On Mon, Dec 14, 2015 at 09:36:25AM +0100, Ingo Molnar wrote:
> > /* deal with it */
> >
> > That way the magic is isolated to the function that needs the magic.
>
> Seconded - this is the usual pattern we use in all assembly functions.
Ok - you want me to write some x86 assembly code (you may regret that).
Initial question ... here's the fixup for __copy_user_nocache()
.section .fixup,"ax"
30: shll $6,%ecx
addl %ecx,%edx
jmp 60f
40: lea (%rdx,%rcx,8),%rdx
jmp 60f
50: movl %ecx,%edx
60: sfence
jmp copy_user_handle_tail
.previous
Are %ecx and %rcx synonyms for the same register? Is there some
super subtle reason we use the 'r' names in the "40" fixup, but
the 'e' names everywhere else in this code (and the 'e' names in
the body of the original function)?
-Tony
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
