1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include "test_attach_probe.skel.h"
4
5 /* this is how USDT semaphore is actually defined, except volatile modifier */
6 volatile unsigned short uprobe_ref_ctr __attribute__((unused)) __attribute((section(".probes")));
7
8 /* uprobe attach point */
trigger_func(void)9 static noinline void trigger_func(void)
10 {
11 asm volatile ("");
12 }
13
14 /* attach point for byname uprobe */
trigger_func2(void)15 static noinline void trigger_func2(void)
16 {
17 asm volatile ("");
18 }
19
20 /* attach point for byname sleepable uprobe */
trigger_func3(void)21 static noinline void trigger_func3(void)
22 {
23 asm volatile ("");
24 }
25
26 static char test_data[] = "test_data";
27
test_attach_probe(void)28 void test_attach_probe(void)
29 {
30 DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
31 struct bpf_link *kprobe_link, *kretprobe_link;
32 struct bpf_link *uprobe_link, *uretprobe_link;
33 struct test_attach_probe* skel;
34 ssize_t uprobe_offset, ref_ctr_offset;
35 struct bpf_link *uprobe_err_link;
36 FILE *devnull;
37 bool legacy;
38
39 /* Check if new-style kprobe/uprobe API is supported.
40 * Kernels that support new FD-based kprobe and uprobe BPF attachment
41 * through perf_event_open() syscall expose
42 * /sys/bus/event_source/devices/kprobe/type and
43 * /sys/bus/event_source/devices/uprobe/type files, respectively. They
44 * contain magic numbers that are passed as "type" field of
45 * perf_event_attr. Lack of such file in the system indicates legacy
46 * kernel with old-style kprobe/uprobe attach interface through
47 * creating per-probe event through tracefs. For such cases
48 * ref_ctr_offset feature is not supported, so we don't test it.
49 */
50 legacy = access("/sys/bus/event_source/devices/kprobe/type", F_OK) != 0;
51
52 uprobe_offset = get_uprobe_offset(&trigger_func);
53 if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset"))
54 return;
55
56 ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr);
57 if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset"))
58 return;
59
60 skel = test_attach_probe__open();
61 if (!ASSERT_OK_PTR(skel, "skel_open"))
62 return;
63
64 /* sleepable kprobe test case needs flags set before loading */
65 if (!ASSERT_OK(bpf_program__set_flags(skel->progs.handle_kprobe_sleepable,
66 BPF_F_SLEEPABLE), "kprobe_sleepable_flags"))
67 goto cleanup;
68
69 if (!ASSERT_OK(test_attach_probe__load(skel), "skel_load"))
70 goto cleanup;
71 if (!ASSERT_OK_PTR(skel->bss, "check_bss"))
72 goto cleanup;
73
74 /* manual-attach kprobe/kretprobe */
75 kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe,
76 false /* retprobe */,
77 SYS_NANOSLEEP_KPROBE_NAME);
78 if (!ASSERT_OK_PTR(kprobe_link, "attach_kprobe"))
79 goto cleanup;
80 skel->links.handle_kprobe = kprobe_link;
81
82 kretprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kretprobe,
83 true /* retprobe */,
84 SYS_NANOSLEEP_KPROBE_NAME);
85 if (!ASSERT_OK_PTR(kretprobe_link, "attach_kretprobe"))
86 goto cleanup;
87 skel->links.handle_kretprobe = kretprobe_link;
88
89 /* auto-attachable kprobe and kretprobe */
90 skel->links.handle_kprobe_auto = bpf_program__attach(skel->progs.handle_kprobe_auto);
91 ASSERT_OK_PTR(skel->links.handle_kprobe_auto, "attach_kprobe_auto");
92
93 skel->links.handle_kretprobe_auto = bpf_program__attach(skel->progs.handle_kretprobe_auto);
94 ASSERT_OK_PTR(skel->links.handle_kretprobe_auto, "attach_kretprobe_auto");
95
96 if (!legacy)
97 ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before");
98
99 uprobe_opts.retprobe = false;
100 uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset;
101 uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe,
102 0 /* self pid */,
103 "/proc/self/exe",
104 uprobe_offset,
105 &uprobe_opts);
106 if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe"))
107 goto cleanup;
108 skel->links.handle_uprobe = uprobe_link;
109
110 if (!legacy)
111 ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after");
112
113 /* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */
114 uprobe_opts.retprobe = true;
115 uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset;
116 uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe,
117 -1 /* any pid */,
118 "/proc/self/exe",
119 uprobe_offset, &uprobe_opts);
120 if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe"))
121 goto cleanup;
122 skel->links.handle_uretprobe = uretprobe_link;
123
124 /* verify auto-attach fails for old-style uprobe definition */
125 uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname);
126 if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -EOPNOTSUPP,
127 "auto-attach should fail for old-style name"))
128 goto cleanup;
129
130 uprobe_opts.func_name = "trigger_func2";
131 uprobe_opts.retprobe = false;
132 uprobe_opts.ref_ctr_offset = 0;
133 skel->links.handle_uprobe_byname =
134 bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname,
135 0 /* this pid */,
136 "/proc/self/exe",
137 0, &uprobe_opts);
138 if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname"))
139 goto cleanup;
140
141 /* verify auto-attach works */
142 skel->links.handle_uretprobe_byname =
143 bpf_program__attach(skel->progs.handle_uretprobe_byname);
144 if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname, "attach_uretprobe_byname"))
145 goto cleanup;
146
147 /* test attach by name for a library function, using the library
148 * as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo().
149 */
150 uprobe_opts.func_name = "fopen";
151 uprobe_opts.retprobe = false;
152 skel->links.handle_uprobe_byname2 =
153 bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2,
154 0 /* this pid */,
155 "libc.so.6",
156 0, &uprobe_opts);
157 if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2"))
158 goto cleanup;
159
160 uprobe_opts.func_name = "fclose";
161 uprobe_opts.retprobe = true;
162 skel->links.handle_uretprobe_byname2 =
163 bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2,
164 -1 /* any pid */,
165 "libc.so.6",
166 0, &uprobe_opts);
167 if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2"))
168 goto cleanup;
169
170 /* sleepable kprobes should not attach successfully */
171 skel->links.handle_kprobe_sleepable = bpf_program__attach(skel->progs.handle_kprobe_sleepable);
172 if (!ASSERT_ERR_PTR(skel->links.handle_kprobe_sleepable, "attach_kprobe_sleepable"))
173 goto cleanup;
174
175 /* test sleepable uprobe and uretprobe variants */
176 skel->links.handle_uprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uprobe_byname3_sleepable);
177 if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3_sleepable, "attach_uprobe_byname3_sleepable"))
178 goto cleanup;
179
180 skel->links.handle_uprobe_byname3 = bpf_program__attach(skel->progs.handle_uprobe_byname3);
181 if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3, "attach_uprobe_byname3"))
182 goto cleanup;
183
184 skel->links.handle_uretprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uretprobe_byname3_sleepable);
185 if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3_sleepable, "attach_uretprobe_byname3_sleepable"))
186 goto cleanup;
187
188 skel->links.handle_uretprobe_byname3 = bpf_program__attach(skel->progs.handle_uretprobe_byname3);
189 if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3, "attach_uretprobe_byname3"))
190 goto cleanup;
191
192 skel->bss->user_ptr = test_data;
193
194 /* trigger & validate kprobe && kretprobe */
195 usleep(1);
196
197 /* trigger & validate shared library u[ret]probes attached by name */
198 devnull = fopen("/dev/null", "r");
199 fclose(devnull);
200
201 /* trigger & validate uprobe & uretprobe */
202 trigger_func();
203
204 /* trigger & validate uprobe attached by name */
205 trigger_func2();
206
207 /* trigger & validate sleepable uprobe attached by name */
208 trigger_func3();
209
210 ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res");
211 ASSERT_EQ(skel->bss->kprobe2_res, 11, "check_kprobe_auto_res");
212 ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res");
213 ASSERT_EQ(skel->bss->kretprobe2_res, 22, "check_kretprobe_auto_res");
214 ASSERT_EQ(skel->bss->uprobe_res, 3, "check_uprobe_res");
215 ASSERT_EQ(skel->bss->uretprobe_res, 4, "check_uretprobe_res");
216 ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res");
217 ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res");
218 ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res");
219 ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res");
220 ASSERT_EQ(skel->bss->uprobe_byname3_sleepable_res, 9, "check_uprobe_byname3_sleepable_res");
221 ASSERT_EQ(skel->bss->uprobe_byname3_res, 10, "check_uprobe_byname3_res");
222 ASSERT_EQ(skel->bss->uretprobe_byname3_sleepable_res, 11, "check_uretprobe_byname3_sleepable_res");
223 ASSERT_EQ(skel->bss->uretprobe_byname3_res, 12, "check_uretprobe_byname3_res");
224
225 cleanup:
226 test_attach_probe__destroy(skel);
227 ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup");
228 }
229