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 #ifdef __x86_64__
25 #define SYS_KPROBE_NAME "__x64_sys_nanosleep"
26 #else
27 #define SYS_KPROBE_NAME "sys_nanosleep"
28 #endif
29 
30 void test_attach_probe(void)
31 {
32 	const char *kprobe_name = "kprobe/sys_nanosleep";
33 	const char *kretprobe_name = "kretprobe/sys_nanosleep";
34 	const char *uprobe_name = "uprobe/trigger_func";
35 	const char *uretprobe_name = "uretprobe/trigger_func";
36 	const int kprobe_idx = 0, kretprobe_idx = 1;
37 	const int uprobe_idx = 2, uretprobe_idx = 3;
38 	const char *file = "./test_attach_probe.o";
39 	struct bpf_program *kprobe_prog, *kretprobe_prog;
40 	struct bpf_program *uprobe_prog, *uretprobe_prog;
41 	struct bpf_object *obj;
42 	int err, prog_fd, duration = 0, res;
43 	struct bpf_link *kprobe_link = NULL;
44 	struct bpf_link *kretprobe_link = NULL;
45 	struct bpf_link *uprobe_link = NULL;
46 	struct bpf_link *uretprobe_link = NULL;
47 	int results_map_fd;
48 	size_t uprobe_offset;
49 	ssize_t base_addr;
50 
51 	base_addr = get_base_addr();
52 	if (CHECK(base_addr < 0, "get_base_addr",
53 		  "failed to find base addr: %zd", base_addr))
54 		return;
55 	uprobe_offset = (size_t)&get_base_addr - base_addr;
56 
57 	/* load programs */
58 	err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd);
59 	if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno))
60 		return;
61 
62 	kprobe_prog = bpf_object__find_program_by_title(obj, kprobe_name);
63 	if (CHECK(!kprobe_prog, "find_probe",
64 		  "prog '%s' not found\n", kprobe_name))
65 		goto cleanup;
66 	kretprobe_prog = bpf_object__find_program_by_title(obj, kretprobe_name);
67 	if (CHECK(!kretprobe_prog, "find_probe",
68 		  "prog '%s' not found\n", kretprobe_name))
69 		goto cleanup;
70 	uprobe_prog = bpf_object__find_program_by_title(obj, uprobe_name);
71 	if (CHECK(!uprobe_prog, "find_probe",
72 		  "prog '%s' not found\n", uprobe_name))
73 		goto cleanup;
74 	uretprobe_prog = bpf_object__find_program_by_title(obj, uretprobe_name);
75 	if (CHECK(!uretprobe_prog, "find_probe",
76 		  "prog '%s' not found\n", uretprobe_name))
77 		goto cleanup;
78 
79 	/* load maps */
80 	results_map_fd = bpf_find_map(__func__, obj, "results_map");
81 	if (CHECK(results_map_fd < 0, "find_results_map",
82 		  "err %d\n", results_map_fd))
83 		goto cleanup;
84 
85 	kprobe_link = bpf_program__attach_kprobe(kprobe_prog,
86 						 false /* retprobe */,
87 						 SYS_KPROBE_NAME);
88 	if (CHECK(IS_ERR(kprobe_link), "attach_kprobe",
89 		  "err %ld\n", PTR_ERR(kprobe_link))) {
90 		kprobe_link = NULL;
91 		goto cleanup;
92 	}
93 	kretprobe_link = bpf_program__attach_kprobe(kretprobe_prog,
94 						    true /* retprobe */,
95 						    SYS_KPROBE_NAME);
96 	if (CHECK(IS_ERR(kretprobe_link), "attach_kretprobe",
97 		  "err %ld\n", PTR_ERR(kretprobe_link))) {
98 		kretprobe_link = NULL;
99 		goto cleanup;
100 	}
101 	uprobe_link = bpf_program__attach_uprobe(uprobe_prog,
102 						 false /* retprobe */,
103 						 0 /* self pid */,
104 						 "/proc/self/exe",
105 						 uprobe_offset);
106 	if (CHECK(IS_ERR(uprobe_link), "attach_uprobe",
107 		  "err %ld\n", PTR_ERR(uprobe_link))) {
108 		uprobe_link = NULL;
109 		goto cleanup;
110 	}
111 	uretprobe_link = bpf_program__attach_uprobe(uretprobe_prog,
112 						    true /* retprobe */,
113 						    -1 /* any pid */,
114 						    "/proc/self/exe",
115 						    uprobe_offset);
116 	if (CHECK(IS_ERR(uretprobe_link), "attach_uretprobe",
117 		  "err %ld\n", PTR_ERR(uretprobe_link))) {
118 		uretprobe_link = NULL;
119 		goto cleanup;
120 	}
121 
122 	/* trigger & validate kprobe && kretprobe */
123 	usleep(1);
124 
125 	err = bpf_map_lookup_elem(results_map_fd, &kprobe_idx, &res);
126 	if (CHECK(err, "get_kprobe_res",
127 		  "failed to get kprobe res: %d\n", err))
128 		goto cleanup;
129 	if (CHECK(res != kprobe_idx + 1, "check_kprobe_res",
130 		  "wrong kprobe res: %d\n", res))
131 		goto cleanup;
132 
133 	err = bpf_map_lookup_elem(results_map_fd, &kretprobe_idx, &res);
134 	if (CHECK(err, "get_kretprobe_res",
135 		  "failed to get kretprobe res: %d\n", err))
136 		goto cleanup;
137 	if (CHECK(res != kretprobe_idx + 1, "check_kretprobe_res",
138 		  "wrong kretprobe res: %d\n", res))
139 		goto cleanup;
140 
141 	/* trigger & validate uprobe & uretprobe */
142 	get_base_addr();
143 
144 	err = bpf_map_lookup_elem(results_map_fd, &uprobe_idx, &res);
145 	if (CHECK(err, "get_uprobe_res",
146 		  "failed to get uprobe res: %d\n", err))
147 		goto cleanup;
148 	if (CHECK(res != uprobe_idx + 1, "check_uprobe_res",
149 		  "wrong uprobe res: %d\n", res))
150 		goto cleanup;
151 
152 	err = bpf_map_lookup_elem(results_map_fd, &uretprobe_idx, &res);
153 	if (CHECK(err, "get_uretprobe_res",
154 		  "failed to get uretprobe res: %d\n", err))
155 		goto cleanup;
156 	if (CHECK(res != uretprobe_idx + 1, "check_uretprobe_res",
157 		  "wrong uretprobe res: %d\n", res))
158 		goto cleanup;
159 
160 cleanup:
161 	bpf_link__destroy(kprobe_link);
162 	bpf_link__destroy(kretprobe_link);
163 	bpf_link__destroy(uprobe_link);
164 	bpf_link__destroy(uretprobe_link);
165 	bpf_object__close(obj);
166 }
167