saner typechecking in generic unaligned.h
authorAl Viro <viro@ftp.linux.org.uk>
Tue, 17 Jul 2007 07:49:35 +0000 (08:49 +0100)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Tue, 17 Jul 2007 18:01:07 +0000 (11:01 -0700)
Verify that types would match for assignment (under sizeof, so we are safe from
side effects or any code actually getting generated), then explicitly cast
everywhere to the fixed-sized types.  Kills a bunch of bogus warnings about
constants being truncated (gcc, sparse), finds a pile of endianness problems
hidden by old noise (sparse).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/asm-generic/unaligned.h

index 09ec447fe2af5de7cb67b142257f28fadb805413..16a466e50681bf5e6cc8a58f3a47a4b3c2c8acf8 100644 (file)
@@ -18,7 +18,8 @@
 #define get_unaligned(ptr) \
        __get_unaligned((ptr), sizeof(*(ptr)))
 #define put_unaligned(x,ptr) \
-       __put_unaligned((__u64)(x), (ptr), sizeof(*(ptr)))
+       ((void)sizeof(*(ptr)=(x)),\
+       __put_unaligned((__force __u64)(x), (ptr), sizeof(*(ptr))))
 
 /*
  * This function doesn't actually exist.  The idea is that when
@@ -95,21 +96,21 @@ static inline void __ustw(__u16 val, __u16 *addr)
        default:                                \
                bad_unaligned_access_length();  \
        };                                      \
-       (__typeof__(*(ptr)))val;                \
+       (__force __typeof__(*(ptr)))val;        \
 })
 
 #define __put_unaligned(val, ptr, size)                \
-do {                                           \
+({                                             \
        void *__gu_p = ptr;                     \
        switch (size) {                         \
        case 1:                                 \
-               *(__u8 *)__gu_p = val;          \
+               *(__u8 *)__gu_p = (__force __u8)val;            \
                break;                          \
        case 2:                                 \
-               __ustw(val, __gu_p);            \
+               __ustw((__force __u16)val, __gu_p);             \
                break;                          \
        case 4:                                 \
-               __ustl(val, __gu_p);            \
+               __ustl((__force __u32)val, __gu_p);             \
                break;                          \
        case 8:                                 \
                __ustq(val, __gu_p);            \
@@ -117,6 +118,7 @@ do {                                                \
        default:                                \
                bad_unaligned_access_length();  \
        };                                      \
-} while(0)
+       (void)0;                                \
+})
 
 #endif /* _ASM_GENERIC_UNALIGNED_H */