Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Jisheng Zhang <Jisheng.Zhang@synaptics.com>
To:     "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
CC:     Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
        Borislav Petkov <bp@alien8.de>,
        Catalin Marinas <catalin.marinas@arm.com>,
        "David S. Miller" <davem@davemloft.net>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Will Deacon <will@kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>
Subject: Re: [PATCH 4/4] arm64: implement KPROBES_ON_FTRACE
Thread-Topic: [PATCH 4/4] arm64: implement KPROBES_ON_FTRACE
Thread-Index: AQHVVoKNUq/zpqtyiEKe+wuBFBglYqcCr98AgACajgA=
Date:   Tue, 20 Aug 2019 02:16:28 +0000
Message-ID: <20190820100522.55bc3f42@xhacker.debian>
References: <20190819192422.5ed79702@xhacker.debian>
        <20190819192706.46ce2c1d@xhacker.debian>
        <1566232996.v8nlwmnjqa.naveen@linux.ibm.com>
In-Reply-To: <1566232996.v8nlwmnjqa.naveen@linux.ibm.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-messagesentrepresentingtype: 1
x-mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu)
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: 566d4848-98f9-405c-5850-08d7251468a7
x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(5600148)(711020)(4605104)(1401327)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(2017052603328)(7193020);SRVR:BYAPR03MB3896;
x-ms-traffictypediagnostic: BYAPR03MB3896:
x-microsoft-antispam-prvs: <BYAPR03MB38960943AD7B44F0486F98D2EDAB0@BYAPR03MB3896.namprd03.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:8882;
x-forefront-prvs: 013568035E
x-forefront-antispam-report: SFV:NSPM;SFS:(10009020)(136003)(366004)(396003)(376002)(39850400004)(346002)(189003)(199004)(6506007)(386003)(316002)(7416002)(229853002)(71200400001)(71190400001)(102836004)(26005)(14454004)(6916009)(6486002)(76176011)(6436002)(1076003)(6512007)(486006)(476003)(9686003)(14444005)(52116002)(256004)(4744005)(7736002)(11346002)(54906003)(186003)(5660300002)(99286004)(305945005)(446003)(478600001)(66066001)(8936002)(25786009)(4326008)(3846002)(6116002)(81166006)(81156014)(8676002)(6246003)(2906002)(53936002)(50226002)(66476007)(64756008)(66446008)(66556008)(66946007)(86362001)(39210200001);DIR:OUT;SFP:1101;SCL:1;SRVR:BYAPR03MB3896;H:BYAPR03MB4773.namprd03.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;MX:1;A:0;
received-spf: None (protection.outlook.com: synaptics.com does not designate
 permitted sender hosts)
x-ms-exchange-senderadcheck: 1
x-microsoft-antispam-message-info: 50xz/V+MdxuhdU8rdQ0+VCbgWlydRVZbPL66Tmdqq7Eo/oXA/Kq26lSMh8//f7RwCLaAagMAdxkfL2ZAejM9Bc2refH6DA4RIQK8uELpq9P8EDIzI4ynXYVfjs2gEWHBEhPl/Y97pfLFbhayquCJf4qFnhj3sEgNuRz46JkQqxcr/W+9xCNEh0YshTn6H0godBe6XYNS0en4+v84kXLYm5z+XnsRGxNNSqK4H34+3RYxT6qQo484YAsyr3QWHs1cTnfmK/kSmlXPkskc/6vQuOkIu2UYlTYJNBRxzFLHoxiZxn7vjYnkIEKmCjQ6cpiRDc56CBaFSCFk/i6yeB2vQ/FuACM/Tmxx0BsD2NmTAffO/yJa/p97iOAciTfJbrMx7pDj++aqsTDcaKLau4v9JsOyw2Rtl2qcbj/aqhLcdGs=
x-ms-exchange-transport-forked: True
Content-Type: text/plain; charset="us-ascii"
Content-ID: <D513D93F6612794EA8269E652E4FC9F8@namprd03.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: synaptics.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 566d4848-98f9-405c-5850-08d7251468a7
X-MS-Exchange-CrossTenant-originalarrivaltime: 20 Aug 2019 02:16:28.3654
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 335d1fbc-2124-4173-9863-17e7051a2a0e
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: XvQOFQFDQin6lhSGmujrZnU7giJKF37UMb5vghHNu0AbuS/zbWra/9IKT3ga+876XJvKRaj6ZaXR1lACuvEcDQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR03MB3896
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, 19 Aug 2019 22:22:12 +0530 "Naveen N. Rao" wrote:


>=20
>=20
> Jisheng Zhang wrote:
> > This patch implements KPROBES_ON_FTRACE for arm64.
> >
> > ~ # mount -t debugfs debugfs /sys/kernel/debug/
> > ~ # cd /sys/kernel/debug/
> > /sys/kernel/debug # echo 'p _do_fork' > tracing/kprobe_events
> >
> > before the patch:
> >
> > /sys/kernel/debug # cat kprobes/list
> > ffffff801009ff7c  k  _do_fork+0x4    [DISABLED] =20
>=20
> This looks wrong -- we should not be allowing kprobe to be registered on

Yes. I made a mistake when dumping this log. The kernel isn't as clean
as "before the patch".


> ftrace address without KPROBES_ON_FTRACE. Is _do_fork+0x4 the location
> of ftrace entry on arm64?

Indeed, w/o KPROBES_ON_FTRACE, it should be _do_fork+0x0

Thanks