[PATCH] crypto, x86: aesni - fix token pasting for clang

[PATCH] crypto, x86: aesni - fix token pasting for clang

[Michael Davidson]

aes_ctrby8_avx-x86_64.S uses the C preprocessor for token pasting
of character sequences that are not valid preprocessor tokens.
While this is allowed when preprocessing assembler files it exposes
an incompatibilty between the clang and gcc preprocessors where
clang does not strip leading white space from macro parameters,
leading to the CONCAT(%xmm, i) macro expansion on line 96 resulting
in a token with a space character embedded in it.

While this could be resolved by deleting the offending space character,
the assembler is perfectly capable of doing the token pasting correctly
for itself so we can just get rid of the preprocessor macros.

Signed-off-by: Michael Davidson <md@google.com>
---
 arch/x86/crypto/aes_ctrby8_avx-x86_64.S | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/crypto/aes_ctrby8_avx-x86_64.S b/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
index a916c4a61165..5f6a5af9c489 100644
--- a/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
+++ b/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
@@ -65,7 +65,6 @@
 #include <linux/linkage.h>
 #include <asm/inst.h>
 
-#define CONCAT(a,b)	a##b
 #define VMOVDQ		vmovdqu
 
 #define xdata0		%xmm0
@@ -92,8 +91,6 @@
 #define num_bytes	%r8
 
 #define tmp		%r10
-#define	DDQ(i)		CONCAT(ddq_add_,i)
-#define	XMM(i)		CONCAT(%xmm, i)
 #define	DDQ_DATA	0
 #define	XDATA		1
 #define KEY_128		1
@@ -131,12 +128,12 @@ ddq_add_8:
 /* generate a unique variable for ddq_add_x */
 
 .macro setddq n
-	var_ddq_add = DDQ(\n)
+	var_ddq_add = ddq_add_\n
 .endm
 
 /* generate a unique variable for xmm register */
 .macro setxdata n
-	var_xdata = XMM(\n)
+	var_xdata = %xmm\n
 .endm
 
 /* club the numeric 'id' to the symbol 'name' */
-- 
2.12.0.367.g23dc2f6d3c-goog

Re: [PATCH] crypto, x86: aesni - fix token pasting for clang

[Herbert Xu]

On Wed, Mar 15, 2017 at 03:36:00PM -0700, Michael Davidson wrote:
> aes_ctrby8_avx-x86_64.S uses the C preprocessor for token pasting
> of character sequences that are not valid preprocessor tokens.
> While this is allowed when preprocessing assembler files it exposes
> an incompatibilty between the clang and gcc preprocessors where
> clang does not strip leading white space from macro parameters,
> leading to the CONCAT(%xmm, i) macro expansion on line 96 resulting
> in a token with a space character embedded in it.
> 
> While this could be resolved by deleting the offending space character,
> the assembler is perfectly capable of doing the token pasting correctly
> for itself so we can just get rid of the preprocessor macros.
> 
> Signed-off-by: Michael Davidson <md@google.com>

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt