From b76377543b738a6b58b0a7b0a42dd9e16436fee1 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Thu, 30 Aug 2018 11:00:15 -0400 Subject: crc-t10dif: Pick better transform if one becomes available T10 CRC library is linked into the kernel thanks to block and SCSI. The crypto accelerators are typically loaded later as modules and are therefore not available when the T10 CRC library is initialized. Use the crypto notifier facility to trigger a switch to a better algorithm if one becomes available after the initial hash has been registered. Use RCU to protect the original transform while the new one is being set up. Suggested-by: Ard Biesheuvel Signed-off-by: Martin K. Petersen Signed-off-by: Herbert Xu --- lib/crc-t10dif.c | 46 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 44 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c index 1ad33e555805..52f577a3868d 100644 --- a/lib/crc-t10dif.c +++ b/lib/crc-t10dif.c @@ -14,10 +14,47 @@ #include #include #include +#include #include +#include -static struct crypto_shash *crct10dif_tfm; +static struct crypto_shash __rcu *crct10dif_tfm; static struct static_key crct10dif_fallback __read_mostly; +DEFINE_MUTEX(crc_t10dif_mutex); + +static int crc_t10dif_rehash(struct notifier_block *self, unsigned long val, void *data) +{ + struct crypto_alg *alg = data; + struct crypto_shash *new, *old; + + if (val != CRYPTO_MSG_ALG_LOADED || + static_key_false(&crct10dif_fallback) || + strncmp(alg->cra_name, CRC_T10DIF_STRING, strlen(CRC_T10DIF_STRING))) + return 0; + + mutex_lock(&crc_t10dif_mutex); + old = rcu_dereference_protected(crct10dif_tfm, + lockdep_is_held(&crc_t10dif_mutex)); + if (!old) { + mutex_unlock(&crc_t10dif_mutex); + return 0; + } + new = crypto_alloc_shash("crct10dif", 0, 0); + if (IS_ERR(new)) { + mutex_unlock(&crc_t10dif_mutex); + return 0; + } + rcu_assign_pointer(crct10dif_tfm, new); + mutex_unlock(&crc_t10dif_mutex); + + synchronize_rcu(); + crypto_free_shash(old); + return 0; +} + +static struct notifier_block crc_t10dif_nb = { + .notifier_call = crc_t10dif_rehash, +}; __u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len) { @@ -30,11 +67,14 @@ __u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len) if (static_key_false(&crct10dif_fallback)) return crc_t10dif_generic(crc, buffer, len); - desc.shash.tfm = crct10dif_tfm; + rcu_read_lock(); + desc.shash.tfm = rcu_dereference(crct10dif_tfm); desc.shash.flags = 0; *(__u16 *)desc.ctx = crc; err = crypto_shash_update(&desc.shash, buffer, len); + rcu_read_unlock(); + BUG_ON(err); return *(__u16 *)desc.ctx; @@ -49,6 +89,7 @@ EXPORT_SYMBOL(crc_t10dif); static int __init crc_t10dif_mod_init(void) { + crypto_register_notifier(&crc_t10dif_nb); crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0); if (IS_ERR(crct10dif_tfm)) { static_key_slow_inc(&crct10dif_fallback); @@ -59,6 +100,7 @@ static int __init crc_t10dif_mod_init(void) static void __exit crc_t10dif_mod_fini(void) { + crypto_unregister_notifier(&crc_t10dif_nb); crypto_free_shash(crct10dif_tfm); } -- cgit v1.2.3 From 11dcb1037f40a19f298845a9b2ec093f7b8b958b Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Thu, 30 Aug 2018 11:00:16 -0400 Subject: crc-t10dif: Allow current transform to be inspected in sysfs Add a way to print the currently active CRC algorithm in: /sys/module/crc_t10dif/parameters/transform Signed-off-by: Martin K. Petersen Signed-off-by: Herbert Xu --- lib/crc-t10dif.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'lib') diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c index 52f577a3868d..6507fa101eff 100644 --- a/lib/crc-t10dif.c +++ b/lib/crc-t10dif.c @@ -107,6 +107,17 @@ static void __exit crc_t10dif_mod_fini(void) module_init(crc_t10dif_mod_init); module_exit(crc_t10dif_mod_fini); +static int crc_t10dif_transform_show(char *buffer, const struct kernel_param *kp) +{ + if (static_key_false(&crct10dif_fallback)) + return sprintf(buffer, "fallback\n"); + + return sprintf(buffer, "%s\n", + crypto_tfm_alg_driver_name(crypto_shash_tfm(crct10dif_tfm))); +} + +module_param_call(transform, NULL, crc_t10dif_transform_show, NULL, 0644); + MODULE_DESCRIPTION("T10 DIF CRC calculation"); MODULE_LICENSE("GPL"); MODULE_SOFTDEP("pre: crct10dif"); -- cgit v1.2.3 From a7e7edfea23fa1f3c910eac897aac41ec9584c38 Mon Sep 17 00:00:00 2001 From: kbuild test robot Date: Wed, 5 Sep 2018 01:52:44 +0800 Subject: crc-t10dif: crc_t10dif_mutex can be static Fixes: b76377543b73 ("crc-t10dif: Pick better transform if one becomes available") Signed-off-by: kbuild test robot Signed-off-by: Herbert Xu --- lib/crc-t10dif.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c index 6507fa101eff..4d0d47c1ffbd 100644 --- a/lib/crc-t10dif.c +++ b/lib/crc-t10dif.c @@ -20,7 +20,7 @@ static struct crypto_shash __rcu *crct10dif_tfm; static struct static_key crct10dif_fallback __read_mostly; -DEFINE_MUTEX(crc_t10dif_mutex); +static DEFINE_MUTEX(crc_t10dif_mutex); static int crc_t10dif_rehash(struct notifier_block *self, unsigned long val, void *data) { -- cgit v1.2.3 From a5e9f557098e54af44ade5d501379be18435bfbf Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 11 Sep 2018 20:05:10 -0700 Subject: crypto: chacha20 - Fix chacha20_block() keystream alignment (again) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In commit 9f480faec58c ("crypto: chacha20 - Fix keystream alignment for chacha20_block()"), I had missed that chacha20_block() can be called directly on the buffer passed to get_random_bytes(), which can have any alignment. So, while my commit didn't break anything, it didn't fully solve the alignment problems. Revert my solution and just update chacha20_block() to use put_unaligned_le32(), so the output buffer need not be aligned. This is simpler, and on many CPUs it's the same speed. But, I kept the 'tmp' buffers in extract_crng_user() and _get_random_bytes() 4-byte aligned, since that alignment is actually needed for _crng_backtrack_protect() too. Reported-by: Stephan Müller Cc: Theodore Ts'o Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- crypto/chacha20_generic.c | 7 ++++--- drivers/char/random.c | 24 ++++++++++++------------ include/crypto/chacha20.h | 3 +-- lib/chacha20.c | 6 +++--- 4 files changed, 20 insertions(+), 20 deletions(-) (limited to 'lib') diff --git a/crypto/chacha20_generic.c b/crypto/chacha20_generic.c index e451c3cb6a56..3ae96587caf9 100644 --- a/crypto/chacha20_generic.c +++ b/crypto/chacha20_generic.c @@ -18,20 +18,21 @@ static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src, unsigned int bytes) { - u32 stream[CHACHA20_BLOCK_WORDS]; + /* aligned to potentially speed up crypto_xor() */ + u8 stream[CHACHA20_BLOCK_SIZE] __aligned(sizeof(long)); if (dst != src) memcpy(dst, src, bytes); while (bytes >= CHACHA20_BLOCK_SIZE) { chacha20_block(state, stream); - crypto_xor(dst, (const u8 *)stream, CHACHA20_BLOCK_SIZE); + crypto_xor(dst, stream, CHACHA20_BLOCK_SIZE); bytes -= CHACHA20_BLOCK_SIZE; dst += CHACHA20_BLOCK_SIZE; } if (bytes) { chacha20_block(state, stream); - crypto_xor(dst, (const u8 *)stream, bytes); + crypto_xor(dst, stream, bytes); } } diff --git a/drivers/char/random.c b/drivers/char/random.c index bf5f99fc36f1..d22d967c50f0 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -433,9 +433,9 @@ static int crng_init_cnt = 0; static unsigned long crng_global_init_time = 0; #define CRNG_INIT_CNT_THRESH (2*CHACHA20_KEY_SIZE) static void _extract_crng(struct crng_state *crng, - __u32 out[CHACHA20_BLOCK_WORDS]); + __u8 out[CHACHA20_BLOCK_SIZE]); static void _crng_backtrack_protect(struct crng_state *crng, - __u32 tmp[CHACHA20_BLOCK_WORDS], int used); + __u8 tmp[CHACHA20_BLOCK_SIZE], int used); static void process_random_ready_list(void); static void _get_random_bytes(void *buf, int nbytes); @@ -921,7 +921,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) unsigned long flags; int i, num; union { - __u32 block[CHACHA20_BLOCK_WORDS]; + __u8 block[CHACHA20_BLOCK_SIZE]; __u32 key[8]; } buf; @@ -968,7 +968,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) } static void _extract_crng(struct crng_state *crng, - __u32 out[CHACHA20_BLOCK_WORDS]) + __u8 out[CHACHA20_BLOCK_SIZE]) { unsigned long v, flags; @@ -985,7 +985,7 @@ static void _extract_crng(struct crng_state *crng, spin_unlock_irqrestore(&crng->lock, flags); } -static void extract_crng(__u32 out[CHACHA20_BLOCK_WORDS]) +static void extract_crng(__u8 out[CHACHA20_BLOCK_SIZE]) { struct crng_state *crng = NULL; @@ -1003,7 +1003,7 @@ static void extract_crng(__u32 out[CHACHA20_BLOCK_WORDS]) * enough) to mutate the CRNG key to provide backtracking protection. */ static void _crng_backtrack_protect(struct crng_state *crng, - __u32 tmp[CHACHA20_BLOCK_WORDS], int used) + __u8 tmp[CHACHA20_BLOCK_SIZE], int used) { unsigned long flags; __u32 *s, *d; @@ -1015,14 +1015,14 @@ static void _crng_backtrack_protect(struct crng_state *crng, used = 0; } spin_lock_irqsave(&crng->lock, flags); - s = &tmp[used / sizeof(__u32)]; + s = (__u32 *) &tmp[used]; d = &crng->state[4]; for (i=0; i < 8; i++) *d++ ^= *s++; spin_unlock_irqrestore(&crng->lock, flags); } -static void crng_backtrack_protect(__u32 tmp[CHACHA20_BLOCK_WORDS], int used) +static void crng_backtrack_protect(__u8 tmp[CHACHA20_BLOCK_SIZE], int used) { struct crng_state *crng = NULL; @@ -1038,7 +1038,7 @@ static void crng_backtrack_protect(__u32 tmp[CHACHA20_BLOCK_WORDS], int used) static ssize_t extract_crng_user(void __user *buf, size_t nbytes) { ssize_t ret = 0, i = CHACHA20_BLOCK_SIZE; - __u32 tmp[CHACHA20_BLOCK_WORDS]; + __u8 tmp[CHACHA20_BLOCK_SIZE] __aligned(4); int large_request = (nbytes > 256); while (nbytes) { @@ -1617,7 +1617,7 @@ static void _warn_unseeded_randomness(const char *func_name, void *caller, */ static void _get_random_bytes(void *buf, int nbytes) { - __u32 tmp[CHACHA20_BLOCK_WORDS]; + __u8 tmp[CHACHA20_BLOCK_SIZE] __aligned(4); trace_get_random_bytes(nbytes, _RET_IP_); @@ -2243,7 +2243,7 @@ u64 get_random_u64(void) if (use_lock) read_lock_irqsave(&batched_entropy_reset_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) { - extract_crng((__u32 *)batch->entropy_u64); + extract_crng((u8 *)batch->entropy_u64); batch->position = 0; } ret = batch->entropy_u64[batch->position++]; @@ -2273,7 +2273,7 @@ u32 get_random_u32(void) if (use_lock) read_lock_irqsave(&batched_entropy_reset_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) { - extract_crng(batch->entropy_u32); + extract_crng((u8 *)batch->entropy_u32); batch->position = 0; } ret = batch->entropy_u32[batch->position++]; diff --git a/include/crypto/chacha20.h b/include/crypto/chacha20.h index b83d66073db0..f76302d99e2b 100644 --- a/include/crypto/chacha20.h +++ b/include/crypto/chacha20.h @@ -13,13 +13,12 @@ #define CHACHA20_IV_SIZE 16 #define CHACHA20_KEY_SIZE 32 #define CHACHA20_BLOCK_SIZE 64 -#define CHACHA20_BLOCK_WORDS (CHACHA20_BLOCK_SIZE / sizeof(u32)) struct chacha20_ctx { u32 key[8]; }; -void chacha20_block(u32 *state, u32 *stream); +void chacha20_block(u32 *state, u8 *stream); void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv); int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key, unsigned int keysize); diff --git a/lib/chacha20.c b/lib/chacha20.c index c1cc50fb68c9..d907fec6a9ed 100644 --- a/lib/chacha20.c +++ b/lib/chacha20.c @@ -16,9 +16,9 @@ #include #include -void chacha20_block(u32 *state, u32 *stream) +void chacha20_block(u32 *state, u8 *stream) { - u32 x[16], *out = stream; + u32 x[16]; int i; for (i = 0; i < ARRAY_SIZE(x); i++) @@ -67,7 +67,7 @@ void chacha20_block(u32 *state, u32 *stream) } for (i = 0; i < ARRAY_SIZE(x); i++) - out[i] = cpu_to_le32(x[i] + state[i]); + put_unaligned_le32(x[i] + state[i], &stream[i * sizeof(u32)]); state[12]++; } -- cgit v1.2.3