diff options
| author | Arun Sharma <arun.sharma@intel.com> | 2004-08-26 20:43:14 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-08-26 20:43:14 -0700 |
| commit | ce18373907856aedaa6251ff3cdd1340ee4af29a (patch) | |
| tree | f6067623ca7a61bc55b122b90c90d147732e5615 /include/asm-generic | |
| parent | fec18575fbb0faf522afbf5b5288962a79ed542f (diff) | |
[PATCH] Fix copying of unaligned data across user/kernel boundary
32 bit compatibility code sometimes needs to copy unaligned data across
kernel/user boundary and currently there is no architecture independent API
to do it.
(1) Introduce new APIs __{get,put}_user_unaligned. These APIs are
necessary because the optimal way to copy unaligned data across
kernel/user boundary is different on different architectures.
Some architectures don't even care about alignment.
On some __put_user is faster than __copy_to_user for small sizes.
(2) Optimize __{get,put}_user_unaligned for ia64, x86-64, s390, ppc64.
(3) Fix compat_filldir64() which is broken on big-endian machines
Thanks to Arnd Bergmann <arnd@arndb.de> for his help.
Signed-off-by: Gordon Jin <gordon.jin@intel.com>
Signed-off-by: Arun Sharma <arun.sharma@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/uaccess.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h new file mode 100644 index 000000000000..4d62a1cf543d --- /dev/null +++ b/include/asm-generic/uaccess.h @@ -0,0 +1,26 @@ +#ifndef _ASM_GENERIC_UACCESS_H_ +#define _ASM_GENERIC_UACCESS_H_ + +/* + * This macro should be used instead of __get_user() when accessing + * values at locations that are not known to be aligned. + */ +#define __get_user_unaligned(x, ptr) \ +({ \ + __typeof__ (*(ptr)) __x; \ + __copy_from_user(&__x, (ptr), sizeof(*(ptr))) ? -EFAULT : 0; \ + (x) = _x; \ +}) + + +/* + * This macro should be used instead of __put_user() when accessing + * values at locations that are not known to be aligned. + */ +#define __put_user_unaligned(x, ptr) \ +({ \ + __typeof__ (*(ptr)) __x = (x); \ + __copy_to_user((ptr), &__x, sizeof(*(ptr))) ? -EFAULT : 0; \ +}) + +#endif /* _ASM_GENERIC_UACCESS_H */ |