Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: 6eox4MqJB7fwa7Xe1R3ya13eNSJhRpMkXIi5rcQeQ7XsfB0XBW3OoZYxnk0haQfEe88pnmwXCY
 YNm7L+iSaHgfF/zmY6mHqabJviOoVnrtZi0hxQel6EaqdbjhYxOOak1twVyBmfoRP58VTqqkT0
 ACtOURbyb946njGnzw5XZrYPQsMM86UVVoqRec9xXm/tCuH2E4VK5tKX7yzsflp4GuqgA1ojnZ
 Scrs3KmBql/2FlSgOkYHEZXt32J10m996O/Al4jkX4wuovmrn/TDPbM8Kemh6HeQXs5C6CSuoh
 g+A=
From:   Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
To:     Peter Zijlstra <peterz@infradead.org>
CC:     =?iso-8859-1?Q?J=FCrgen_Gro=DF?= <jgross@suse.com>,
        Andy Lutomirski <luto@kernel.org>,
        Andrew Cooper <andrew.cooper3@citrix.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Nicholas Piggin <npiggin@gmail.com>,
        Damien Le Moal <Damien.LeMoal@wdc.com>,
        X86 ML <x86@kernel.org>
Subject: Re: WARNING: can't access registers at asm_common_interrupt
Thread-Topic: WARNING: can't access registers at asm_common_interrupt
Thread-Index: AQHWtAKoC1N6UC8gbUaAN5Wk5A+R6KnDMbkAgAALvACAAAc6AIAACUOAgAAPgQCAAAS5AIAAAmAAgAACHwCAAALvAIAC9PyAgARYcQCAABLpgIACu3AAgAAaoACAAcx5gIAAAuYAgAANSgA=
Date:   Thu, 19 Nov 2020 12:48:57 +0000
Message-ID: <20201119124856.wpvhzstbtrujvdxa@shindev.dhcp.fujisawa.hgst.com>
References: <20201111200730.GM2628@hirez.programming.kicks-ass.net>
 <20201111201506.bftpmx4svxn376tn@treble>
 <61b2538f-7be6-8f4a-9395-03071b5cc6f0@citrix.com>
 <CALCETrXcTKB_j9MQC1mcZobKGt_cZ5ivDPjU3zwRBmj7DAUCsA@mail.gmail.com>
 <f105a63d-6b51-3afb-83e0-e899ea40813e@suse.com>
 <20201116130413.GC3121392@hirez.programming.kicks-ass.net>
 <e1ca6c8c-e32d-879a-1972-5605f0892176@suse.com>
 <20201118082254.GH3121378@hirez.programming.kicks-ass.net>
 <20201119115059.dns4hvull3l3dwx3@shindev.dhcp.fujisawa.hgst.com>
 <20201119120122.GJ3121392@hirez.programming.kicks-ass.net>
In-Reply-To: <20201119120122.GJ3121392@hirez.programming.kicks-ass.net>
Accept-Language: en-US
Content-Language: en-US
wdcipoutbound: EOP-TRUE
Content-Type: text/plain; charset="iso-8859-1"
Content-ID: <F957B247B4AF654F8940DE8D0635A8A6@namprd04.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 8248d38b-4a71-445c-fe84-08d88c897b55
X-MS-Exchange-CrossTenant-originalarrivaltime: 19 Nov 2020 12:48:57.9767
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: b61c8803-16f3-4c35-9b17-6f65f441df86
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: KWIV9MwtiAvYSwG+D+BL+4oGwykghJbQpnJH9mIoQkJCx+Jh3xpy4XBf2kGSaYQPCueTU5XT/602ymZ5odZRdQQAutLVGkYw/kO12asbhUs=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR04MB7583
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Nov 19, 2020 / 13:01, Peter Zijlstra wrote:
> On Thu, Nov 19, 2020 at 11:51:00AM +0000, Shinichiro Kawasaki wrote:
> > I tried Peter's patch in my test system and result looks good. The warn=
ing is
> > still observed with 5.10-rc4. With the patch on top of 5.10-rc4, the wa=
rning
> > disappeared.
>=20
> The patch on its own is not sufficient to fix things; there needs to be
> an accompanying objtool patch to generate the correct unwind
> information.
>=20
> This patch only ensures objtool has enough information to be able to
> dtrt, but as it stands it shouldn't even compile, it should complain
> about an alternative trying to modify the stack and bail.

Thanks for the clarification. It was too early to try out... When it gets r=
eady
to try and test, please let me know.

--=20
Best Regards,
Shin'ichiro Kawasaki=