[PATCH] x86: Avoid undefined behavior in macro expansion

From: Vinicius Tinti
Date: Wed Mar 16 2016 - 22:48:50 EST


C11 standard (at 6.10.3.3) says that ## operator (paste) has undefined
behavior when one of the result operands is not a valid preprocessing
token.

Therefore the macro expansion may depend on compiler implementation
which may or no preserve the leading white space.

Moreover other places in kernel use CONCAT(a,b) instead of CONCAT(a, b).
Changing favors concise usage.

Signed-off-by: Vinicius Tinti <viniciustinti@xxxxxxxxx>
Acked-by: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>
---
arch/x86/crypto/aes_ctrby8_avx-x86_64.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/crypto/aes_ctrby8_avx-x86_64.S b/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
index a916c4a..7a71553 100644
--- a/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
+++ b/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
@@ -93,7 +93,7 @@

#define tmp %r10
#define DDQ(i) CONCAT(ddq_add_,i)
-#define XMM(i) CONCAT(%xmm, i)
+#define XMM(i) CONCAT(%xmm,i)
#define DDQ_DATA 0
#define XDATA 1
#define KEY_128 1
--
2.7.3