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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8F8CC433F5 for ; Wed, 29 Sep 2021 03:30:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E0F8613CE for ; Wed, 29 Sep 2021 03:30:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242625AbhI2Dbq (ORCPT ); Tue, 28 Sep 2021 23:31:46 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:35460 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243349AbhI2Dbq (ORCPT ); Tue, 28 Sep 2021 23:31:46 -0400 Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 18SM2GD7029081 for ; Tue, 28 Sep 2021 20:30:05 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=xxyXBtLFlaDvXgtPB9efuwFpfhNbW9tujO822tjJ2Hs=; b=ARCkobavGTkwKup0y0ihkgQaveDj2soVGbYAPipL/sxHdhzOKP2Nc3IpilnFN81pNwOB fCFp+LU2jIAA2oHZ6nJ8Mu1VlA9xb9jd1lPlSZtGBgC9s2BMdyyNwr7Q2uMhZQLcQ0mK 6fDeAvH5WgcX2HrB/jWO+Pl9L5UCpcaAa90= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 3bcbfespqt-10 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 28 Sep 2021 20:30:05 -0700 Received: from intmgw006.03.ash8.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.14; Tue, 28 Sep 2021 20:30:02 -0700 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 485F06A0395; Tue, 28 Sep 2021 20:30:00 -0700 (PDT) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Subject: [PATCH bpf-next v2] selftests/bpf: fix probe_user test failure with clang build kernel Date: Tue, 28 Sep 2021 20:30:00 -0700 Message-ID: <20210929033000.3711921-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-FB-Source: Intern X-Proofpoint-ORIG-GUID: tsECoRAuLsWhXcYTo9yri45lxCjP_JK0 X-Proofpoint-GUID: tsECoRAuLsWhXcYTo9yri45lxCjP_JK0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.391,FMLib:17.0.607.475 definitions=2021-09-29_01,2021-09-28_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 mlxlogscore=667 impostorscore=0 priorityscore=1501 lowpriorityscore=0 clxscore=1015 phishscore=0 spamscore=0 malwarescore=0 suspectscore=0 bulkscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109230001 definitions=main-2109290020 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org clang build kernel failed the selftest probe_user. $ ./test_progs -t probe_user $ ... $ test_probe_user:PASS:get_kprobe_res 0 nsec $ test_probe_user:FAIL:check_kprobe_res wrong kprobe res from probe rea= d: 0.0.0.0:0 $ #94 probe_user:FAIL The test attached to kernel function __sys_connect(). In net/socket.c, we= have int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrle= n) { ...... } ... SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr, int, addrlen) { return __sys_connect(fd, uservaddr, addrlen); } The gcc compiler (8.5.0) does not inline __sys_connect() in syscall entry function. But latest clang trunk did the inlining. So the bpf program is not triggered. To make the test more reliable, let us kprobe the syscall entry function instead. Note that x86_64, arm64 and s390 have syscall wrappers and they = have to be handled specially. Signed-off-by: Yonghong Song --- .../selftests/bpf/prog_tests/probe_user.c | 4 +-- .../selftests/bpf/progs/test_probe_user.c | 28 +++++++++++++++++-- 2 files changed, 28 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/probe_user.c b/tools/= testing/selftests/bpf/prog_tests/probe_user.c index 95bd12097358..52fe157e2a90 100644 --- a/tools/testing/selftests/bpf/prog_tests/probe_user.c +++ b/tools/testing/selftests/bpf/prog_tests/probe_user.c @@ -3,7 +3,7 @@ =20 void test_probe_user(void) { - const char *prog_name =3D "kprobe/__sys_connect"; + const char *prog_name =3D "handle_sys_connect"; const char *obj_file =3D "./test_probe_user.o"; DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, ); int err, results_map_fd, sock_fd, duration =3D 0; @@ -18,7 +18,7 @@ void test_probe_user(void) if (!ASSERT_OK_PTR(obj, "obj_open_file")) return; =20 - kprobe_prog =3D bpf_object__find_program_by_title(obj, prog_name); + kprobe_prog =3D bpf_object__find_program_by_name(obj, prog_name); if (CHECK(!kprobe_prog, "find_probe", "prog '%s' not found\n", prog_name)) goto cleanup; diff --git a/tools/testing/selftests/bpf/progs/test_probe_user.c b/tools/= testing/selftests/bpf/progs/test_probe_user.c index 89b3532ccc75..8812a90da4eb 100644 --- a/tools/testing/selftests/bpf/progs/test_probe_user.c +++ b/tools/testing/selftests/bpf/progs/test_probe_user.c @@ -8,13 +8,37 @@ #include #include =20 +#if defined(__TARGET_ARCH_x86) +#define SYSCALL_WRAPPER 1 +#define SYS_PREFIX "__x64_" +#elif defined(__TARGET_ARCH_s390) +#define SYSCALL_WRAPPER 1 +#define SYS_PREFIX "__s390x_" +#elif defined(__TARGET_ARCH_arm64) +#define SYSCALL_WRAPPER 1 +#define SYS_PREFIX "__arm64_" +#else +#define SYSCALL_WRAPPER 0 +#define SYS_PREFIX "" +#endif + static struct sockaddr_in old; =20 -SEC("kprobe/__sys_connect") +SEC("kprobe/" SYS_PREFIX "sys_connect") int BPF_KPROBE(handle_sys_connect) { - void *ptr =3D (void *)PT_REGS_PARM2(ctx); +#if SYSCALL_WRAPPER =3D=3D 1 + struct pt_regs *real_regs; +#endif struct sockaddr_in new; + void *ptr; + +#if SYSCALL_WRAPPER =3D=3D 0 + ptr =3D (void *)PT_REGS_PARM2(ctx); +#else + real_regs =3D (struct pt_regs *)PT_REGS_PARM1(ctx); + bpf_probe_read_kernel(&ptr, sizeof(ptr), &PT_REGS_PARM2(real_regs)); +#endif =20 bpf_probe_read_user(&old, sizeof(old), ptr); __builtin_memset(&new, 0xab, sizeof(new)); --=20 2.30.2