[llvmlinux] [PATCH] v2: Fix bug in statement as pointed out by Herbert Xu. Kudos to pipacs.

dl9pf at gmx.de dl9pf at gmx.de
Thu Aug 29 17:20:49 UTC 2013


From: Jan-Simon Möller <dl9pf at gmx.de>

Fix bitoperation for compilation with clang

Author:  PaX Team <pageexec at freemail.hu>
ML-Post: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120507/142707.html
URL:     http://llvm.linuxfoundation.org

Merge:   Jan-Simon Möller <dl9pf at gmx.de>

Description:

Fix for warning:
linux/crypto/fcrypt.c:143:47: warning: signed shift result (0x598000000) requires 36 bits to
      represent, but 'int' only has 32 bits [-Wshift-overflow]
        Z(0xef), Z(0x70), Z(0xcf), Z(0xc2), Z(0x2a), Z(0xb3), Z(0x61), Z(0xad),
                                                     ^~~~~~~
linux/crypto/fcrypt.c:113:29: note: expanded from macro 'Z'
                            ^  ~~
linux/include/uapi/linux/byteorder/little_endian.h:38:53: note: expanded from macro
      '__cpu_to_be32'
                                                    ^
linux/include/uapi/linux/swab.h:116:21: note: expanded from macro '__swab32'
        ___constant_swab32(x) :                 \
                           ^
linux/include/uapi/linux/swab.h:18:12: note: expanded from macro '___constant_swab32'
        (((__u32)(x) & (__u32)0x0000ff00UL) <<  8) |            \
                  ^

Solution - make sure we don't exceed the 32 bit range.
 #define Z(x) cpu_to_be32(((x & 0x1f) << 27) | (x >> 5))

Signed-off-by: Jan-Simon Möller <dl9pf at gmx.de>
CC: pageexec at freemail.hu
CC: llvmlinux at lists.linuxfoundation.org
CC: behanw at converseincode.com
CC: herbert at gondor.apana.org.au
CC: davem at favemloft.net
CC: linux-crypto at vger.kernel.org
CC: linux-kernel at vger.kernel.org
---
 crypto/fcrypt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/fcrypt.c b/crypto/fcrypt.c
index 3b2cf56..021d7fe 100644
--- a/crypto/fcrypt.c
+++ b/crypto/fcrypt.c
@@ -110,7 +110,7 @@ static const __be32 sbox0[256] = {
 };
 
 #undef Z
-#define Z(x) cpu_to_be32((x << 27) | (x >> 5))
+#define Z(x) cpu_to_be32(((x & 0x1f) << 27) | (x >> 5))
 static const __be32 sbox1[256] = {
 	Z(0x77), Z(0x14), Z(0xa6), Z(0xfe), Z(0xb2), Z(0x5e), Z(0x8c), Z(0x3e),
 	Z(0x67), Z(0x6c), Z(0xa1), Z(0x0d), Z(0xc2), Z(0xa2), Z(0xc1), Z(0x85),
-- 
1.8.1.4



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