[PATCH v2] crypto, x86/sha: Eliminate casts on asm implementations

Kees Cook
2020-01-15T02:28:53Z

In order to avoid CFI function prototype mismatches, this removes the
casts on assembly implementations of sha1/256/512 accelerators. The
safety checks from BUILD_BUG_ON() remain.

Additionally, this renames various arguments for clarity, as suggested
by Eric Biggers.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
I'm calling this v2 since it's now stand-alone. I think I caught
everything now...
v2: clean up more comments (ebiggers)
v1: https://lore.kernel.org/lkml/20191122030620.GD32523@sol.localdomain/
---
arch/x86/crypto/sha1_avx2_x86_64_asm.S | 6 +--
arch/x86/crypto/sha1_ssse3_asm.S | 14 ++++--
arch/x86/crypto/sha1_ssse3_glue.c | 68 +++++++++++---------------
arch/x86/crypto/sha256-avx-asm.S | 4 +-
arch/x86/crypto/sha256-avx2-asm.S | 4 +-
arch/x86/crypto/sha256-ssse3-asm.S | 6 ++-
arch/x86/crypto/sha256_ssse3_glue.c | 34 ++++++-------
arch/x86/crypto/sha512-avx-asm.S | 11 +++--
arch/x86/crypto/sha512-avx2-asm.S | 11 +++--
arch/x86/crypto/sha512-ssse3-asm.S | 13 +++--
arch/x86/crypto/sha512_ssse3_glue.c | 31 ++++++------
11 files changed, 101 insertions(+), 101 deletions(-)

diff --git a/arch/x86/crypto/sha1_avx2_x86_64_asm.S b/arch/x86/crypto/sha1_avx2_x86_64_asm.S
index 6decc85ef7b7..1e594d60afa5 100644
--- a/arch/x86/crypto/sha1_avx2_x86_64_asm.S
+++ b/arch/x86/crypto/sha1_avx2_x86_64_asm.S
@@ -62,11 +62,11 @@
*Visit http://software.intel.com/en-us/articles/
*and refer to improving-the-performance-of-the-secure-hash-algorithm-1/
*
- *Updates 20-byte SHA-1 record in 'hash' for even number of
- *'num_blocks' consecutive 64-byte blocks
+ *Updates 20-byte SHA-1 record at start of 'state', from 'input', for
+ *even number of 'blocks' consecutive 64-byte blocks.
*
*extern "C" void sha1_transform_avx2(
- * int *hash, const char* input, size_t num_blocks );
+ * struct sha1_state *state, const u8* input, int blocks );
*/

#include <linux/linkage.h>
diff --git a/arch/x86/crypto/sha1_ssse3_asm.S b/arch/x86/crypto/sha1_ssse3_asm.S
index 5d03c1173690..12e2d19d7402 100644
--- a/arch/x86/crypto/sha1_ssse3_asm.S
+++ b/arch/x86/crypto/sha1_ssse3_asm.S
@@ -457,9 +457,13 @@ W_PRECALC_SSSE3
movdqu \a,\b
.endm

-/* SSSE3 optimized implementation:
- * extern "C" void sha1_transform_ssse3(u32 *digest, const char *data, u32 *ws,
- * unsigned int rounds);
+/*
+ * SSSE3 optimized implementation:
+ *
+ * extern "C" void sha1_transform_ssse3(struct sha1_state *state,
+ * const u8 *data, int blocks);
+ *
+ * Note that struct sha1_state is assumed to begin with u32 state[5].
*/
SHA1_VECTOR_ASM sha1_transform_ssse3

@@ -545,8 +549,8 @@ W_PRECALC_AVX

/* AVX optimized implementation:
- * extern "C" void sha1_transform_avx(u32 *digest, const char *data, u32 *ws,
- * unsigned int rounds);
+ * extern "C" void sha1_transform_avx(struct sha1_state *state,
+ * const u8 *data, int blocks);
*/
SHA1_VECTOR_ASM sha1_transform_avx

diff --git a/arch/x86/crypto/sha1_ssse3_glue.c b/arch/x86/crypto/sha1_ssse3_glue.c
index 639d4c2fd6a8..f7c8d043f6c1 100644
--- a/arch/x86/crypto/sha1_ssse3_glue.c
+++ b/arch/x86/crypto/sha1_ssse3_glue.c
@@ -27,11 +27,8 @@
#include <crypto/sha1_base.h>
#include <asm/simd.h>

-typedef void (sha1_transform_fn)(u32 *digest, const char *data,
- unsigned int rounds);
-
static int sha1_update(struct shash_desc *desc, const u8 *data,
- unsigned int len, sha1_transform_fn *sha1_xform)
+ unsigned int len, sha1_block_fn *sha1_xform)
{
struct sha1_state *sctx = shash_desc_ctx(desc);

@@ -39,48 +36,47 @@ static int sha1_update(struct shash_desc *desc, const u8 *data,
(sctx->count % SHA1_BLOCK_SIZE) + len < SHA1_BLOCK_SIZE)
return crypto_sha1_update(desc, data, len);

- /* make sure casting to sha1_block_fn() is safe */
+ /*
+ * Make sure struct sha1_state begins directly with the SHA1
+ * 160-bit internal state, as this is what the asm functions expect.
+ */
BUILD_BUG_ON(offsetof(struct sha1_state, state) != 0);

kernel_fpu_begin();
- sha1_base_do_update(desc, data, len,
- (sha1_block_fn *)sha1_xform);
+ sha1_base_do_update(desc, data, len, sha1_xform);
kernel_fpu_end();

return 0;
}

static int sha1_finup(struct shash_desc *desc, const u8 *data,
- unsigned int len, u8 *out, sha1_transform_fn *sha1_xform)
+ unsigned int len, u8 *out, sha1_block_fn *sha1_xform)
{
if (!crypto_simd_usable())
return crypto_sha1_finup(desc, data, len, out);

kernel_fpu_begin();
if (len)
- sha1_base_do_update(desc, data, len,
- (sha1_block_fn *)sha1_xform);
- sha1_base_do_finalize(desc, (sha1_block_fn *)sha1_xform);
+ sha1_base_do_update(desc, data, len, sha1_xform);
+ sha1_base_do_finalize(desc, sha1_xform);
kernel_fpu_end();

return sha1_base_finish(desc, out);
}

-asmlinkage void sha1_transform_ssse3(u32 *digest, const char *data,
- unsigned int rounds);
+asmlinkage void sha1_transform_ssse3(struct sha1_state *state,
+ const u8 *data, int blocks);

static int sha1_ssse3_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
- return sha1_update(desc, data, len,
- (sha1_transform_fn *) sha1_transform_ssse3);
+ return sha1_update(desc, data, len, sha1_transform_ssse3);
}

static int sha1_ssse3_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
- return sha1_finup(desc, data, len, out,
- (sha1_transform_fn *) sha1_transform_ssse3);
+ return sha1_finup(desc, data, len, out, sha1_transform_ssse3);
}

/* Add padding and return the message digest. */
@@ -119,21 +115,19 @@ static void unregister_sha1_ssse3(void)
}

#ifdef CONFIG_AS_AVX
-asmlinkage void sha1_transform_avx(u32 *digest, const char *data,
- unsigned int rounds);
+asmlinkage void sha1_transform_avx(struct sha1_state *state,
+ const u8 *data, int blocks);

static int sha1_avx_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
- return sha1_update(desc, data, len,
- (sha1_transform_fn *) sha1_transform_avx);
+ return sha1_update(desc, data, len, sha1_transform_avx);
}

static int sha1_avx_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
- return sha1_finup(desc, data, len, out,
- (sha1_transform_fn *) sha1_transform_avx);
+ return sha1_finup(desc, data, len, out, sha1_transform_avx);
}

static int sha1_avx_final(struct shash_desc *desc, u8 *out)
@@ -190,8 +184,8 @@ static inline void unregister_sha1_avx(void) { }
#if defined(CONFIG_AS_AVX2) && (CONFIG_AS_AVX)
#define SHA1_AVX2_BLOCK_OPTSIZE 4 /* optimal 4*64 bytes of SHA1 blocks */

-asmlinkage void sha1_transform_avx2(u32 *digest, const char *data,
- unsigned int rounds);
+asmlinkage void sha1_transform_avx2(struct sha1_state *state,
+ const u8 *data, int blocks);

static bool avx2_usable(void)
{
@@ -203,28 +197,26 @@ static bool avx2_usable(void)
return false;
}

-static void sha1_apply_transform_avx2(u32 *digest, const char *data,
- unsigned int rounds)
+static void sha1_apply_transform_avx2(struct sha1_state *state,
+ const u8 *data, int blocks)
{
/* Select the optimal transform based on data block size */
if (rounds >= SHA1_AVX2_BLOCK_OPTSIZE)
- sha1_transform_avx2(digest, data, rounds);
+ sha1_transform_avx2(state, data, blocks);
else
- sha1_transform_avx(digest, data, rounds);
+ sha1_transform_avx(state, data, blocks);
}

static int sha1_avx2_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
- return sha1_update(desc, data, len,
- (sha1_transform_fn *) sha1_apply_transform_avx2);
+ return sha1_update(desc, data, len, sha1_apply_transform_avx2);
}

static int sha1_avx2_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
- return sha1_finup(desc, data, len, out,
- (sha1_transform_fn *) sha1_apply_transform_avx2);
+ return sha1_finup(desc, data, len, out, sha1_apply_transform_avx2);
}

static int sha1_avx2_final(struct shash_desc *desc, u8 *out)
@@ -267,21 +259,19 @@ static inline void unregister_sha1_avx2(void) { }
#endif

#ifdef CONFIG_AS_SHA1_NI
-asmlinkage void sha1_ni_transform(u32 *digest, const char *data,
- unsigned int rounds);
+asmlinkage void sha1_ni_transform(struct sha1_state *digest, const u8 *data,
+ int rounds);

static int sha1_ni_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
- return sha1_update(desc, data, len,
- (sha1_transform_fn *) sha1_ni_transform);
+ return sha1_update(desc, data, len, sha1_ni_transform);
}

static int sha1_ni_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
- return sha1_finup(desc, data, len, out,
- (sha1_transform_fn *) sha1_ni_transform);
+ return sha1_finup(desc, data, len, out, sha1_ni_transform);
}

static int sha1_ni_final(struct shash_desc *desc, u8 *out)
diff --git a/arch/x86/crypto/sha256-avx-asm.S b/arch/x86/crypto/sha256-avx-asm.S
index 22e14c8dd2e4..fcbc30f58c38 100644
--- a/arch/x86/crypto/sha256-avx-asm.S
+++ b/arch/x86/crypto/sha256-avx-asm.S
@@ -341,8 +341,8 @@ a = TMP_
.endm

########################################################################
-## void sha256_transform_avx(void *input_data, UINT32 digest[8], UINT64 num_blks)
-## arg 1 : pointer to digest
+## void sha256_transform_avx(state sha256_state *state, const u8 *data, int blocks)
+## arg 1 : pointer to state
## arg 2 : pointer to input data
## arg 3 : Num blocks
########################################################################
diff --git a/arch/x86/crypto/sha256-avx2-asm.S b/arch/x86/crypto/sha256-avx2-asm.S
index 519b551ad576..499d9ec129de 100644
--- a/arch/x86/crypto/sha256-avx2-asm.S
+++ b/arch/x86/crypto/sha256-avx2-asm.S
@@ -520,8 +520,8 @@ STACK_SIZE = _RSP + _RSP_SIZE
.endm

########################################################################
-## void sha256_transform_rorx(void *input_data, UINT32 digest[8], UINT64 num_blks)
-## arg 1 : pointer to digest
+## void sha256_transform_rorx(struct sha256_state *state, const u8 *data, int blocks)
+## arg 1 : pointer to state
## arg 2 : pointer to input data
## arg 3 : Num blocks
########################################################################
diff --git a/arch/x86/crypto/sha256-ssse3-asm.S b/arch/x86/crypto/sha256-ssse3-asm.S
index 69cc2f91dc4c..ddfa863b4ee3 100644
--- a/arch/x86/crypto/sha256-ssse3-asm.S
+++ b/arch/x86/crypto/sha256-ssse3-asm.S
@@ -347,8 +347,10 @@ a = TMP_
.endm

########################################################################
-## void sha256_transform_ssse3(void *input_data, UINT32 digest[8], UINT64 num_blks)
-## arg 1 : pointer to digest
+## void sha256_transform_ssse3(struct sha256_state *state, const u8 *data,
+## int blocks);
+## arg 1 : pointer to state
+## (struct sha256_state is assumed to begin with u32 state[8])
## arg 2 : pointer to input data
## arg 3 : Num blocks
########################################################################
diff --git a/arch/x86/crypto/sha256_ssse3_glue.c b/arch/x86/crypto/sha256_ssse3_glue.c
index f9aff31fe59e..03ad657c04bd 100644
--- a/arch/x86/crypto/sha256_ssse3_glue.c
+++ b/arch/x86/crypto/sha256_ssse3_glue.c
@@ -41,12 +41,11 @@
#include <linux/string.h>
#include <asm/simd.h>

-asmlinkage void sha256_transform_ssse3(u32 *digest, const char *data,
- u64 rounds);
-typedef void (sha256_transform_fn)(u32 *digest, const char *data, u64 rounds);
+asmlinkage void sha256_transform_ssse3(struct sha256_state *state,
+ const u8 *data, int blocks);

static int _sha256_update(struct shash_desc *desc, const u8 *data,
- unsigned int len, sha256_transform_fn *sha256_xform)
+ unsigned int len, sha256_block_fn *sha256_xform)
{
struct sha256_state *sctx = shash_desc_ctx(desc);

@@ -54,28 +53,29 @@ static int _sha256_update(struct shash_desc *desc, const u8 *data,
(sctx->count % SHA256_BLOCK_SIZE) + len < SHA256_BLOCK_SIZE)
return crypto_sha256_update(desc, data, len);

- /* make sure casting to sha256_block_fn() is safe */
+ /*
+ * Make sure struct sha256_state begins directly with the SHA256
+ * 256-bit internal state, as this is what the asm functions expect.
+ */
BUILD_BUG_ON(offsetof(struct sha256_state, state) != 0);

kernel_fpu_begin();
- sha256_base_do_update(desc, data, len,
- (sha256_block_fn *)sha256_xform);
+ sha256_base_do_update(desc, data, len, sha256_xform);
kernel_fpu_end();

return 0;
}

static int sha256_finup(struct shash_desc *desc, const u8 *data,
- unsigned int len, u8 *out, sha256_transform_fn *sha256_xform)
+ unsigned int len, u8 *out, sha256_block_fn *sha256_xform)
{
if (!crypto_simd_usable())
return crypto_sha256_finup(desc, data, len, out);

kernel_fpu_begin();
if (len)
- sha256_base_do_update(desc, data, len,
- (sha256_block_fn *)sha256_xform);
- sha256_base_do_finalize(desc, (sha256_block_fn *)sha256_xform);
+ sha256_base_do_update(desc, data, len, sha256_xform);
+ sha256_base_do_finalize(desc, sha256_xform);
kernel_fpu_end();

return sha256_base_finish(desc, out);
@@ -145,8 +145,8 @@ static void unregister_sha256_ssse3(void)
}

#ifdef CONFIG_AS_AVX
-asmlinkage void sha256_transform_avx(u32 *digest, const char *data,
- u64 rounds);
+asmlinkage void sha256_transform_avx(struct sha256_state *state,
+ const u8 *data, int blocks);

static int sha256_avx_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
@@ -227,8 +227,8 @@ static inline void unregister_sha256_avx(void) { }
#endif

#if defined(CONFIG_AS_AVX2) && defined(CONFIG_AS_AVX)
-asmlinkage void sha256_transform_rorx(u32 *digest, const char *data,
- u64 rounds);
+asmlinkage void sha256_transform_rorx(struct sha256_state *state,
+ const u8 *data, int blocks);

static int sha256_avx2_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
@@ -307,8 +307,8 @@ static inline void unregister_sha256_avx2(void) { }
#endif

#ifdef CONFIG_AS_SHA256_NI
-asmlinkage void sha256_ni_transform(u32 *digest, const char *data,
- u64 rounds); /*unsigned int rounds);*/
+asmlinkage void sha256_ni_transform(struct sha256_state *digest,
+ const u8 *data, int rounds);

static int sha256_ni_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
diff --git a/arch/x86/crypto/sha512-avx-asm.S b/arch/x86/crypto/sha512-avx-asm.S
index 3704ddd7e5d5..90ea945ba5e6 100644
--- a/arch/x86/crypto/sha512-avx-asm.S
+++ b/arch/x86/crypto/sha512-avx-asm.S
@@ -271,11 +271,12 @@ frame_size = frame_GPRSAVE + GPRSAVE_SIZE
.endm

########################################################################
-# void sha512_transform_avx(void* D, const void* M, u64 L)
-# Purpose: Updates the SHA512 digest stored at D with the message stored in M.
-# The size of the message pointed to by M must be an integer multiple of SHA512
-# message blocks.
-# L is the message length in SHA512 blocks
+# void sha512_transform_avx(sha512_state *state, const u8 *data, int blocks)
+# Purpose: Updates the SHA512 digest stored at "state" with the message
+# stored in "data".
+# The size of the message pointed to by "data" must be an integer multiple
+# of SHA512 message blocks.
+# "blocks" is the message length in SHA512 blocks
########################################################################
SYM_FUNC_START(sha512_transform_avx)
cmp $0, msglen
diff --git a/arch/x86/crypto/sha512-avx2-asm.S b/arch/x86/crypto/sha512-avx2-asm.S
index 80d830e7ee09..3dd886b14e7d 100644
--- a/arch/x86/crypto/sha512-avx2-asm.S
+++ b/arch/x86/crypto/sha512-avx2-asm.S
@@ -563,11 +563,12 @@ frame_size = frame_GPRSAVE + GPRSAVE_SIZE
.endm

########################################################################
-# void sha512_transform_rorx(void* D, const void* M, uint64_t L)#
-# Purpose: Updates the SHA512 digest stored at D with the message stored in M.
-# The size of the message pointed to by M must be an integer multiple of SHA512
-# message blocks.
-# L is the message length in SHA512 blocks
+# void sha512_transform_rorx(sha512_state *state, const u8 *data, int blocks)
+# Purpose: Updates the SHA512 digest stored at "state" with the message
+# stored in "data".
+# The size of the message pointed to by "data" must be an integer multiple
+# of SHA512 message blocks.
+# "blocks" is the message length in SHA512 blocks
########################################################################
SYM_FUNC_START(sha512_transform_rorx)
# Allocate Stack Space
diff --git a/arch/x86/crypto/sha512-ssse3-asm.S b/arch/x86/crypto/sha512-ssse3-asm.S
index 838f984e95d9..7946a1bee85b 100644
--- a/arch/x86/crypto/sha512-ssse3-asm.S
+++ b/arch/x86/crypto/sha512-ssse3-asm.S
@@ -269,11 +269,14 @@ frame_size = frame_GPRSAVE + GPRSAVE_SIZE
.endm

########################################################################
-# void sha512_transform_ssse3(void* D, const void* M, u64 L)#
-# Purpose: Updates the SHA512 digest stored at D with the message stored in M.
-# The size of the message pointed to by M must be an integer multiple of SHA512
-# message blocks.
-# L is the message length in SHA512 blocks.
+## void sha512_transform_ssse3(struct sha512_state *state, const u8 *data,
+## int blocks);
+# (struct sha512_state is assumed to begin with u64 state[8])
+# Purpose: Updates the SHA512 digest stored at "state" with the message
+# stored in "data".
+# The size of the message pointed to by "data" must be an integer multiple
+# of SHA512 message blocks.
+# "blocks" is the message length in SHA512 blocks.
########################################################################
SYM_FUNC_START(sha512_transform_ssse3)

diff --git a/arch/x86/crypto/sha512_ssse3_glue.c b/arch/x86/crypto/sha512_ssse3_glue.c
index 458356a3f124..1c444f41037c 100644
--- a/arch/x86/crypto/sha512_ssse3_glue.c
+++ b/arch/x86/crypto/sha512_ssse3_glue.c
@@ -39,13 +39,11 @@
#include <crypto/sha512_base.h>
#include <asm/simd.h>

-asmlinkage void sha512_transform_ssse3(u64 *digest, const char *data,
- u64 rounds);
-
-typedef void (sha512_transform_fn)(u64 *digest, const char *data, u64 rounds);
+asmlinkage void sha512_transform_ssse3(struct sha512_state *state,
+ const u8 *data, int blocks);

static int sha512_update(struct shash_desc *desc, const u8 *data,
- unsigned int len, sha512_transform_fn *sha512_xform)
+ unsigned int len, sha512_block_fn *sha512_xform)
{
struct sha512_state *sctx = shash_desc_ctx(desc);

@@ -53,28 +51,29 @@ static int sha512_update(struct shash_desc *desc, const u8 *data,
(sctx->count[0] % SHA512_BLOCK_SIZE) + len < SHA512_BLOCK_SIZE)
return crypto_sha512_update(desc, data, len);

- /* make sure casting to sha512_block_fn() is safe */
+ /*
+ * Make sure struct sha512_state begins directly with the SHA512
+ * 512-bit internal state, as this is what the asm functions expect.
+ */
BUILD_BUG_ON(offsetof(struct sha512_state, state) != 0);

kernel_fpu_begin();
- sha512_base_do_update(desc, data, len,
- (sha512_block_fn *)sha512_xform);
+ sha512_base_do_update(desc, data, len, sha512_xform);
kernel_fpu_end();

return 0;
}

static int sha512_finup(struct shash_desc *desc, const u8 *data,
- unsigned int len, u8 *out, sha512_transform_fn *sha512_xform)
+ unsigned int len, u8 *out, sha512_block_fn *sha512_xform)
{
if (!crypto_simd_usable())
return crypto_sha512_finup(desc, data, len, out);

kernel_fpu_begin();
if (len)
- sha512_base_do_update(desc, data, len,
- (sha512_block_fn *)sha512_xform);
- sha512_base_do_finalize(desc, (sha512_block_fn *)sha512_xform);
+ sha512_base_do_update(desc, data, len, sha512_xform);
+ sha512_base_do_finalize(desc, sha512_xform);
kernel_fpu_end();

return sha512_base_finish(desc, out);
@@ -144,8 +143,8 @@ static void unregister_sha512_ssse3(void)
}

#ifdef CONFIG_AS_AVX
-asmlinkage void sha512_transform_avx(u64 *digest, const char *data,
- u64 rounds);
+asmlinkage void sha512_transform_avx(struct sha512_state *state,
+ const u8 *data, int blocks);
static bool avx_usable(void)
{
if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) {
@@ -225,8 +224,8 @@ static inline void unregister_sha512_avx(void) { }
#endif

#if defined(CONFIG_AS_AVX2) && defined(CONFIG_AS_AVX)
-asmlinkage void sha512_transform_rorx(u64 *digest, const char *data,
- u64 rounds);
+asmlinkage void sha512_transform_rorx(struct sha512_state *state,
+ const u8 *data, int blocks);

static int sha512_avx2_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
--
2.20.1

--
Kees Cook