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, 20 insertions, 17 deletions

diff --git a/arch/x86/crypto/twofish_glue_3way.c b/arch/x86/crypto/twofish_glue_3way.c
index 1dc9e29f221e..768af6075479 100644
--- a/arch/x86/crypto/twofish_glue_3way.c
+++ b/arch/x86/crypto/twofish_glue_3way.c
@@ -25,21 +25,22 @@ static int twofish_setkey_skcipher(struct crypto_skcipher *tfm,
 	return twofish_setkey(&tfm->base, key, keylen);
 }
 
-static inline void twofish_enc_blk_3way(struct twofish_ctx *ctx, u8 *dst,
-					const u8 *src)
+static inline void twofish_enc_blk_3way(const void *ctx, u8 *dst, const u8 *src)
 {
 	__twofish_enc_blk_3way(ctx, dst, src, false);
 }
 
-static inline void twofish_enc_blk_xor_3way(struct twofish_ctx *ctx, u8 *dst,
+static inline void twofish_enc_blk_xor_3way(const void *ctx, u8 *dst,
 					    const u8 *src)
 {
 	__twofish_enc_blk_3way(ctx, dst, src, true);
 }
 
-void twofish_dec_blk_cbc_3way(void *ctx, u128 *dst, const u128 *src)
+void twofish_dec_blk_cbc_3way(const void *ctx, u8 *d, const u8 *s)
 {
 	u128 ivs[2];
+	u128 *dst = (u128 *)d;
+	const u128 *src = (const u128 *)s;
 
 	ivs[0] = src[0];
 	ivs[1] = src[1];
@@ -51,9 +52,11 @@ void twofish_dec_blk_cbc_3way(void *ctx, u128 *dst, const u128 *src)
 }
 EXPORT_SYMBOL_GPL(twofish_dec_blk_cbc_3way);
 
-void twofish_enc_blk_ctr(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+void twofish_enc_blk_ctr(const void *ctx, u8 *d, const u8 *s, le128 *iv)
 {
 	be128 ctrblk;
+	u128 *dst = (u128 *)d;
+	const u128 *src = (const u128 *)s;
 
 	if (dst != src)
 		*dst = *src;
@@ -66,10 +69,11 @@ void twofish_enc_blk_ctr(void *ctx, u128 *dst, const u128 *src, le128 *iv)
 }
 EXPORT_SYMBOL_GPL(twofish_enc_blk_ctr);
 
-void twofish_enc_blk_ctr_3way(void *ctx, u128 *dst, const u128 *src,
-			      le128 *iv)
+void twofish_enc_blk_ctr_3way(const void *ctx, u8 *d, const u8 *s, le128 *iv)
 {
 	be128 ctrblks[3];
+	u128 *dst = (u128 *)d;
+	const u128 *src = (const u128 *)s;
 
 	if (dst != src) {
 		dst[0] = src[0];
@@ -94,10 +98,10 @@ static const struct common_glue_ctx twofish_enc = {
 
 	.funcs = { {
 		.num_blocks = 3,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_3way) }
+		.fn_u = { .ecb = twofish_enc_blk_3way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk) }
+		.fn_u = { .ecb = twofish_enc_blk }
 	} }
 };
 
@@ -107,10 +111,10 @@ static const struct common_glue_ctx twofish_ctr = {
 
 	.funcs = { {
 		.num_blocks = 3,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_ctr_3way) }
+		.fn_u = { .ctr = twofish_enc_blk_ctr_3way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_ctr) }
+		.fn_u = { .ctr = twofish_enc_blk_ctr }
 	} }
 };
 
@@ -120,10 +124,10 @@ static const struct common_glue_ctx twofish_dec = {
 
 	.funcs = { {
 		.num_blocks = 3,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk_3way) }
+		.fn_u = { .ecb = twofish_dec_blk_3way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk) }
+		.fn_u = { .ecb = twofish_dec_blk }
 	} }
 };
 
@@ -133,10 +137,10 @@ static const struct common_glue_ctx twofish_dec_cbc = {
 
 	.funcs = { {
 		.num_blocks = 3,
-		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk_cbc_3way) }
+		.fn_u = { .cbc = twofish_dec_blk_cbc_3way }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk) }
+		.fn_u = { .cbc = twofish_dec_blk }
 	} }
 };
 
@@ -152,8 +156,7 @@ 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(twofish_enc_blk),
-					   req);
+	return glue_cbc_encrypt_req_128bit(twofish_enc_blk, req);
 }
 
 static int cbc_decrypt(struct skcipher_request *req)