linux-kernel - Re: [PATCH v6 2/4] x86/traps: Print address on #GP

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Message-ID: <20191211172945.GE14821@zn.tnic>
Date:   Wed, 11 Dec 2019 18:29:45 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Andy Lutomirski <luto@...capital.net>
Cc:     Jann Horn <jannh@...gle.com>, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        Alexander Potapenko <glider@...gle.com>,
        Dmitry Vyukov <dvyukov@...gle.com>, kasan-dev@...glegroups.com,
        linux-kernel@...r.kernel.org,
        Andrey Konovalov <andreyknvl@...gle.com>,
        Andy Lutomirski <luto@...nel.org>,
        Sean Christopherson <sean.j.christopherson@...el.com>
Subject: Re: [PATCH v6 2/4] x86/traps: Print address on #GP

On Wed, Dec 11, 2019 at 09:22:30AM -0800, Andy Lutomirski wrote:
> Could we spare a few extra bytes to make this more readable?  I can never keep track of which number is the oops count, which is the cpu, and which is the error code.  How about:
> 
> OOPS 1: general protection blah blah blah (CPU 0)
> 
> and put in the next couple lines “#GP(0)”.

Well, right now it is:

[    2.470492] general protection fault, probably for non-canonical address 0xdfff000000000001: 0000 [#1] PREEMPT SMP
[    2.471615] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc1+ #6

and the CPU is on the second line, the error code is before the number -
[#1] - in that case.

If we pull the number in front, we can do:

[    2.470492] [#1] general protection fault, probably for non-canonical address 0xdfff000000000001: 0000 PREEMPT SMP
[    2.471615] [#1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc1+ #6

and this way you know that the error code is there, after the first
line's description.

I guess we can do:

[    2.470492] [#1] general protection fault, probably for non-canonical address 0xdfff000000000001 Error Code: 0000 PREEMPT SMP

to make it even more explicit...

-- 
Regards/Gruss,
    Boris.

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