crypto: x86 - Regularize glue function prototypes

The crypto glue performed function prototype casting via macros to make
indirect calls to assembly routines. Instead of performing casts at the
call sites (which trips Control Flow Integrity prototype checking), switch
each prototype to a common standard set of arguments which allows the
removal of the existing macros. In order to keep pointer math unchanged,
internal casting between u128 pointers and u8 pointers is added.

Co-developed-by: João Moreira <joao.moreira@intel.com>
Signed-off-by: João Moreira <joao.moreira@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 31 insertions, 37 deletions

diff --git a/arch/x86/crypto/cast6_avx_glue.c b/arch/x86/crypto/cast6_avx_glue.c
index a8a38fffb4a9..da5297475f9e 100644
--- a/arch/x86/crypto/cast6_avx_glue.c
+++ b/arch/x86/crypto/cast6_avx_glue.c
@@ -20,20 +20,17 @@
 
 #define CAST6_PARALLEL_BLOCKS 8
 
-asmlinkage void cast6_ecb_enc_8way(struct cast6_ctx *ctx, u8 *dst,
-				   const u8 *src);
-asmlinkage void cast6_ecb_dec_8way(struct cast6_ctx *ctx, u8 *dst,
-				   const u8 *src);
-
-asmlinkage void cast6_cbc_dec_8way(struct cast6_ctx *ctx, u8 *dst,
-				   const u8 *src);
-asmlinkage void cast6_ctr_8way(struct cast6_ctx *ctx, u8 *dst, const u8 *src,
+asmlinkage void cast6_ecb_enc_8way(const void *ctx, u8 *dst, const u8 *src);
+asmlinkage void cast6_ecb_dec_8way(const void *ctx, u8 *dst, const u8 *src);
+
+asmlinkage void cast6_cbc_dec_8way(const void *ctx, u8 *dst, const u8 *src);
+asmlinkage void cast6_ctr_8way(const void *ctx, u8 *dst, const u8 *src,
 			       le128 *iv);
 
-asmlinkage void cast6_xts_enc_8way(struct cast6_ctx *ctx, u8 *dst,
-				   const u8 *src, le128 *iv);
-asmlinkage void cast6_xts_dec_8way(struct cast6_ctx *ctx, u8 *dst,
-				   const u8 *src, le128 *iv);
+asmlinkage void cast6_xts_enc_8way(const void *ctx, u8 *dst, const u8 *src,
+				   le128 *iv);
+asmlinkage void cast6_xts_dec_8way(const void *ctx, u8 *dst, const u8 *src,
+				   le128 *iv);
 
 static int cast6_setkey_skcipher(struct crypto_skcipher *tfm,
 				 const u8 *key, unsigned int keylen)
@@ -41,21 +38,21 @@ static int cast6_setkey_skcipher(struct crypto_skcipher *tfm,
 	return cast6_setkey(&tfm->base, key, keylen);
 }
 
-static void cast6_xts_enc(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+static void cast6_xts_enc(const void *ctx, u8 *dst, const u8 *src, le128 *iv)
 {
-	glue_xts_crypt_128bit_one(ctx, dst, src, iv,
-				  GLUE_FUNC_CAST(__cast6_encrypt));
+	glue_xts_crypt_128bit_one(ctx, dst, src, iv, __cast6_encrypt);
 }
 
-static void cast6_xts_dec(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+static void cast6_xts_dec(const void *ctx, u8 *dst, const u8 *src, le128 *iv)
 {
-	glue_xts_crypt_128bit_one(ctx, dst, src, iv,
-				  GLUE_FUNC_CAST(__cast6_decrypt));
+	glue_xts_crypt_128bit_one(ctx, dst, src, iv, __cast6_decrypt);
 }
 
-static void cast6_crypt_ctr(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+static void cast6_crypt_ctr(const void *ctx, u8 *d, const u8 *s, le128 *iv)
 {
 	be128 ctrblk;
+	u128 *dst = (u128 *)d;
+	const u128 *src = (const u128 *)s;
 
 	le128_to_be128(&ctrblk, iv);
 	le128_inc(iv);
@@ -70,10 +67,10 @@ static const struct common_glue_ctx cast6_enc = {
 
 	.funcs = { {
 		.num_blocks = CAST6_PARALLEL_BLOCKS,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(cast6_ecb_enc_8way) }
+		.fn_u = { .ecb = cast6_ecb_enc_8way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(__cast6_encrypt) }
+		.fn_u = { .ecb = __cast6_encrypt }
 	} }
 };
 
@@ -83,10 +80,10 @@ static const struct common_glue_ctx cast6_ctr = {
 
 	.funcs = { {
 		.num_blocks = CAST6_PARALLEL_BLOCKS,
-		.fn_u = { .ctr = GLUE_CTR_FUNC_CAST(cast6_ctr_8way) }
+		.fn_u = { .ctr = cast6_ctr_8way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .ctr = GLUE_CTR_FUNC_CAST(cast6_crypt_ctr) }
+		.fn_u = { .ctr = cast6_crypt_ctr }
 	} }
 };
 
@@ -96,10 +93,10 @@ static const struct common_glue_ctx cast6_enc_xts = {
 
 	.funcs = { {
 		.num_blocks = CAST6_PARALLEL_BLOCKS,
-		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(cast6_xts_enc_8way) }
+		.fn_u = { .xts = cast6_xts_enc_8way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(cast6_xts_enc) }
+		.fn_u = { .xts = cast6_xts_enc }
 	} }
 };
 
@@ -109,10 +106,10 @@ static const struct common_glue_ctx cast6_dec = {
 
 	.funcs = { {
 		.num_blocks = CAST6_PARALLEL_BLOCKS,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(cast6_ecb_dec_8way) }
+		.fn_u = { .ecb = cast6_ecb_dec_8way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(__cast6_decrypt) }
+		.fn_u = { .ecb = __cast6_decrypt }
 	} }
 };
 
@@ -122,10 +119,10 @@ static const struct common_glue_ctx cast6_dec_cbc = {
 
 	.funcs = { {
 		.num_blocks = CAST6_PARALLEL_BLOCKS,
-		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(cast6_cbc_dec_8way) }
+		.fn_u = { .cbc = cast6_cbc_dec_8way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(__cast6_decrypt) }
+		.fn_u = { .cbc = __cast6_decrypt }
 	} }
 };
 
@@ -135,10 +132,10 @@ static const struct common_glue_ctx cast6_dec_xts = {
 
 	.funcs = { {
 		.num_blocks = CAST6_PARALLEL_BLOCKS,
-		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(cast6_xts_dec_8way) }
+		.fn_u = { .xts = cast6_xts_dec_8way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(cast6_xts_dec) }
+		.fn_u = { .xts = cast6_xts_dec }
 	} }
 };
 
@@ -154,8 +151,7 @@ static int ecb_decrypt(struct skcipher_request *req)
 
 static int cbc_encrypt(struct skcipher_request *req)
 {
-	return glue_cbc_encrypt_req_128bit(GLUE_FUNC_CAST(__cast6_encrypt),
-					   req);
+	return glue_cbc_encrypt_req_128bit(__cast6_encrypt, req);
 }
 
 static int cbc_decrypt(struct skcipher_request *req)
@@ -199,8 +195,7 @@ static int xts_encrypt(struct skcipher_request *req)
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct cast6_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 
-	return glue_xts_req_128bit(&cast6_enc_xts, req,
-				   XTS_TWEAK_CAST(__cast6_encrypt),
+	return glue_xts_req_128bit(&cast6_enc_xts, req, __cast6_encrypt,
 				   &ctx->tweak_ctx, &ctx->crypt_ctx, false);
 }
 
@@ -209,8 +204,7 @@ static int xts_decrypt(struct skcipher_request *req)
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct cast6_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 
-	return glue_xts_req_128bit(&cast6_dec_xts, req,
-				   XTS_TWEAK_CAST(__cast6_encrypt),
+	return glue_xts_req_128bit(&cast6_dec_xts, req, __cast6_encrypt,
 				   &ctx->tweak_ctx, &ctx->crypt_ctx, true);
 }