Messages in this thread | | | Date | Fri, 26 May 2023 09:09:52 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v2] x86/mce: set MCE_IN_KERNEL_COPYIN for all MC-Safe Copy |
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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
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