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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2017 Facebook
*/
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <linux/perf_event.h>
#include <errno.h>
#include <bpf/libbpf.h>
#include <bpf/bpf.h>
/* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*.
* This requires kernel CONFIG_FTRACE_SYSCALLS to be set.
*/
static void usage(const char *cmd)
{
printf("USAGE: %s [-i num_progs] [-h]\n", cmd);
printf(" -i num_progs # number of progs of the test\n");
printf(" -h # help\n");
}
static void verify_map(int map_id)
{
__u32 key = 0;
__u32 val;
if (bpf_map_lookup_elem(map_id, &key, &val) != 0) {
fprintf(stderr, "map_lookup failed: %s\n", strerror(errno));
return;
}
if (val == 0) {
fprintf(stderr, "failed: map #%d returns value 0\n", map_id);
return;
}
printf("verify map:%d val: %d\n", map_id, val);
val = 0;
if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) {
fprintf(stderr, "map_update failed: %s\n", strerror(errno));
return;
}
}
static int test(char *filename, int num_progs)
{
int map0_fds[num_progs], map1_fds[num_progs], fd, i, j = 0;
struct bpf_link *links[num_progs * 4];
struct bpf_object *objs[num_progs];
struct bpf_program *prog;
for (i = 0; i < num_progs; i++) {
objs[i] = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(objs[i])) {
fprintf(stderr, "opening BPF object file failed\n");
objs[i] = NULL;
goto cleanup;
}
/* load BPF program */
if (bpf_object__load(objs[i])) {
fprintf(stderr, "loading BPF object file failed\n");
goto cleanup;
}
map0_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
"enter_open_map");
map1_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
"exit_open_map");
if (map0_fds[i] < 0 || map1_fds[i] < 0) {
fprintf(stderr, "finding a map in obj file failed\n");
goto cleanup;
}
bpf_object__for_each_program(prog, objs[i]) {
links[j] = bpf_program__attach(prog);
if (libbpf_get_error(links[j])) {
fprintf(stderr, "bpf_program__attach failed\n");
links[j] = NULL;
goto cleanup;
}
j++;
}
printf("prog #%d: map ids %d %d\n", i, map0_fds[i], map1_fds[i]);
}
/* current load_bpf_file has perf_event_open default pid = -1
* and cpu = 0, which permits attached bpf execution on
* all cpus for all pid's. bpf program execution ignores
* cpu affinity.
*/
/* trigger some "open" operations */
fd = open(filename, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "open failed: %s\n", strerror(errno));
return 1;
}
close(fd);
/* verify the map */
for (i = 0; i < num_progs; i++) {
verify_map(map0_fds[i]);
verify_map(map1_fds[i]);
}
cleanup:
for (j--; j >= 0; j--)
bpf_link__destroy(links[j]);
for (i--; i >= 0; i--)
bpf_object__close(objs[i]);
return 0;
}
int main(int argc, char **argv)
{
int opt, num_progs = 1;
char filename[256];
while ((opt = getopt(argc, argv, "i:h")) != -1) {
switch (opt) {
case 'i':
num_progs = atoi(optarg);
break;
case 'h':
default:
usage(argv[0]);
return 0;
}
}
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
return test(filename, num_progs);
}
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