Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'libbpf-introduce-line_info-and-func_info-getters'
Mykyta Yatsenko says:
====================
libbpf: introduce line_info and func_info getters
From: Mykyta Yatsenko <yatsenko@meta.com>
This patchset introduces new libbpf API getters that enable the retrieval
of .BTF.ext line and func info.
This change enables users to load bpf_program directly using bpf_prog_load,
bypassing the higher-level bpf_object__load API. Providing line and
function info is essential for BPF program verification in some cases.
v3 -> v5
* Fix tests on s390x, nits.
v2 -> v3
* Return ENOTSUPP if func or line info struct size differs from the one in
uapi linux headers.
* Add selftests.
v1 -> v2
Move bpf_line_info_min and bpf_func_info_min from libbpf_internal.h to
btf.h. Did not remove _min suffix, because there already are bpf_line_info
and bpf_func_info structs in uapi/../bpf.h.
====================
Link: https://patch.msgid.link/20250408234417.452565-1-mykyta.yatsenko5@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
+120
+24
tools/lib/bpf/libbpf.c
+24
tools/lib/bpf/libbpf.c
···
9446
9446
return 0;
9447
9447
}
9448
9448
9449
+
struct bpf_func_info *bpf_program__func_info(const struct bpf_program *prog)
9450
+
{
9451
+
if (prog->func_info_rec_size != sizeof(struct bpf_func_info))
9452
+
return libbpf_err_ptr(-EOPNOTSUPP);
9453
+
return prog->func_info;
9454
+
}
9455
+
9456
+
__u32 bpf_program__func_info_cnt(const struct bpf_program *prog)
9457
+
{
9458
+
return prog->func_info_cnt;
9459
+
}
9460
+
9461
+
struct bpf_line_info *bpf_program__line_info(const struct bpf_program *prog)
9462
+
{
9463
+
if (prog->line_info_rec_size != sizeof(struct bpf_line_info))
9464
+
return libbpf_err_ptr(-EOPNOTSUPP);
9465
+
return prog->line_info;
9466
+
}
9467
+
9468
+
__u32 bpf_program__line_info_cnt(const struct bpf_program *prog)
9469
+
{
9470
+
return prog->line_info_cnt;
9471
+
}
9472
+
9449
9473
#define SEC_DEF(sec_pfx, ptype, atype, flags, ...) { \
9450
9474
.sec = (char *)sec_pfx, \
9451
9475
.prog_type = BPF_PROG_TYPE_##ptype, \
+6
tools/lib/bpf/libbpf.h
+6
tools/lib/bpf/libbpf.h
···
940
940
LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
941
941
LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
942
942
943
+
LIBBPF_API struct bpf_func_info *bpf_program__func_info(const struct bpf_program *prog);
944
+
LIBBPF_API __u32 bpf_program__func_info_cnt(const struct bpf_program *prog);
945
+
946
+
LIBBPF_API struct bpf_line_info *bpf_program__line_info(const struct bpf_program *prog);
947
+
LIBBPF_API __u32 bpf_program__line_info_cnt(const struct bpf_program *prog);
948
+
943
949
/**
944
950
* @brief **bpf_program__set_attach_target()** sets BTF-based attach target
945
951
* for supported BPF program types:
+4
tools/lib/bpf/libbpf.map
+4
tools/lib/bpf/libbpf.map
+64
tools/testing/selftests/bpf/prog_tests/test_btf_ext.c
+64
tools/testing/selftests/bpf/prog_tests/test_btf_ext.c
···
1
+
// SPDX-License-Identifier: GPL-2.0
2
+
/* Copyright (c) 2025 Meta Platforms Inc. */
3
+
#include <test_progs.h>
4
+
#include "test_btf_ext.skel.h"
5
+
#include "btf_helpers.h"
6
+
7
+
static void subtest_line_func_info(void)
8
+
{
9
+
struct test_btf_ext *skel;
10
+
struct bpf_prog_info info;
11
+
struct bpf_line_info line_info[128], *libbpf_line_info;
12
+
struct bpf_func_info func_info[128], *libbpf_func_info;
13
+
__u32 info_len = sizeof(info), libbbpf_line_info_cnt, libbbpf_func_info_cnt;
14
+
int err, fd;
15
+
16
+
skel = test_btf_ext__open_and_load();
17
+
if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
18
+
return;
19
+
20
+
fd = bpf_program__fd(skel->progs.global_func);
21
+
22
+
memset(&info, 0, sizeof(info));
23
+
info.line_info = ptr_to_u64(&line_info);
24
+
info.nr_line_info = sizeof(line_info);
25
+
info.line_info_rec_size = sizeof(*line_info);
26
+
err = bpf_prog_get_info_by_fd(fd, &info, &info_len);
27
+
if (!ASSERT_OK(err, "prog_line_info"))
28
+
goto out;
29
+
30
+
libbpf_line_info = bpf_program__line_info(skel->progs.global_func);
31
+
libbbpf_line_info_cnt = bpf_program__line_info_cnt(skel->progs.global_func);
32
+
33
+
memset(&info, 0, sizeof(info));
34
+
info.func_info = ptr_to_u64(&func_info);
35
+
info.nr_func_info = sizeof(func_info);
36
+
info.func_info_rec_size = sizeof(*func_info);
37
+
err = bpf_prog_get_info_by_fd(fd, &info, &info_len);
38
+
if (!ASSERT_OK(err, "prog_func_info"))
39
+
goto out;
40
+
41
+
libbpf_func_info = bpf_program__func_info(skel->progs.global_func);
42
+
libbbpf_func_info_cnt = bpf_program__func_info_cnt(skel->progs.global_func);
43
+
44
+
if (!ASSERT_OK_PTR(libbpf_line_info, "bpf_program__line_info"))
45
+
goto out;
46
+
if (!ASSERT_EQ(libbbpf_line_info_cnt, info.nr_line_info, "line_info_cnt"))
47
+
goto out;
48
+
if (!ASSERT_OK_PTR(libbpf_func_info, "bpf_program__func_info"))
49
+
goto out;
50
+
if (!ASSERT_EQ(libbbpf_func_info_cnt, info.nr_func_info, "func_info_cnt"))
51
+
goto out;
52
+
ASSERT_MEMEQ(libbpf_line_info, line_info, libbbpf_line_info_cnt * sizeof(*line_info),
53
+
"line_info");
54
+
ASSERT_MEMEQ(libbpf_func_info, func_info, libbbpf_func_info_cnt * sizeof(*func_info),
55
+
"func_info");
56
+
out:
57
+
test_btf_ext__destroy(skel);
58
+
}
59
+
60
+
void test_btf_ext(void)
61
+
{
62
+
if (test__start_subtest("line_func_info"))
63
+
subtest_line_func_info();
64
+
}
+22
tools/testing/selftests/bpf/progs/test_btf_ext.c
+22
tools/testing/selftests/bpf/progs/test_btf_ext.c
···
1
+
// SPDX-License-Identifier: GPL-2.0-only
2
+
/* Copyright (c) 2025 Meta Platforms Inc. */
3
+
4
+
#include <linux/bpf.h>
5
+
#include <bpf/bpf_helpers.h>
6
+
#include "bpf_misc.h"
7
+
8
+
char _license[] SEC("license") = "GPL";
9
+
10
+
__noinline static void f0(void)
11
+
{
12
+
__u64 a = 1;
13
+
14
+
__sink(a);
15
+
}
16
+
17
+
SEC("xdp")
18
+
__u64 global_func(struct xdp_md *xdp)
19
+
{
20
+
f0();
21
+
return XDP_DROP;
22
+
}