Re: [patch V4 part 1 29/36] x86/mce: Send #MC singal from task work

[Borislav Petkov]

On Thu, May 07, 2020 at 11:02:09AM -0700, Andy Lutomirski wrote:
> IOW, if we want to recover from CPL0 #MC, we will need a different mechanism.

Recovering from CPL0 #MC is mostly doomed to failure. Except this mcsafe
crap with the exception handling:

                /*
                 * Handle an MCE which has happened in kernel space but from
                 * which the kernel can recover: ex_has_fault_handler() has
                 * already verified that the rIP at which the error happened is
                 * a rIP from which the kernel can recover (by jumping to
                 * recovery code specified in _ASM_EXTABLE_FAULT()) and the
                 * corresponding exception handler which would do that is the
                 * proper one.
                 */
                if (m.kflags & MCE_IN_KERNEL_RECOV) {
                        if (!fixup_exception(regs, X86_TRAP_MC, error_code, 0))
                                mce_panic("Failed kernel mode recovery", &m, msg);


Other than that, we iz done.

-- 
Regards/Gruss,
    Boris.

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