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6
7#define pr_fmt(fmt) "trace_boot: " fmt
8
9#include <linux/bootconfig.h>
10#include <linux/cpumask.h>
11#include <linux/ftrace.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/mutex.h>
15#include <linux/string.h>
16#include <linux/slab.h>
17#include <linux/trace.h>
18#include <linux/trace_events.h>
19
20#include "trace.h"
21
22#define MAX_BUF_LEN 256
23
24static void __init
25trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
26{
27 struct xbc_node *anode;
28 const char *p;
29 char buf[MAX_BUF_LEN];
30 unsigned long v = 0;
31
32
33 xbc_node_for_each_array_value(node, "options", anode, p) {
34 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
35 pr_err("String is too long: %s\n", p);
36 continue;
37 }
38
39 if (trace_set_options(tr, buf) < 0)
40 pr_err("Failed to set option: %s\n", buf);
41 }
42
43 p = xbc_node_find_value(node, "tracing_on", NULL);
44 if (p && *p != '\0') {
45 if (kstrtoul(p, 10, &v))
46 pr_err("Failed to set tracing on: %s\n", p);
47 if (v)
48 tracer_tracing_on(tr);
49 else
50 tracer_tracing_off(tr);
51 }
52
53 p = xbc_node_find_value(node, "trace_clock", NULL);
54 if (p && *p != '\0') {
55 if (tracing_set_clock(tr, p) < 0)
56 pr_err("Failed to set trace clock: %s\n", p);
57 }
58
59 p = xbc_node_find_value(node, "buffer_size", NULL);
60 if (p && *p != '\0') {
61 v = memparse(p, NULL);
62 if (v < PAGE_SIZE)
63 pr_err("Buffer size is too small: %s\n", p);
64 if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
65 pr_err("Failed to resize trace buffer to %s\n", p);
66 }
67
68 p = xbc_node_find_value(node, "cpumask", NULL);
69 if (p && *p != '\0') {
70 cpumask_var_t new_mask;
71
72 if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
73 if (cpumask_parse(p, new_mask) < 0 ||
74 tracing_set_cpumask(tr, new_mask) < 0)
75 pr_err("Failed to set new CPU mask %s\n", p);
76 free_cpumask_var(new_mask);
77 }
78 }
79}
80
81#ifdef CONFIG_EVENT_TRACING
82static void __init
83trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node)
84{
85 struct xbc_node *anode;
86 char buf[MAX_BUF_LEN];
87 const char *p;
88
89 xbc_node_for_each_array_value(node, "events", anode, p) {
90 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
91 pr_err("String is too long: %s\n", p);
92 continue;
93 }
94
95 if (ftrace_set_clr_event(tr, buf, 1) < 0)
96 pr_err("Failed to enable event: %s\n", p);
97 }
98}
99
100#ifdef CONFIG_KPROBE_EVENTS
101static int __init
102trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
103{
104 struct dynevent_cmd cmd;
105 struct xbc_node *anode;
106 char buf[MAX_BUF_LEN];
107 const char *val;
108 int ret = 0;
109
110 xbc_node_for_each_array_value(node, "probes", anode, val) {
111 kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
112
113 ret = kprobe_event_gen_cmd_start(&cmd, event, val);
114 if (ret) {
115 pr_err("Failed to generate probe: %s\n", buf);
116 break;
117 }
118
119 ret = kprobe_event_gen_cmd_end(&cmd);
120 if (ret) {
121 pr_err("Failed to add probe: %s\n", buf);
122 break;
123 }
124 }
125
126 return ret;
127}
128#else
129static inline int __init
130trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
131{
132 pr_err("Kprobe event is not supported.\n");
133 return -ENOTSUPP;
134}
135#endif
136
137#ifdef CONFIG_SYNTH_EVENTS
138static int __init
139trace_boot_add_synth_event(struct xbc_node *node, const char *event)
140{
141 struct dynevent_cmd cmd;
142 struct xbc_node *anode;
143 char buf[MAX_BUF_LEN];
144 const char *p;
145 int ret;
146
147 synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
148
149 ret = synth_event_gen_cmd_start(&cmd, event, NULL);
150 if (ret)
151 return ret;
152
153 xbc_node_for_each_array_value(node, "fields", anode, p) {
154 ret = synth_event_add_field_str(&cmd, p);
155 if (ret)
156 return ret;
157 }
158
159 ret = synth_event_gen_cmd_end(&cmd);
160 if (ret < 0)
161 pr_err("Failed to add synthetic event: %s\n", buf);
162
163 return ret;
164}
165#else
166static inline int __init
167trace_boot_add_synth_event(struct xbc_node *node, const char *event)
168{
169 pr_err("Synthetic event is not supported.\n");
170 return -ENOTSUPP;
171}
172#endif
173
174#ifdef CONFIG_HIST_TRIGGERS
175static int __init __printf(3, 4)
176append_printf(char **bufp, char *end, const char *fmt, ...)
177{
178 va_list args;
179 int ret;
180
181 if (*bufp == end)
182 return -ENOSPC;
183
184 va_start(args, fmt);
185 ret = vsnprintf(*bufp, end - *bufp, fmt, args);
186 if (ret < end - *bufp) {
187 *bufp += ret;
188 } else {
189 *bufp = end;
190 ret = -ERANGE;
191 }
192 va_end(args);
193
194 return ret;
195}
196
197static int __init
198append_str_nospace(char **bufp, char *end, const char *str)
199{
200 char *p = *bufp;
201 int len;
202
203 while (p < end - 1 && *str != '\0') {
204 if (!isspace(*str))
205 *(p++) = *str;
206 str++;
207 }
208 *p = '\0';
209 if (p == end - 1) {
210 *bufp = end;
211 return -ENOSPC;
212 }
213 len = p - *bufp;
214 *bufp = p;
215 return (int)len;
216}
217
218static int __init
219trace_boot_hist_add_array(struct xbc_node *hnode, char **bufp,
220 char *end, const char *key)
221{
222 struct xbc_node *anode;
223 const char *p;
224 char sep;
225
226 p = xbc_node_find_value(hnode, key, &anode);
227 if (p) {
228 if (!anode) {
229 pr_err("hist.%s requires value(s).\n", key);
230 return -EINVAL;
231 }
232
233 append_printf(bufp, end, ":%s", key);
234 sep = '=';
235 xbc_array_for_each_value(anode, p) {
236 append_printf(bufp, end, "%c%s", sep, p);
237 if (sep == '=')
238 sep = ',';
239 }
240 } else
241 return -ENOENT;
242
243 return 0;
244}
245
246static int __init
247trace_boot_hist_add_one_handler(struct xbc_node *hnode, char **bufp,
248 char *end, const char *handler,
249 const char *param)
250{
251 struct xbc_node *knode, *anode;
252 const char *p;
253 char sep;
254
255
256 p = xbc_node_find_value(hnode, param, NULL);
257 if (!p) {
258 pr_err("hist.%s requires '%s' option.\n",
259 xbc_node_get_data(hnode), param);
260 return -EINVAL;
261 }
262 append_printf(bufp, end, ":%s(%s)", handler, p);
263
264
265 knode = xbc_node_find_subkey(hnode, "trace");
266 if (!knode)
267 knode = xbc_node_find_subkey(hnode, "save");
268
269 if (knode) {
270 anode = xbc_node_get_child(knode);
271 if (!anode || !xbc_node_is_value(anode)) {
272 pr_err("hist.%s.%s requires value(s).\n",
273 xbc_node_get_data(hnode),
274 xbc_node_get_data(knode));
275 return -EINVAL;
276 }
277
278 append_printf(bufp, end, ".%s", xbc_node_get_data(knode));
279 sep = '(';
280 xbc_array_for_each_value(anode, p) {
281 append_printf(bufp, end, "%c%s", sep, p);
282 if (sep == '(')
283 sep = ',';
284 }
285 append_printf(bufp, end, ")");
286 } else if (xbc_node_find_subkey(hnode, "snapshot")) {
287 append_printf(bufp, end, ".snapshot()");
288 } else {
289 pr_err("hist.%s requires an action.\n",
290 xbc_node_get_data(hnode));
291 return -EINVAL;
292 }
293
294 return 0;
295}
296
297static int __init
298trace_boot_hist_add_handlers(struct xbc_node *hnode, char **bufp,
299 char *end, const char *param)
300{
301 struct xbc_node *node;
302 const char *p, *handler;
303 int ret;
304
305 handler = xbc_node_get_data(hnode);
306
307 xbc_node_for_each_subkey(hnode, node) {
308 p = xbc_node_get_data(node);
309 if (!isdigit(p[0]))
310 continue;
311
312 ret = trace_boot_hist_add_one_handler(node, bufp, end, handler, param);
313 if (ret < 0)
314 break;
315 }
316
317 if (xbc_node_find_subkey(hnode, param))
318 ret = trace_boot_hist_add_one_handler(hnode, bufp, end, handler, param);
319
320 return ret;
321}
322
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337
338
339
340
341
342
343
344
345static int __init
346trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size)
347{
348 struct xbc_node *node, *knode;
349 char *end = buf + size;
350 const char *p;
351 int ret = 0;
352
353 append_printf(&buf, end, "hist");
354
355 ret = trace_boot_hist_add_array(hnode, &buf, end, "keys");
356 if (ret < 0) {
357 if (ret == -ENOENT)
358 pr_err("hist requires keys.\n");
359 return -EINVAL;
360 }
361
362 ret = trace_boot_hist_add_array(hnode, &buf, end, "values");
363 if (ret == -EINVAL)
364 return ret;
365 ret = trace_boot_hist_add_array(hnode, &buf, end, "sort");
366 if (ret == -EINVAL)
367 return ret;
368
369 p = xbc_node_find_value(hnode, "size", NULL);
370 if (p)
371 append_printf(&buf, end, ":size=%s", p);
372
373 p = xbc_node_find_value(hnode, "name", NULL);
374 if (p)
375 append_printf(&buf, end, ":name=%s", p);
376
377 node = xbc_node_find_subkey(hnode, "var");
378 if (node) {
379 xbc_node_for_each_key_value(node, knode, p) {
380
381 append_printf(&buf, end, ":%s=",
382 xbc_node_get_data(knode));
383 append_str_nospace(&buf, end, p);
384 }
385 }
386
387
388 if (xbc_node_find_value(hnode, "pause", NULL))
389 append_printf(&buf, end, ":pause");
390 else if (xbc_node_find_value(hnode, "continue", NULL))
391 append_printf(&buf, end, ":continue");
392 else if (xbc_node_find_value(hnode, "clear", NULL))
393 append_printf(&buf, end, ":clear");
394
395
396 node = xbc_node_find_subkey(hnode, "onmax");
397 if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0)
398 return -EINVAL;
399 node = xbc_node_find_subkey(hnode, "onchange");
400 if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0)
401 return -EINVAL;
402 node = xbc_node_find_subkey(hnode, "onmatch");
403 if (node && trace_boot_hist_add_handlers(node, &buf, end, "event") < 0)
404 return -EINVAL;
405
406 p = xbc_node_find_value(hnode, "filter", NULL);
407 if (p)
408 append_printf(&buf, end, " if %s", p);
409
410 if (buf == end) {
411 pr_err("hist exceeds the max command length.\n");
412 return -E2BIG;
413 }
414
415 return 0;
416}
417
418static void __init
419trace_boot_init_histograms(struct trace_event_file *file,
420 struct xbc_node *hnode, char *buf, size_t size)
421{
422 struct xbc_node *node;
423 const char *p;
424 char *tmp;
425
426 xbc_node_for_each_subkey(hnode, node) {
427 p = xbc_node_get_data(node);
428 if (!isdigit(p[0]))
429 continue;
430
431 if (trace_boot_compose_hist_cmd(node, buf, size) == 0) {
432 tmp = kstrdup(buf, GFP_KERNEL);
433 if (trigger_process_regex(file, buf) < 0)
434 pr_err("Failed to apply hist trigger: %s\n", tmp);
435 kfree(tmp);
436 }
437 }
438
439 if (xbc_node_find_subkey(hnode, "keys")) {
440 if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0) {
441 tmp = kstrdup(buf, GFP_KERNEL);
442 if (trigger_process_regex(file, buf) < 0)
443 pr_err("Failed to apply hist trigger: %s\n", tmp);
444 kfree(tmp);
445 }
446 }
447}
448#else
449static void __init
450trace_boot_init_histograms(struct trace_event_file *file,
451 struct xbc_node *hnode, char *buf, size_t size)
452{
453
454}
455#endif
456
457static void __init
458trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
459 struct xbc_node *enode)
460{
461 struct trace_event_file *file;
462 struct xbc_node *anode;
463 char buf[MAX_BUF_LEN];
464 const char *p, *group, *event;
465
466 group = xbc_node_get_data(gnode);
467 event = xbc_node_get_data(enode);
468
469 if (!strcmp(group, "kprobes"))
470 if (trace_boot_add_kprobe_event(enode, event) < 0)
471 return;
472 if (!strcmp(group, "synthetic"))
473 if (trace_boot_add_synth_event(enode, event) < 0)
474 return;
475
476 mutex_lock(&event_mutex);
477 file = find_event_file(tr, group, event);
478 if (!file) {
479 pr_err("Failed to find event: %s:%s\n", group, event);
480 goto out;
481 }
482
483 p = xbc_node_find_value(enode, "filter", NULL);
484 if (p && *p != '\0') {
485 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
486 pr_err("filter string is too long: %s\n", p);
487 else if (apply_event_filter(file, buf) < 0)
488 pr_err("Failed to apply filter: %s\n", buf);
489 }
490
491 if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) {
492 xbc_node_for_each_array_value(enode, "actions", anode, p) {
493 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
494 pr_err("action string is too long: %s\n", p);
495 else if (trigger_process_regex(file, buf) < 0)
496 pr_err("Failed to apply an action: %s\n", p);
497 }
498 anode = xbc_node_find_subkey(enode, "hist");
499 if (anode)
500 trace_boot_init_histograms(file, anode, buf, ARRAY_SIZE(buf));
501 } else if (xbc_node_find_value(enode, "actions", NULL))
502 pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n");
503
504 if (xbc_node_find_value(enode, "enable", NULL)) {
505 if (trace_event_enable_disable(file, 1, 0) < 0)
506 pr_err("Failed to enable event node: %s:%s\n",
507 group, event);
508 }
509out:
510 mutex_unlock(&event_mutex);
511}
512
513static void __init
514trace_boot_init_events(struct trace_array *tr, struct xbc_node *node)
515{
516 struct xbc_node *gnode, *enode;
517 bool enable, enable_all = false;
518 const char *data;
519
520 node = xbc_node_find_subkey(node, "event");
521 if (!node)
522 return;
523
524 xbc_node_for_each_subkey(node, gnode) {
525 data = xbc_node_get_data(gnode);
526 if (!strcmp(data, "enable")) {
527 enable_all = true;
528 continue;
529 }
530 enable = false;
531 xbc_node_for_each_subkey(gnode, enode) {
532 data = xbc_node_get_data(enode);
533 if (!strcmp(data, "enable")) {
534 enable = true;
535 continue;
536 }
537 trace_boot_init_one_event(tr, gnode, enode);
538 }
539
540 if (enable) {
541 data = xbc_node_get_data(gnode);
542 trace_array_set_clr_event(tr, data, NULL, true);
543 }
544 }
545
546 if (enable_all)
547 trace_array_set_clr_event(tr, NULL, NULL, true);
548}
549#else
550#define trace_boot_enable_events(tr, node) do {} while (0)
551#define trace_boot_init_events(tr, node) do {} while (0)
552#endif
553
554#ifdef CONFIG_DYNAMIC_FTRACE
555static void __init
556trace_boot_set_ftrace_filter(struct trace_array *tr, struct xbc_node *node)
557{
558 struct xbc_node *anode;
559 const char *p;
560 char *q;
561
562 xbc_node_for_each_array_value(node, "ftrace.filters", anode, p) {
563 q = kstrdup(p, GFP_KERNEL);
564 if (!q)
565 return;
566 if (ftrace_set_filter(tr->ops, q, strlen(q), 0) < 0)
567 pr_err("Failed to add %s to ftrace filter\n", p);
568 else
569 ftrace_filter_param = true;
570 kfree(q);
571 }
572 xbc_node_for_each_array_value(node, "ftrace.notraces", anode, p) {
573 q = kstrdup(p, GFP_KERNEL);
574 if (!q)
575 return;
576 if (ftrace_set_notrace(tr->ops, q, strlen(q), 0) < 0)
577 pr_err("Failed to add %s to ftrace filter\n", p);
578 else
579 ftrace_filter_param = true;
580 kfree(q);
581 }
582}
583#else
584#define trace_boot_set_ftrace_filter(tr, node) do {} while (0)
585#endif
586
587static void __init
588trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
589{
590 const char *p;
591
592 trace_boot_set_ftrace_filter(tr, node);
593
594 p = xbc_node_find_value(node, "tracer", NULL);
595 if (p && *p != '\0') {
596 if (tracing_set_tracer(tr, p) < 0)
597 pr_err("Failed to set given tracer: %s\n", p);
598 }
599
600
601 if (xbc_node_find_value(node, "alloc_snapshot", NULL)) {
602 if (tracing_alloc_snapshot_instance(tr) < 0)
603 pr_err("Failed to allocate snapshot buffer\n");
604 }
605}
606
607static void __init
608trace_boot_init_one_instance(struct trace_array *tr, struct xbc_node *node)
609{
610 trace_boot_set_instance_options(tr, node);
611 trace_boot_init_events(tr, node);
612 trace_boot_enable_events(tr, node);
613 trace_boot_enable_tracer(tr, node);
614}
615
616static void __init
617trace_boot_init_instances(struct xbc_node *node)
618{
619 struct xbc_node *inode;
620 struct trace_array *tr;
621 const char *p;
622
623 node = xbc_node_find_subkey(node, "instance");
624 if (!node)
625 return;
626
627 xbc_node_for_each_subkey(node, inode) {
628 p = xbc_node_get_data(inode);
629 if (!p || *p == '\0')
630 continue;
631
632 tr = trace_array_get_by_name(p);
633 if (!tr) {
634 pr_err("Failed to get trace instance %s\n", p);
635 continue;
636 }
637 trace_boot_init_one_instance(tr, inode);
638 trace_array_put(tr);
639 }
640}
641
642static int __init trace_boot_init(void)
643{
644 struct xbc_node *trace_node;
645 struct trace_array *tr;
646
647 trace_node = xbc_find_node("ftrace");
648 if (!trace_node)
649 return 0;
650
651 tr = top_trace_array();
652 if (!tr)
653 return 0;
654
655
656 trace_boot_init_one_instance(tr, trace_node);
657 trace_boot_init_instances(trace_node);
658
659 disable_tracing_selftest("running boot-time tracing");
660
661 return 0;
662}
663
664
665
666
667core_initcall_sync(trace_boot_init);
668
