On Fri, May 26, 2023 at 02:32:42PM +0800, Kefeng Wang wrote:
> The best way to fix them is set MCE_IN_KERNEL_COPYIN for MC-Safe Copy,
> then let the core do_machine_check() to isolate corrupted page instead
> of doing it one-by-one.
No, this whole thing is confused.
* Indicates an MCE that happened in kernel space while copying data
* from user.
#define MCE_IN_KERNEL_COPYIN
This is a very specific exception type: EX_TYPE_COPY which got added by
278b917f8cb9 ("x86/mce: Add _ASM_EXTABLE_CPY for copy user access")
but Linus then removed all such user copy exception points in
034ff37d3407 ("x86: rewrite '__copy_user_nocache' function")
So now that EX_TYPE_COPY never happens.
And what you're doing is lumping the handling for
EX_TYPE_DEFAULT_MCE_SAFE and EX_TYPE_FAULT_MCE_SAFE together and saying
that the MCE happened while copying data from user.
And XSTATE_OP() is one example where this is not really the case.
So no, this is not correct.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
