Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Song Liu <songliubraving@fb.com>
To:     Steven Rostedt <rostedt@goodmis.org>
CC:     Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Kernel Team <Kernel-team@fb.com>, Jiri Olsa <jolsa@kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Song Liu <song@kernel.org>
Subject: Re: [PATCH v2 bpf-next 0/5] ftrace: host klp and bpf trampoline
 together
Thread-Topic: [PATCH v2 bpf-next 0/5] ftrace: host klp and bpf trampoline
 together
Thread-Index: AQHYdrnMgR7UbO/WnEm8o1uHxIdxmK1DBAOA
Date:   Mon, 6 Jun 2022 22:57:02 +0000
Message-ID: <22E9FBBD-754F-4CAA-907F-29F4223DAAB7@fb.com>
References: <20220602193706.2607681-1-song@kernel.org>
In-Reply-To: <20220602193706.2607681-1-song@kernel.org>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?vh3dp1g92DclsSk5RmjVGZ5k5dEtob4EnAP5Hz5gor1Rj7G06uobP3Clc3xx?=
 =?us-ascii?Q?Ua8BCJey4SUBfiEUyLvs+BIqgT+LthO85LD/3Qc2Z2tOb1Yi6kI0ZXqr5sUY?=
 =?us-ascii?Q?S1tmCfpOzbicB406yY4Tzi0E8dgqjaVWxlsMwbq9zU/uEOUrQDE/rHKW4cCY?=
 =?us-ascii?Q?hjcTKNfwrpqVdj+P2ag//gbegLbSd6ejIbrs9z3f3F0hq0h3RfIKQKk4INC8?=
 =?us-ascii?Q?ByUv+aBy9hv1XGb0IAchA1c+R58xzoII/ncfZRSQ5oqIGUMmslNWaWsY7A1C?=
 =?us-ascii?Q?HW8Npthn9FNHMKj6H9WBelwXEyoBh6LsvvZohXbWCEzNatPufwM+C9YpTGE9?=
 =?us-ascii?Q?7fl9NskepjqDmnENvWjpiEVxkUfCQWj58wzZ8T+33j5p4nVAJcE1IHQPPzHr?=
 =?us-ascii?Q?6ErjAMxiSZFQszc9Q9kl5rRHFdfK/z+ZAg7glbx5gY0IdtAD/cJceg0atpg9?=
 =?us-ascii?Q?9v2FZT651f8hHQkDFLcizRiZvycmWnUO3flEvF6+M/nsuzZgmy5iAOpZY3DM?=
 =?us-ascii?Q?Yz9LhfH5mpUWDcf9idef62Erv12xtm/nhfRmlz5OXKVCAIge9Smfe5NAqAiE?=
 =?us-ascii?Q?YlzWXT4eXhKZQL9n7mKyrkxt4LY1wIjCxzjfu1tjMiMlCv06hLwm2Jrh719T?=
 =?us-ascii?Q?7aG/De8dlYXw32QgQg6dOsMJrLt8OlkABEnBVzXUNDuVUYHTDGn508lqUZ//?=
 =?us-ascii?Q?G3WGP95YCUCdG3rNLuqrba/IYxD8c5Ns44UFdoVU7qAygUQPebQjfpi/8CCK?=
 =?us-ascii?Q?vFESFagXOjG3IdYhpfn2Rc16F1cb5WiWHU9YIhuCph/Zc7G7vxTo8gosj24P?=
 =?us-ascii?Q?rnMkJe88luzmGgTKO9XPYUZSyftB7nyI/2iabvYGatxg0Ay0lDm9EioZshpI?=
 =?us-ascii?Q?AZRpPFcFP8aVOFlBbTZlMNVP/ZmRXkfUiit1B9Rt9IHisf/kai6AI/3o0IJF?=
 =?us-ascii?Q?q2fqlUYqwFY3OFOSClEaYhpRt0SU0Riz00uEmNUOo89ThOGhW4ZN3mYVvCpW?=
 =?us-ascii?Q?4gGUnXGhcnS+4S5NakZF5uR2DvYU6TcVE68aV8mVnO1O7Onjl6dIOiu4zr/b?=
 =?us-ascii?Q?WpCtTxUdPruuw6nTscSwa44L0NIA9HbHjCesNKwQHO8uD9VksD+i1ntwzhqK?=
 =?us-ascii?Q?kJtC3fV4LB3gqYtsNnHYlPtYxVGdmB6GD9TRWZFGCFbKL8KVp4FnJmHSJTsq?=
 =?us-ascii?Q?4+8IRMIe0V0orDHqSBWR1QMuk2Pikt4XlYpBEFluTUU7QTEzTdiLAwfuaOZJ?=
 =?us-ascii?Q?DXi9SokP1pZ4SLZaANsioX4ZpOMVzXX6VydxDo+lKBoya+FogltYBNLn4HjW?=
 =?us-ascii?Q?Irkx33RTMwbtlJimzfyTO+WyCROhqo5ZrrfG45p1ANZpWjiL149/E1bh9Udv?=
 =?us-ascii?Q?xj2gcQk6zfDdlz7BnnseUnoZDqgtcm9F4OsN6txBG79qxvmH3FmK8vJzxYXZ?=
 =?us-ascii?Q?sla2Qqie8a0DxH7JM1ic+XEwtLS4FmcEWX8JThP0Qb3bqnOmVyn3lHjRYE00?=
 =?us-ascii?Q?d2lFPOmLNWMjjeSokFNCq+ef0gmY3aQwBwy4e40Ffbw9J7EWoa88gM0GPUBz?=
 =?us-ascii?Q?rmPyUZdTT5BUo7ZZFdbZ5Mzs5F5PgcsEg8QxTbm/OGLmyfBrU/gIv0U/ePRF?=
 =?us-ascii?Q?NR2FFWYRxMS4usdlxiZoFMOyOWJ7R1HPTFEpvlCSa+774QCr1hmU1qLwPJ9z?=
 =?us-ascii?Q?qO9K8ect05RwfalMorKgnRFeVP7tZ80rojiBKB7EtAMl2c1edg04AuTekC9q?=
 =?us-ascii?Q?ta98/xp2o2DC8+x/uObuZ/+7G6sWcaTiZDL6rjyEc2cIRsXMBnDy?=
Content-Type: text/plain; charset="us-ascii"
Content-ID: <70BAFBEBA2042B40867D2C42693936AA@namprd15.prod.outlook.com>
MIME-Version: 1.0
X-OriginatorOrg: fb.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: SA1PR15MB5109.namprd15.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 843e96cd-2fc8-49e2-69a7-08da480fdeda
X-MS-Exchange-CrossTenant-originalarrivaltime: 06 Jun 2022 22:57:02.6286
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: M0ZGVrlydibCQb92dj26xNE9aw1Fjr0/1gPevs68wl+NNJh1KHTdfItxg+I6WLKrjS8h0GlW3ZZIqXzHmMFMYQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW2PR1501MB2076
X-Proofpoint-ORIG-GUID: XYYZNR3s61UOmebxU0n4zwWP_HYpHtlt
X-Proofpoint-GUID: XYYZNR3s61UOmebxU0n4zwWP_HYpHtlt
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.517,FMLib:17.11.64.514
 definitions=2022-06-06_07,2022-06-03_01,2022-02-23_01
X-Spam-Status: No, score=-4.0 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,
        T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Steven, 

> On Jun 2, 2022, at 12:37 PM, Song Liu <song@kernel.org> wrote:
> 
> Changes v1 => v2:
> 1. Fix build errors for different config. (kernel test robot)
> 
> Kernel Live Patch (livepatch, or klp) and bpf trampoline are important
> features for modern systems. This set allows the two to work on the same
> kernel function as the same time.
> 
> live patch uses ftrace with IPMODIFY, while bpf trampoline use direct
> ftrace. Existing policy does not allow the two to attach to the same kernel
> function. This is changed by fine tuning ftrace IPMODIFY policy, and allows
> one non-DIRECT IPMODIFY ftrace_ops and one non-IPMODIFY DIRECT ftrace_ops
> on the same kernel function at the same time. Please see 3/5 for more
> details on this.
> 
> Note that, one of the constraint here is to let bpf trampoline use direct
> call when it is not working on the same function as live patch. This is
> achieved by allowing ftrace code to ask bpf trampoline to make changes.

Could you please share your comments on this set? 

Thanks!
Song

> 
> Jiri Olsa (1):
>  bpf, x64: Allow to use caller address from stack
> 
> Song Liu (4):
>  ftrace: allow customized flags for ftrace_direct_multi ftrace_ops
>  ftrace: add modify_ftrace_direct_multi_nolock
>  ftrace: introduce FTRACE_OPS_FL_SHARE_IPMODIFY
>  bpf: trampoline: support FTRACE_OPS_FL_SHARE_IPMODIFY
> 
> arch/x86/net/bpf_jit_comp.c |  13 +-
> include/linux/bpf.h         |   8 ++
> include/linux/ftrace.h      |  79 +++++++++++
> kernel/bpf/trampoline.c     | 109 +++++++++++++--
> kernel/trace/ftrace.c       | 269 +++++++++++++++++++++++++++++++-----
> 5 files changed, 424 insertions(+), 54 deletions(-)
> 
> --
> 2.30.2