On 09/24/2010 01:34 AM, Jean-Christophe PLAGNIOL-VILLARD wrote:
On 09:43 Fri 24 Sep , Sascha Hauer wrote:
On Fri, Sep 24, 2010 at 12:00:42AM -0700, Andre wrote:
On 09/21/2010 06:28 AM, Jean-Christophe PLAGNIOL-VILLARD wrote:
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD<plagnioj at jcrosoft.com>
---
lib/sha1.c | 20 +++-----------------
lib/sha256.c | 19 +++----------------
2 files changed, 6 insertions(+), 33 deletions(-)
diff --git a/lib/sha1.c b/lib/sha1.c
index 0e8aed1..b4e2abc 100644
--- a/lib/sha1.c
+++ b/lib/sha1.c
@@ -29,6 +29,7 @@
#include<digest.h>
#include<init.h>
#include<linux/string.h>
+#include<asm/byteorder.h>
#define SHA1_SUM_POS -0x20
#define SHA1_SUM_LEN 20
@@ -44,23 +45,8 @@ sha1_context;
/*
* 32-bit integer manipulation macros (big endian)
*/
-#ifndef GET_UINT32_BE
-#define GET_UINT32_BE(n,b,i) { \
- (n) = ( (uint32_t) (b)[(i) ]<< 24 ) \
- | ( (uint32_t) (b)[(i) + 1]<< 16 ) \
- | ( (uint32_t) (b)[(i) + 2]<< 8 ) \
- | ( (uint32_t) (b)[(i) + 3] ); \
-}
-#endif
-
-#ifndef PUT_UINT32_BE
-#define PUT_UINT32_BE(n,b,i) { \
- (b)[(i) ] = (unsigned char) ( (n)>> 24 ); \
- (b)[(i) + 1] = (unsigned char) ( (n)>> 16 ); \
- (b)[(i) + 2] = (unsigned char) ( (n)>> 8 ); \
- (b)[(i) + 3] = (unsigned char) ( (n) ); \
-}
-#endif
+#define GET_UINT32_BE(n,b,i) (n) = be32_to_cpu(((uint32_t*)(b))[i / 4])
+#define PUT_UINT32_BE(n,b,i) ((uint32_t*)(b))[i / 4] = cpu_to_be32(n)
The previous macros served two purposes: endian swapping and performing
the memory accesses byte-by-byte. New versions are unsafe for CPUs which
do not support misaligned 32bit memory accesses.
Indeed. We have get_unaligned_be32() / put_unaligned_be32(). These should be
the correct functions, right?
>
no-nned IIRC as be32_to_cpu and cpu_to_be32 already handle this
depending on the arch
I think get_unaligned_be32() / put_unaligned_be32() are correct in this
case. be32_to_cpu / cpu_to_be32 perform endian swapping (if required)
with source and destination both being 32bit variables, not memory
locations ?
Of course the easy way to test any version is to build for an
architecture which cares about alignment and look at the disassembly. If
the compiler generates one 32bit load/store instruction instead of 4
byte accesses then the code is wrong.
In any case, this looks dubious:
#define PUT_UINT32_BE(n,b,i) ((uint32_t*)(b))[i / 4] = cpu_to_be32(n)
Behaviour when i == 0 is the same as when i == 1, which wasn't the case
with the old macros. Also, if b is not 32bit aligned, store will be
misaligned regardless of having cpu_to_be32(), or anything else, on the rhs.
Andre
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