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, 18 insertions, 12 deletions

diff --git a/arch/x86/crypto/serpent_sse2_glue.c b/arch/x86/crypto/serpent_sse2_glue.c
index 5fdf1931d069..4fed8d26b91a 100644
--- a/arch/x86/crypto/serpent_sse2_glue.c
+++ b/arch/x86/crypto/serpent_sse2_glue.c
@@ -31,9 +31,11 @@ static int serpent_setkey_skcipher(struct crypto_skcipher *tfm,
 	return __serpent_setkey(crypto_skcipher_ctx(tfm), key, keylen);
 }
 
-static void serpent_decrypt_cbc_xway(void *ctx, u128 *dst, const u128 *src)
+static void serpent_decrypt_cbc_xway(const void *ctx, u8 *d, const u8 *s)
 {
 	u128 ivs[SERPENT_PARALLEL_BLOCKS - 1];
+	u128 *dst = (u128 *)d;
+	const u128 *src = (const u128 *)s;
 	unsigned int j;
 
 	for (j = 0; j < SERPENT_PARALLEL_BLOCKS - 1; j++)
@@ -45,9 +47,11 @@ static void serpent_decrypt_cbc_xway(void *ctx, u128 *dst, const u128 *src)
 		u128_xor(dst + (j + 1), dst + (j + 1), ivs + j);
 }
 
-static void serpent_crypt_ctr(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+static void serpent_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);
@@ -56,10 +60,12 @@ static void serpent_crypt_ctr(void *ctx, u128 *dst, const u128 *src, le128 *iv)
 	u128_xor(dst, src, (u128 *)&ctrblk);
 }
 
-static void serpent_crypt_ctr_xway(void *ctx, u128 *dst, const u128 *src,
+static void serpent_crypt_ctr_xway(const void *ctx, u8 *d, const u8 *s,
 				   le128 *iv)
 {
 	be128 ctrblks[SERPENT_PARALLEL_BLOCKS];
+	u128 *dst = (u128 *)d;
+	const u128 *src = (const u128 *)s;
 	unsigned int i;
 
 	for (i = 0; i < SERPENT_PARALLEL_BLOCKS; i++) {
@@ -79,10 +85,10 @@ static const struct common_glue_ctx serpent_enc = {
 
 	.funcs = { {
 		.num_blocks = SERPENT_PARALLEL_BLOCKS,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(serpent_enc_blk_xway) }
+		.fn_u = { .ecb = serpent_enc_blk_xway }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(__serpent_encrypt) }
+		.fn_u = { .ecb = __serpent_encrypt }
 	} }
 };
 
@@ -92,10 +98,10 @@ static const struct common_glue_ctx serpent_ctr = {
 
 	.funcs = { {
 		.num_blocks = SERPENT_PARALLEL_BLOCKS,
-		.fn_u = { .ctr = GLUE_CTR_FUNC_CAST(serpent_crypt_ctr_xway) }
+		.fn_u = { .ctr = serpent_crypt_ctr_xway }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .ctr = GLUE_CTR_FUNC_CAST(serpent_crypt_ctr) }
+		.fn_u = { .ctr = serpent_crypt_ctr }
 	} }
 };
 
@@ -105,10 +111,10 @@ static const struct common_glue_ctx serpent_dec = {
 
 	.funcs = { {
 		.num_blocks = SERPENT_PARALLEL_BLOCKS,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(serpent_dec_blk_xway) }
+		.fn_u = { .ecb = serpent_dec_blk_xway }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .ecb = GLUE_FUNC_CAST(__serpent_decrypt) }
+		.fn_u = { .ecb = __serpent_decrypt }
 	} }
 };
 
@@ -118,10 +124,10 @@ static const struct common_glue_ctx serpent_dec_cbc = {
 
 	.funcs = { {
 		.num_blocks = SERPENT_PARALLEL_BLOCKS,
-		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(serpent_decrypt_cbc_xway) }
+		.fn_u = { .cbc = serpent_decrypt_cbc_xway }
 	}, {
 		.num_blocks = 1,
-		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(__serpent_decrypt) }
+		.fn_u = { .cbc = __serpent_decrypt }
 	} }
 };
 
@@ -137,7 +143,7 @@ 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(__serpent_encrypt),
+	return glue_cbc_encrypt_req_128bit(__serpent_encrypt,
 					   req);
 }