SYMBOL_GPL(crypto_register_alg); @@ -604,6 +624,7 @@ int crypto_register_instance(struct crypto_template *tmpl, { struct crypto_larval *larval; struct crypto_spawn *spawn; + LIST_HEAD(algs_to_put); int err; err = crypto_check_alg(&inst->alg); @@ -631,7 +652,7 @@ int crypto_register_instance(struct crypto_template *tmpl, spawn = next; } - larval = __crypto_register_alg(&inst->alg); + larval = __crypto_register_alg(&inst->alg, &algs_to_put); if (IS_ERR(larval)) goto unlock; else if (larval) @@ -643,15 +664,12 @@ int crypto_register_instance(struct crypto_template *tmpl, unlock: up_write(&crypto_alg_sem); - err = PTR_ERR(larval); - if (IS_ERR_OR_NULL(larval)) - goto err; - - crypto_wait_for_test(larval); - err = 0; - -err: - return err; + if (IS_ERR(larval)) + return PTR_ERR(larval); + if (larval) + crypto_wait_for_test(larval); + crypto_remove_final(&algs_to_put); + return 0; } EXPORT_SYMBOL_GPL(crypto_register_instance); diff --git a/crypto/api.c b/crypto/api.c index 7ddfe946dd56..04c9d30ef0c6 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -172,9 +172,6 @@ void crypto_wait_for_test(struct crypto_larval *larval) err = wait_for_completion_killable(&larval->completion); WARN_ON(err); - if (!err) - crypto_notify(CRYPTO_MSG_ALG_LOADED, larval); - out: crypto_larval_kill(&larval->alg); }