Re: [GIT PULL] x86/mm for 6.4

From: Alexander Potapenko
Date: Mon Jun 19 2023 - 08:04:40 EST


On Fri, Jun 16, 2023 at 6:22 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, 16 Jun 2023 at 01:47, Alexander Potapenko <glider@xxxxxxxxxx> wrote:
> >
> > Shouldn't ex_handler_copy() be fixed in the same way?
>
> I don't think ex_handler_copy() is actually reachable any more.
>
> The only thing ex_handler_copy() did was to set %ax to the fault type.
>
> It was used by the strange copy_user_generic_unrolled() that had
> special machine check case for "don't do the tail if we get
> X86_TRAP_MC".

Oh, I see, thanks!
I am using a downstream kernel (way before 034ff37d3407) that still
has _ASM_EXTABLE_CPY.
Looks like I just need to adjust ex_handler_copy() in my code.