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
 26static void usage(const char *cmd)
 27{
 28	printf("USAGE: %s [-i num_progs] [-h]\n", cmd);
 29	printf("       -i num_progs      # number of progs of the test\n");
 30	printf("       -h                # help\n");
 31}
 32
 33static void verify_map(int map_id)
 34{
 35	__u32 key = 0;
 36	__u32 val;
 37
 38	if (bpf_map_lookup_elem(map_id, &key, &val) != 0) {
 39		fprintf(stderr, "map_lookup failed: %s\n", strerror(errno));
 40		return;
 41	}
 42	if (val == 0) {
 43		fprintf(stderr, "failed: map #%d returns value 0\n", map_id);
 44		return;
 45	}
 46	val = 0;
 47	if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) {
 48		fprintf(stderr, "map_update failed: %s\n", strerror(errno));
 49		return;
 50	}
 51}
 52
 53static int test(char *filename, int num_progs)
 54{
 55	int i, fd, map0_fds[num_progs], map1_fds[num_progs];
 56
 57	for (i = 0; i < num_progs; i++) {
 58		if (load_bpf_file(filename)) {
 59			fprintf(stderr, "%s", bpf_log_buf);
 60			return 1;
 61		}
 62		printf("prog #%d: map ids %d %d\n", i, map_fd[0], map_fd[1]);
 63		map0_fds[i] = map_fd[0];
 64		map1_fds[i] = map_fd[1];
 65	}
 66
 67	/* current load_bpf_file has perf_event_open default pid = -1
 68	 * and cpu = 0, which permits attached bpf execution on
 69	 * all cpus for all pid's. bpf program execution ignores
 70	 * cpu affinity.
 71	 */
 72	/* trigger some "open" operations */
 73	fd = open(filename, O_RDONLY);
 74	if (fd < 0) {
 75		fprintf(stderr, "open failed: %s\n", strerror(errno));
 76		return 1;
 77	}
 78	close(fd);
 79
 80	/* verify the map */
 81	for (i = 0; i < num_progs; i++) {
 82		verify_map(map0_fds[i]);
 83		verify_map(map1_fds[i]);
 84	}
 85
 86	return 0;
 87}
 88
 89int main(int argc, char **argv)
 90{
 91	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 92	int opt, num_progs = 1;
 93	char filename[256];
 94
 95	while ((opt = getopt(argc, argv, "i:h")) != -1) {
 96		switch (opt) {
 97		case 'i':
 98			num_progs = atoi(optarg);
 99			break;
100		case 'h':
101		default:
102			usage(argv[0]);
103			return 0;
104		}
105	}
106
107	setrlimit(RLIMIT_MEMLOCK, &r);
108	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
109
110	return test(filename, num_progs);
111}