Re: PROBLEM: consolidated IDT invalidation causes kexec to reboot

From: Ingo Molnar
Date: Mon Dec 25 2017 - 04:58:04 EST



* Alexandru Chirvasitu <achirvasub@xxxxxxxxx> wrote:

> The first attachment is the config I initially used last night after
> that second patch (removing 'local' etc.).
>
> As you guessed, all four options are set, hence the name of the file
> (ending in '-y'). The other config I'm attaching was treated as you
> lay out (2-config-n).
>
> I used the '-n' config to compile two kernels just now:
>
> (a) e802a51, that same first commit giving me trouble.
>
> The changes made no difference to kexec behaviour: with the e802a51
> kernel calling kexec boot directly with -e and triggering a panic both
> kick off a full reboot, though the crash kernel registers as loaded.
>
> (b) the kernel in the branch I made last night, with the set_idt kexec
> (for good measure, I thought I might as well do this one too).
>
> No difference here either: the crash dump kernel boots fine both ways
> (directly and upon intentional crashing).

Thanks for all the info!

Detailed analysis from me (or Thomas) will have to wait after the Christmas
hollidays.

Thanks,

Ingo