1 // SPDX-License-Identifier: GPL-2.0
2 #include <inttypes.h>
3 #include <pthread.h>
4 #include <stdbool.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <sys/mount.h>
8 #include <sys/time.h>
9 #include <unistd.h>
10 #include "../../../../../include/linux/kernel.h"
11 #include "aolib.h"
12
13 static char ftrace_path[] = "ksft-ftrace-XXXXXX";
14 static bool ftrace_mounted;
15 uint64_t ns_cookie1, ns_cookie2;
16
17 struct test_ftracer {
18 pthread_t tracer_thread;
19 int error;
20 char *instance_path;
21 FILE *trace_pipe;
22
23 enum ftracer_op (*process_line)(const char *line);
24 void (*destructor)(struct test_ftracer *tracer);
25 bool (*expecting_more)(void);
26
27 char **saved_lines;
28 size_t saved_lines_size;
29 size_t next_line_ind;
30
31 pthread_cond_t met_all_expected;
32 pthread_mutex_t met_all_expected_lock;
33
34 struct test_ftracer *next;
35 };
36
37 static struct test_ftracer *ftracers;
38 static pthread_mutex_t ftracers_lock = PTHREAD_MUTEX_INITIALIZER;
39
40 static int mount_ftrace(void)
41 {
42 if (!mkdtemp(ftrace_path))
43 test_error("Can't create temp dir");
44
45 if (mount("tracefs", ftrace_path, "tracefs", 0, "rw"))
46 return -errno;
47
48 ftrace_mounted = true;
49
50 return 0;
51 }
52
53 static void unmount_ftrace(void)
54 {
55 if (ftrace_mounted && umount(ftrace_path))
56 test_print("Failed on cleanup: can't unmount tracefs: %m");
57
58 if (rmdir(ftrace_path))
59 test_error("Failed on cleanup: can't remove ftrace dir %s",
60 ftrace_path);
61 }
62
63 struct opts_list_t {
64 char *opt_name;
65 struct opts_list_t *next;
66 };
67
68 static int disable_trace_options(const char *ftrace_path)
69 {
70 struct opts_list_t *opts_list = NULL;
71 char *fopts, *line = NULL;
72 size_t buf_len = 0;
73 ssize_t line_len;
74 int ret = 0;
75 FILE *opts;
76
77 fopts = test_sprintf("%s/%s", ftrace_path, "trace_options");
78 if (!fopts)
79 return -ENOMEM;
80
81 opts = fopen(fopts, "r+");
82 if (!opts) {
83 ret = -errno;
84 goto out_free;
85 }
86
87 while ((line_len = getline(&line, &buf_len, opts)) != -1) {
88 struct opts_list_t *tmp;
89
90 if (!strncmp(line, "no", 2))
91 continue;
92
93 tmp = malloc(sizeof(*tmp));
94 if (!tmp) {
95 ret = -ENOMEM;
96 goto out_free_opts_list;
97 }
98 tmp->next = opts_list;
99 tmp->opt_name = test_sprintf("no%s", line);
100 if (!tmp->opt_name) {
101 ret = -ENOMEM;
102 free(tmp);
103 goto out_free_opts_list;
104 }
105 opts_list = tmp;
106 }
107
108 while (opts_list) {
109 struct opts_list_t *tmp = opts_list;
110
111 fseek(opts, 0, SEEK_SET);
112 fwrite(tmp->opt_name, 1, strlen(tmp->opt_name), opts);
113
114 opts_list = opts_list->next;
115 free(tmp->opt_name);
116 free(tmp);
117 }
118
119 out_free_opts_list:
120 while (opts_list) {
121 struct opts_list_t *tmp = opts_list;
122
123 opts_list = opts_list->next;
124 free(tmp->opt_name);
125 free(tmp);
126 }
127 free(line);
128 fclose(opts);
129 out_free:
130 free(fopts);
131 return ret;
132 }
133
134 static int setup_buffer_size(const char *ftrace_path, size_t sz)
135 {
136 char *fbuf_size = test_sprintf("%s/buffer_size_kb", ftrace_path);
137 int ret;
138
139 if (!fbuf_size)
140 return -1;
141
142 ret = test_echo(fbuf_size, 0, "%zu", sz);
143 free(fbuf_size);
144 return ret;
145 }
146
147 static int setup_ftrace_instance(struct test_ftracer *tracer, const char *name)
148 {
149 char *tmp;
150
151 tmp = test_sprintf("%s/instances/ksft-%s-XXXXXX", ftrace_path, name);
152 if (!tmp)
153 return -ENOMEM;
154
155 tracer->instance_path = mkdtemp(tmp);
156 if (!tracer->instance_path) {
157 free(tmp);
158 return -errno;
159 }
160
161 return 0;
162 }
163
164 static void remove_ftrace_instance(struct test_ftracer *tracer)
165 {
166 if (rmdir(tracer->instance_path))
167 test_print("Failed on cleanup: can't remove ftrace instance %s",
168 tracer->instance_path);
169 free(tracer->instance_path);
170 }
171
172 static void tracer_cleanup(void *arg)
173 {
174 struct test_ftracer *tracer = arg;
175
176 fclose(tracer->trace_pipe);
177 }
178
179 static void tracer_set_error(struct test_ftracer *tracer, int error)
180 {
181 if (!tracer->error)
182 tracer->error = error;
183 }
184
185 const size_t tracer_get_savedlines_nr(struct test_ftracer *tracer)
186 {
187 return tracer->next_line_ind;
188 }
189
190 const char **tracer_get_savedlines(struct test_ftracer *tracer)
191 {
192 return (const char **)tracer->saved_lines;
193 }
194
195 static void *tracer_thread_func(void *arg)
196 {
197 struct test_ftracer *tracer = arg;
198
199 pthread_cleanup_push(tracer_cleanup, arg);
200
201 while (tracer->next_line_ind < tracer->saved_lines_size) {
202 char **lp = &tracer->saved_lines[tracer->next_line_ind];
203 enum ftracer_op op;
204 size_t buf_len = 0;
205 ssize_t line_len;
206
207 line_len = getline(lp, &buf_len, tracer->trace_pipe);
208 if (line_len == -1)
209 break;
210
211 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
212 op = tracer->process_line(*lp);
213 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
214
215 if (tracer->expecting_more) {
216 pthread_mutex_lock(&tracer->met_all_expected_lock);
217 if (!tracer->expecting_more())
218 pthread_cond_signal(&tracer->met_all_expected);
219 pthread_mutex_unlock(&tracer->met_all_expected_lock);
220 }
221
222 if (op == FTRACER_LINE_DISCARD)
223 continue;
224 if (op == FTRACER_EXIT)
225 break;
226 if (op != FTRACER_LINE_PRESERVE)
227 test_error("unexpected tracer command %d", op);
228
229 tracer->next_line_ind++;
230 buf_len = 0;
231 }
232 test_print("too many lines in ftracer buffer %zu, exiting tracer",
233 tracer->next_line_ind);
234
235 pthread_cleanup_pop(1);
236 return NULL;
237 }
238
239 static int setup_trace_thread(struct test_ftracer *tracer)
240 {
241 int ret = 0;
242 char *path;
243
244 path = test_sprintf("%s/trace_pipe", tracer->instance_path);
245 if (!path)
246 return -ENOMEM;
247
248 tracer->trace_pipe = fopen(path, "r");
249 if (!tracer->trace_pipe) {
250 ret = -errno;
251 goto out_free;
252 }
253
254 if (pthread_create(&tracer->tracer_thread, NULL,
255 tracer_thread_func, (void *)tracer)) {
256 ret = -errno;
257 fclose(tracer->trace_pipe);
258 }
259
260 out_free:
261 free(path);
262 return ret;
263 }
264
265 static void stop_trace_thread(struct test_ftracer *tracer)
266 {
267 void *res;
268
269 if (pthread_cancel(tracer->tracer_thread)) {
270 test_print("Can't stop tracer pthread: %m");
271 tracer_set_error(tracer, -errno);
272 }
273 if (pthread_join(tracer->tracer_thread, &res)) {
274 test_print("Can't join tracer pthread: %m");
275 tracer_set_error(tracer, -errno);
276 }
277 if (res != PTHREAD_CANCELED) {
278 test_print("Tracer thread wasn't canceled");
279 tracer_set_error(tracer, -errno);
280 }
281 if (tracer->error)
282 test_fail("tracer errored by %s", strerror(tracer->error));
283 }
284
285 static void final_wait_for_events(struct test_ftracer *tracer,
286 unsigned timeout_sec)
287 {
288 struct timespec timeout;
289 struct timeval now;
290 int ret = 0;
291
292 if (!tracer->expecting_more)
293 return;
294
295 pthread_mutex_lock(&tracer->met_all_expected_lock);
296 gettimeofday(&now, NULL);
297 timeout.tv_sec = now.tv_sec + timeout_sec;
298 timeout.tv_nsec = now.tv_usec * 1000;
299
300 while (tracer->expecting_more() && ret != ETIMEDOUT)
301 ret = pthread_cond_timedwait(&tracer->met_all_expected,
302 &tracer->met_all_expected_lock, &timeout);
303 pthread_mutex_unlock(&tracer->met_all_expected_lock);
304 }
305
306 int setup_trace_event(struct test_ftracer *tracer,
307 const char *event, const char *filter)
308 {
309 char *enable_path, *filter_path, *instance = tracer->instance_path;
310 int ret;
311
312 enable_path = test_sprintf("%s/events/%s/enable", instance, event);
313 if (!enable_path)
314 return -ENOMEM;
315
316 filter_path = test_sprintf("%s/events/%s/filter", instance, event);
317 if (!filter_path) {
318 ret = -ENOMEM;
319 goto out_free;
320 }
321
322 ret = test_echo(filter_path, 0, "%s", filter);
323 if (!ret)
324 ret = test_echo(enable_path, 0, "1");
325
326 out_free:
327 free(filter_path);
328 free(enable_path);
329 return ret;
330 }
331
332 struct test_ftracer *create_ftracer(const char *name,
333 enum ftracer_op (*process_line)(const char *line),
334 void (*destructor)(struct test_ftracer *tracer),
335 bool (*expecting_more)(void),
336 size_t lines_buf_sz, size_t buffer_size_kb)
337 {
338 struct test_ftracer *tracer;
339 int err;
340
341 /* XXX: separate __create_ftracer() helper and do here
342 * if (!kernel_config_has(KCONFIG_FTRACE))
343 * return NULL;
344 */
345
346 tracer = malloc(sizeof(*tracer));
347 if (!tracer) {
348 test_print("malloc()");
349 return NULL;
350 }
351
352 memset(tracer, 0, sizeof(*tracer));
353
354 err = setup_ftrace_instance(tracer, name);
355 if (err) {
356 test_print("setup_ftrace_instance(): %d", err);
357 goto err_free;
358 }
359
360 err = disable_trace_options(tracer->instance_path);
361 if (err) {
362 test_print("disable_trace_options(): %d", err);
363 goto err_remove;
364 }
365
366 err = setup_buffer_size(tracer->instance_path, buffer_size_kb);
367 if (err) {
368 test_print("disable_trace_options(): %d", err);
369 goto err_remove;
370 }
371
372 tracer->saved_lines = calloc(lines_buf_sz, sizeof(tracer->saved_lines[0]));
373 if (!tracer->saved_lines) {
374 test_print("calloc()");
375 goto err_remove;
376 }
377 tracer->saved_lines_size = lines_buf_sz;
378
379 tracer->process_line = process_line;
380 tracer->destructor = destructor;
381 tracer->expecting_more = expecting_more;
382
383 err = pthread_cond_init(&tracer->met_all_expected, NULL);
384 if (err) {
385 test_print("pthread_cond_init(): %d", err);
386 goto err_free_lines;
387 }
388
389 err = pthread_mutex_init(&tracer->met_all_expected_lock, NULL);
390 if (err) {
391 test_print("pthread_mutex_init(): %d", err);
392 goto err_cond_destroy;
393 }
394
395 err = setup_trace_thread(tracer);
396 if (err) {
397 test_print("setup_trace_thread(): %d", err);
398 goto err_mutex_destroy;
399 }
400
401 pthread_mutex_lock(&ftracers_lock);
402 tracer->next = ftracers;
403 ftracers = tracer;
404 pthread_mutex_unlock(&ftracers_lock);
405
406 return tracer;
407
408 err_mutex_destroy:
409 pthread_mutex_destroy(&tracer->met_all_expected_lock);
410 err_cond_destroy:
411 pthread_cond_destroy(&tracer->met_all_expected);
412 err_free_lines:
413 free(tracer->saved_lines);
414 err_remove:
415 remove_ftrace_instance(tracer);
416 err_free:
417 free(tracer);
418 return NULL;
419 }
420
421 static void __destroy_ftracer(struct test_ftracer *tracer)
422 {
423 size_t i;
424
425 final_wait_for_events(tracer, TEST_TIMEOUT_SEC);
426 stop_trace_thread(tracer);
427 remove_ftrace_instance(tracer);
428 if (tracer->destructor)
429 tracer->destructor(tracer);
430 for (i = 0; i < tracer->saved_lines_size; i++)
431 free(tracer->saved_lines[i]);
432 pthread_cond_destroy(&tracer->met_all_expected);
433 pthread_mutex_destroy(&tracer->met_all_expected_lock);
434 free(tracer);
435 }
436
437 void destroy_ftracer(struct test_ftracer *tracer)
438 {
439 pthread_mutex_lock(&ftracers_lock);
440 if (tracer == ftracers) {
441 ftracers = tracer->next;
442 } else {
443 struct test_ftracer *f = ftracers;
444
445 while (f->next != tracer) {
446 if (!f->next)
447 test_error("tracers list corruption or double free %p", tracer);
448 f = f->next;
449 }
450 f->next = tracer->next;
451 }
452 tracer->next = NULL;
453 pthread_mutex_unlock(&ftracers_lock);
454 __destroy_ftracer(tracer);
455 }
456
457 static void destroy_all_ftracers(void)
458 {
459 struct test_ftracer *f;
460
461 pthread_mutex_lock(&ftracers_lock);
462 f = ftracers;
463 ftracers = NULL;
464 pthread_mutex_unlock(&ftracers_lock);
465
466 while (f) {
467 struct test_ftracer *n = f->next;
468
469 f->next = NULL;
470 __destroy_ftracer(f);
471 f = n;
472 }
473 }
474
475 static void test_unset_tracing(void)
476 {
477 destroy_all_ftracers();
478 unmount_ftrace();
479 }
480
481 int test_setup_tracing(void)
482 {
483 /*
484 * Just a basic protection - this should be called only once from
485 * lib/kconfig. Not thread safe, which is fine as it's early, before
486 * threads are created.
487 */
488 static int already_set;
489 int err;
490
491 if (already_set)
492 return -1;
493
494 /* Needs net-namespace cookies for filters */
495 if (ns_cookie1 == ns_cookie2) {
496 test_print("net-namespace cookies: %" PRIu64 " == %" PRIu64 ", can't set up tracing",
497 ns_cookie1, ns_cookie2);
498 return -1;
499 }
500
501 already_set = 1;
502
503 test_add_destructor(test_unset_tracing);
504
505 err = mount_ftrace();
506 if (err) {
507 test_print("failed to mount_ftrace(): %d", err);
508 return err;
509 }
510
511 return setup_aolib_ftracer();
512 }
513
514 static int get_ns_cookie(int nsfd, uint64_t *out)
515 {
516 int old_ns = switch_save_ns(nsfd);
517 socklen_t size = sizeof(*out);
518 int sk;
519
520 sk = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
521 if (sk < 0) {
522 test_print("socket(): %m");
523 return -errno;
524 }
525
526 if (getsockopt(sk, SOL_SOCKET, SO_NETNS_COOKIE, out, &size)) {
527 test_print("getsockopt(SO_NETNS_COOKIE): %m");
528 close(sk);
529 return -errno;
530 }
531
532 close(sk);
533 switch_close_ns(old_ns);
534 return 0;
535 }
536
537 void test_init_ftrace(int nsfd1, int nsfd2)
538 {
539 get_ns_cookie(nsfd1, &ns_cookie1);
540 get_ns_cookie(nsfd2, &ns_cookie2);
541 /* Populate kernel config state */
542 kernel_config_has(KCONFIG_FTRACE);
543 }
544
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