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:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Mark Rutland <mark.rutland@arm.com>
CC:     "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Torsten Duwe <duwe@suse.de>
Subject: [PATCH 1/3] ftrace: introdue ftrace_call_init
Thread-Topic: [PATCH 1/3] ftrace: introdue ftrace_call_init
Thread-Index: AQHVVoEVwhJ6aER5rUqFs9/8RPsn7A==
Date:   Mon, 19 Aug 2019 11:27:28 +0000
Message-ID: <20190819191622.57050fdf@xhacker.debian>
References: <20190819191530.0f47b9b1@xhacker.debian>
In-Reply-To: <20190819191530.0f47b9b1@xhacker.debian>
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: c9c6fb15-3290-4c27-6da9-08d72498374d
x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600148)(711020)(4605104)(1401327)(2017052603328)(7193020);SRVR:BYAPR03MB3528;
x-ms-traffictypediagnostic: BYAPR03MB3528:
x-microsoft-antispam-prvs: <BYAPR03MB352803F65D299B97FDA2C602EDA80@BYAPR03MB3528.namprd03.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:2089;
x-forefront-prvs: 0134AD334F
x-forefront-antispam-report: SFV:NSPM;SFS:(10009020)(396003)(39860400002)(346002)(136003)(376002)(366004)(189003)(199004)(5660300002)(8936002)(50226002)(86362001)(81156014)(81166006)(71200400001)(71190400001)(25786009)(486006)(476003)(8676002)(11346002)(14444005)(446003)(66446008)(64756008)(66556008)(66476007)(66946007)(1076003)(6512007)(66066001)(9686003)(26005)(6486002)(305945005)(99286004)(186003)(102836004)(2906002)(52116002)(54906003)(53936002)(3846002)(6116002)(316002)(256004)(4326008)(76176011)(14454004)(6506007)(386003)(6436002)(7736002)(478600001)(110136005)(39210200001);DIR:OUT;SFP:1101;SCL:1;SRVR:BYAPR03MB3528;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: uOlTLWm4Z9VLib/KTEEqxeJFypMT9a1I2ZkwEtSDt2fpsST8b8Tu1+uVjbQPePc7IfQaQp3+19UXzucHcRCaKYhPZO3bT5sLuJ9OYdaCsr2Afsx64be/PdT0nHHR1o8v7ujn427ezzZyWn6c3NSE/bORa1iFb1sT3NzXpKVa8p7GhWJdYxFBicE6adhs0AI8ruTQlDzwelM337khOhJOYWPu6Nv0168XynyfCorvCcaAoaplNLsKEBXCAGyPXi3yO/VtrsBPnNm80/wGum55E1aCKdewwGiyZ2pJPxkOHlOrfIpBOnn7lF3T6/wY30rFrz2F21wZEr8W8fvZWSEv9EFijeBMtEjLPU0+WDn4JtDbUhE8IfHC39svij5Mo93BX+yK9VWzPZtej3E1mlnNhWlyaHlXupvk++xKPdAKYwU=
x-ms-exchange-transport-forked: True
Content-Type: text/plain; charset="us-ascii"
Content-ID: <65D3633956CC7442B998474B06CF6B85@namprd03.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: synaptics.com
X-MS-Exchange-CrossTenant-Network-Message-Id: c9c6fb15-3290-4c27-6da9-08d72498374d
X-MS-Exchange-CrossTenant-originalarrivaltime: 19 Aug 2019 11:27:28.1102
 (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: YptC0TCH7bmLao00rAzP769ogt5dQnz6ucWI9LnufRUuoYtvPdSDS0SGJ4H8HqMmjJDl4m7Q3c7pYrazejFdyw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR03MB3528
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 some arch, the FTRACE_WITH_REGS is implemented with gcc's
 -fpatchable-function-entry (=3D2), gcc adds 2 NOPs at the beginning
of each function, so this makes the MCOUNT_ADDR useless. In ftrace
common framework, MCOUNT_ADDR is mostly used to "init" the nop, so
let's introcude ftrace_call_init().

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
---
 include/linux/ftrace.h | 1 +
 kernel/trace/ftrace.c  | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 8a8cb3c401b2..8175ffb671f0 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -458,6 +458,7 @@ extern void ftrace_regs_caller(void);
 extern void ftrace_call(void);
 extern void ftrace_regs_call(void);
 extern void mcount_call(void);
+extern int ftrace_call_init(struct module *mod, struct dyn_ftrace *rec);
=20
 void ftrace_modify_all_code(int command);
=20
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index eca34503f178..9df5a66a6811 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2500,7 +2500,11 @@ ftrace_code_disable(struct module *mod, struct dyn_f=
trace *rec)
 	if (unlikely(ftrace_disabled))
 		return 0;
=20
+#ifdef MCOUNT_ADDR
 	ret =3D ftrace_make_nop(mod, rec, MCOUNT_ADDR);
+#else
+	ret =3D ftrace_call_init(mod, rec);
+#endif
 	if (ret) {
 		ftrace_bug_type =3D FTRACE_BUG_INIT;
 		ftrace_bug(ret, rec);
--=20
2.23.0.rc1