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Commit 05d88a49 authored by Vineet Gupta's avatar Vineet Gupta
Browse files

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



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: default avatarVineet Gupta <vgupta@synopsys.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 43697cb0

include/asm-generic/uaccess.h

+11 −0
Original line number Diff line number Diff line
@@ -169,12 +169,18 @@ static inline __must_check long __copy_to_user(void __user *to, 
		-EFAULT;					\

})



#ifndef __put_user_fn



static inline int __put_user_fn(size_t size, void __user *ptr, void *x)

{

	size = __copy_to_user(ptr, x, 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));



#define __get_user(x, ptr)					\
@@ -225,12 +231,17 @@ extern int __put_user_bad(void) __attribute__((noreturn)); 
		-EFAULT;					\

})



#ifndef __get_user_fn

static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)

{

	size = __copy_from_user(x, ptr, 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));



#ifndef __copy_from_user_inatomic