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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25A6FC0502A for ; Sun, 28 Aug 2022 02:54:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229694AbiH1Cyy (ORCPT ); Sat, 27 Aug 2022 22:54:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229493AbiH1Cyx (ORCPT ); Sat, 27 Aug 2022 22:54:53 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6CA54FD2F for ; Sat, 27 Aug 2022 19:54:51 -0700 (PDT) Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 27S2Dbgn011520 for ; Sat, 27 Aug 2022 19:54:51 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : content-type : content-transfer-encoding : mime-version; s=facebook; bh=KbYaRCHnm1bzRxS2TgbOqriUPFKT5PjElkgGFGqfLfE=; b=RJ6a/41YtXCj/jva+afmFHZhWQY7pMD7XDgcy7lY93b/DE3KUu/imBKbT1b51oHoy7R0 ninsbyCYO4f4hHq40inxqM/I5TGR88UtibG9+ZTWdmcPQ/Lxw1IGpUlc2Xv2zq+DQCb7 /wL7Jv0ZXNg5PFEmSxfasvgUVsIabQA8ACA= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3j7ekmuavw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Sat, 27 Aug 2022 19:54:51 -0700 Received: from twshared25017.14.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Sat, 27 Aug 2022 19:54:49 -0700 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 6FFB0EA747A8; Sat, 27 Aug 2022 19:54:38 -0700 (PDT) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Subject: [PATCH bpf-next v3 0/7] bpf: Support struct argument for trampoline base progs Date: Sat, 27 Aug 2022 19:54:38 -0700 Message-ID: <20220828025438.142798-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: PRBkPf9gXOl48pKT7rY9Do3GkGFAfj1L X-Proofpoint-GUID: PRBkPf9gXOl48pKT7rY9Do3GkGFAfj1L Content-Transfer-Encoding: quoted-printable X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-27_10,2022-08-25_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Currently struct arguments are not supported for trampoline based progs. One of major reason is that struct argument may pass by value which may use more than one registers. This breaks trampoline progs where each argument is assumed to take one register. bcc community reported the issue ([1]) where struct argument is not supported for fentry program. typedef struct { uid_t val; } kuid_t; typedef struct { gid_t val; } kgid_t; int security_path_chown(struct path *path, kuid_t uid, kgid_t gid); Inside Meta, we also have a use case to attach to tcp_setsockopt() typedef struct { union {=20 void *kernel; void __user *user; }; bool is_kernel : 1; } sockptr_t; int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, unsigned int optlen); This patch added struct value support for bpf tracing programs which uses trampoline. Only <=3D 16 byte struct size is supported for now which covers use cases in the above. For x86/arm64/bpf, <=3D 16 struct value will be passed in registers instead of by reference. Only x86_64 is supported in this patch. arm64 support can be added later. [1] https://github.com/iovisor/bcc/issues/3657 Changelog: v2 -> v3: - previously struct arguments (<=3D 16 bytes) are passed by reference for bpf programs. Suggested by Alexei, it is passed by value now. - in order to support passing <=3D 16 struct value, a new macro BPF_PROG2 is invented. rfc v1 -> v2: - changed bpf_func_model struct info fields to arg_flags[] to make it easy to iterate arguments in arch specific {save|restore}_regs() functions. - added fexit tests to test return values with struct arguments. Yonghong Song (7): bpf: Allow struct argument in trampoline based programs bpf: x86: Support in-register struct arguments in trampoline programs bpf: Update descriptions for helpers bpf_get_func_arg[_cnt]() bpf: arm64: No support of struct argument in trampoline programs libbpf: Add new BPF_PROG2 macro selftests/bpf: Add struct argument tests with fentry/fexit programs. selftests/bpf: Use BPF_PROG2 for some fentry programs without struct arguments arch/arm64/net/bpf_jit_comp.c | 8 +- arch/x86/net/bpf_jit_comp.c | 68 ++++++++--- include/linux/bpf.h | 4 + include/uapi/linux/bpf.h | 9 +- kernel/bpf/btf.c | 42 ++++++- tools/include/uapi/linux/bpf.h | 9 +- tools/lib/bpf/bpf_tracing.h | 82 +++++++++++++ .../selftests/bpf/bpf_testmod/bpf_testmod.c | 48 ++++++++ .../selftests/bpf/prog_tests/tracing_struct.c | 63 ++++++++++ tools/testing/selftests/bpf/progs/timer.c | 4 +- .../selftests/bpf/progs/tracing_struct.c | 114 ++++++++++++++++++ 11 files changed, 417 insertions(+), 34 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/tracing_struct.c create mode 100644 tools/testing/selftests/bpf/progs/tracing_struct.c --=20 2.30.2