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>

1 files changed, 30 insertions, 40 deletions

diff --git a/arch/x86/crypto/sha1_ssse3_glue.c b/arch/x86/crypto/sha1_ssse3_glue.c
index 639d4c2fd6a8..d70b40ad594c 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);
+	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)