On Thu, Mar 07, 2019 at 12:45:14PM +0100, Peter Zijlstra wrote: > /* > + * Try to copy last bytes and clear the rest if needed. > + * Since protection fault in copy_from/to_user is not a normal situation, > + * it is not necessary to optimize tail handling. > + * > + * Input: > + * rdi destination > + * rsi source > + * rdx count > + * > + * Output: > + * eax uncopied bytes or 0 if successful. > + */ > +ALIGN; > +copy_user_handle_tail: > + movl %edx,%ecx > +1: rep movsb > +2: mov %ecx,%eax > + ASM_CLAC > + ret > + > + _ASM_EXTABLE_UA(1b, 2b) > +ENDPROC(copy_user_handle_tail)
This is an unstructured piece of code rather than a callable function, END would probably be more appropriate. Or maybe it should just be a local label (.Lcopy_user_handle_tail) because I don't think the alignment and ELF symbol size are even needed. -- Josh
