Commit e5043894 authored by Hengqi Chen's avatar Hengqi Chen Committed by Andrii Nakryiko
Browse files

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: default avatarHengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211115012436.3143318-1-hengqi.chen@gmail.com
parent c874dff4

tools/bpf/bpftool/btf.c

+5 −4
Original line number Diff line number Diff line
@@ -421,8 +421,9 @@ static int dump_btf_c(const struct btf *btf, 
	int err = 0, i;



	d = btf_dump__new(btf, btf_dump_printf, NULL, NULL);

	if (IS_ERR(d))

		return PTR_ERR(d);

	err = libbpf_get_error(d);

	if (err)

		return err;



	printf("#ifndef __VMLINUX_H__\n");

	printf("#define __VMLINUX_H__\n");
@@ -549,8 +550,8 @@ static int do_dump(int argc, char **argv) 
		}



		btf = btf__parse_split(*argv, base ?: base_btf);

		if (IS_ERR(btf)) {

			err = -PTR_ERR(btf);

		err = libbpf_get_error(btf);

		if (err) {

			btf = NULL;

			p_err("failed to load BTF from %s: %s",

			      *argv, strerror(err));

tools/bpf/bpftool/gen.c

+6 −4
Original line number Diff line number Diff line
@@ -219,8 +219,9 @@ static int codegen_datasecs(struct bpf_object *obj, const char *obj_name) 
	int i, err = 0;



	d = btf_dump__new(btf, codegen_btf_dump_printf, NULL, NULL);

	if (IS_ERR(d))

		return PTR_ERR(d);

	err = libbpf_get_error(d);

	if (err)

		return err;



	bpf_object__for_each_map(map, obj) {

		/* only generate definitions for memory-mapped internal maps */
@@ -719,10 +720,11 @@ static int do_skeleton(int argc, char **argv) 
		get_obj_name(obj_name, file);

	opts.object_name = obj_name;

	obj = bpf_object__open_mem(obj_data, file_sz, &opts);

	if (IS_ERR(obj)) {

	err = libbpf_get_error(obj);

	if (err) {

		char err_buf[256];



		libbpf_strerror(PTR_ERR(obj), err_buf, sizeof(err_buf));

		libbpf_strerror(err, err_buf, sizeof(err_buf));

		p_err("failed to open BPF object file: %s", err_buf);

		obj = NULL;

		goto out;

tools/bpf/bpftool/iter.c

+4 −3
Original line number Diff line number Diff line
@@ -46,7 +46,8 @@ static int do_pin(int argc, char **argv) 
	}



	obj = bpf_object__open(objfile);

	if (IS_ERR(obj)) {

	err = libbpf_get_error(obj);

	if (err) {

		p_err("can't open objfile %s", objfile);

		goto close_map_fd;

	}
@@ -64,8 +65,8 @@ static int do_pin(int argc, char **argv) 
	}



	link = bpf_program__attach_iter(prog, &iter_opts);

	if (IS_ERR(link)) {

		err = PTR_ERR(link);

	err = libbpf_get_error(link);

	if (err) {

		p_err("attach_iter failed for program %s",

		      bpf_program__name(prog));

		goto close_obj;

tools/bpf/bpftool/map.c

+5 −5
Original line number Diff line number Diff line
@@ -812,7 +812,7 @@ static struct btf *get_map_kv_btf(const struct bpf_map_info *info) 
	if (info->btf_vmlinux_value_type_id) {

		if (!btf_vmlinux) {

			btf_vmlinux = libbpf_find_kernel_btf();

			if (IS_ERR(btf_vmlinux))

			if (libbpf_get_error(btf_vmlinux))

				p_err("failed to get kernel btf");

		}

		return btf_vmlinux;
@@ -832,13 +832,13 @@ static struct btf *get_map_kv_btf(const struct bpf_map_info *info) 


static void free_map_kv_btf(struct btf *btf)

{

	if (!IS_ERR(btf) && btf != btf_vmlinux)

	if (!libbpf_get_error(btf) && btf != btf_vmlinux)

		btf__free(btf);

}



static void free_btf_vmlinux(void)

{

	if (!IS_ERR(btf_vmlinux))

	if (!libbpf_get_error(btf_vmlinux))

		btf__free(btf_vmlinux);

}
@@ -863,8 +863,8 @@ map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr, 


	if (wtr) {

		btf = get_map_kv_btf(info);

		if (IS_ERR(btf)) {

			err = PTR_ERR(btf);

		err = libbpf_get_error(btf);

		if (err) {

			goto exit_free;

		}

tools/bpf/bpftool/struct_ops.c

+7 −7
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ static const struct btf *get_btf_vmlinux(void) 
		return btf_vmlinux;



	btf_vmlinux = libbpf_find_kernel_btf();

	if (IS_ERR(btf_vmlinux))

	if (libbpf_get_error(btf_vmlinux))

		p_err("struct_ops requires kernel CONFIG_DEBUG_INFO_BTF=y");



	return btf_vmlinux;
@@ -45,7 +45,7 @@ static const char *get_kern_struct_ops_name(const struct bpf_map_info *info) 
	const char *st_ops_name;



	kern_btf = get_btf_vmlinux();

	if (IS_ERR(kern_btf))

	if (libbpf_get_error(kern_btf))

		return "<btf_vmlinux_not_found>";



	t = btf__type_by_id(kern_btf, info->btf_vmlinux_value_type_id);
@@ -63,7 +63,7 @@ static __s32 get_map_info_type_id(void) 
		return map_info_type_id;



	kern_btf = get_btf_vmlinux();

	if (IS_ERR(kern_btf)) {

	if (libbpf_get_error(kern_btf)) {

		map_info_type_id = PTR_ERR(kern_btf);

		return map_info_type_id;

	}
@@ -415,7 +415,7 @@ static int do_dump(int argc, char **argv) 
	}



	kern_btf = get_btf_vmlinux();

	if (IS_ERR(kern_btf))

	if (libbpf_get_error(kern_btf))

		return -1;



	if (!json_output) {
@@ -495,7 +495,7 @@ static int do_register(int argc, char **argv) 
	file = GET_ARG();



	obj = bpf_object__open(file);

	if (IS_ERR_OR_NULL(obj))

	if (libbpf_get_error(obj))

		return -1;



	set_max_rlimit();
@@ -516,7 +516,7 @@ static int do_register(int argc, char **argv) 
			continue;



		link = bpf_map__attach_struct_ops(map);

		if (IS_ERR(link)) {

		if (libbpf_get_error(link)) {

			p_err("can't register struct_ops %s: %s",

			      bpf_map__name(map),

			      strerror(-PTR_ERR(link)));
@@ -596,7 +596,7 @@ int do_struct_ops(int argc, char **argv) 


	err = cmd_select(cmds, argc, argv, do_help);



	if (!IS_ERR(btf_vmlinux))

	if (!libbpf_get_error(btf_vmlinux))

		btf__free(btf_vmlinux);



	return err;