linux/tools/bpf/bpftool/iter.c
Hengqi Chen e5043894b2 bpftool: Use libbpf_get_error() to check error
Currently, LIBBPF_STRICT_ALL mode is enabled by default for
bpftool which means on error cases, some libbpf APIs would
return NULL pointers. This makes IS_ERR check failed to detect
such cases and result in segfault error. Use libbpf_get_error()
instead like we do in libbpf itself.

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211115012436.3143318-1-hengqi.chen@gmail.com
2021-11-14 18:38:13 -08:00

120 lines
2.3 KiB
C

// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
// Copyright (C) 2020 Facebook
#define _GNU_SOURCE
#include <unistd.h>
#include <linux/err.h>
#include <bpf/libbpf.h>
#include "main.h"
static int do_pin(int argc, char **argv)
{
DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, iter_opts);
union bpf_iter_link_info linfo;
const char *objfile, *path;
struct bpf_program *prog;
struct bpf_object *obj;
struct bpf_link *link;
int err = -1, map_fd = -1;
if (!REQ_ARGS(2))
usage();
objfile = GET_ARG();
path = GET_ARG();
/* optional arguments */
if (argc) {
if (is_prefix(*argv, "map")) {
NEXT_ARG();
if (!REQ_ARGS(2)) {
p_err("incorrect map spec");
return -1;
}
map_fd = map_parse_fd(&argc, &argv);
if (map_fd < 0)
return -1;
memset(&linfo, 0, sizeof(linfo));
linfo.map.map_fd = map_fd;
iter_opts.link_info = &linfo;
iter_opts.link_info_len = sizeof(linfo);
}
}
obj = bpf_object__open(objfile);
err = libbpf_get_error(obj);
if (err) {
p_err("can't open objfile %s", objfile);
goto close_map_fd;
}
err = bpf_object__load(obj);
if (err) {
p_err("can't load objfile %s", objfile);
goto close_obj;
}
prog = bpf_object__next_program(obj, NULL);
if (!prog) {
p_err("can't find bpf program in objfile %s", objfile);
goto close_obj;
}
link = bpf_program__attach_iter(prog, &iter_opts);
err = libbpf_get_error(link);
if (err) {
p_err("attach_iter failed for program %s",
bpf_program__name(prog));
goto close_obj;
}
err = mount_bpffs_for_pin(path);
if (err)
goto close_link;
err = bpf_link__pin(link, path);
if (err) {
p_err("pin_iter failed for program %s to path %s",
bpf_program__name(prog), path);
goto close_link;
}
close_link:
bpf_link__destroy(link);
close_obj:
bpf_object__close(obj);
close_map_fd:
if (map_fd >= 0)
close(map_fd);
return err;
}
static int do_help(int argc, char **argv)
{
fprintf(stderr,
"Usage: %1$s %2$s pin OBJ PATH [map MAP]\n"
" %1$s %2$s help\n"
"\n"
" " HELP_SPEC_MAP "\n"
" " HELP_SPEC_OPTIONS " }\n"
"",
bin_name, "iter");
return 0;
}
static const struct cmd cmds[] = {
{ "help", do_help },
{ "pin", do_pin },
{ 0 }
};
int do_iter(int argc, char **argv)
{
return cmd_select(cmds, argc, argv, do_help);
}