1 /* Copyright (c) 2017 Facebook 2 * 3 * This program is free software; you can redistribute it and/or 4 * modify it under the terms of version 2 of the GNU General Public 5 * License as published by the Free Software Foundation. 6 */ 7 #include <stdio.h> 8 #include <unistd.h> 9 #include <fcntl.h> 10 #include <stdlib.h> 11 #include <signal.h> 12 #include <linux/bpf.h> 13 #include <string.h> 14 #include <linux/perf_event.h> 15 #include <errno.h> 16 #include <assert.h> 17 #include <stdbool.h> 18 #include <sys/resource.h> 19 #include "libbpf.h" 20 #include "bpf_load.h" 21 22 /* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*. 23 * This requires kernel CONFIG_FTRACE_SYSCALLS to be set. 24 */ 25 26 static void verify_map(int map_id) 27 { 28 __u32 key = 0; 29 __u32 val; 30 31 if (bpf_map_lookup_elem(map_id, &key, &val) != 0) { 32 fprintf(stderr, "map_lookup failed: %s\n", strerror(errno)); 33 return; 34 } 35 if (val == 0) 36 fprintf(stderr, "failed: map #%d returns value 0\n", map_id); 37 } 38 39 int main(int argc, char **argv) 40 { 41 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; 42 char filename[256]; 43 int fd; 44 45 setrlimit(RLIMIT_MEMLOCK, &r); 46 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 47 48 if (load_bpf_file(filename)) { 49 fprintf(stderr, "%s", bpf_log_buf); 50 return 1; 51 } 52 53 /* current load_bpf_file has perf_event_open default pid = -1 54 * and cpu = 0, which permits attached bpf execution on 55 * all cpus for all pid's. bpf program execution ignores 56 * cpu affinity. 57 */ 58 /* trigger some "open" operations */ 59 fd = open(filename, O_RDONLY); 60 if (fd < 0) { 61 fprintf(stderr, "open failed: %s\n", strerror(errno)); 62 return 1; 63 } 64 close(fd); 65 66 /* verify the map */ 67 verify_map(map_fd[0]); 68 verify_map(map_fd[1]); 69 70 return 0; 71 } 72