Linux Perf
bpf-script-test-relocation.c
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1 /*
2  * bpf-script-test-relocation.c
3  * Test BPF loader checking relocation
4  */
5 #ifndef LINUX_VERSION_CODE
6 # error Need LINUX_VERSION_CODE
7 # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
8 #endif
9 #define BPF_ANY 0
10 #define BPF_MAP_TYPE_ARRAY 2
11 #define BPF_FUNC_map_lookup_elem 1
12 #define BPF_FUNC_map_update_elem 2
13 
14 static void *(*bpf_map_lookup_elem)(void *map, void *key) =
15  (void *) BPF_FUNC_map_lookup_elem;
16 static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) =
17  (void *) BPF_FUNC_map_update_elem;
18 
19 struct bpf_map_def {
20  unsigned int type;
21  unsigned int key_size;
22  unsigned int value_size;
23  unsigned int max_entries;
24 };
25 
26 #define SEC(NAME) __attribute__((section(NAME), used))
27 struct bpf_map_def SEC("maps") my_table = {
28  .type = BPF_MAP_TYPE_ARRAY,
29  .key_size = sizeof(int),
30  .value_size = sizeof(int),
31  .max_entries = 1,
32 };
33 
35 
36 SEC("func=sys_write")
37 int bpf_func__sys_write(void *ctx)
38 {
39  int key = 0;
40  int value = 0;
41 
42  /*
43  * Incorrect relocation. Should not allow this program be
44  * loaded into kernel.
45  */
46  bpf_map_update_elem(&this_is_a_global_val, &key, &value, 0);
47  return 0;
48 }
49 char _license[] SEC("license") = "GPL";
50 int _version SEC("version") = LINUX_VERSION_CODE;
int value
Definition: python.c:1143
unsigned int value_size
int bpf_func__sys_write(void *ctx)
const char * key
Definition: bpf-loader.c:196
#define SEC(NAME)
static void *(* bpf_map_update_elem)(void *map, void *key, void *value, int flags)
Definition: map.h:58
unsigned int max_entries
int this_is_a_global_val
Definition: jevents.c:228
#define BPF_FUNC_map_lookup_elem
u32 flags
unsigned int type
#define BPF_FUNC_map_update_elem
#define BPF_MAP_TYPE_ARRAY
unsigned int key_size