Re: [PATCH v3 2/2] x86/mce/dev-mcelog: Fix updating kflags in AMD systems

From: Borislav Petkov
Date: Mon Sep 14 2020 - 11:35:39 EST


On Thu, Sep 03, 2020 at 06:45:31PM -0500, Smita Koralahalli wrote:
> The mcelog utility is not commonly used on AMD systems. Therefore, errors
> logged only by the dev_mce_log() notifier will be missed. This may occur
> if the EDAC modules are not loaded in which case it's preferable to print
> the error record by the default notifier.
>
> However, the mce->kflags set by dev_mce_log() notifier makes the default
> notifier to skip over the errors assuming they are processed by
> dev_mce_log().
>
> Do not update kflags in the dev_mce_log() notifier on AMD systems.
>
> Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@xxxxxxx>
> ---
> Link:
> https://lkml.kernel.org/r/20200828203332.11129-3-Smita.KoralahalliChannabasappa@xxxxxxx
>
> v3:
> No change
> v2:
> No change
> ---
> arch/x86/kernel/cpu/mce/dev-mcelog.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/mce/dev-mcelog.c b/arch/x86/kernel/cpu/mce/dev-mcelog.c
> index 03e51053592a..100fbeebdc72 100644
> --- a/arch/x86/kernel/cpu/mce/dev-mcelog.c
> +++ b/arch/x86/kernel/cpu/mce/dev-mcelog.c
> @@ -67,7 +67,9 @@ static int dev_mce_log(struct notifier_block *nb, unsigned long val,
> unlock:
> mutex_unlock(&mce_chrdev_read_mutex);
>
> - mce->kflags |= MCE_HANDLED_MCELOG;
> + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
> + mce->kflags |= MCE_HANDLED_MCELOG;
> +
> return NOTIFY_OK;
> }
>
> --

This one is not related to your 1/2 so it sounds to me like I should
take this one now, independently?

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette