1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 
4 ssize_t get_base_addr() {
5 	size_t start;
6 	char buf[256];
7 	FILE *f;
8 
9 	f = fopen("/proc/self/maps", "r");
10 	if (!f)
11 		return -errno;
12 
13 	while (fscanf(f, "%zx-%*x %s %*s\n", &start, buf) == 2) {
14 		if (strcmp(buf, "r-xp") == 0) {
15 			fclose(f);
16 			return start;
17 		}
18 	}
19 
20 	fclose(f);
21 	return -EINVAL;
22 }
23 
24 void test_attach_probe(void)
25 {
26 	const char *kprobe_name = "kprobe/sys_nanosleep";
27 	const char *kretprobe_name = "kretprobe/sys_nanosleep";
28 	const char *uprobe_name = "uprobe/trigger_func";
29 	const char *uretprobe_name = "uretprobe/trigger_func";
30 	const int kprobe_idx = 0, kretprobe_idx = 1;
31 	const int uprobe_idx = 2, uretprobe_idx = 3;
32 	const char *file = "./test_attach_probe.o";
33 	struct bpf_program *kprobe_prog, *kretprobe_prog;
34 	struct bpf_program *uprobe_prog, *uretprobe_prog;
35 	struct bpf_object *obj;
36 	int err, prog_fd, duration = 0, res;
37 	struct bpf_link *kprobe_link = NULL;
38 	struct bpf_link *kretprobe_link = NULL;
39 	struct bpf_link *uprobe_link = NULL;
40 	struct bpf_link *uretprobe_link = NULL;
41 	int results_map_fd;
42 	size_t uprobe_offset;
43 	ssize_t base_addr;
44 
45 	base_addr = get_base_addr();
46 	if (CHECK(base_addr < 0, "get_base_addr",
47 		  "failed to find base addr: %zd", base_addr))
48 		return;
49 	uprobe_offset = (size_t)&get_base_addr - base_addr;
50 
51 	/* load programs */
52 	err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd);
53 	if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno))
54 		return;
55 
56 	kprobe_prog = bpf_object__find_program_by_title(obj, kprobe_name);
57 	if (CHECK(!kprobe_prog, "find_probe",
58 		  "prog '%s' not found\n", kprobe_name))
59 		goto cleanup;
60 	kretprobe_prog = bpf_object__find_program_by_title(obj, kretprobe_name);
61 	if (CHECK(!kretprobe_prog, "find_probe",
62 		  "prog '%s' not found\n", kretprobe_name))
63 		goto cleanup;
64 	uprobe_prog = bpf_object__find_program_by_title(obj, uprobe_name);
65 	if (CHECK(!uprobe_prog, "find_probe",
66 		  "prog '%s' not found\n", uprobe_name))
67 		goto cleanup;
68 	uretprobe_prog = bpf_object__find_program_by_title(obj, uretprobe_name);
69 	if (CHECK(!uretprobe_prog, "find_probe",
70 		  "prog '%s' not found\n", uretprobe_name))
71 		goto cleanup;
72 
73 	/* load maps */
74 	results_map_fd = bpf_find_map(__func__, obj, "results_map");
75 	if (CHECK(results_map_fd < 0, "find_results_map",
76 		  "err %d\n", results_map_fd))
77 		goto cleanup;
78 
79 	kprobe_link = bpf_program__attach_kprobe(kprobe_prog,
80 						 false /* retprobe */,
81 						 SYS_NANOSLEEP_KPROBE_NAME);
82 	if (CHECK(IS_ERR(kprobe_link), "attach_kprobe",
83 		  "err %ld\n", PTR_ERR(kprobe_link))) {
84 		kprobe_link = NULL;
85 		goto cleanup;
86 	}
87 	kretprobe_link = bpf_program__attach_kprobe(kretprobe_prog,
88 						    true /* retprobe */,
89 						    SYS_NANOSLEEP_KPROBE_NAME);
90 	if (CHECK(IS_ERR(kretprobe_link), "attach_kretprobe",
91 		  "err %ld\n", PTR_ERR(kretprobe_link))) {
92 		kretprobe_link = NULL;
93 		goto cleanup;
94 	}
95 	uprobe_link = bpf_program__attach_uprobe(uprobe_prog,
96 						 false /* retprobe */,
97 						 0 /* self pid */,
98 						 "/proc/self/exe",
99 						 uprobe_offset);
100 	if (CHECK(IS_ERR(uprobe_link), "attach_uprobe",
101 		  "err %ld\n", PTR_ERR(uprobe_link))) {
102 		uprobe_link = NULL;
103 		goto cleanup;
104 	}
105 	uretprobe_link = bpf_program__attach_uprobe(uretprobe_prog,
106 						    true /* retprobe */,
107 						    -1 /* any pid */,
108 						    "/proc/self/exe",
109 						    uprobe_offset);
110 	if (CHECK(IS_ERR(uretprobe_link), "attach_uretprobe",
111 		  "err %ld\n", PTR_ERR(uretprobe_link))) {
112 		uretprobe_link = NULL;
113 		goto cleanup;
114 	}
115 
116 	/* trigger & validate kprobe && kretprobe */
117 	usleep(1);
118 
119 	err = bpf_map_lookup_elem(results_map_fd, &kprobe_idx, &res);
120 	if (CHECK(err, "get_kprobe_res",
121 		  "failed to get kprobe res: %d\n", err))
122 		goto cleanup;
123 	if (CHECK(res != kprobe_idx + 1, "check_kprobe_res",
124 		  "wrong kprobe res: %d\n", res))
125 		goto cleanup;
126 
127 	err = bpf_map_lookup_elem(results_map_fd, &kretprobe_idx, &res);
128 	if (CHECK(err, "get_kretprobe_res",
129 		  "failed to get kretprobe res: %d\n", err))
130 		goto cleanup;
131 	if (CHECK(res != kretprobe_idx + 1, "check_kretprobe_res",
132 		  "wrong kretprobe res: %d\n", res))
133 		goto cleanup;
134 
135 	/* trigger & validate uprobe & uretprobe */
136 	get_base_addr();
137 
138 	err = bpf_map_lookup_elem(results_map_fd, &uprobe_idx, &res);
139 	if (CHECK(err, "get_uprobe_res",
140 		  "failed to get uprobe res: %d\n", err))
141 		goto cleanup;
142 	if (CHECK(res != uprobe_idx + 1, "check_uprobe_res",
143 		  "wrong uprobe res: %d\n", res))
144 		goto cleanup;
145 
146 	err = bpf_map_lookup_elem(results_map_fd, &uretprobe_idx, &res);
147 	if (CHECK(err, "get_uretprobe_res",
148 		  "failed to get uretprobe res: %d\n", err))
149 		goto cleanup;
150 	if (CHECK(res != uretprobe_idx + 1, "check_uretprobe_res",
151 		  "wrong uretprobe res: %d\n", res))
152 		goto cleanup;
153 
154 cleanup:
155 	bpf_link__destroy(kprobe_link);
156 	bpf_link__destroy(kretprobe_link);
157 	bpf_link__destroy(uprobe_link);
158 	bpf_link__destroy(uretprobe_link);
159 	bpf_object__close(obj);
160 }
161