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 
9 char _license[] SEC("license") = "GPL";
10 
11 struct {
12 	char in[256];
13 	char out[256];
14 } data = {};
15 
16 struct core_reloc_flavors {
17 	int a;
18 	int b;
19 	int c;
20 };
21 
22 /* local flavor with reversed layout */
23 struct core_reloc_flavors___reversed {
24 	int c;
25 	int b;
26 	int a;
27 };
28 
29 /* local flavor with nested/overlapping layout */
30 struct core_reloc_flavors___weird {
31 	struct {
32 		int b;
33 	};
34 	/* a and c overlap in local flavor, but this should still work
35 	 * correctly with target original flavor
36 	 */
37 	union {
38 		int a;
39 		int c;
40 	};
41 };
42 
43 #define CORE_READ(dst, src) bpf_core_read(dst, sizeof(*(dst)), src)
44 
45 SEC("raw_tracepoint/sys_enter")
test_core_flavors(void * ctx)46 int test_core_flavors(void *ctx)
47 {
48 	struct core_reloc_flavors *in_orig = (void *)&data.in;
49 	struct core_reloc_flavors___reversed *in_rev = (void *)&data.in;
50 	struct core_reloc_flavors___weird *in_weird = (void *)&data.in;
51 	struct core_reloc_flavors *out = (void *)&data.out;
52 
53 	/* read a using weird layout */
54 	if (CORE_READ(&out->a, &in_weird->a))
55 		return 1;
56 	/* read b using reversed layout */
57 	if (CORE_READ(&out->b, &in_rev->b))
58 		return 1;
59 	/* read c using original layout */
60 	if (CORE_READ(&out->c, &in_orig->c))
61 		return 1;
62 
63 	return 0;
64 }
65 
66