linux-kernel - Re: [PATCH] x86/MCE/AMD: Always give PANIC severity for UC errors in kernel context

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Message-ID: <20170926222054.sshmh4t2tson3hyd@pd.tnic>
Date:   Wed, 27 Sep 2017 00:20:54 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     "Ghannam, Yazen" <Yazen.Ghannam@....com>
Cc:     "linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
        Tony Luck <tony.luck@...el.com>,
        "x86@...nel.org" <x86@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86/MCE/AMD: Always give PANIC severity for UC errors in
 kernel context

On Tue, Sep 26, 2017 at 03:21:22PM +0000, Ghannam, Yazen wrote:
> How should I CC:stable?

Documentation/process/stable-kernel-rules.rst

> There are the stable branches on kernel.org and some distro kernels based on
> older kernel versions.
> 
> The AMD severity grading function was introduced in v4.1 and has this issue.
> However, the following commit was included in v4.6 and masks the issue.
> 
> b2f9d678e28c x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries
> 
> This patch will apply to v4.9 and later. Another version will be needed to apply
> to the v4.1 and v4.4. stable branches.

Then write that in the commit message. But *also* add the main reason
why you're doing this - to explicitly state that IN_KERNEL context is
panicked on on AMD. Because if it weren't for it, old kernels should
simply backport b2f9d678e28c and be done with it.

And I still don't understand the IN_KERNEL_RECOV thing you mention in
the commit message. That's Intel-only, what does it have to do with AMD?

Btw, while at it, fix that signature

static int mce_severity_amd_smca(struct mce *m, int err_ctx)

to

static int mce_severity_amd_smca(struct mce *m, enum context err_ctx)

Thx.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.