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ecb96f7f YS |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | ||
3 | #include <stdio.h> | |
4 | #include <stdlib.h> | |
5 | #include <signal.h> | |
6 | #include <unistd.h> | |
7 | #include <stdbool.h> | |
8 | #include <string.h> | |
9 | #include <stdint.h> | |
10 | #include <fcntl.h> | |
11 | #include <linux/bpf.h> | |
12 | #include <sys/ioctl.h> | |
13 | #include <sys/resource.h> | |
14 | #include <sys/types.h> | |
15 | #include <sys/stat.h> | |
16 | ||
17 | #include "libbpf.h" | |
18 | #include "bpf_load.h" | |
19 | #include "bpf_util.h" | |
20 | #include "perf-sys.h" | |
21 | #include "trace_helpers.h" | |
22 | ||
23 | #define CHECK_PERROR_RET(condition) ({ \ | |
24 | int __ret = !!(condition); \ | |
25 | if (__ret) { \ | |
26 | printf("FAIL: %s:\n", __func__); \ | |
27 | perror(" "); \ | |
28 | return -1; \ | |
29 | } \ | |
30 | }) | |
31 | ||
32 | #define CHECK_AND_RET(condition) ({ \ | |
33 | int __ret = !!(condition); \ | |
34 | if (__ret) \ | |
35 | return -1; \ | |
36 | }) | |
37 | ||
38 | static __u64 ptr_to_u64(void *ptr) | |
39 | { | |
40 | return (__u64) (unsigned long) ptr; | |
41 | } | |
42 | ||
43 | #define PMU_TYPE_FILE "/sys/bus/event_source/devices/%s/type" | |
44 | static int bpf_find_probe_type(const char *event_type) | |
45 | { | |
46 | char buf[256]; | |
47 | int fd, ret; | |
48 | ||
49 | ret = snprintf(buf, sizeof(buf), PMU_TYPE_FILE, event_type); | |
50 | CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf)); | |
51 | ||
52 | fd = open(buf, O_RDONLY); | |
53 | CHECK_PERROR_RET(fd < 0); | |
54 | ||
55 | ret = read(fd, buf, sizeof(buf)); | |
56 | close(fd); | |
57 | CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf)); | |
58 | ||
59 | errno = 0; | |
60 | ret = (int)strtol(buf, NULL, 10); | |
61 | CHECK_PERROR_RET(errno); | |
62 | return ret; | |
63 | } | |
64 | ||
65 | #define PMU_RETPROBE_FILE "/sys/bus/event_source/devices/%s/format/retprobe" | |
66 | static int bpf_get_retprobe_bit(const char *event_type) | |
67 | { | |
68 | char buf[256]; | |
69 | int fd, ret; | |
70 | ||
71 | ret = snprintf(buf, sizeof(buf), PMU_RETPROBE_FILE, event_type); | |
72 | CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf)); | |
73 | ||
74 | fd = open(buf, O_RDONLY); | |
75 | CHECK_PERROR_RET(fd < 0); | |
76 | ||
77 | ret = read(fd, buf, sizeof(buf)); | |
78 | close(fd); | |
79 | CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf)); | |
80 | CHECK_PERROR_RET(strlen(buf) < strlen("config:")); | |
81 | ||
82 | errno = 0; | |
83 | ret = (int)strtol(buf + strlen("config:"), NULL, 10); | |
84 | CHECK_PERROR_RET(errno); | |
85 | return ret; | |
86 | } | |
87 | ||
88 | static int test_debug_fs_kprobe(int prog_fd_idx, const char *fn_name, | |
89 | __u32 expected_fd_type) | |
90 | { | |
91 | __u64 probe_offset, probe_addr; | |
92 | __u32 len, prog_id, fd_type; | |
93 | char buf[256]; | |
94 | int err; | |
95 | ||
96 | len = sizeof(buf); | |
97 | err = bpf_task_fd_query(getpid(), event_fd[prog_fd_idx], 0, buf, &len, | |
98 | &prog_id, &fd_type, &probe_offset, | |
99 | &probe_addr); | |
100 | if (err < 0) { | |
101 | printf("FAIL: %s, for event_fd idx %d, fn_name %s\n", | |
102 | __func__, prog_fd_idx, fn_name); | |
103 | perror(" :"); | |
104 | return -1; | |
105 | } | |
106 | if (strcmp(buf, fn_name) != 0 || | |
107 | fd_type != expected_fd_type || | |
108 | probe_offset != 0x0 || probe_addr != 0x0) { | |
109 | printf("FAIL: bpf_trace_event_query(event_fd[%d]):\n", | |
110 | prog_fd_idx); | |
111 | printf("buf: %s, fd_type: %u, probe_offset: 0x%llx," | |
112 | " probe_addr: 0x%llx\n", | |
113 | buf, fd_type, probe_offset, probe_addr); | |
114 | return -1; | |
115 | } | |
116 | return 0; | |
117 | } | |
118 | ||
119 | static int test_nondebug_fs_kuprobe_common(const char *event_type, | |
120 | const char *name, __u64 offset, __u64 addr, bool is_return, | |
121 | char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type, | |
122 | __u64 *probe_offset, __u64 *probe_addr) | |
123 | { | |
124 | int is_return_bit = bpf_get_retprobe_bit(event_type); | |
125 | int type = bpf_find_probe_type(event_type); | |
126 | struct perf_event_attr attr = {}; | |
127 | int fd; | |
128 | ||
129 | if (type < 0 || is_return_bit < 0) { | |
130 | printf("FAIL: %s incorrect type (%d) or is_return_bit (%d)\n", | |
131 | __func__, type, is_return_bit); | |
132 | return -1; | |
133 | } | |
134 | ||
135 | attr.sample_period = 1; | |
136 | attr.wakeup_events = 1; | |
137 | if (is_return) | |
138 | attr.config |= 1 << is_return_bit; | |
139 | ||
140 | if (name) { | |
141 | attr.config1 = ptr_to_u64((void *)name); | |
142 | attr.config2 = offset; | |
143 | } else { | |
144 | attr.config1 = 0; | |
145 | attr.config2 = addr; | |
146 | } | |
147 | attr.size = sizeof(attr); | |
148 | attr.type = type; | |
149 | ||
150 | fd = sys_perf_event_open(&attr, -1, 0, -1, 0); | |
151 | CHECK_PERROR_RET(fd < 0); | |
152 | ||
153 | CHECK_PERROR_RET(ioctl(fd, PERF_EVENT_IOC_ENABLE, 0) < 0); | |
154 | CHECK_PERROR_RET(ioctl(fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) < 0); | |
155 | CHECK_PERROR_RET(bpf_task_fd_query(getpid(), fd, 0, buf, buf_len, | |
156 | prog_id, fd_type, probe_offset, probe_addr) < 0); | |
157 | ||
158 | return 0; | |
159 | } | |
160 | ||
161 | static int test_nondebug_fs_probe(const char *event_type, const char *name, | |
162 | __u64 offset, __u64 addr, bool is_return, | |
163 | __u32 expected_fd_type, | |
164 | __u32 expected_ret_fd_type, | |
165 | char *buf, __u32 buf_len) | |
166 | { | |
167 | __u64 probe_offset, probe_addr; | |
168 | __u32 prog_id, fd_type; | |
169 | int err; | |
170 | ||
171 | err = test_nondebug_fs_kuprobe_common(event_type, name, | |
172 | offset, addr, is_return, | |
173 | buf, &buf_len, &prog_id, | |
174 | &fd_type, &probe_offset, | |
175 | &probe_addr); | |
176 | if (err < 0) { | |
177 | printf("FAIL: %s, " | |
178 | "for name %s, offset 0x%llx, addr 0x%llx, is_return %d\n", | |
179 | __func__, name ? name : "", offset, addr, is_return); | |
180 | perror(" :"); | |
181 | return -1; | |
182 | } | |
183 | if ((is_return && fd_type != expected_ret_fd_type) || | |
184 | (!is_return && fd_type != expected_fd_type)) { | |
185 | printf("FAIL: %s, incorrect fd_type %u\n", | |
186 | __func__, fd_type); | |
187 | return -1; | |
188 | } | |
189 | if (name) { | |
190 | if (strcmp(name, buf) != 0) { | |
191 | printf("FAIL: %s, incorrect buf %s\n", __func__, buf); | |
192 | return -1; | |
193 | } | |
194 | if (probe_offset != offset) { | |
195 | printf("FAIL: %s, incorrect probe_offset 0x%llx\n", | |
196 | __func__, probe_offset); | |
197 | return -1; | |
198 | } | |
199 | } else { | |
200 | if (buf_len != 0) { | |
201 | printf("FAIL: %s, incorrect buf %p\n", | |
202 | __func__, buf); | |
203 | return -1; | |
204 | } | |
205 | ||
206 | if (probe_addr != addr) { | |
207 | printf("FAIL: %s, incorrect probe_addr 0x%llx\n", | |
208 | __func__, probe_addr); | |
209 | return -1; | |
210 | } | |
211 | } | |
212 | return 0; | |
213 | } | |
214 | ||
215 | static int test_debug_fs_uprobe(char *binary_path, long offset, bool is_return) | |
216 | { | |
217 | const char *event_type = "uprobe"; | |
218 | struct perf_event_attr attr = {}; | |
219 | char buf[256], event_alias[256]; | |
220 | __u64 probe_offset, probe_addr; | |
221 | __u32 len, prog_id, fd_type; | |
222 | int err, res, kfd, efd; | |
223 | ssize_t bytes; | |
224 | ||
225 | snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events", | |
226 | event_type); | |
227 | kfd = open(buf, O_WRONLY | O_APPEND, 0); | |
228 | CHECK_PERROR_RET(kfd < 0); | |
229 | ||
230 | res = snprintf(event_alias, sizeof(event_alias), "test_%d", getpid()); | |
231 | CHECK_PERROR_RET(res < 0 || res >= sizeof(event_alias)); | |
232 | ||
233 | res = snprintf(buf, sizeof(buf), "%c:%ss/%s %s:0x%lx", | |
234 | is_return ? 'r' : 'p', event_type, event_alias, | |
235 | binary_path, offset); | |
236 | CHECK_PERROR_RET(res < 0 || res >= sizeof(buf)); | |
237 | CHECK_PERROR_RET(write(kfd, buf, strlen(buf)) < 0); | |
238 | ||
239 | close(kfd); | |
240 | kfd = -1; | |
241 | ||
242 | snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id", | |
243 | event_type, event_alias); | |
244 | efd = open(buf, O_RDONLY, 0); | |
245 | CHECK_PERROR_RET(efd < 0); | |
246 | ||
247 | bytes = read(efd, buf, sizeof(buf)); | |
248 | CHECK_PERROR_RET(bytes <= 0 || bytes >= sizeof(buf)); | |
249 | close(efd); | |
250 | buf[bytes] = '\0'; | |
251 | ||
252 | attr.config = strtol(buf, NULL, 0); | |
253 | attr.type = PERF_TYPE_TRACEPOINT; | |
254 | attr.sample_period = 1; | |
255 | attr.wakeup_events = 1; | |
256 | kfd = sys_perf_event_open(&attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC); | |
257 | CHECK_PERROR_RET(kfd < 0); | |
258 | CHECK_PERROR_RET(ioctl(kfd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) < 0); | |
259 | CHECK_PERROR_RET(ioctl(kfd, PERF_EVENT_IOC_ENABLE, 0) < 0); | |
260 | ||
261 | len = sizeof(buf); | |
262 | err = bpf_task_fd_query(getpid(), kfd, 0, buf, &len, | |
263 | &prog_id, &fd_type, &probe_offset, | |
264 | &probe_addr); | |
265 | if (err < 0) { | |
266 | printf("FAIL: %s, binary_path %s\n", __func__, binary_path); | |
267 | perror(" :"); | |
268 | return -1; | |
269 | } | |
270 | if ((is_return && fd_type != BPF_FD_TYPE_URETPROBE) || | |
271 | (!is_return && fd_type != BPF_FD_TYPE_UPROBE)) { | |
272 | printf("FAIL: %s, incorrect fd_type %u\n", __func__, | |
273 | fd_type); | |
274 | return -1; | |
275 | } | |
276 | if (strcmp(binary_path, buf) != 0) { | |
277 | printf("FAIL: %s, incorrect buf %s\n", __func__, buf); | |
278 | return -1; | |
279 | } | |
280 | if (probe_offset != offset) { | |
281 | printf("FAIL: %s, incorrect probe_offset 0x%llx\n", __func__, | |
282 | probe_offset); | |
283 | return -1; | |
284 | } | |
285 | ||
286 | close(kfd); | |
287 | return 0; | |
288 | } | |
289 | ||
290 | int main(int argc, char **argv) | |
291 | { | |
292 | struct rlimit r = {1024*1024, RLIM_INFINITY}; | |
293 | extern char __executable_start; | |
294 | char filename[256], buf[256]; | |
295 | __u64 uprobe_file_offset; | |
296 | ||
297 | snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); | |
298 | if (setrlimit(RLIMIT_MEMLOCK, &r)) { | |
299 | perror("setrlimit(RLIMIT_MEMLOCK)"); | |
300 | return 1; | |
301 | } | |
302 | ||
303 | if (load_kallsyms()) { | |
304 | printf("failed to process /proc/kallsyms\n"); | |
305 | return 1; | |
306 | } | |
307 | ||
308 | if (load_bpf_file(filename)) { | |
309 | printf("%s", bpf_log_buf); | |
310 | return 1; | |
311 | } | |
312 | ||
313 | /* test two functions in the corresponding *_kern.c file */ | |
d2e614cb | 314 | CHECK_AND_RET(test_debug_fs_kprobe(0, "blk_mq_start_request", |
ecb96f7f YS |
315 | BPF_FD_TYPE_KPROBE)); |
316 | CHECK_AND_RET(test_debug_fs_kprobe(1, "blk_account_io_completion", | |
317 | BPF_FD_TYPE_KRETPROBE)); | |
318 | ||
319 | /* test nondebug fs kprobe */ | |
320 | CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0, | |
321 | false, BPF_FD_TYPE_KPROBE, | |
322 | BPF_FD_TYPE_KRETPROBE, | |
323 | buf, sizeof(buf))); | |
324 | #ifdef __x86_64__ | |
325 | /* set a kprobe on "bpf_check + 0x5", which is x64 specific */ | |
326 | CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x5, 0x0, | |
327 | false, BPF_FD_TYPE_KPROBE, | |
328 | BPF_FD_TYPE_KRETPROBE, | |
329 | buf, sizeof(buf))); | |
330 | #endif | |
331 | CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0, | |
332 | true, BPF_FD_TYPE_KPROBE, | |
333 | BPF_FD_TYPE_KRETPROBE, | |
334 | buf, sizeof(buf))); | |
335 | CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0, | |
336 | ksym_get_addr("bpf_check"), false, | |
337 | BPF_FD_TYPE_KPROBE, | |
338 | BPF_FD_TYPE_KRETPROBE, | |
339 | buf, sizeof(buf))); | |
340 | CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0, | |
341 | ksym_get_addr("bpf_check"), false, | |
342 | BPF_FD_TYPE_KPROBE, | |
343 | BPF_FD_TYPE_KRETPROBE, | |
344 | NULL, 0)); | |
345 | CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0, | |
346 | ksym_get_addr("bpf_check"), true, | |
347 | BPF_FD_TYPE_KPROBE, | |
348 | BPF_FD_TYPE_KRETPROBE, | |
349 | buf, sizeof(buf))); | |
350 | CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0, | |
351 | ksym_get_addr("bpf_check"), true, | |
352 | BPF_FD_TYPE_KPROBE, | |
353 | BPF_FD_TYPE_KRETPROBE, | |
354 | 0, 0)); | |
355 | ||
356 | /* test nondebug fs uprobe */ | |
357 | /* the calculation of uprobe file offset is based on gcc 7.3.1 on x64 | |
358 | * and the default linker script, which defines __executable_start as | |
359 | * the start of the .text section. The calculation could be different | |
360 | * on different systems with different compilers. The right way is | |
361 | * to parse the ELF file. We took a shortcut here. | |
362 | */ | |
363 | uprobe_file_offset = (__u64)main - (__u64)&__executable_start; | |
364 | CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0], | |
365 | uprobe_file_offset, 0x0, false, | |
366 | BPF_FD_TYPE_UPROBE, | |
367 | BPF_FD_TYPE_URETPROBE, | |
368 | buf, sizeof(buf))); | |
369 | CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0], | |
370 | uprobe_file_offset, 0x0, true, | |
371 | BPF_FD_TYPE_UPROBE, | |
372 | BPF_FD_TYPE_URETPROBE, | |
373 | buf, sizeof(buf))); | |
374 | ||
375 | /* test debug fs uprobe */ | |
376 | CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset, | |
377 | false)); | |
378 | CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset, | |
379 | true)); | |
380 | ||
381 | return 0; | |
382 | } |