[Crash-utility] [PATCH] x86_64: do not process zero size exception stack

[Alexey Makhalov]

Hi Kazu,
> 
> Apparently the following patch causes this and it's in 5.10-rc ?
> 
> commit 02772fb9b68e6a72a5e17f994048df832fe2b15e
> Author: Joerg Roedel <jroedel at suse.de>
> Date:   Mon Sep 7 15:15:43 2020 +0200
> 
>    x86/sev-es: Allocate and map an IST stack for #VC handler
> 
> If so, it seems we should support this properly.
> 
Not this one. I use 5.9.6 kernel for testing. It does not use VC handlers ( no SEV-ES support yet).
First look in the kernel - didn’t show anything that sets 5th stack. Address seems valid. Will dig
deeper. Might need to take a look at crash code, around ebase[] fetching. 
Will send update on my findings.

> btw, hopefully we would like to release the new version (7.2.9) of crash
> next week and are preparing, so some patches might be deferred to the next
> (7.3.0 ?), especially patches for Linux 5.10.
Got it. Thanks for update.
My bigger patch that I've sent Today should definitely go post 7.2.9.

Thanks,
—Alexey