linux-kernel - Re: Ping: [PATCH 0/2] x86/Xen/32: xen_iret_crit

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Message-ID: <40267a5b-8f1b-6463-72cd-f8f354c58bc4@oracle.com>
Date:   Tue, 19 Nov 2019 12:50:05 -0500
From:   Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:     Jan Beulich <jbeulich@...e.com>, Juergen Gross <jgross@...e.com>
Cc:     lkml <linux-kernel@...r.kernel.org>,
        the arch/x86 maintainers <x86@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        "xen-devel@...ts.xenproject.org" <xen-devel@...ts.xenproject.org>
Subject: Re: Ping: [PATCH 0/2] x86/Xen/32: xen_iret_crit_fixup adjustments

On 11/19/19 7:58 AM, Jan Beulich wrote:
> On 11.11.2019 15:30, Jan Beulich wrote:
>> The first patch here fixes another regression from 3c88c692c287
>> ("x86/stackframe/32: Provide consistent pt_regs"), besides the
>> one already addressed by
>> https://lists.xenproject.org/archives/html/xen-devel/2019-10/msg01988.html.
>> The second patch is a minimal bit of cleanup on top.
>>
>> 1: make xen_iret_crit_fixup independent of frame layout
>> 2: simplify xen_iret_crit_fixup's ring check
> Seeing that the other regression fix has been taken into -tip,
> what is the situation here? Should 5.4 really ship with this
> still unfixed?


I am still unable to boot a 32-bit guest with those patches, crashing in
int3_exception_notify with regs->sp zero.

When I revert to 3c88c692c287 the guest actually boots so my (?) problem
was introduced somewhere in-between.

-boris