From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0295FC5DF60 for ; Fri, 8 Nov 2019 06:56:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF661214DB for ; Fri, 8 Nov 2019 06:56:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="PUtqPAij"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="Bk33YAeI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726039AbfKHG4Z (ORCPT ); Fri, 8 Nov 2019 01:56:25 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:39596 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725802AbfKHG4Z (ORCPT ); Fri, 8 Nov 2019 01:56:25 -0500 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.42/8.16.0.42) with SMTP id xA86sR8v005861; Thu, 7 Nov 2019 22:56:10 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=facebook; bh=DIIv6R8TBPz7ajbhc2bCK3VyB9cIeLzK4UBrU5uOlPw=; b=PUtqPAijDRKs5aER3ZrAn8KM/sR8+WfIDKCX8Vu8fmkjze1v2wwn5uW5PQoaqxz/XZPy cFlWy7E3zPcBqqDvwNkFRW6lPu71EI5oTkR4bRiyBYYkfOBhY/vEi+jsOuyGSxGkOtYA g9ZXKIdTI2Ra0d/HMLalV248S+xkLJmn7Mc= Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by m0089730.ppops.net with ESMTP id 2w4ujfa2se-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Thu, 07 Nov 2019 22:56:10 -0800 Received: from prn-hub05.TheFacebook.com (2620:10d:c081:35::129) by prn-hub06.TheFacebook.com (2620:10d:c081:35::130) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.1713.5; Thu, 7 Nov 2019 22:56:09 -0800 Received: from NAM02-CY1-obe.outbound.protection.outlook.com (192.168.54.28) by o365-in.thefacebook.com (192.168.16.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.1713.5 via Frontend Transport; Thu, 7 Nov 2019 22:56:08 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=WJURgngGi4I33Xm7U+c87WUtWgo/8o17gP+OMLjilpyk9PE0hPmtlCkF+yF2tJ1DcwuSWY+4F9Ek445X4z2LcLopjTHhYyyz9DWPsUDLu7bDcruxY+1aW9k45bHv712vekr7ez8pKUidF+OJ15BThB+3PkJyHlzfE/CNIo1WEO/JNcede41kRH5cQbjzqXQxoxesFQmUK9apr15OFcEi0virie6YzkXbP3kFV13+2perZUC1vese7th/YWLuJH4qKLpmiZ0GIPMY+3HlIu4UtUSO6S/dMoHSTy60JwaKI0PhlQzmmuF4+pM4Ah5yzLje9iPrgM1JFEygQATOum702Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=DIIv6R8TBPz7ajbhc2bCK3VyB9cIeLzK4UBrU5uOlPw=; b=dH+8uEhUJxy7BuzFe3HRzEvPIvWaLPkBqEPuflVn/XLf++kFp3gaeAs1GxShSvBTwV4m4TD3/D6KFkg4+2nAifPsizvHCkkaHEopiIYgJfc4QgtSbnzpayas2ItSYBEXVM8jtv+RiloVb9uBb3P1aDhTzzf+NSIXhZ7yVK3M07oAO/sO3OJFYBCyemvxk9xfSTjbk1FPxLwUZIKtFmF6qxrWk+mSsn4zD/IPZqt3ZTqNdbLflYM2Vm9cn6dQ/kV2M7QFowKbmUy3czNijY7TGrFsnk1GGxrrk9D2v3P3xOmIRWsePnyKi14urd0W5HOa4LWutZA0MLnnn0HCyFfT+Q== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=fb.com; dmarc=pass action=none header.from=fb.com; dkim=pass header.d=fb.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector2-fb-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=DIIv6R8TBPz7ajbhc2bCK3VyB9cIeLzK4UBrU5uOlPw=; b=Bk33YAeI/mK3XdDge67JfN/NrJjiT5qKLWrsTmksX+9FbtgLkalDGPlk+yMmMspKgzApRjiZXuGwhS0WpSKZ6N7oEZl9vRH19utQB3QxStCKvr3jFUyxyIUevLhFNUrv5tl19gQjnyw1ctFY1/QZomJSlC3wnNVj5FvtiWnOfP8= Received: from MWHPR15MB1165.namprd15.prod.outlook.com (10.175.3.22) by MWHPR15MB1503.namprd15.prod.outlook.com (10.173.234.135) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2430.22; Fri, 8 Nov 2019 06:56:07 +0000 Received: from MWHPR15MB1165.namprd15.prod.outlook.com ([fe80::fdc8:5546:bace:15f5]) by MWHPR15MB1165.namprd15.prod.outlook.com ([fe80::fdc8:5546:bace:15f5%5]) with mapi id 15.20.2430.020; Fri, 8 Nov 2019 06:56:07 +0000 From: Song Liu To: Alexei Starovoitov CC: David Miller , "daniel@iogearbox.net" , "x86@kernel.org" , "netdev@vger.kernel.org" , "bpf@vger.kernel.org" , Kernel Team Subject: Re: [PATCH v3 bpf-next 02/18] bpf: Add bpf_arch_text_poke() helper Thread-Topic: [PATCH v3 bpf-next 02/18] bpf: Add bpf_arch_text_poke() helper Thread-Index: AQHVlf98N1QW0kBnUUGjttfnnSDRSKeA1zGA Date: Fri, 8 Nov 2019 06:56:07 +0000 Message-ID: <201D1F23-B4D5-4EB4-8450-128C6E2C1971@fb.com> References: <20191108064039.2041889-1-ast@kernel.org> <20191108064039.2041889-3-ast@kernel.org> In-Reply-To: <20191108064039.2041889-3-ast@kernel.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: Apple Mail (2.3601.0.10) x-originating-ip: [2620:10d:c090:180::c4b] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 9de68d86-9945-42a2-f84b-08d76418bb19 x-ms-traffictypediagnostic: MWHPR15MB1503: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:7219; x-forefront-prvs: 0215D7173F x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(366004)(346002)(136003)(39860400002)(396003)(376002)(199004)(189003)(66476007)(66556008)(7736002)(11346002)(478600001)(36756003)(6436002)(99286004)(229853002)(8936002)(6916009)(256004)(186003)(6116002)(4326008)(46003)(2906002)(14444005)(316002)(54906003)(81156014)(305945005)(76116006)(50226002)(81166006)(86362001)(76176011)(6486002)(33656002)(53546011)(66946007)(66446008)(14454004)(25786009)(446003)(5660300002)(102836004)(6246003)(71190400001)(6512007)(64756008)(486006)(2616005)(476003)(8676002)(71200400001)(6506007);DIR:OUT;SFP:1102;SCL:1;SRVR:MWHPR15MB1503;H:MWHPR15MB1165.namprd15.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; received-spf: None (protection.outlook.com: fb.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 0qzwwOHwNo6Pv6LkCTI2zrX4XOG7srvlqUZtTd8LkKWrBY8qZpa1xAGHrwjdtJm6XxURPTcNiJfPcjkloR5R6RPZ1Rqx76q5UmxYyNiwXGXl/u9sxJsFy9wUcguGrjn2miyHuhjUAkgCvuS7r+cPQCvo31I1NSrX7GRVidtfcHuGIdGbBpzrS9w3pPGsH1ckCcwaJ3qcqMUj5YbiN4w7nQ2/edsW82SGscRVh2vzIyYMKVd+tNDoBMcUPk+q/47euCO29+OOSb9SLQNSlH/2atOD2Eeg+x0rs3o1lK8/OY5pYVCHzp/DmBD9LO/Pvni1bV6A+HRQV48c8YNPVdjdL9i6T31Q8xlRtUb3bj+iEFYih3ilWJNqyF1+ga+d54OMODlD4CDPD9CmIE7DOvKAs+po9l1n90igWwvU5nmKP1zW78IENDh1HVDG3mBRshIC Content-Type: text/plain; charset="us-ascii" Content-ID: <62FF096D0C3E5844B258E4E169259FFA@namprd15.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: 9de68d86-9945-42a2-f84b-08d76418bb19 X-MS-Exchange-CrossTenant-originalarrivaltime: 08 Nov 2019 06:56:07.4409 (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: rxP5I0vcjnfClNX/29i04kkxqtJcDTRN5XdS3efLk8Qjhaq3ovYoG4ssx8fe77HPWSogcHbNSWrlIOUZk6KwLg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR15MB1503 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-11-08_01:2019-11-07,2019-11-08 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 malwarescore=0 suspectscore=0 impostorscore=0 spamscore=0 lowpriorityscore=0 adultscore=0 mlxscore=0 bulkscore=0 phishscore=0 priorityscore=1501 mlxlogscore=999 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1911080067 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org > On Nov 7, 2019, at 10:40 PM, Alexei Starovoitov wrote: >=20 > Add bpf_arch_text_poke() helper that is used by BPF trampoline logic to p= atch > nops/calls in kernel text into calls into BPF trampoline and to patch > calls/nops inside BPF programs too. >=20 > Signed-off-by: Alexei Starovoitov Acked-by: Song Liu > --- > arch/x86/net/bpf_jit_comp.c | 51 +++++++++++++++++++++++++++++++++++++ > include/linux/bpf.h | 8 ++++++ > kernel/bpf/core.c | 6 +++++ > 3 files changed, 65 insertions(+) >=20 > diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c > index 0399b1f83c23..bb8467fd6715 100644 > --- a/arch/x86/net/bpf_jit_comp.c > +++ b/arch/x86/net/bpf_jit_comp.c > @@ -9,9 +9,11 @@ > #include > #include > #include > +#include > #include > #include > #include > +#include >=20 > static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) > { > @@ -487,6 +489,55 @@ static int emit_call(u8 **pprog, void *func, void *i= p) > return 0; > } >=20 > +int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, > + void *old_addr, void *new_addr) > +{ > + u8 old_insn[X86_CALL_SIZE] =3D {}; > + u8 new_insn[X86_CALL_SIZE] =3D {}; > + u8 *prog; > + int ret; > + > + if (!is_kernel_text((long)ip)) > + /* BPF trampoline in modules is not supported */ > + return -EINVAL; > + > + if (old_addr) { > + prog =3D old_insn; > + ret =3D emit_call(&prog, old_addr, (void *)ip); > + if (ret) > + return ret; > + } > + if (new_addr) { > + prog =3D new_insn; > + ret =3D emit_call(&prog, new_addr, (void *)ip); > + if (ret) > + return ret; > + } > + ret =3D -EBUSY; > + mutex_lock(&text_mutex); > + switch (t) { > + case BPF_MOD_NOP_TO_CALL: > + if (memcmp(ip, ideal_nops[NOP_ATOMIC5], X86_CALL_SIZE)) > + goto out; > + text_poke(ip, new_insn, X86_CALL_SIZE); > + break; > + case BPF_MOD_CALL_TO_CALL: > + if (memcmp(ip, old_insn, X86_CALL_SIZE)) > + goto out; > + text_poke(ip, new_insn, X86_CALL_SIZE); > + break; > + case BPF_MOD_CALL_TO_NOP: > + if (memcmp(ip, old_insn, X86_CALL_SIZE)) > + goto out; > + text_poke(ip, ideal_nops[NOP_ATOMIC5], X86_CALL_SIZE); > + break; > + } > + ret =3D 0; > +out: > + mutex_unlock(&text_mutex); > + return ret; > +} > + > static bool ex_handler_bpf(const struct exception_table_entry *x, > struct pt_regs *regs, int trapnr, > unsigned long error_code, unsigned long fault_addr) > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index 7c7f518811a6..8b90db25348a 100644 > --- a/include/linux/bpf.h > +++ b/include/linux/bpf.h > @@ -1157,4 +1157,12 @@ static inline u32 bpf_xdp_sock_convert_ctx_access(= enum bpf_access_type type, > } > #endif /* CONFIG_INET */ >=20 > +enum bpf_text_poke_type { > + BPF_MOD_NOP_TO_CALL, > + BPF_MOD_CALL_TO_CALL, > + BPF_MOD_CALL_TO_NOP, > +}; > +int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, > + void *addr1, void *addr2); > + > #endif /* _LINUX_BPF_H */ > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c > index c1fde0303280..c4bcec1014a9 100644 > --- a/kernel/bpf/core.c > +++ b/kernel/bpf/core.c > @@ -2140,6 +2140,12 @@ int __weak skb_copy_bits(const struct sk_buff *skb= , int offset, void *to, > return -EFAULT; > } >=20 > +int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, > + void *addr1, void *addr2) > +{ > + return -ENOTSUPP; > +} > + > DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); > EXPORT_SYMBOL(bpf_stats_enabled_key); >=20 > --=20 > 2.23.0 >=20