Re: [Possible BUG] arm64: efi: efi_runtime_fixup_exception() and efi_call_virt_check_flags() both taint the kernel #forregzbot

From: Thorsten Leemhuis
Date: Tue Nov 08 2022 - 07:20:07 EST


[Note: this mail is primarily send for documentation purposes and/or for
regzbot, my Linux kernel regression tracking bot. That's why I removed
most or all folks from the list of recipients, but left any that looked
like a mailing lists. These mails usually contain '#forregzbot' in the
subject, to make them easy to spot and filter out.]

[TLDR: I'm adding this regression report to the list of tracked
regressions; all text from me you find below is based on a few templates
paragraphs you might have encountered already already in similar form.]

Hi, this is your Linux kernel regression tracker.

On 07.11.22 18:27, Alexandru Elisei wrote:
> I'm going to preface this by saying that I'm extremely unfamiliar with the
> EFI code.
>
> Commit d3549a938b73 ("efi/arm64: libstub: avoid SetVirtualAddressMap() when
> possible") skipped the call to SetVirtualAddressMap() for certain
> configurations, and that started causing kernel panics on an Ampere Altra
> machine due to an EFI synchronous exception.
>
> Commit 23715a26c8d8 ("arm64: efi: Recover from synchronous exceptions
> occurring in firmware") made the EFI exception non-fatal.

Thanks for the report. To be sure below issue doesn't fall through the
cracks unnoticed, I'm adding it to regzbot, my Linux kernel regression
tracking bot:

#regzbot ^introduced d3549a938b73
#regzbot title efi: arm64: updating the firmware is not feasible anymore
#regzbot ignore-activity

This isn't a regression? This issue or a fix for it are already
discussed somewhere else? It was fixed already? You want to clarify when
the regression started to happen? Or point out I got the title or
something else totally wrong? Then just reply -- ideally with also
telling regzbot about it, as explained here:
https://linux-regtracking.leemhuis.info/tracked-regression/

Reminder for developers: When fixing the issue, add 'Link:' tags
pointing to the report (the mail this one replies to), as explained for
in the Linux kernel's documentation; above webpage explains why this is
important for tracked regressions.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.