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

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Date:   Tue, 19 Nov 2019 21:39:21 -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 9:17 PM, Boris Ostrovsky wrote:
> On 11/19/19 12:50 PM, Boris Ostrovsky wrote:
>> 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.
> Nevermind this. I didn't read your patches correctly.

BTW, I'd rather this not go into 5.4 this late. 3c88c692c287 has been
there since 5.2 and noone complained.

-boris