x86: introduce copy_user_handle_tail() routine

Introduce generic C routine for handling necessary tail operations after
protection fault in copy_*_user on x86.

Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/asm-x86/uaccess_64.h b/include/asm-x86/uaccess_64.h
index 4e3ec004e14a..515d4dce96b5 100644
--- a/include/asm-x86/uaccess_64.h
+++ b/include/asm-x86/uaccess_64.h
@@ -195,4 +195,7 @@ static inline int __copy_from_user_inatomic_nocache(void *dst,
         return __copy_user_nocache(dst, src, size, 0);
 }
 
+unsigned long
+copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest);
+
 #endif /* __X86_64_UACCESS_H */