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 CA64AC433FE for ; Sat, 5 Mar 2022 01:01:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229589AbiCEBCb convert rfc822-to-8bit (ORCPT ); Fri, 4 Mar 2022 20:02:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229479AbiCEBC2 (ORCPT ); Fri, 4 Mar 2022 20:02:28 -0500 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C4E01AE66B for ; Fri, 4 Mar 2022 17:01:39 -0800 (PST) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 224HQQib015606 for ; Fri, 4 Mar 2022 17:01:39 -0800 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3ek4jkscqf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 04 Mar 2022 17:01:38 -0800 Received: from twshared2439.42.prn1.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:11d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Fri, 4 Mar 2022 17:01:38 -0800 Received: by devbig019.vll3.facebook.com (Postfix, from userid 137359) id 4A7DA132C9938; Fri, 4 Mar 2022 17:01:36 -0800 (PST) From: Andrii Nakryiko To: , , CC: , , Alan Maguire Subject: [PATCH v5 bpf-next 3/3] selftests/bpf: add custom SEC() handling selftest Date: Fri, 4 Mar 2022 17:01:29 -0800 Message-ID: <20220305010129.1549719-4-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220305010129.1549719-1-andrii@kernel.org> References: <20220305010129.1549719-1-andrii@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: RStdWeTTfZ08UmYYfOa3LUj1H3w9CNrU X-Proofpoint-ORIG-GUID: RStdWeTTfZ08UmYYfOa3LUj1H3w9CNrU X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-03-04_09,2022-03-04_01,2022-02-23_01 X-Proofpoint-Spam-Details: rule=fb_outbound_notspam policy=fb_outbound score=0 malwarescore=0 mlxlogscore=999 clxscore=1015 priorityscore=1501 adultscore=0 phishscore=0 suspectscore=0 spamscore=0 lowpriorityscore=0 mlxscore=0 bulkscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000 definitions=main-2203050002 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add a selftest validating various aspects of libbpf's handling of custom SEC() handlers. It also demonstrates how libraries can ensure very early callbacks registration and unregistration using __attribute__((constructor))/__attribute__((destructor)) functions. Reviewed-by: Alan Maguire Tested-by: Alan Maguire Signed-off-by: Andrii Nakryiko --- .../bpf/prog_tests/custom_sec_handlers.c | 176 ++++++++++++++++++ .../bpf/progs/test_custom_sec_handlers.c | 63 +++++++ 2 files changed, 239 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/custom_sec_handlers.c create mode 100644 tools/testing/selftests/bpf/progs/test_custom_sec_handlers.c diff --git a/tools/testing/selftests/bpf/prog_tests/custom_sec_handlers.c b/tools/testing/selftests/bpf/prog_tests/custom_sec_handlers.c new file mode 100644 index 000000000000..b2dfc5954aea --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/custom_sec_handlers.c @@ -0,0 +1,176 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Facebook */ + +#include +#include "test_custom_sec_handlers.skel.h" + +#define COOKIE_ABC1 1 +#define COOKIE_ABC2 2 +#define COOKIE_CUSTOM 3 +#define COOKIE_FALLBACK 4 +#define COOKIE_KPROBE 5 + +static int custom_setup_prog(struct bpf_program *prog, long cookie) +{ + if (cookie == COOKIE_ABC1) + bpf_program__set_autoload(prog, false); + + return 0; +} + +static int custom_prepare_load_prog(struct bpf_program *prog, + struct bpf_prog_load_opts *opts, long cookie) +{ + if (cookie == COOKIE_FALLBACK) + opts->prog_flags |= BPF_F_SLEEPABLE; + else if (cookie == COOKIE_ABC1) + ASSERT_FALSE(true, "unexpected preload for abc"); + + return 0; +} + +static int custom_attach_prog(const struct bpf_program *prog, long cookie, + struct bpf_link **link) +{ + switch (cookie) { + case COOKIE_ABC2: + *link = bpf_program__attach_raw_tracepoint(prog, "sys_enter"); + return libbpf_get_error(*link); + case COOKIE_CUSTOM: + *link = bpf_program__attach_tracepoint(prog, "syscalls", "sys_enter_nanosleep"); + return libbpf_get_error(*link); + case COOKIE_KPROBE: + case COOKIE_FALLBACK: + /* no auto-attach for SEC("xyz") and SEC("kprobe") */ + *link = NULL; + return 0; + default: + ASSERT_FALSE(true, "unexpected cookie"); + return -EINVAL; + } +} + +static int abc1_id; +static int abc2_id; +static int custom_id; +static int fallback_id; +static int kprobe_id; + +__attribute__((constructor)) +static void register_sec_handlers(void) +{ + LIBBPF_OPTS(libbpf_prog_handler_opts, abc1_opts, + .cookie = COOKIE_ABC1, + .prog_setup_fn = custom_setup_prog, + .prog_prepare_load_fn = custom_prepare_load_prog, + .prog_attach_fn = NULL, + ); + LIBBPF_OPTS(libbpf_prog_handler_opts, abc2_opts, + .cookie = COOKIE_ABC2, + .prog_setup_fn = custom_setup_prog, + .prog_prepare_load_fn = custom_prepare_load_prog, + .prog_attach_fn = custom_attach_prog, + ); + LIBBPF_OPTS(libbpf_prog_handler_opts, custom_opts, + .cookie = COOKIE_CUSTOM, + .prog_setup_fn = NULL, + .prog_prepare_load_fn = NULL, + .prog_attach_fn = custom_attach_prog, + ); + + abc1_id = libbpf_register_prog_handler("abc", BPF_PROG_TYPE_RAW_TRACEPOINT, 0, &abc1_opts); + abc2_id = libbpf_register_prog_handler("abc/", BPF_PROG_TYPE_RAW_TRACEPOINT, 0, &abc2_opts); + custom_id = libbpf_register_prog_handler("custom+", BPF_PROG_TYPE_TRACEPOINT, 0, &custom_opts); +} + +__attribute__((destructor)) +static void unregister_sec_handlers(void) +{ + libbpf_unregister_prog_handler(abc1_id); + libbpf_unregister_prog_handler(abc2_id); + libbpf_unregister_prog_handler(custom_id); +} + +void test_custom_sec_handlers(void) +{ + LIBBPF_OPTS(libbpf_prog_handler_opts, opts, + .prog_setup_fn = custom_setup_prog, + .prog_prepare_load_fn = custom_prepare_load_prog, + .prog_attach_fn = custom_attach_prog, + ); + struct test_custom_sec_handlers* skel; + int err; + + ASSERT_GT(abc1_id, 0, "abc1_id"); + ASSERT_GT(abc2_id, 0, "abc2_id"); + ASSERT_GT(custom_id, 0, "custom_id"); + + /* override libbpf's handle of SEC("kprobe/...") but also allow pure + * SEC("kprobe") due to "kprobe+" specifier. Register it as + * TRACEPOINT, just for fun. + */ + opts.cookie = COOKIE_KPROBE; + kprobe_id = libbpf_register_prog_handler("kprobe+", BPF_PROG_TYPE_TRACEPOINT, 0, &opts); + /* fallback treats everything as BPF_PROG_TYPE_SYSCALL program to test + * setting custom BPF_F_SLEEPABLE bit in preload handler + */ + opts.cookie = COOKIE_FALLBACK; + fallback_id = libbpf_register_prog_handler(NULL, BPF_PROG_TYPE_SYSCALL, 0, &opts); + + if (!ASSERT_GT(fallback_id, 0, "fallback_id") /* || !ASSERT_GT(kprobe_id, 0, "kprobe_id")*/) { + if (fallback_id > 0) + libbpf_unregister_prog_handler(fallback_id); + if (kprobe_id > 0) + libbpf_unregister_prog_handler(kprobe_id); + return; + } + + /* open skeleton and validate assumptions */ + skel = test_custom_sec_handlers__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + goto cleanup; + + ASSERT_EQ(bpf_program__type(skel->progs.abc1), BPF_PROG_TYPE_RAW_TRACEPOINT, "abc1_type"); + ASSERT_FALSE(bpf_program__autoload(skel->progs.abc1), "abc1_autoload"); + + ASSERT_EQ(bpf_program__type(skel->progs.abc2), BPF_PROG_TYPE_RAW_TRACEPOINT, "abc2_type"); + ASSERT_EQ(bpf_program__type(skel->progs.custom1), BPF_PROG_TYPE_TRACEPOINT, "custom1_type"); + ASSERT_EQ(bpf_program__type(skel->progs.custom2), BPF_PROG_TYPE_TRACEPOINT, "custom2_type"); + ASSERT_EQ(bpf_program__type(skel->progs.kprobe1), BPF_PROG_TYPE_TRACEPOINT, "kprobe1_type"); + ASSERT_EQ(bpf_program__type(skel->progs.xyz), BPF_PROG_TYPE_SYSCALL, "xyz_type"); + + skel->rodata->my_pid = getpid(); + + /* now attempt to load everything */ + err = test_custom_sec_handlers__load(skel); + if (!ASSERT_OK(err, "skel_load")) + goto cleanup; + + /* now try to auto-attach everything */ + err = test_custom_sec_handlers__attach(skel); + if (!ASSERT_OK(err, "skel_attach")) + goto cleanup; + + skel->links.xyz = bpf_program__attach(skel->progs.kprobe1); + ASSERT_EQ(errno, EOPNOTSUPP, "xyz_attach_err"); + ASSERT_ERR_PTR(skel->links.xyz, "xyz_attach"); + + /* trigger programs */ + usleep(1); + + /* SEC("abc") is set to not auto-loaded */ + ASSERT_FALSE(skel->bss->abc1_called, "abc1_called"); + ASSERT_TRUE(skel->bss->abc2_called, "abc2_called"); + ASSERT_TRUE(skel->bss->custom1_called, "custom1_called"); + ASSERT_TRUE(skel->bss->custom2_called, "custom2_called"); + /* SEC("kprobe") shouldn't be auto-attached */ + ASSERT_FALSE(skel->bss->kprobe1_called, "kprobe1_called"); + /* SEC("xyz") shouldn't be auto-attached */ + ASSERT_FALSE(skel->bss->xyz_called, "xyz_called"); + +cleanup: + test_custom_sec_handlers__destroy(skel); + + ASSERT_OK(libbpf_unregister_prog_handler(fallback_id), "unregister_fallback"); + ASSERT_OK(libbpf_unregister_prog_handler(kprobe_id), "unregister_kprobe"); +} diff --git a/tools/testing/selftests/bpf/progs/test_custom_sec_handlers.c b/tools/testing/selftests/bpf/progs/test_custom_sec_handlers.c new file mode 100644 index 000000000000..4061f701ca50 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_custom_sec_handlers.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Facebook */ + +#include "vmlinux.h" +#include +#include + +const volatile int my_pid; + +bool abc1_called; +bool abc2_called; +bool custom1_called; +bool custom2_called; +bool kprobe1_called; +bool xyz_called; + +SEC("abc") +int abc1(void *ctx) +{ + abc1_called = true; + return 0; +} + +SEC("abc/whatever") +int abc2(void *ctx) +{ + abc2_called = true; + return 0; +} + +SEC("custom") +int custom1(void *ctx) +{ + custom1_called = true; + return 0; +} + +SEC("custom/something") +int custom2(void *ctx) +{ + custom2_called = true; + return 0; +} + +SEC("kprobe") +int kprobe1(void *ctx) +{ + kprobe1_called = true; + return 0; +} + +SEC("xyz/blah") +int xyz(void *ctx) +{ + int whatever; + + /* use sleepable helper, custom handler should set sleepable flag */ + bpf_copy_from_user(&whatever, sizeof(whatever), NULL); + xyz_called = true; + return 0; +} + +char _license[] SEC("license") = "GPL"; -- 2.30.2