linux-kernel - Re: [Patch V1 1/7] x86/microcode/intel: Remove redundant microcode rev pr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87cz91pr8d.ffs@tglx>
Date:   Fri, 02 Dec 2022 19:58:42 +0100
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Ashok Raj <ashok.raj@...el.com>, Borislav Petkov <bp@...en8.de>
Cc:     X86-kernel <x86@...nel.org>,
        LKML Mailing List <linux-kernel@...r.kernel.org>,
        Ashok Raj <ashok.raj@...el.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Tony Luck <tony.luck@...el.com>, alison.schofield@...el.com,
        reinette.chatre@...el.com
Subject: Re: [Patch V1 1/7] x86/microcode/intel: Remove redundant microcode
 rev pr_info()s

Ashok!

On Tue, Nov 29 2022 at 13:08, Ashok Raj wrote:
> There is a pr_info() to dump information about newly loaded microcode.

There... Somewhere, right?

> The code intends this pr_info() to be just once, but the check to ensure
> is racy. Unfortunately this happens quite often in with this new change
> resulting in multiple redundant prints on the console.

-ENOPARSE. Can you try to express that in coherent sentences please?

> microcode_init()->schedule_on_each_cpu(setup_online_cpu)->collect_cpu_info
>
> [   33.688639] microcode: sig=0x50654, pf=0x80, revision=0x2006e05
> [   33.688659] microcode: sig=0x50654, pf=0x80, revision=0x2006e05
> [   33.688660] microcode: sig=0x50654, pf=0x80, revision=0x2006e05
>
> There is already a pr_info() in microcode/core.c as shown below:
>
> microcode: Reload completed, microcode revision: 0x2b000041 -> 0x2b000070

There are quite some pr_info()'s in microcode/core.c...

$function_name() prints the new and the previous microcode revision once
when the load has completed:

  microcode: Reload completed, microcode revision: 0x2b000041 -> 0x2b000070

Hmm?

> The sig and pf aren't that useful to end user, they are available via

The sig and pf ?!? Come on, you really can do better.

> /proc/cpuinfo and this never changes between microcode loads.
>
> Remove the redundant pr_info() and the racy single print checks. This
> removes the race entirely, zap the duplicated pr_info() spam and
> simplify the code.

The last sentence does not qualify as coherent either.

Other than that. Nice cleanup.

Thanks,

        tglx