xref: /linux/tools/testing/selftests/bpf/prog_tests/attach_probe.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include "test_attach_kprobe_sleepable.skel.h"
4 #include "test_attach_probe_manual.skel.h"
5 #include "test_attach_probe.skel.h"
6 
7 /* this is how USDT semaphore is actually defined, except volatile modifier */
8 volatile unsigned short uprobe_ref_ctr __attribute__((unused)) __attribute((section(".probes")));
9 
10 /* uprobe attach point */
11 static noinline void trigger_func(void)
12 {
13 	asm volatile ("");
14 }
15 
16 /* attach point for byname uprobe */
17 static noinline void trigger_func2(void)
18 {
19 	asm volatile ("");
20 }
21 
22 /* attach point for byname sleepable uprobe */
23 static noinline void trigger_func3(void)
24 {
25 	asm volatile ("");
26 }
27 
28 /* attach point for ref_ctr */
29 static noinline void trigger_func4(void)
30 {
31 	asm volatile ("");
32 }
33 
34 static char test_data[] = "test_data";
35 
36 /* manual attach kprobe/kretprobe/uprobe/uretprobe testings */
37 static void test_attach_probe_manual(enum probe_attach_mode attach_mode)
38 {
39 	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
40 	DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, kprobe_opts);
41 	struct bpf_link *kprobe_link, *kretprobe_link;
42 	struct bpf_link *uprobe_link, *uretprobe_link;
43 	struct test_attach_probe_manual *skel;
44 	ssize_t uprobe_offset;
45 
46 	skel = test_attach_probe_manual__open_and_load();
47 	if (!ASSERT_OK_PTR(skel, "skel_kprobe_manual_open_and_load"))
48 		return;
49 
50 	uprobe_offset = get_uprobe_offset(&trigger_func);
51 	if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset"))
52 		goto cleanup;
53 
54 	/* manual-attach kprobe/kretprobe */
55 	kprobe_opts.attach_mode = attach_mode;
56 	kprobe_opts.retprobe = false;
57 	kprobe_link = bpf_program__attach_kprobe_opts(skel->progs.handle_kprobe,
58 						      SYS_NANOSLEEP_KPROBE_NAME,
59 						      &kprobe_opts);
60 	if (!ASSERT_OK_PTR(kprobe_link, "attach_kprobe"))
61 		goto cleanup;
62 	skel->links.handle_kprobe = kprobe_link;
63 
64 	kprobe_opts.retprobe = true;
65 	kretprobe_link = bpf_program__attach_kprobe_opts(skel->progs.handle_kretprobe,
66 							 SYS_NANOSLEEP_KPROBE_NAME,
67 							 &kprobe_opts);
68 	if (!ASSERT_OK_PTR(kretprobe_link, "attach_kretprobe"))
69 		goto cleanup;
70 	skel->links.handle_kretprobe = kretprobe_link;
71 
72 	/* manual-attach uprobe/uretprobe */
73 	uprobe_opts.attach_mode = attach_mode;
74 	uprobe_opts.ref_ctr_offset = 0;
75 	uprobe_opts.retprobe = false;
76 	uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe,
77 						      0 /* self pid */,
78 						      "/proc/self/exe",
79 						      uprobe_offset,
80 						      &uprobe_opts);
81 	if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe"))
82 		goto cleanup;
83 	skel->links.handle_uprobe = uprobe_link;
84 
85 	uprobe_opts.retprobe = true;
86 	uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe,
87 							 -1 /* any pid */,
88 							 "/proc/self/exe",
89 							 uprobe_offset, &uprobe_opts);
90 	if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe"))
91 		goto cleanup;
92 	skel->links.handle_uretprobe = uretprobe_link;
93 
94 	/* attach uprobe by function name manually */
95 	uprobe_opts.func_name = "trigger_func2";
96 	uprobe_opts.retprobe = false;
97 	uprobe_opts.ref_ctr_offset = 0;
98 	skel->links.handle_uprobe_byname =
99 			bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname,
100 							0 /* this pid */,
101 							"/proc/self/exe",
102 							0, &uprobe_opts);
103 	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname"))
104 		goto cleanup;
105 
106 	/* trigger & validate kprobe && kretprobe */
107 	usleep(1);
108 
109 	/* trigger & validate uprobe & uretprobe */
110 	trigger_func();
111 
112 	/* trigger & validate uprobe attached by name */
113 	trigger_func2();
114 
115 	ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res");
116 	ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res");
117 	ASSERT_EQ(skel->bss->uprobe_res, 3, "check_uprobe_res");
118 	ASSERT_EQ(skel->bss->uretprobe_res, 4, "check_uretprobe_res");
119 	ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res");
120 
121 cleanup:
122 	test_attach_probe_manual__destroy(skel);
123 }
124 
125 static void test_attach_probe_auto(struct test_attach_probe *skel)
126 {
127 	struct bpf_link *uprobe_err_link;
128 
129 	/* auto-attachable kprobe and kretprobe */
130 	skel->links.handle_kprobe_auto = bpf_program__attach(skel->progs.handle_kprobe_auto);
131 	ASSERT_OK_PTR(skel->links.handle_kprobe_auto, "attach_kprobe_auto");
132 
133 	skel->links.handle_kretprobe_auto = bpf_program__attach(skel->progs.handle_kretprobe_auto);
134 	ASSERT_OK_PTR(skel->links.handle_kretprobe_auto, "attach_kretprobe_auto");
135 
136 	/* verify auto-attach fails for old-style uprobe definition */
137 	uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname);
138 	if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -EOPNOTSUPP,
139 		       "auto-attach should fail for old-style name"))
140 		return;
141 
142 	/* verify auto-attach works */
143 	skel->links.handle_uretprobe_byname =
144 			bpf_program__attach(skel->progs.handle_uretprobe_byname);
145 	if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname, "attach_uretprobe_byname"))
146 		return;
147 
148 	/* trigger & validate kprobe && kretprobe */
149 	usleep(1);
150 
151 	/* trigger & validate uprobe attached by name */
152 	trigger_func2();
153 
154 	ASSERT_EQ(skel->bss->kprobe2_res, 11, "check_kprobe_auto_res");
155 	ASSERT_EQ(skel->bss->kretprobe2_res, 22, "check_kretprobe_auto_res");
156 	ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res");
157 }
158 
159 static void test_uprobe_lib(struct test_attach_probe *skel)
160 {
161 	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
162 	FILE *devnull;
163 
164 	/* test attach by name for a library function, using the library
165 	 * as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo().
166 	 */
167 	uprobe_opts.func_name = "fopen";
168 	uprobe_opts.retprobe = false;
169 	skel->links.handle_uprobe_byname2 =
170 			bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2,
171 							0 /* this pid */,
172 							"libc.so.6",
173 							0, &uprobe_opts);
174 	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2"))
175 		return;
176 
177 	uprobe_opts.func_name = "fclose";
178 	uprobe_opts.retprobe = true;
179 	skel->links.handle_uretprobe_byname2 =
180 			bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2,
181 							-1 /* any pid */,
182 							"libc.so.6",
183 							0, &uprobe_opts);
184 	if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2"))
185 		return;
186 
187 	/* trigger & validate shared library u[ret]probes attached by name */
188 	devnull = fopen("/dev/null", "r");
189 	fclose(devnull);
190 
191 	ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res");
192 	ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res");
193 }
194 
195 static void test_uprobe_ref_ctr(struct test_attach_probe *skel)
196 {
197 	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
198 	struct bpf_link *uprobe_link, *uretprobe_link;
199 	ssize_t uprobe_offset, ref_ctr_offset;
200 
201 	uprobe_offset = get_uprobe_offset(&trigger_func4);
202 	if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset_ref_ctr"))
203 		return;
204 
205 	ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr);
206 	if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset"))
207 		return;
208 
209 	ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before");
210 
211 	uprobe_opts.retprobe = false;
212 	uprobe_opts.ref_ctr_offset = ref_ctr_offset;
213 	uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_ref_ctr,
214 						      0 /* self pid */,
215 						      "/proc/self/exe",
216 						      uprobe_offset,
217 						      &uprobe_opts);
218 	if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe_ref_ctr"))
219 		return;
220 	skel->links.handle_uprobe_ref_ctr = uprobe_link;
221 
222 	ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after");
223 
224 	/* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */
225 	uprobe_opts.retprobe = true;
226 	uprobe_opts.ref_ctr_offset = ref_ctr_offset;
227 	uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_ref_ctr,
228 							 -1 /* any pid */,
229 							 "/proc/self/exe",
230 							 uprobe_offset, &uprobe_opts);
231 	if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe_ref_ctr"))
232 		return;
233 	skel->links.handle_uretprobe_ref_ctr = uretprobe_link;
234 }
235 
236 static void test_kprobe_sleepable(void)
237 {
238 	struct test_attach_kprobe_sleepable *skel;
239 
240 	skel = test_attach_kprobe_sleepable__open();
241 	if (!ASSERT_OK_PTR(skel, "skel_kprobe_sleepable_open"))
242 		return;
243 
244 	/* sleepable kprobe test case needs flags set before loading */
245 	if (!ASSERT_OK(bpf_program__set_flags(skel->progs.handle_kprobe_sleepable,
246 		BPF_F_SLEEPABLE), "kprobe_sleepable_flags"))
247 		goto cleanup;
248 
249 	if (!ASSERT_OK(test_attach_kprobe_sleepable__load(skel),
250 		       "skel_kprobe_sleepable_load"))
251 		goto cleanup;
252 
253 	/* sleepable kprobes should not attach successfully */
254 	skel->links.handle_kprobe_sleepable = bpf_program__attach(skel->progs.handle_kprobe_sleepable);
255 	ASSERT_ERR_PTR(skel->links.handle_kprobe_sleepable, "attach_kprobe_sleepable");
256 
257 cleanup:
258 	test_attach_kprobe_sleepable__destroy(skel);
259 }
260 
261 static void test_uprobe_sleepable(struct test_attach_probe *skel)
262 {
263 	/* test sleepable uprobe and uretprobe variants */
264 	skel->links.handle_uprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uprobe_byname3_sleepable);
265 	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3_sleepable, "attach_uprobe_byname3_sleepable"))
266 		return;
267 
268 	skel->links.handle_uprobe_byname3 = bpf_program__attach(skel->progs.handle_uprobe_byname3);
269 	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3, "attach_uprobe_byname3"))
270 		return;
271 
272 	skel->links.handle_uretprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uretprobe_byname3_sleepable);
273 	if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3_sleepable, "attach_uretprobe_byname3_sleepable"))
274 		return;
275 
276 	skel->links.handle_uretprobe_byname3 = bpf_program__attach(skel->progs.handle_uretprobe_byname3);
277 	if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3, "attach_uretprobe_byname3"))
278 		return;
279 
280 	skel->bss->user_ptr = test_data;
281 
282 	/* trigger & validate sleepable uprobe attached by name */
283 	trigger_func3();
284 
285 	ASSERT_EQ(skel->bss->uprobe_byname3_sleepable_res, 9, "check_uprobe_byname3_sleepable_res");
286 	ASSERT_EQ(skel->bss->uprobe_byname3_str_sleepable_res, 10, "check_uprobe_byname3_str_sleepable_res");
287 	ASSERT_EQ(skel->bss->uprobe_byname3_res, 11, "check_uprobe_byname3_res");
288 	ASSERT_EQ(skel->bss->uretprobe_byname3_sleepable_res, 12, "check_uretprobe_byname3_sleepable_res");
289 	ASSERT_EQ(skel->bss->uretprobe_byname3_str_sleepable_res, 13, "check_uretprobe_byname3_str_sleepable_res");
290 	ASSERT_EQ(skel->bss->uretprobe_byname3_res, 14, "check_uretprobe_byname3_res");
291 }
292 
293 void test_attach_probe(void)
294 {
295 	struct test_attach_probe *skel;
296 
297 	skel = test_attach_probe__open();
298 	if (!ASSERT_OK_PTR(skel, "skel_open"))
299 		return;
300 
301 	if (!ASSERT_OK(test_attach_probe__load(skel), "skel_load"))
302 		goto cleanup;
303 	if (!ASSERT_OK_PTR(skel->bss, "check_bss"))
304 		goto cleanup;
305 
306 	if (test__start_subtest("manual-default"))
307 		test_attach_probe_manual(PROBE_ATTACH_MODE_DEFAULT);
308 	if (test__start_subtest("manual-legacy"))
309 		test_attach_probe_manual(PROBE_ATTACH_MODE_LEGACY);
310 	if (test__start_subtest("manual-perf"))
311 		test_attach_probe_manual(PROBE_ATTACH_MODE_PERF);
312 	if (test__start_subtest("manual-link"))
313 		test_attach_probe_manual(PROBE_ATTACH_MODE_LINK);
314 
315 	if (test__start_subtest("auto"))
316 		test_attach_probe_auto(skel);
317 	if (test__start_subtest("kprobe-sleepable"))
318 		test_kprobe_sleepable();
319 	if (test__start_subtest("uprobe-lib"))
320 		test_uprobe_lib(skel);
321 	if (test__start_subtest("uprobe-sleepable"))
322 		test_uprobe_sleepable(skel);
323 	if (test__start_subtest("uprobe-ref_ctr"))
324 		test_uprobe_ref_ctr(skel);
325 
326 cleanup:
327 	test_attach_probe__destroy(skel);
328 	ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup");
329 }
330