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_helpers.h"
7 
8 char _license[] SEC("license") = "GPL";
9 
10 static volatile struct data {
11 	char in[256];
12 	char out[256];
13 } data;
14 
15 struct core_reloc_flavors {
16 	int a;
17 	int b;
18 	int c;
19 };
20 
21 /* local flavor with reversed layout */
22 struct core_reloc_flavors___reversed {
23 	int c;
24 	int b;
25 	int a;
26 };
27 
28 /* local flavor with nested/overlapping layout */
29 struct core_reloc_flavors___weird {
30 	struct {
31 		int b;
32 	};
33 	/* a and c overlap in local flavor, but this should still work
34 	 * correctly with target original flavor
35 	 */
36 	union {
37 		int a;
38 		int c;
39 	};
40 };
41 
42 SEC("raw_tracepoint/sys_enter")
43 int test_core_flavors(void *ctx)
44 {
45 	struct core_reloc_flavors *in_orig = (void *)&data.in;
46 	struct core_reloc_flavors___reversed *in_rev = (void *)&data.in;
47 	struct core_reloc_flavors___weird *in_weird = (void *)&data.in;
48 	struct core_reloc_flavors *out = (void *)&data.out;
49 
50 	/* read a using weird layout */
51 	if (BPF_CORE_READ(&out->a, &in_weird->a))
52 		return 1;
53 	/* read b using reversed layout */
54 	if (BPF_CORE_READ(&out->b, &in_rev->b))
55 		return 1;
56 	/* read c using original layout */
57 	if (BPF_CORE_READ(&out->c, &in_orig->c))
58 		return 1;
59 
60 	return 0;
61 }
62 
63