Re: [PATCH v2] x86/mce: set MCE_IN_KERNEL_COPYIN for all MC-Safe Copy

[Kefeng Wang]

On 2023/6/3 0:01, Borislav Petkov wrote:
> On Fri, Jun 02, 2023 at 03:12:30PM +0000, Luck, Tony wrote:
> > > As mentioned above, I am focus on copy_mc_XXX calling, it will
> > > abort if the exception fires when accessing the source, and we
> > > want to isolate the corrupted src page, maybe we could a new flag
> > > to indicate this scenario, the *Final Goals* is to let core
> > > do_machine_check to deal with the corrupted src page.
> >
> > A new flag seems like a good direction.
>
> Before anything happens here, the fate of the now unused EX_TYPE_COPY
> needs to be decided first. Then new stuff.

EX_TYPE_COPY is actually not related EX_TYPE_DEFAULT_MCE_SAFE, but we 
could recheck it again, it seems that mce recover from copy from user
is broken now. Maybe change _ASM_EXTABLE_UA to _ASM_EXTABLE_CPY in
copy_user_64.S again as commit[1] did before.

Thank you for the advice.

[1] 278b917f8cb9 x86/mce: Add _ASM_EXTABLE_CPY for copy user access


> Thx.