1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2017 Facebook 3 */ 4 #include <stdio.h> 5 #include <unistd.h> 6 #include <fcntl.h> 7 #include <stdlib.h> 8 #include <signal.h> 9 #include <linux/bpf.h> 10 #include <string.h> 11 #include <linux/perf_event.h> 12 #include <errno.h> 13 #include <assert.h> 14 #include <stdbool.h> 15 #include <sys/resource.h> 16 #include <bpf/bpf.h> 17 #include "bpf_load.h" 18 19 /* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*. 20 * This requires kernel CONFIG_FTRACE_SYSCALLS to be set. 21 */ 22 23 static void usage(const char *cmd) 24 { 25 printf("USAGE: %s [-i num_progs] [-h]\n", cmd); 26 printf(" -i num_progs # number of progs of the test\n"); 27 printf(" -h # help\n"); 28 } 29 30 static void verify_map(int map_id) 31 { 32 __u32 key = 0; 33 __u32 val; 34 35 if (bpf_map_lookup_elem(map_id, &key, &val) != 0) { 36 fprintf(stderr, "map_lookup failed: %s\n", strerror(errno)); 37 return; 38 } 39 if (val == 0) { 40 fprintf(stderr, "failed: map #%d returns value 0\n", map_id); 41 return; 42 } 43 val = 0; 44 if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) { 45 fprintf(stderr, "map_update failed: %s\n", strerror(errno)); 46 return; 47 } 48 } 49 50 static int test(char *filename, int num_progs) 51 { 52 int i, fd, map0_fds[num_progs], map1_fds[num_progs]; 53 54 for (i = 0; i < num_progs; i++) { 55 if (load_bpf_file(filename)) { 56 fprintf(stderr, "%s", bpf_log_buf); 57 return 1; 58 } 59 printf("prog #%d: map ids %d %d\n", i, map_fd[0], map_fd[1]); 60 map0_fds[i] = map_fd[0]; 61 map1_fds[i] = map_fd[1]; 62 } 63 64 /* current load_bpf_file has perf_event_open default pid = -1 65 * and cpu = 0, which permits attached bpf execution on 66 * all cpus for all pid's. bpf program execution ignores 67 * cpu affinity. 68 */ 69 /* trigger some "open" operations */ 70 fd = open(filename, O_RDONLY); 71 if (fd < 0) { 72 fprintf(stderr, "open failed: %s\n", strerror(errno)); 73 return 1; 74 } 75 close(fd); 76 77 /* verify the map */ 78 for (i = 0; i < num_progs; i++) { 79 verify_map(map0_fds[i]); 80 verify_map(map1_fds[i]); 81 } 82 83 return 0; 84 } 85 86 int main(int argc, char **argv) 87 { 88 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; 89 int opt, num_progs = 1; 90 char filename[256]; 91 92 while ((opt = getopt(argc, argv, "i:h")) != -1) { 93 switch (opt) { 94 case 'i': 95 num_progs = atoi(optarg); 96 break; 97 case 'h': 98 default: 99 usage(argv[0]); 100 return 0; 101 } 102 } 103 104 setrlimit(RLIMIT_MEMLOCK, &r); 105 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 106 107 return test(filename, num_progs); 108 } 109