1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2019 Facebook
3
4#include <linux/bpf.h>
5#include <stdint.h>
6#include <bpf/bpf_helpers.h>
7#include <bpf/bpf_core_read.h>
8
9char _license[] SEC("license") = "GPL";
10
11struct {
12 char in[256];
13 char out[256];
14} data = {};
15
16struct core_reloc_bitfields {
17 /* unsigned bitfields */
18 uint8_t ub1: 1;
19 uint8_t ub2: 2;
20 uint32_t ub7: 7;
21 /* signed bitfields */
22 int8_t sb4: 4;
23 int32_t sb20: 20;
24 /* non-bitfields */
25 uint32_t u32;
26 int32_t s32;
27};
28
29/* bitfield read results, all as plain integers */
30struct core_reloc_bitfields_output {
31 int64_t ub1;
32 int64_t ub2;
33 int64_t ub7;
34 int64_t sb4;
35 int64_t sb20;
36 int64_t u32;
37 int64_t s32;
38};
39
40struct pt_regs;
41
42struct trace_sys_enter {
43 struct pt_regs *regs;
44 long id;
45};
46
47SEC("tp_btf/sys_enter")
48int test_core_bitfields_direct(void *ctx)
49{
50 struct core_reloc_bitfields *in = (void *)&data.in;
51 struct core_reloc_bitfields_output *out = (void *)&data.out;
52
53 out->ub1 = BPF_CORE_READ_BITFIELD(in, ub1);
54 out->ub2 = BPF_CORE_READ_BITFIELD(in, ub2);
55 out->ub7 = BPF_CORE_READ_BITFIELD(in, ub7);
56 out->sb4 = BPF_CORE_READ_BITFIELD(in, sb4);
57 out->sb20 = BPF_CORE_READ_BITFIELD(in, sb20);
58 out->u32 = BPF_CORE_READ_BITFIELD(in, u32);
59 out->s32 = BPF_CORE_READ_BITFIELD(in, s32);
60
61 return 0;
62}
63
64

source code of linux/tools/testing/selftests/bpf/progs/test_core_reloc_bitfields_direct.c