156 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright (c) 2017 Facebook3 */4#include <stdio.h>5#include <unistd.h>6#include <fcntl.h>7#include <stdlib.h>8#include <string.h>9#include <linux/perf_event.h>10#include <errno.h>11#include <bpf/libbpf.h>12#include <bpf/bpf.h>13 14/* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*.15 * This requires kernel CONFIG_FTRACE_SYSCALLS to be set.16 */17 18static void usage(const char *cmd)19{20 printf("USAGE: %s [-i nr_tests] [-h]\n", cmd);21 printf(" -i nr_tests # rounds of test to run\n");22 printf(" -h # help\n");23}24 25static void verify_map(int map_id)26{27 __u32 key = 0;28 __u32 val;29 30 if (bpf_map_lookup_elem(map_id, &key, &val) != 0) {31 fprintf(stderr, "map_lookup failed: %s\n", strerror(errno));32 return;33 }34 if (val == 0) {35 fprintf(stderr, "failed: map #%d returns value 0\n", map_id);36 return;37 }38 39 printf("verify map:%d val: %d\n", map_id, val);40 41 val = 0;42 if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) {43 fprintf(stderr, "map_update failed: %s\n", strerror(errno));44 return;45 }46}47 48static int test(char *filename, int nr_tests)49{50 int map0_fds[nr_tests], map1_fds[nr_tests], fd, i, j = 0;51 struct bpf_link **links = NULL;52 struct bpf_object *objs[nr_tests];53 struct bpf_program *prog;54 55 for (i = 0; i < nr_tests; i++) {56 objs[i] = bpf_object__open_file(filename, NULL);57 if (libbpf_get_error(objs[i])) {58 fprintf(stderr, "opening BPF object file failed\n");59 objs[i] = NULL;60 goto cleanup;61 }62 63 /* One-time initialization */64 if (!links) {65 int nr_progs = 0;66 67 bpf_object__for_each_program(prog, objs[i])68 nr_progs += 1;69 70 links = calloc(nr_progs * nr_tests, sizeof(struct bpf_link *));71 72 if (!links)73 goto cleanup;74 }75 76 /* load BPF program */77 if (bpf_object__load(objs[i])) {78 fprintf(stderr, "loading BPF object file failed\n");79 goto cleanup;80 }81 82 map0_fds[i] = bpf_object__find_map_fd_by_name(objs[i],83 "enter_open_map");84 map1_fds[i] = bpf_object__find_map_fd_by_name(objs[i],85 "exit_open_map");86 if (map0_fds[i] < 0 || map1_fds[i] < 0) {87 fprintf(stderr, "finding a map in obj file failed\n");88 goto cleanup;89 }90 91 bpf_object__for_each_program(prog, objs[i]) {92 links[j] = bpf_program__attach(prog);93 if (libbpf_get_error(links[j])) {94 fprintf(stderr, "bpf_program__attach failed\n");95 links[j] = NULL;96 goto cleanup;97 }98 j++;99 }100 printf("prog #%d: map ids %d %d\n", i, map0_fds[i], map1_fds[i]);101 }102 103 /* current load_bpf_file has perf_event_open default pid = -1104 * and cpu = 0, which permits attached bpf execution on105 * all cpus for all pid's. bpf program execution ignores106 * cpu affinity.107 */108 /* trigger some "open" operations */109 fd = open(filename, O_RDONLY);110 if (fd < 0) {111 fprintf(stderr, "open failed: %s\n", strerror(errno));112 return 1;113 }114 close(fd);115 116 /* verify the map */117 for (i = 0; i < nr_tests; i++) {118 verify_map(map0_fds[i]);119 verify_map(map1_fds[i]);120 }121 122cleanup:123 if (links) {124 for (j--; j >= 0; j--)125 bpf_link__destroy(links[j]);126 127 free(links);128 }129 130 for (i--; i >= 0; i--)131 bpf_object__close(objs[i]);132 return 0;133}134 135int main(int argc, char **argv)136{137 int opt, nr_tests = 1;138 char filename[256];139 140 while ((opt = getopt(argc, argv, "i:h")) != -1) {141 switch (opt) {142 case 'i':143 nr_tests = atoi(optarg);144 break;145 case 'h':146 default:147 usage(argv[0]);148 return 0;149 }150 }151 152 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);153 154 return test(filename, nr_tests);155}156