crypto: x86/sha - Eliminate casts on asm implementations

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>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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>

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
 

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);
+	if (blocks >= SHA1_AVX2_BLOCK_OPTSIZE)
+		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)

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
 ########################################################################

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
 ########################################################################

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
 ########################################################################

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)

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

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

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)
 

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)