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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 6106BC43603 for ; Sat, 14 Dec 2019 01:47:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 463BF2077B for ; Sat, 14 Dec 2019 01:47:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="fEkzVENH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726777AbfLNBrX (ORCPT ); Fri, 13 Dec 2019 20:47:23 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:49204 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726668AbfLNBrX (ORCPT ); Fri, 13 Dec 2019 20:47:23 -0500 Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xBE1is8N030365 for ; Fri, 13 Dec 2019 17:47:22 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=bBXZ63a9rcKujy+xrzoX4Ykj/zksbnlYCqcC/OGosQY=; b=fEkzVENHtQuxi71qaCURAsDaCJ37tHZiMg/MX5e1D5hi64v4SXJvhbOHQcFAJJ6lOmIv i8CQN8Hlpt21IWv4P8wgPkFIQCHKokfntPKQa0+tBrsZJKYJebsolBh7RShi5qq41BjH 6mUvyFDBzUmYTXSMDwRtkHr9FTOtpdwY0q0= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 2wv1r0w2vc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 13 Dec 2019 17:47:22 -0800 Received: from intmgw001.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Fri, 13 Dec 2019 17:47:21 -0800 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 1BB112EC1D7C; Fri, 13 Dec 2019 17:47:21 -0800 (PST) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v4 bpf-next 4/4] selftests/bpf: add tests for libbpf-provided externs Date: Fri, 13 Dec 2019 17:47:10 -0800 Message-ID: <20191214014710.3449601-5-andriin@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191214014710.3449601-1-andriin@fb.com> References: <20191214014710.3449601-1-andriin@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-13_09:2019-12-13,2019-12-13 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 priorityscore=1501 clxscore=1015 bulkscore=0 spamscore=0 mlxscore=0 lowpriorityscore=0 malwarescore=0 impostorscore=0 phishscore=0 mlxlogscore=999 suspectscore=8 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912140007 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add a set of tests validating libbpf-provided extern variables. One crucial feature that's tested is dead code elimination together with using invalid BPF helper. CONFIG_MISSING is not supposed to exist and should always be specified by libbpf as zero, which allows BPF verifier to correctly do branch pruning and not fail validation, when invalid BPF helper is called from dead if branch. Signed-off-by: Andrii Nakryiko --- .../selftests/bpf/prog_tests/core_extern.c | 195 ++++++++++++++++++ .../selftests/bpf/prog_tests/skeleton.c | 18 +- .../selftests/bpf/progs/test_core_extern.c | 62 ++++++ .../selftests/bpf/progs/test_skeleton.c | 9 + 4 files changed, 283 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/core_extern.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_extern.c diff --git a/tools/testing/selftests/bpf/prog_tests/core_extern.c b/tools/testing/selftests/bpf/prog_tests/core_extern.c new file mode 100644 index 000000000000..30a7972e9012 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/core_extern.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Facebook */ + +#include +#include +#include +#include +#include "test_core_extern.skel.h" + +static uint32_t get_kernel_version(void) +{ + uint32_t major, minor, patch; + struct utsname info; + + uname(&info); + if (sscanf(info.release, "%u.%u.%u", &major, &minor, &patch) != 3) + return 0; + return KERNEL_VERSION(major, minor, patch); +} + +#define CFG "CONFIG_BPF_SYSCALL=n\n" + +static struct test_case { + const char *name; + const char *cfg; + const char *cfg_path; + bool fails; + struct test_core_extern__data data; +} test_cases[] = { + { .name = "default search path", .cfg_path = NULL, + .data = { .bpf_syscall = true } }, + { .name = "/proc/config.gz", .cfg_path = "/proc/config.gz", + .data = { .bpf_syscall = true } }, + { .name = "missing config", .fails = true, + .cfg_path = "/proc/invalid-config.gz" }, + { + .name = "custom values", + .cfg = "CONFIG_BPF_SYSCALL=y\n" + "CONFIG_TRISTATE=m\n" + "CONFIG_BOOL=y\n" + "CONFIG_CHAR=100\n" + "CONFIG_USHORT=30000\n" + "CONFIG_INT=123456\n" + "CONFIG_ULONG=0xDEADBEEFC0DE\n" + "CONFIG_STR=\"abracad\"\n" + "CONFIG_MISSING=0", + .data = { + .bpf_syscall = true, + .tristate_val = TRI_MODULE, + .bool_val = true, + .char_val = 100, + .ushort_val = 30000, + .int_val = 123456, + .ulong_val = 0xDEADBEEFC0DE, + .str_val = "abracad", + }, + }, + /* TRISTATE */ + { .name = "tristate (y)", .cfg = CFG"CONFIG_TRISTATE=y\n", + .data = { .tristate_val = TRI_YES } }, + { .name = "tristate (n)", .cfg = CFG"CONFIG_TRISTATE=n\n", + .data = { .tristate_val = TRI_NO } }, + { .name = "tristate (m)", .cfg = CFG"CONFIG_TRISTATE=m\n", + .data = { .tristate_val = TRI_MODULE } }, + { .name = "tristate (int)", .fails = 1, .cfg = CFG"CONFIG_TRISTATE=1" }, + { .name = "tristate (bad)", .fails = 1, .cfg = CFG"CONFIG_TRISTATE=M" }, + /* BOOL */ + { .name = "bool (y)", .cfg = CFG"CONFIG_BOOL=y\n", + .data = { .bool_val = true } }, + { .name = "bool (n)", .cfg = CFG"CONFIG_BOOL=n\n", + .data = { .bool_val = false } }, + { .name = "bool (tristate)", .fails = 1, .cfg = CFG"CONFIG_BOOL=m" }, + { .name = "bool (int)", .fails = 1, .cfg = CFG"CONFIG_BOOL=1" }, + /* CHAR */ + { .name = "char (tristate)", .cfg = CFG"CONFIG_CHAR=m\n", + .data = { .char_val = 'm' } }, + { .name = "char (bad)", .fails = 1, .cfg = CFG"CONFIG_CHAR=q\n" }, + { .name = "char (empty)", .fails = 1, .cfg = CFG"CONFIG_CHAR=\n" }, + { .name = "char (str)", .fails = 1, .cfg = CFG"CONFIG_CHAR=\"y\"\n" }, + /* STRING */ + { .name = "str (empty)", .cfg = CFG"CONFIG_STR=\"\"\n", + .data = { .str_val = "\0\0\0\0\0\0\0" } }, + { .name = "str (padded)", .cfg = CFG"CONFIG_STR=\"abra\"\n", + .data = { .str_val = "abra\0\0\0" } }, + { .name = "str (too long)", .cfg = CFG"CONFIG_STR=\"abracada\"\n", + .data = { .str_val = "abracad" } }, + { .name = "str (no value)", .fails = 1, .cfg = CFG"CONFIG_STR=\n" }, + { .name = "str (bad value)", .fails = 1, .cfg = CFG"CONFIG_STR=bla\n" }, + /* INTEGERS */ + { + .name = "integer forms", + .cfg = CFG + "CONFIG_CHAR=0xA\n" + "CONFIG_USHORT=0462\n" + "CONFIG_INT=-100\n" + "CONFIG_ULONG=+1000000000000", + .data = { + .char_val = 0xA, + .ushort_val = 0462, + .int_val = -100, + .ulong_val = 1000000000000, + }, + }, + { .name = "int (bad)", .fails = 1, .cfg = CFG"CONFIG_INT=abc" }, + { .name = "int (str)", .fails = 1, .cfg = CFG"CONFIG_INT=\"abc\"" }, + { .name = "int (empty)", .fails = 1, .cfg = CFG"CONFIG_INT=" }, + { .name = "int (mixed)", .fails = 1, .cfg = CFG"CONFIG_INT=123abc" }, + { .name = "int (max)", .cfg = CFG"CONFIG_INT=2147483647", + .data = { .int_val = 2147483647 } }, + { .name = "int (min)", .cfg = CFG"CONFIG_INT=-2147483648", + .data = { .int_val = -2147483648 } }, + { .name = "int (max+1)", .fails = 1, .cfg = CFG"CONFIG_INT=2147483648" }, + { .name = "int (min-1)", .fails = 1, .cfg = CFG"CONFIG_INT=-2147483649" }, + { .name = "ushort (max)", .cfg = CFG"CONFIG_USHORT=65535", + .data = { .ushort_val = 65535 } }, + { .name = "ushort (min)", .cfg = CFG"CONFIG_USHORT=0", + .data = { .ushort_val = 0 } }, + { .name = "ushort (max+1)", .fails = 1, .cfg = CFG"CONFIG_USHORT=65536" }, + { .name = "ushort (min-1)", .fails = 1, .cfg = CFG"CONFIG_USHORT=-1" }, + { .name = "u64 (max)", .cfg = CFG"CONFIG_ULONG=0xffffffffffffffff", + .data = { .ulong_val = 0xffffffffffffffff } }, + { .name = "u64 (min)", .cfg = CFG"CONFIG_ULONG=0", + .data = { .ulong_val = 0 } }, + { .name = "u64 (max+1)", .fails = 1, .cfg = CFG"CONFIG_ULONG=0x10000000000000000" }, +}; + +BPF_EMBED_OBJ(core_extern, "test_core_extern.o"); + +void test_core_extern(void) +{ + const uint32_t kern_ver = get_kernel_version(); + int err, duration = 0, i, j; + struct test_core_extern *skel = NULL; + uint64_t *got, *exp; + int n = sizeof(*skel->data) / sizeof(uint64_t); + + for (i = 0; i < ARRAY_SIZE(test_cases); i++) { + char tmp_cfg_path[] = "/tmp/test_core_extern_cfg.XXXXXX"; + struct test_case *t = &test_cases[i]; + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, + .kconfig_path = t->cfg_path, + ); + + if (!test__start_subtest(t->name)) + continue; + + if (t->cfg) { + size_t n = strlen(t->cfg) + 1; + int fd = mkstemp(tmp_cfg_path); + int written; + + if (CHECK(fd < 0, "mkstemp", "errno: %d\n", errno)) + continue; + printf("using '%s' as config file\n", tmp_cfg_path); + written = write(fd, t->cfg, n); + close(fd); + if (CHECK_FAIL(written != n)) + goto cleanup; + opts.kconfig_path = tmp_cfg_path; + } + + skel = test_core_extern__open_opts(&core_extern_embed, &opts); + if (CHECK(!skel, "skel_open", "skeleton open failed\n")) + goto cleanup; + err = test_core_extern__load(skel); + if (t->fails) { + CHECK(!err, "skel_load", + "shouldn't succeed open/load of skeleton\n"); + goto cleanup; + } else if (CHECK(err, "skel_load", + "failed to open/load skeleton\n")) { + goto cleanup; + } + err = test_core_extern__attach(skel); + if (CHECK(err, "attach_raw_tp", "failed attach: %d\n", err)) + goto cleanup; + + usleep(1); + + t->data.kern_ver = kern_ver; + t->data.missing_val = 0xDEADC0DE; + got = (uint64_t *)skel->data; + exp = (uint64_t *)&t->data; + for (j = 0; j < n; j++) { + CHECK(got[j] != exp[j], "check_res", + "result #%d: expected %lx, but got %lx\n", + j, exp[j], got[j]); + } +cleanup: + if (t->cfg) + unlink(tmp_cfg_path); + test_core_extern__destroy(skel); + skel = NULL; + } +} diff --git a/tools/testing/selftests/bpf/prog_tests/skeleton.c b/tools/testing/selftests/bpf/prog_tests/skeleton.c index 79f8d13e6740..151cdad3ad0d 100644 --- a/tools/testing/selftests/bpf/prog_tests/skeleton.c +++ b/tools/testing/selftests/bpf/prog_tests/skeleton.c @@ -17,11 +17,21 @@ void test_skeleton(void) int duration = 0, err; struct test_skeleton* skel; struct test_skeleton__bss *bss; + struct test_skeleton__externs *exts; - skel = test_skeleton__open_and_load(&skeleton_embed); + skel = test_skeleton__open(&skeleton_embed); if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) return; + printf("EXTERNS BEFORE: %p\n", skel->externs); + if (CHECK(skel->externs, "skel_externs", "externs are mmaped()!\n")) + goto cleanup; + + err = test_skeleton__load(skel); + if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err)) + goto cleanup; + printf("EXTERNS AFTER: %p\n", skel->externs); + bss = skel->bss; bss->in1 = 1; bss->in2 = 2; @@ -29,6 +39,7 @@ void test_skeleton(void) bss->in4 = 4; bss->in5.a = 5; bss->in5.b = 6; + exts = skel->externs; err = test_skeleton__attach(skel); if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) @@ -46,6 +57,11 @@ void test_skeleton(void) CHECK(bss->handler_out5.b != 6, "res6", "got %lld != exp %d\n", bss->handler_out5.b, 6); + CHECK(bss->bpf_syscall != exts->CONFIG_BPF_SYSCALL, "ext1", + "got %d != exp %d\n", bss->bpf_syscall, exts->CONFIG_BPF_SYSCALL); + CHECK(bss->kern_ver != exts->LINUX_KERNEL_VERSION, "ext2", + "got %d != exp %d\n", bss->kern_ver, exts->LINUX_KERNEL_VERSION); + cleanup: test_skeleton__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/test_core_extern.c b/tools/testing/selftests/bpf/progs/test_core_extern.c new file mode 100644 index 000000000000..e12f09f9e881 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_core_extern.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Facebook */ + +#include +#include +#include +#include +#include "bpf_helpers.h" + +/* non-existing BPF helper, to test dead code elimination */ +static int (*bpf_missing_helper)(const void *arg1, int arg2) = (void *) 999; + +extern int LINUX_KERNEL_VERSION; +extern bool CONFIG_BPF_SYSCALL; /* strong */ +extern enum libbpf_tristate CONFIG_TRISTATE __weak; +extern bool CONFIG_BOOL __weak; +extern char CONFIG_CHAR __weak; +extern uint16_t CONFIG_USHORT __weak; +extern int CONFIG_INT __weak; +extern uint64_t CONFIG_ULONG __weak; +extern const char CONFIG_STR[8] __weak; +extern uint64_t CONFIG_MISSING __weak; + +uint64_t kern_ver = -1; +uint64_t bpf_syscall = -1; +uint64_t tristate_val = -1; +uint64_t bool_val = -1; +uint64_t char_val = -1; +uint64_t ushort_val = -1; +uint64_t int_val = -1; +uint64_t ulong_val = -1; +char str_val[8] = {-1, -1, -1, -1, -1, -1, -1, -1}; +uint64_t missing_val = -1; + +SEC("raw_tp/sys_enter") +int handle_sys_enter(struct pt_regs *ctx) +{ + int i; + + kern_ver = LINUX_KERNEL_VERSION; + bpf_syscall = CONFIG_BPF_SYSCALL; + tristate_val = CONFIG_TRISTATE; + bool_val = CONFIG_BOOL; + char_val = CONFIG_CHAR; + ushort_val = CONFIG_USHORT; + int_val = CONFIG_INT; + ulong_val = CONFIG_ULONG; + + for (i = 0; i < sizeof(CONFIG_STR); i++) { + str_val[i] = CONFIG_STR[i]; + } + + if (CONFIG_MISSING) + /* invalid, but dead code - never executed */ + missing_val = bpf_missing_helper(ctx, 123); + else + missing_val = 0xDEADC0DE; + + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_skeleton.c b/tools/testing/selftests/bpf/progs/test_skeleton.c index c0013d2e16f2..9caa44758ea2 100644 --- a/tools/testing/selftests/bpf/progs/test_skeleton.c +++ b/tools/testing/selftests/bpf/progs/test_skeleton.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2019 Facebook */ +#include #include #include "bpf_helpers.h" @@ -20,6 +21,10 @@ char out3 = 0; long long out4 = 0; int out1 = 0; +extern bool CONFIG_BPF_SYSCALL; +extern int LINUX_KERNEL_VERSION; +bool bpf_syscall = 0; +int kern_ver = 0; SEC("raw_tp/sys_enter") int handler(const void *ctx) @@ -31,6 +36,10 @@ int handler(const void *ctx) out3 = in3; out4 = in4; out5 = in5; + + bpf_syscall = CONFIG_BPF_SYSCALL; + kern_ver = LINUX_KERNEL_VERSION; + return 0; } -- 2.17.1