From 29195232fa2f722449c1c6850277b4ca9fa5f781 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 9 Jun 2020 23:39:43 -0700 Subject: [PATCH] crc-t10dif: clean up some more things - Correctly compare the algorithm name in crc_t10dif_notify(). - Use proper NOTIFY_* status codes instead of 0. - Consistently use CRC_T10DIF_STRING instead of "crct10dif" directly. - Use a proper type for the shash_desc context. - Use crypto_shash_driver_name() instead of open-coding it. - Make crc_t10dif_transform_show() use snprintf() rather than sprintf(). This isn't actually necessary since the buffer has size PAGE_SIZE and CRYPTO_MAX_ALG_NAME < PAGE_SIZE, but it's good practice. - Give the "transform" sysfs file mode 0444 rather than 0644, since it doesn't implement a setter method. - Adjust the module description to not be the same as crct10dif-generic. Cc: Martin K. Petersen Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- lib/crc-t10dif.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c index af3613367ef9..1ed2ed487097 100644 --- a/lib/crc-t10dif.c +++ b/lib/crc-t10dif.c @@ -26,11 +26,11 @@ static int crc_t10dif_notify(struct notifier_block *self, unsigned long val, voi struct crypto_alg *alg = data; if (val != CRYPTO_MSG_ALG_LOADED || - strncmp(alg->cra_name, CRC_T10DIF_STRING, strlen(CRC_T10DIF_STRING))) - return 0; + strcmp(alg->cra_name, CRC_T10DIF_STRING)) + return NOTIFY_DONE; schedule_work(&crct10dif_rehash_work); - return 0; + return NOTIFY_OK; } static void crc_t10dif_rehash(struct work_struct *work) @@ -40,7 +40,7 @@ static void crc_t10dif_rehash(struct work_struct *work) mutex_lock(&crc_t10dif_mutex); old = rcu_dereference_protected(crct10dif_tfm, lockdep_is_held(&crc_t10dif_mutex)); - new = crypto_alloc_shash("crct10dif", 0, 0); + new = crypto_alloc_shash(CRC_T10DIF_STRING, 0, 0); if (IS_ERR(new)) { mutex_unlock(&crc_t10dif_mutex); return; @@ -64,7 +64,7 @@ __u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len) { struct { struct shash_desc shash; - char ctx[2]; + __u16 crc; } desc; int err; @@ -73,14 +73,13 @@ __u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len) rcu_read_lock(); desc.shash.tfm = rcu_dereference(crct10dif_tfm); - *(__u16 *)desc.ctx = crc; - + desc.crc = crc; err = crypto_shash_update(&desc.shash, buffer, len); rcu_read_unlock(); BUG_ON(err); - return *(__u16 *)desc.ctx; + return desc.crc; } EXPORT_SYMBOL(crc_t10dif_update); @@ -111,7 +110,6 @@ module_exit(crc_t10dif_mod_fini); static int crc_t10dif_transform_show(char *buffer, const struct kernel_param *kp) { struct crypto_shash *tfm; - const char *name; int len; if (static_branch_unlikely(&crct10dif_fallback)) @@ -119,15 +117,15 @@ static int crc_t10dif_transform_show(char *buffer, const struct kernel_param *kp rcu_read_lock(); tfm = rcu_dereference(crct10dif_tfm); - name = crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm)); - len = sprintf(buffer, "%s\n", name); + len = snprintf(buffer, PAGE_SIZE, "%s\n", + crypto_shash_driver_name(tfm)); rcu_read_unlock(); return len; } -module_param_call(transform, NULL, crc_t10dif_transform_show, NULL, 0644); +module_param_call(transform, NULL, crc_t10dif_transform_show, NULL, 0444); -MODULE_DESCRIPTION("T10 DIF CRC calculation"); +MODULE_DESCRIPTION("T10 DIF CRC calculation (library API)"); MODULE_LICENSE("GPL"); MODULE_SOFTDEP("pre: crct10dif");