1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdio.h> 2 #include <stdio.h>
3 #include <unistd.h> 3 #include <unistd.h>
4 #include <string.h> 4 #include <string.h>
5 #include <assert.h> 5 #include <assert.h>
6 #include <bpf/libbpf.h> 6 #include <bpf/libbpf.h>
7 #include <bpf/bpf.h> 7 #include <bpf/bpf.h>
8 #include "trace_helpers.h" 8 #include "trace_helpers.h"
9 9
10 int main(int ac, char **argv) 10 int main(int ac, char **argv)
11 { 11 {
>> 12 char filename[256], symbol[256];
12 struct bpf_object *obj = NULL; 13 struct bpf_object *obj = NULL;
13 struct bpf_link *links[20]; 14 struct bpf_link *links[20];
14 long key, next_key, value; 15 long key, next_key, value;
15 struct bpf_program *prog; 16 struct bpf_program *prog;
16 int map_fd, i, j = 0; 17 int map_fd, i, j = 0;
17 char filename[256]; !! 18 const char *section;
18 struct ksym *sym; 19 struct ksym *sym;
19 20
20 if (load_kallsyms()) { 21 if (load_kallsyms()) {
21 printf("failed to process /pro 22 printf("failed to process /proc/kallsyms\n");
22 return 2; 23 return 2;
23 } 24 }
24 25
25 snprintf(filename, sizeof(filename), " !! 26 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
26 obj = bpf_object__open_file(filename, 27 obj = bpf_object__open_file(filename, NULL);
27 if (libbpf_get_error(obj)) { 28 if (libbpf_get_error(obj)) {
28 fprintf(stderr, "ERROR: openin 29 fprintf(stderr, "ERROR: opening BPF object file failed\n");
29 obj = NULL; 30 obj = NULL;
30 goto cleanup; 31 goto cleanup;
31 } 32 }
32 33
33 /* load BPF program */ 34 /* load BPF program */
34 if (bpf_object__load(obj)) { 35 if (bpf_object__load(obj)) {
35 fprintf(stderr, "ERROR: loadin 36 fprintf(stderr, "ERROR: loading BPF object file failed\n");
36 goto cleanup; 37 goto cleanup;
37 } 38 }
38 39
39 map_fd = bpf_object__find_map_fd_by_na 40 map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
40 if (map_fd < 0) { 41 if (map_fd < 0) {
41 fprintf(stderr, "ERROR: findin 42 fprintf(stderr, "ERROR: finding a map in obj file failed\n");
42 goto cleanup; 43 goto cleanup;
43 } 44 }
44 45
45 bpf_object__for_each_program(prog, obj 46 bpf_object__for_each_program(prog, obj) {
46 links[j] = bpf_program__attach !! 47 section = bpf_program__section_name(prog);
47 if (libbpf_get_error(links[j]) !! 48 if (sscanf(section, "kprobe/%s", symbol) != 1)
48 fprintf(stderr, "bpf_p !! 49 continue;
49 links[j] = NULL; !! 50
50 goto cleanup; !! 51 /* Attach prog only when symbol exists */
>> 52 if (ksym_get_addr(symbol)) {
>> 53 links[j] = bpf_program__attach(prog);
>> 54 if (libbpf_get_error(links[j])) {
>> 55 fprintf(stderr, "bpf_program__attach failed\n");
>> 56 links[j] = NULL;
>> 57 goto cleanup;
>> 58 }
>> 59 j++;
51 } 60 }
52 j++; <<
53 } 61 }
54 62
55 for (i = 0; i < 5; i++) { 63 for (i = 0; i < 5; i++) {
56 key = 0; 64 key = 0;
57 printf("kprobing funcs:"); 65 printf("kprobing funcs:");
58 while (bpf_map_get_next_key(ma 66 while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
59 bpf_map_lookup_elem(ma 67 bpf_map_lookup_elem(map_fd, &next_key, &value);
60 assert(next_key == val 68 assert(next_key == value);
61 sym = ksym_search(valu 69 sym = ksym_search(value);
62 key = next_key; 70 key = next_key;
63 if (!sym) { 71 if (!sym) {
64 printf("ksym n 72 printf("ksym not found. Is kallsyms loaded?\n");
65 continue; 73 continue;
66 } 74 }
67 75
68 printf(" %s", sym->nam 76 printf(" %s", sym->name);
69 } 77 }
70 if (key) 78 if (key)
71 printf("\n"); 79 printf("\n");
72 key = 0; 80 key = 0;
73 while (bpf_map_get_next_key(ma 81 while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0)
74 bpf_map_delete_elem(ma 82 bpf_map_delete_elem(map_fd, &next_key);
75 sleep(1); 83 sleep(1);
76 } 84 }
77 85
78 cleanup: 86 cleanup:
79 for (j--; j >= 0; j--) 87 for (j--; j >= 0; j--)
80 bpf_link__destroy(links[j]); 88 bpf_link__destroy(links[j]);
81 89
82 bpf_object__close(obj); 90 bpf_object__close(obj);
83 return 0; 91 return 0;
84 } 92 }
85 93
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