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asm-generic: uaccess: Allow arches to over-ride __{get,put}_user_fn()

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As of now these default to calling the arch provided __copy_{to,from}_user()
routines which being general purpose (w.r.t buffer alignment and lengths)
would lead to alignment checks in generated code (for arches which don't
support unaligned load/stores).

Given that in this case we already know that data involved is "unit"
sized and aligned, using the vanilla copy backend is a bit wasteful.

This change thus allows arches to over-ride the aforementioned routines.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Vineet Gupta
2013-01-18 15:12:16 +05:30
parent 43697cb097
commit 05d88a4937
1 changed files with 11 additions and 0 deletions
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11
include/asm-generic/uaccess.h
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@@ -169,12 +169,18 @@ static inline __must_check long __copy_to_user(void __user *to,
-EFAULT; \ -EFAULT; \
}) })
#ifndef __put_user_fn
static inline int __put_user_fn(size_t size, void __user *ptr, void *x) static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
{ {
size = __copy_to_user(ptr, x, size); size = __copy_to_user(ptr, x, size);
return size ? -EFAULT : size; return size ? -EFAULT : size;
} }
#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
#endif
extern int __put_user_bad(void) __attribute__((noreturn)); extern int __put_user_bad(void) __attribute__((noreturn));
#define __get_user(x, ptr) \ #define __get_user(x, ptr) \
@@ -225,12 +231,17 @@ extern int __put_user_bad(void) __attribute__((noreturn));
-EFAULT; \ -EFAULT; \
}) })
#ifndef __get_user_fn
static inline int __get_user_fn(size_t size, const void __user *ptr, void *x) static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
{ {
size = __copy_from_user(x, ptr, size); size = __copy_from_user(x, ptr, size);
return size ? -EFAULT : size; return size ? -EFAULT : size;
} }
#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
#endif
extern int __get_user_bad(void) __attribute__((noreturn)); extern int __get_user_bad(void) __attribute__((noreturn));
#ifndef __copy_from_user_inatomic #ifndef __copy_from_user_inatomic