xref: /linux/kernel/trace/trace_events_hist.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * trace_events_hist - trace event hist triggers
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com>
15  */
16 
17 #include <linux/module.h>
18 #include <linux/kallsyms.h>
19 #include <linux/mutex.h>
20 #include <linux/slab.h>
21 #include <linux/stacktrace.h>
22 #include <linux/rculist.h>
23 
24 #include "tracing_map.h"
25 #include "trace.h"
26 
27 struct hist_field;
28 
29 typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
30 
31 struct hist_field {
32 	struct ftrace_event_field	*field;
33 	unsigned long			flags;
34 	hist_field_fn_t			fn;
35 	unsigned int			size;
36 	unsigned int			offset;
37 };
38 
39 static u64 hist_field_none(struct hist_field *field, void *event)
40 {
41 	return 0;
42 }
43 
44 static u64 hist_field_counter(struct hist_field *field, void *event)
45 {
46 	return 1;
47 }
48 
49 static u64 hist_field_string(struct hist_field *hist_field, void *event)
50 {
51 	char *addr = (char *)(event + hist_field->field->offset);
52 
53 	return (u64)(unsigned long)addr;
54 }
55 
56 static u64 hist_field_dynstring(struct hist_field *hist_field, void *event)
57 {
58 	u32 str_item = *(u32 *)(event + hist_field->field->offset);
59 	int str_loc = str_item & 0xffff;
60 	char *addr = (char *)(event + str_loc);
61 
62 	return (u64)(unsigned long)addr;
63 }
64 
65 static u64 hist_field_pstring(struct hist_field *hist_field, void *event)
66 {
67 	char **addr = (char **)(event + hist_field->field->offset);
68 
69 	return (u64)(unsigned long)*addr;
70 }
71 
72 static u64 hist_field_log2(struct hist_field *hist_field, void *event)
73 {
74 	u64 val = *(u64 *)(event + hist_field->field->offset);
75 
76 	return (u64) ilog2(roundup_pow_of_two(val));
77 }
78 
79 #define DEFINE_HIST_FIELD_FN(type)					\
80 static u64 hist_field_##type(struct hist_field *hist_field, void *event)\
81 {									\
82 	type *addr = (type *)(event + hist_field->field->offset);	\
83 									\
84 	return (u64)(unsigned long)*addr;				\
85 }
86 
87 DEFINE_HIST_FIELD_FN(s64);
88 DEFINE_HIST_FIELD_FN(u64);
89 DEFINE_HIST_FIELD_FN(s32);
90 DEFINE_HIST_FIELD_FN(u32);
91 DEFINE_HIST_FIELD_FN(s16);
92 DEFINE_HIST_FIELD_FN(u16);
93 DEFINE_HIST_FIELD_FN(s8);
94 DEFINE_HIST_FIELD_FN(u8);
95 
96 #define for_each_hist_field(i, hist_data)	\
97 	for ((i) = 0; (i) < (hist_data)->n_fields; (i)++)
98 
99 #define for_each_hist_val_field(i, hist_data)	\
100 	for ((i) = 0; (i) < (hist_data)->n_vals; (i)++)
101 
102 #define for_each_hist_key_field(i, hist_data)	\
103 	for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++)
104 
105 #define HIST_STACKTRACE_DEPTH	16
106 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
107 #define HIST_STACKTRACE_SKIP	5
108 
109 #define HITCOUNT_IDX		0
110 #define HIST_KEY_SIZE_MAX	(MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE)
111 
112 enum hist_field_flags {
113 	HIST_FIELD_FL_HITCOUNT		= 1,
114 	HIST_FIELD_FL_KEY		= 2,
115 	HIST_FIELD_FL_STRING		= 4,
116 	HIST_FIELD_FL_HEX		= 8,
117 	HIST_FIELD_FL_SYM		= 16,
118 	HIST_FIELD_FL_SYM_OFFSET	= 32,
119 	HIST_FIELD_FL_EXECNAME		= 64,
120 	HIST_FIELD_FL_SYSCALL		= 128,
121 	HIST_FIELD_FL_STACKTRACE	= 256,
122 	HIST_FIELD_FL_LOG2		= 512,
123 };
124 
125 struct hist_trigger_attrs {
126 	char		*keys_str;
127 	char		*vals_str;
128 	char		*sort_key_str;
129 	char		*name;
130 	bool		pause;
131 	bool		cont;
132 	bool		clear;
133 	unsigned int	map_bits;
134 };
135 
136 struct hist_trigger_data {
137 	struct hist_field               *fields[TRACING_MAP_FIELDS_MAX];
138 	unsigned int			n_vals;
139 	unsigned int			n_keys;
140 	unsigned int			n_fields;
141 	unsigned int			key_size;
142 	struct tracing_map_sort_key	sort_keys[TRACING_MAP_SORT_KEYS_MAX];
143 	unsigned int			n_sort_keys;
144 	struct trace_event_file		*event_file;
145 	struct hist_trigger_attrs	*attrs;
146 	struct tracing_map		*map;
147 };
148 
149 static hist_field_fn_t select_value_fn(int field_size, int field_is_signed)
150 {
151 	hist_field_fn_t fn = NULL;
152 
153 	switch (field_size) {
154 	case 8:
155 		if (field_is_signed)
156 			fn = hist_field_s64;
157 		else
158 			fn = hist_field_u64;
159 		break;
160 	case 4:
161 		if (field_is_signed)
162 			fn = hist_field_s32;
163 		else
164 			fn = hist_field_u32;
165 		break;
166 	case 2:
167 		if (field_is_signed)
168 			fn = hist_field_s16;
169 		else
170 			fn = hist_field_u16;
171 		break;
172 	case 1:
173 		if (field_is_signed)
174 			fn = hist_field_s8;
175 		else
176 			fn = hist_field_u8;
177 		break;
178 	}
179 
180 	return fn;
181 }
182 
183 static int parse_map_size(char *str)
184 {
185 	unsigned long size, map_bits;
186 	int ret;
187 
188 	strsep(&str, "=");
189 	if (!str) {
190 		ret = -EINVAL;
191 		goto out;
192 	}
193 
194 	ret = kstrtoul(str, 0, &size);
195 	if (ret)
196 		goto out;
197 
198 	map_bits = ilog2(roundup_pow_of_two(size));
199 	if (map_bits < TRACING_MAP_BITS_MIN ||
200 	    map_bits > TRACING_MAP_BITS_MAX)
201 		ret = -EINVAL;
202 	else
203 		ret = map_bits;
204  out:
205 	return ret;
206 }
207 
208 static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
209 {
210 	if (!attrs)
211 		return;
212 
213 	kfree(attrs->name);
214 	kfree(attrs->sort_key_str);
215 	kfree(attrs->keys_str);
216 	kfree(attrs->vals_str);
217 	kfree(attrs);
218 }
219 
220 static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str)
221 {
222 	struct hist_trigger_attrs *attrs;
223 	int ret = 0;
224 
225 	attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
226 	if (!attrs)
227 		return ERR_PTR(-ENOMEM);
228 
229 	while (trigger_str) {
230 		char *str = strsep(&trigger_str, ":");
231 
232 		if ((strncmp(str, "key=", strlen("key=")) == 0) ||
233 		    (strncmp(str, "keys=", strlen("keys=")) == 0))
234 			attrs->keys_str = kstrdup(str, GFP_KERNEL);
235 		else if ((strncmp(str, "val=", strlen("val=")) == 0) ||
236 			 (strncmp(str, "vals=", strlen("vals=")) == 0) ||
237 			 (strncmp(str, "values=", strlen("values=")) == 0))
238 			attrs->vals_str = kstrdup(str, GFP_KERNEL);
239 		else if (strncmp(str, "sort=", strlen("sort=")) == 0)
240 			attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
241 		else if (strncmp(str, "name=", strlen("name=")) == 0)
242 			attrs->name = kstrdup(str, GFP_KERNEL);
243 		else if (strcmp(str, "pause") == 0)
244 			attrs->pause = true;
245 		else if ((strcmp(str, "cont") == 0) ||
246 			 (strcmp(str, "continue") == 0))
247 			attrs->cont = true;
248 		else if (strcmp(str, "clear") == 0)
249 			attrs->clear = true;
250 		else if (strncmp(str, "size=", strlen("size=")) == 0) {
251 			int map_bits = parse_map_size(str);
252 
253 			if (map_bits < 0) {
254 				ret = map_bits;
255 				goto free;
256 			}
257 			attrs->map_bits = map_bits;
258 		} else {
259 			ret = -EINVAL;
260 			goto free;
261 		}
262 	}
263 
264 	if (!attrs->keys_str) {
265 		ret = -EINVAL;
266 		goto free;
267 	}
268 
269 	return attrs;
270  free:
271 	destroy_hist_trigger_attrs(attrs);
272 
273 	return ERR_PTR(ret);
274 }
275 
276 static inline void save_comm(char *comm, struct task_struct *task)
277 {
278 	if (!task->pid) {
279 		strcpy(comm, "<idle>");
280 		return;
281 	}
282 
283 	if (WARN_ON_ONCE(task->pid < 0)) {
284 		strcpy(comm, "<XXX>");
285 		return;
286 	}
287 
288 	memcpy(comm, task->comm, TASK_COMM_LEN);
289 }
290 
291 static void hist_trigger_elt_comm_free(struct tracing_map_elt *elt)
292 {
293 	kfree((char *)elt->private_data);
294 }
295 
296 static int hist_trigger_elt_comm_alloc(struct tracing_map_elt *elt)
297 {
298 	struct hist_trigger_data *hist_data = elt->map->private_data;
299 	struct hist_field *key_field;
300 	unsigned int i;
301 
302 	for_each_hist_key_field(i, hist_data) {
303 		key_field = hist_data->fields[i];
304 
305 		if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
306 			unsigned int size = TASK_COMM_LEN + 1;
307 
308 			elt->private_data = kzalloc(size, GFP_KERNEL);
309 			if (!elt->private_data)
310 				return -ENOMEM;
311 			break;
312 		}
313 	}
314 
315 	return 0;
316 }
317 
318 static void hist_trigger_elt_comm_copy(struct tracing_map_elt *to,
319 				       struct tracing_map_elt *from)
320 {
321 	char *comm_from = from->private_data;
322 	char *comm_to = to->private_data;
323 
324 	if (comm_from)
325 		memcpy(comm_to, comm_from, TASK_COMM_LEN + 1);
326 }
327 
328 static void hist_trigger_elt_comm_init(struct tracing_map_elt *elt)
329 {
330 	char *comm = elt->private_data;
331 
332 	if (comm)
333 		save_comm(comm, current);
334 }
335 
336 static const struct tracing_map_ops hist_trigger_elt_comm_ops = {
337 	.elt_alloc	= hist_trigger_elt_comm_alloc,
338 	.elt_copy	= hist_trigger_elt_comm_copy,
339 	.elt_free	= hist_trigger_elt_comm_free,
340 	.elt_init	= hist_trigger_elt_comm_init,
341 };
342 
343 static void destroy_hist_field(struct hist_field *hist_field)
344 {
345 	kfree(hist_field);
346 }
347 
348 static struct hist_field *create_hist_field(struct ftrace_event_field *field,
349 					    unsigned long flags)
350 {
351 	struct hist_field *hist_field;
352 
353 	if (field && is_function_field(field))
354 		return NULL;
355 
356 	hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
357 	if (!hist_field)
358 		return NULL;
359 
360 	if (flags & HIST_FIELD_FL_HITCOUNT) {
361 		hist_field->fn = hist_field_counter;
362 		goto out;
363 	}
364 
365 	if (flags & HIST_FIELD_FL_STACKTRACE) {
366 		hist_field->fn = hist_field_none;
367 		goto out;
368 	}
369 
370 	if (flags & HIST_FIELD_FL_LOG2) {
371 		hist_field->fn = hist_field_log2;
372 		goto out;
373 	}
374 
375 	if (WARN_ON_ONCE(!field))
376 		goto out;
377 
378 	if (is_string_field(field)) {
379 		flags |= HIST_FIELD_FL_STRING;
380 
381 		if (field->filter_type == FILTER_STATIC_STRING)
382 			hist_field->fn = hist_field_string;
383 		else if (field->filter_type == FILTER_DYN_STRING)
384 			hist_field->fn = hist_field_dynstring;
385 		else
386 			hist_field->fn = hist_field_pstring;
387 	} else {
388 		hist_field->fn = select_value_fn(field->size,
389 						 field->is_signed);
390 		if (!hist_field->fn) {
391 			destroy_hist_field(hist_field);
392 			return NULL;
393 		}
394 	}
395  out:
396 	hist_field->field = field;
397 	hist_field->flags = flags;
398 
399 	return hist_field;
400 }
401 
402 static void destroy_hist_fields(struct hist_trigger_data *hist_data)
403 {
404 	unsigned int i;
405 
406 	for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) {
407 		if (hist_data->fields[i]) {
408 			destroy_hist_field(hist_data->fields[i]);
409 			hist_data->fields[i] = NULL;
410 		}
411 	}
412 }
413 
414 static int create_hitcount_val(struct hist_trigger_data *hist_data)
415 {
416 	hist_data->fields[HITCOUNT_IDX] =
417 		create_hist_field(NULL, HIST_FIELD_FL_HITCOUNT);
418 	if (!hist_data->fields[HITCOUNT_IDX])
419 		return -ENOMEM;
420 
421 	hist_data->n_vals++;
422 
423 	if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
424 		return -EINVAL;
425 
426 	return 0;
427 }
428 
429 static int create_val_field(struct hist_trigger_data *hist_data,
430 			    unsigned int val_idx,
431 			    struct trace_event_file *file,
432 			    char *field_str)
433 {
434 	struct ftrace_event_field *field = NULL;
435 	unsigned long flags = 0;
436 	char *field_name;
437 	int ret = 0;
438 
439 	if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
440 		return -EINVAL;
441 
442 	field_name = strsep(&field_str, ".");
443 	if (field_str) {
444 		if (strcmp(field_str, "hex") == 0)
445 			flags |= HIST_FIELD_FL_HEX;
446 		else {
447 			ret = -EINVAL;
448 			goto out;
449 		}
450 	}
451 
452 	field = trace_find_event_field(file->event_call, field_name);
453 	if (!field) {
454 		ret = -EINVAL;
455 		goto out;
456 	}
457 
458 	hist_data->fields[val_idx] = create_hist_field(field, flags);
459 	if (!hist_data->fields[val_idx]) {
460 		ret = -ENOMEM;
461 		goto out;
462 	}
463 
464 	++hist_data->n_vals;
465 
466 	if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
467 		ret = -EINVAL;
468  out:
469 	return ret;
470 }
471 
472 static int create_val_fields(struct hist_trigger_data *hist_data,
473 			     struct trace_event_file *file)
474 {
475 	char *fields_str, *field_str;
476 	unsigned int i, j;
477 	int ret;
478 
479 	ret = create_hitcount_val(hist_data);
480 	if (ret)
481 		goto out;
482 
483 	fields_str = hist_data->attrs->vals_str;
484 	if (!fields_str)
485 		goto out;
486 
487 	strsep(&fields_str, "=");
488 	if (!fields_str)
489 		goto out;
490 
491 	for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
492 		     j < TRACING_MAP_VALS_MAX; i++) {
493 		field_str = strsep(&fields_str, ",");
494 		if (!field_str)
495 			break;
496 		if (strcmp(field_str, "hitcount") == 0)
497 			continue;
498 		ret = create_val_field(hist_data, j++, file, field_str);
499 		if (ret)
500 			goto out;
501 	}
502 	if (fields_str && (strcmp(fields_str, "hitcount") != 0))
503 		ret = -EINVAL;
504  out:
505 	return ret;
506 }
507 
508 static int create_key_field(struct hist_trigger_data *hist_data,
509 			    unsigned int key_idx,
510 			    unsigned int key_offset,
511 			    struct trace_event_file *file,
512 			    char *field_str)
513 {
514 	struct ftrace_event_field *field = NULL;
515 	unsigned long flags = 0;
516 	unsigned int key_size;
517 	int ret = 0;
518 
519 	if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX))
520 		return -EINVAL;
521 
522 	flags |= HIST_FIELD_FL_KEY;
523 
524 	if (strcmp(field_str, "stacktrace") == 0) {
525 		flags |= HIST_FIELD_FL_STACKTRACE;
526 		key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
527 	} else {
528 		char *field_name = strsep(&field_str, ".");
529 
530 		if (field_str) {
531 			if (strcmp(field_str, "hex") == 0)
532 				flags |= HIST_FIELD_FL_HEX;
533 			else if (strcmp(field_str, "sym") == 0)
534 				flags |= HIST_FIELD_FL_SYM;
535 			else if (strcmp(field_str, "sym-offset") == 0)
536 				flags |= HIST_FIELD_FL_SYM_OFFSET;
537 			else if ((strcmp(field_str, "execname") == 0) &&
538 				 (strcmp(field_name, "common_pid") == 0))
539 				flags |= HIST_FIELD_FL_EXECNAME;
540 			else if (strcmp(field_str, "syscall") == 0)
541 				flags |= HIST_FIELD_FL_SYSCALL;
542 			else if (strcmp(field_str, "log2") == 0)
543 				flags |= HIST_FIELD_FL_LOG2;
544 			else {
545 				ret = -EINVAL;
546 				goto out;
547 			}
548 		}
549 
550 		field = trace_find_event_field(file->event_call, field_name);
551 		if (!field) {
552 			ret = -EINVAL;
553 			goto out;
554 		}
555 
556 		if (is_string_field(field))
557 			key_size = MAX_FILTER_STR_VAL;
558 		else
559 			key_size = field->size;
560 	}
561 
562 	hist_data->fields[key_idx] = create_hist_field(field, flags);
563 	if (!hist_data->fields[key_idx]) {
564 		ret = -ENOMEM;
565 		goto out;
566 	}
567 
568 	key_size = ALIGN(key_size, sizeof(u64));
569 	hist_data->fields[key_idx]->size = key_size;
570 	hist_data->fields[key_idx]->offset = key_offset;
571 	hist_data->key_size += key_size;
572 	if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
573 		ret = -EINVAL;
574 		goto out;
575 	}
576 
577 	hist_data->n_keys++;
578 
579 	if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
580 		return -EINVAL;
581 
582 	ret = key_size;
583  out:
584 	return ret;
585 }
586 
587 static int create_key_fields(struct hist_trigger_data *hist_data,
588 			     struct trace_event_file *file)
589 {
590 	unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
591 	char *fields_str, *field_str;
592 	int ret = -EINVAL;
593 
594 	fields_str = hist_data->attrs->keys_str;
595 	if (!fields_str)
596 		goto out;
597 
598 	strsep(&fields_str, "=");
599 	if (!fields_str)
600 		goto out;
601 
602 	for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
603 		field_str = strsep(&fields_str, ",");
604 		if (!field_str)
605 			break;
606 		ret = create_key_field(hist_data, i, key_offset,
607 				       file, field_str);
608 		if (ret < 0)
609 			goto out;
610 		key_offset += ret;
611 	}
612 	if (fields_str) {
613 		ret = -EINVAL;
614 		goto out;
615 	}
616 	ret = 0;
617  out:
618 	return ret;
619 }
620 
621 static int create_hist_fields(struct hist_trigger_data *hist_data,
622 			      struct trace_event_file *file)
623 {
624 	int ret;
625 
626 	ret = create_val_fields(hist_data, file);
627 	if (ret)
628 		goto out;
629 
630 	ret = create_key_fields(hist_data, file);
631 	if (ret)
632 		goto out;
633 
634 	hist_data->n_fields = hist_data->n_vals + hist_data->n_keys;
635  out:
636 	return ret;
637 }
638 
639 static int is_descending(const char *str)
640 {
641 	if (!str)
642 		return 0;
643 
644 	if (strcmp(str, "descending") == 0)
645 		return 1;
646 
647 	if (strcmp(str, "ascending") == 0)
648 		return 0;
649 
650 	return -EINVAL;
651 }
652 
653 static int create_sort_keys(struct hist_trigger_data *hist_data)
654 {
655 	char *fields_str = hist_data->attrs->sort_key_str;
656 	struct ftrace_event_field *field = NULL;
657 	struct tracing_map_sort_key *sort_key;
658 	int descending, ret = 0;
659 	unsigned int i, j;
660 
661 	hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
662 
663 	if (!fields_str)
664 		goto out;
665 
666 	strsep(&fields_str, "=");
667 	if (!fields_str) {
668 		ret = -EINVAL;
669 		goto out;
670 	}
671 
672 	for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
673 		char *field_str, *field_name;
674 
675 		sort_key = &hist_data->sort_keys[i];
676 
677 		field_str = strsep(&fields_str, ",");
678 		if (!field_str) {
679 			if (i == 0)
680 				ret = -EINVAL;
681 			break;
682 		}
683 
684 		if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
685 			ret = -EINVAL;
686 			break;
687 		}
688 
689 		field_name = strsep(&field_str, ".");
690 		if (!field_name) {
691 			ret = -EINVAL;
692 			break;
693 		}
694 
695 		if (strcmp(field_name, "hitcount") == 0) {
696 			descending = is_descending(field_str);
697 			if (descending < 0) {
698 				ret = descending;
699 				break;
700 			}
701 			sort_key->descending = descending;
702 			continue;
703 		}
704 
705 		for (j = 1; j < hist_data->n_fields; j++) {
706 			field = hist_data->fields[j]->field;
707 			if (field && (strcmp(field_name, field->name) == 0)) {
708 				sort_key->field_idx = j;
709 				descending = is_descending(field_str);
710 				if (descending < 0) {
711 					ret = descending;
712 					goto out;
713 				}
714 				sort_key->descending = descending;
715 				break;
716 			}
717 		}
718 		if (j == hist_data->n_fields) {
719 			ret = -EINVAL;
720 			break;
721 		}
722 	}
723 	hist_data->n_sort_keys = i;
724  out:
725 	return ret;
726 }
727 
728 static void destroy_hist_data(struct hist_trigger_data *hist_data)
729 {
730 	destroy_hist_trigger_attrs(hist_data->attrs);
731 	destroy_hist_fields(hist_data);
732 	tracing_map_destroy(hist_data->map);
733 	kfree(hist_data);
734 }
735 
736 static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
737 {
738 	struct tracing_map *map = hist_data->map;
739 	struct ftrace_event_field *field;
740 	struct hist_field *hist_field;
741 	int i, idx;
742 
743 	for_each_hist_field(i, hist_data) {
744 		hist_field = hist_data->fields[i];
745 		if (hist_field->flags & HIST_FIELD_FL_KEY) {
746 			tracing_map_cmp_fn_t cmp_fn;
747 
748 			field = hist_field->field;
749 
750 			if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
751 				cmp_fn = tracing_map_cmp_none;
752 			else if (is_string_field(field))
753 				cmp_fn = tracing_map_cmp_string;
754 			else
755 				cmp_fn = tracing_map_cmp_num(field->size,
756 							     field->is_signed);
757 			idx = tracing_map_add_key_field(map,
758 							hist_field->offset,
759 							cmp_fn);
760 
761 		} else
762 			idx = tracing_map_add_sum_field(map);
763 
764 		if (idx < 0)
765 			return idx;
766 	}
767 
768 	return 0;
769 }
770 
771 static bool need_tracing_map_ops(struct hist_trigger_data *hist_data)
772 {
773 	struct hist_field *key_field;
774 	unsigned int i;
775 
776 	for_each_hist_key_field(i, hist_data) {
777 		key_field = hist_data->fields[i];
778 
779 		if (key_field->flags & HIST_FIELD_FL_EXECNAME)
780 			return true;
781 	}
782 
783 	return false;
784 }
785 
786 static struct hist_trigger_data *
787 create_hist_data(unsigned int map_bits,
788 		 struct hist_trigger_attrs *attrs,
789 		 struct trace_event_file *file)
790 {
791 	const struct tracing_map_ops *map_ops = NULL;
792 	struct hist_trigger_data *hist_data;
793 	int ret = 0;
794 
795 	hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL);
796 	if (!hist_data)
797 		return ERR_PTR(-ENOMEM);
798 
799 	hist_data->attrs = attrs;
800 
801 	ret = create_hist_fields(hist_data, file);
802 	if (ret)
803 		goto free;
804 
805 	ret = create_sort_keys(hist_data);
806 	if (ret)
807 		goto free;
808 
809 	if (need_tracing_map_ops(hist_data))
810 		map_ops = &hist_trigger_elt_comm_ops;
811 
812 	hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
813 					    map_ops, hist_data);
814 	if (IS_ERR(hist_data->map)) {
815 		ret = PTR_ERR(hist_data->map);
816 		hist_data->map = NULL;
817 		goto free;
818 	}
819 
820 	ret = create_tracing_map_fields(hist_data);
821 	if (ret)
822 		goto free;
823 
824 	ret = tracing_map_init(hist_data->map);
825 	if (ret)
826 		goto free;
827 
828 	hist_data->event_file = file;
829  out:
830 	return hist_data;
831  free:
832 	hist_data->attrs = NULL;
833 
834 	destroy_hist_data(hist_data);
835 
836 	hist_data = ERR_PTR(ret);
837 
838 	goto out;
839 }
840 
841 static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
842 				    struct tracing_map_elt *elt,
843 				    void *rec)
844 {
845 	struct hist_field *hist_field;
846 	unsigned int i;
847 	u64 hist_val;
848 
849 	for_each_hist_val_field(i, hist_data) {
850 		hist_field = hist_data->fields[i];
851 		hist_val = hist_field->fn(hist_field, rec);
852 		tracing_map_update_sum(elt, i, hist_val);
853 	}
854 }
855 
856 static inline void add_to_key(char *compound_key, void *key,
857 			      struct hist_field *key_field, void *rec)
858 {
859 	size_t size = key_field->size;
860 
861 	if (key_field->flags & HIST_FIELD_FL_STRING) {
862 		struct ftrace_event_field *field;
863 
864 		field = key_field->field;
865 		if (field->filter_type == FILTER_DYN_STRING)
866 			size = *(u32 *)(rec + field->offset) >> 16;
867 		else if (field->filter_type == FILTER_PTR_STRING)
868 			size = strlen(key);
869 		else if (field->filter_type == FILTER_STATIC_STRING)
870 			size = field->size;
871 
872 		/* ensure NULL-termination */
873 		if (size > key_field->size - 1)
874 			size = key_field->size - 1;
875 	}
876 
877 	memcpy(compound_key + key_field->offset, key, size);
878 }
879 
880 static void event_hist_trigger(struct event_trigger_data *data, void *rec)
881 {
882 	struct hist_trigger_data *hist_data = data->private_data;
883 	bool use_compound_key = (hist_data->n_keys > 1);
884 	unsigned long entries[HIST_STACKTRACE_DEPTH];
885 	char compound_key[HIST_KEY_SIZE_MAX];
886 	struct stack_trace stacktrace;
887 	struct hist_field *key_field;
888 	struct tracing_map_elt *elt;
889 	u64 field_contents;
890 	void *key = NULL;
891 	unsigned int i;
892 
893 	memset(compound_key, 0, hist_data->key_size);
894 
895 	for_each_hist_key_field(i, hist_data) {
896 		key_field = hist_data->fields[i];
897 
898 		if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
899 			stacktrace.max_entries = HIST_STACKTRACE_DEPTH;
900 			stacktrace.entries = entries;
901 			stacktrace.nr_entries = 0;
902 			stacktrace.skip = HIST_STACKTRACE_SKIP;
903 
904 			memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE);
905 			save_stack_trace(&stacktrace);
906 
907 			key = entries;
908 		} else {
909 			field_contents = key_field->fn(key_field, rec);
910 			if (key_field->flags & HIST_FIELD_FL_STRING) {
911 				key = (void *)(unsigned long)field_contents;
912 				use_compound_key = true;
913 			} else
914 				key = (void *)&field_contents;
915 		}
916 
917 		if (use_compound_key)
918 			add_to_key(compound_key, key, key_field, rec);
919 	}
920 
921 	if (use_compound_key)
922 		key = compound_key;
923 
924 	elt = tracing_map_insert(hist_data->map, key);
925 	if (elt)
926 		hist_trigger_elt_update(hist_data, elt, rec);
927 }
928 
929 static void hist_trigger_stacktrace_print(struct seq_file *m,
930 					  unsigned long *stacktrace_entries,
931 					  unsigned int max_entries)
932 {
933 	char str[KSYM_SYMBOL_LEN];
934 	unsigned int spaces = 8;
935 	unsigned int i;
936 
937 	for (i = 0; i < max_entries; i++) {
938 		if (stacktrace_entries[i] == ULONG_MAX)
939 			return;
940 
941 		seq_printf(m, "%*c", 1 + spaces, ' ');
942 		sprint_symbol(str, stacktrace_entries[i]);
943 		seq_printf(m, "%s\n", str);
944 	}
945 }
946 
947 static void
948 hist_trigger_entry_print(struct seq_file *m,
949 			 struct hist_trigger_data *hist_data, void *key,
950 			 struct tracing_map_elt *elt)
951 {
952 	struct hist_field *key_field;
953 	char str[KSYM_SYMBOL_LEN];
954 	bool multiline = false;
955 	unsigned int i;
956 	u64 uval;
957 
958 	seq_puts(m, "{ ");
959 
960 	for_each_hist_key_field(i, hist_data) {
961 		key_field = hist_data->fields[i];
962 
963 		if (i > hist_data->n_vals)
964 			seq_puts(m, ", ");
965 
966 		if (key_field->flags & HIST_FIELD_FL_HEX) {
967 			uval = *(u64 *)(key + key_field->offset);
968 			seq_printf(m, "%s: %llx",
969 				   key_field->field->name, uval);
970 		} else if (key_field->flags & HIST_FIELD_FL_SYM) {
971 			uval = *(u64 *)(key + key_field->offset);
972 			sprint_symbol_no_offset(str, uval);
973 			seq_printf(m, "%s: [%llx] %-45s",
974 				   key_field->field->name, uval, str);
975 		} else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
976 			uval = *(u64 *)(key + key_field->offset);
977 			sprint_symbol(str, uval);
978 			seq_printf(m, "%s: [%llx] %-55s",
979 				   key_field->field->name, uval, str);
980 		} else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
981 			char *comm = elt->private_data;
982 
983 			uval = *(u64 *)(key + key_field->offset);
984 			seq_printf(m, "%s: %-16s[%10llu]",
985 				   key_field->field->name, comm, uval);
986 		} else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
987 			const char *syscall_name;
988 
989 			uval = *(u64 *)(key + key_field->offset);
990 			syscall_name = get_syscall_name(uval);
991 			if (!syscall_name)
992 				syscall_name = "unknown_syscall";
993 
994 			seq_printf(m, "%s: %-30s[%3llu]",
995 				   key_field->field->name, syscall_name, uval);
996 		} else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
997 			seq_puts(m, "stacktrace:\n");
998 			hist_trigger_stacktrace_print(m,
999 						      key + key_field->offset,
1000 						      HIST_STACKTRACE_DEPTH);
1001 			multiline = true;
1002 		} else if (key_field->flags & HIST_FIELD_FL_LOG2) {
1003 			seq_printf(m, "%s: ~ 2^%-2llu", key_field->field->name,
1004 				   *(u64 *)(key + key_field->offset));
1005 		} else if (key_field->flags & HIST_FIELD_FL_STRING) {
1006 			seq_printf(m, "%s: %-50s", key_field->field->name,
1007 				   (char *)(key + key_field->offset));
1008 		} else {
1009 			uval = *(u64 *)(key + key_field->offset);
1010 			seq_printf(m, "%s: %10llu", key_field->field->name,
1011 				   uval);
1012 		}
1013 	}
1014 
1015 	if (!multiline)
1016 		seq_puts(m, " ");
1017 
1018 	seq_puts(m, "}");
1019 
1020 	seq_printf(m, " hitcount: %10llu",
1021 		   tracing_map_read_sum(elt, HITCOUNT_IDX));
1022 
1023 	for (i = 1; i < hist_data->n_vals; i++) {
1024 		if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
1025 			seq_printf(m, "  %s: %10llx",
1026 				   hist_data->fields[i]->field->name,
1027 				   tracing_map_read_sum(elt, i));
1028 		} else {
1029 			seq_printf(m, "  %s: %10llu",
1030 				   hist_data->fields[i]->field->name,
1031 				   tracing_map_read_sum(elt, i));
1032 		}
1033 	}
1034 
1035 	seq_puts(m, "\n");
1036 }
1037 
1038 static int print_entries(struct seq_file *m,
1039 			 struct hist_trigger_data *hist_data)
1040 {
1041 	struct tracing_map_sort_entry **sort_entries = NULL;
1042 	struct tracing_map *map = hist_data->map;
1043 	int i, n_entries;
1044 
1045 	n_entries = tracing_map_sort_entries(map, hist_data->sort_keys,
1046 					     hist_data->n_sort_keys,
1047 					     &sort_entries);
1048 	if (n_entries < 0)
1049 		return n_entries;
1050 
1051 	for (i = 0; i < n_entries; i++)
1052 		hist_trigger_entry_print(m, hist_data,
1053 					 sort_entries[i]->key,
1054 					 sort_entries[i]->elt);
1055 
1056 	tracing_map_destroy_sort_entries(sort_entries, n_entries);
1057 
1058 	return n_entries;
1059 }
1060 
1061 static void hist_trigger_show(struct seq_file *m,
1062 			      struct event_trigger_data *data, int n)
1063 {
1064 	struct hist_trigger_data *hist_data;
1065 	int n_entries, ret = 0;
1066 
1067 	if (n > 0)
1068 		seq_puts(m, "\n\n");
1069 
1070 	seq_puts(m, "# event histogram\n#\n# trigger info: ");
1071 	data->ops->print(m, data->ops, data);
1072 	seq_puts(m, "#\n\n");
1073 
1074 	hist_data = data->private_data;
1075 	n_entries = print_entries(m, hist_data);
1076 	if (n_entries < 0) {
1077 		ret = n_entries;
1078 		n_entries = 0;
1079 	}
1080 
1081 	seq_printf(m, "\nTotals:\n    Hits: %llu\n    Entries: %u\n    Dropped: %llu\n",
1082 		   (u64)atomic64_read(&hist_data->map->hits),
1083 		   n_entries, (u64)atomic64_read(&hist_data->map->drops));
1084 }
1085 
1086 static int hist_show(struct seq_file *m, void *v)
1087 {
1088 	struct event_trigger_data *data;
1089 	struct trace_event_file *event_file;
1090 	int n = 0, ret = 0;
1091 
1092 	mutex_lock(&event_mutex);
1093 
1094 	event_file = event_file_data(m->private);
1095 	if (unlikely(!event_file)) {
1096 		ret = -ENODEV;
1097 		goto out_unlock;
1098 	}
1099 
1100 	list_for_each_entry_rcu(data, &event_file->triggers, list) {
1101 		if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
1102 			hist_trigger_show(m, data, n++);
1103 	}
1104 
1105  out_unlock:
1106 	mutex_unlock(&event_mutex);
1107 
1108 	return ret;
1109 }
1110 
1111 static int event_hist_open(struct inode *inode, struct file *file)
1112 {
1113 	return single_open(file, hist_show, file);
1114 }
1115 
1116 const struct file_operations event_hist_fops = {
1117 	.open = event_hist_open,
1118 	.read = seq_read,
1119 	.llseek = seq_lseek,
1120 	.release = single_release,
1121 };
1122 
1123 static const char *get_hist_field_flags(struct hist_field *hist_field)
1124 {
1125 	const char *flags_str = NULL;
1126 
1127 	if (hist_field->flags & HIST_FIELD_FL_HEX)
1128 		flags_str = "hex";
1129 	else if (hist_field->flags & HIST_FIELD_FL_SYM)
1130 		flags_str = "sym";
1131 	else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
1132 		flags_str = "sym-offset";
1133 	else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
1134 		flags_str = "execname";
1135 	else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
1136 		flags_str = "syscall";
1137 	else if (hist_field->flags & HIST_FIELD_FL_LOG2)
1138 		flags_str = "log2";
1139 
1140 	return flags_str;
1141 }
1142 
1143 static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
1144 {
1145 	seq_printf(m, "%s", hist_field->field->name);
1146 	if (hist_field->flags) {
1147 		const char *flags_str = get_hist_field_flags(hist_field);
1148 
1149 		if (flags_str)
1150 			seq_printf(m, ".%s", flags_str);
1151 	}
1152 }
1153 
1154 static int event_hist_trigger_print(struct seq_file *m,
1155 				    struct event_trigger_ops *ops,
1156 				    struct event_trigger_data *data)
1157 {
1158 	struct hist_trigger_data *hist_data = data->private_data;
1159 	struct hist_field *key_field;
1160 	unsigned int i;
1161 
1162 	seq_puts(m, "hist:");
1163 
1164 	if (data->name)
1165 		seq_printf(m, "%s:", data->name);
1166 
1167 	seq_puts(m, "keys=");
1168 
1169 	for_each_hist_key_field(i, hist_data) {
1170 		key_field = hist_data->fields[i];
1171 
1172 		if (i > hist_data->n_vals)
1173 			seq_puts(m, ",");
1174 
1175 		if (key_field->flags & HIST_FIELD_FL_STACKTRACE)
1176 			seq_puts(m, "stacktrace");
1177 		else
1178 			hist_field_print(m, key_field);
1179 	}
1180 
1181 	seq_puts(m, ":vals=");
1182 
1183 	for_each_hist_val_field(i, hist_data) {
1184 		if (i == HITCOUNT_IDX)
1185 			seq_puts(m, "hitcount");
1186 		else {
1187 			seq_puts(m, ",");
1188 			hist_field_print(m, hist_data->fields[i]);
1189 		}
1190 	}
1191 
1192 	seq_puts(m, ":sort=");
1193 
1194 	for (i = 0; i < hist_data->n_sort_keys; i++) {
1195 		struct tracing_map_sort_key *sort_key;
1196 
1197 		sort_key = &hist_data->sort_keys[i];
1198 
1199 		if (i > 0)
1200 			seq_puts(m, ",");
1201 
1202 		if (sort_key->field_idx == HITCOUNT_IDX)
1203 			seq_puts(m, "hitcount");
1204 		else {
1205 			unsigned int idx = sort_key->field_idx;
1206 
1207 			if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX))
1208 				return -EINVAL;
1209 
1210 			hist_field_print(m, hist_data->fields[idx]);
1211 		}
1212 
1213 		if (sort_key->descending)
1214 			seq_puts(m, ".descending");
1215 	}
1216 
1217 	seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
1218 
1219 	if (data->filter_str)
1220 		seq_printf(m, " if %s", data->filter_str);
1221 
1222 	if (data->paused)
1223 		seq_puts(m, " [paused]");
1224 	else
1225 		seq_puts(m, " [active]");
1226 
1227 	seq_putc(m, '\n');
1228 
1229 	return 0;
1230 }
1231 
1232 static int event_hist_trigger_init(struct event_trigger_ops *ops,
1233 				   struct event_trigger_data *data)
1234 {
1235 	struct hist_trigger_data *hist_data = data->private_data;
1236 
1237 	if (!data->ref && hist_data->attrs->name)
1238 		save_named_trigger(hist_data->attrs->name, data);
1239 
1240 	data->ref++;
1241 
1242 	return 0;
1243 }
1244 
1245 static void event_hist_trigger_free(struct event_trigger_ops *ops,
1246 				    struct event_trigger_data *data)
1247 {
1248 	struct hist_trigger_data *hist_data = data->private_data;
1249 
1250 	if (WARN_ON_ONCE(data->ref <= 0))
1251 		return;
1252 
1253 	data->ref--;
1254 	if (!data->ref) {
1255 		if (data->name)
1256 			del_named_trigger(data);
1257 		trigger_data_free(data);
1258 		destroy_hist_data(hist_data);
1259 	}
1260 }
1261 
1262 static struct event_trigger_ops event_hist_trigger_ops = {
1263 	.func			= event_hist_trigger,
1264 	.print			= event_hist_trigger_print,
1265 	.init			= event_hist_trigger_init,
1266 	.free			= event_hist_trigger_free,
1267 };
1268 
1269 static int event_hist_trigger_named_init(struct event_trigger_ops *ops,
1270 					 struct event_trigger_data *data)
1271 {
1272 	data->ref++;
1273 
1274 	save_named_trigger(data->named_data->name, data);
1275 
1276 	event_hist_trigger_init(ops, data->named_data);
1277 
1278 	return 0;
1279 }
1280 
1281 static void event_hist_trigger_named_free(struct event_trigger_ops *ops,
1282 					  struct event_trigger_data *data)
1283 {
1284 	if (WARN_ON_ONCE(data->ref <= 0))
1285 		return;
1286 
1287 	event_hist_trigger_free(ops, data->named_data);
1288 
1289 	data->ref--;
1290 	if (!data->ref) {
1291 		del_named_trigger(data);
1292 		trigger_data_free(data);
1293 	}
1294 }
1295 
1296 static struct event_trigger_ops event_hist_trigger_named_ops = {
1297 	.func			= event_hist_trigger,
1298 	.print			= event_hist_trigger_print,
1299 	.init			= event_hist_trigger_named_init,
1300 	.free			= event_hist_trigger_named_free,
1301 };
1302 
1303 static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
1304 							    char *param)
1305 {
1306 	return &event_hist_trigger_ops;
1307 }
1308 
1309 static void hist_clear(struct event_trigger_data *data)
1310 {
1311 	struct hist_trigger_data *hist_data = data->private_data;
1312 
1313 	if (data->name)
1314 		pause_named_trigger(data);
1315 
1316 	synchronize_sched();
1317 
1318 	tracing_map_clear(hist_data->map);
1319 
1320 	if (data->name)
1321 		unpause_named_trigger(data);
1322 }
1323 
1324 static bool compatible_field(struct ftrace_event_field *field,
1325 			     struct ftrace_event_field *test_field)
1326 {
1327 	if (field == test_field)
1328 		return true;
1329 	if (field == NULL || test_field == NULL)
1330 		return false;
1331 	if (strcmp(field->name, test_field->name) != 0)
1332 		return false;
1333 	if (strcmp(field->type, test_field->type) != 0)
1334 		return false;
1335 	if (field->size != test_field->size)
1336 		return false;
1337 	if (field->is_signed != test_field->is_signed)
1338 		return false;
1339 
1340 	return true;
1341 }
1342 
1343 static bool hist_trigger_match(struct event_trigger_data *data,
1344 			       struct event_trigger_data *data_test,
1345 			       struct event_trigger_data *named_data,
1346 			       bool ignore_filter)
1347 {
1348 	struct tracing_map_sort_key *sort_key, *sort_key_test;
1349 	struct hist_trigger_data *hist_data, *hist_data_test;
1350 	struct hist_field *key_field, *key_field_test;
1351 	unsigned int i;
1352 
1353 	if (named_data && (named_data != data_test) &&
1354 	    (named_data != data_test->named_data))
1355 		return false;
1356 
1357 	if (!named_data && is_named_trigger(data_test))
1358 		return false;
1359 
1360 	hist_data = data->private_data;
1361 	hist_data_test = data_test->private_data;
1362 
1363 	if (hist_data->n_vals != hist_data_test->n_vals ||
1364 	    hist_data->n_fields != hist_data_test->n_fields ||
1365 	    hist_data->n_sort_keys != hist_data_test->n_sort_keys)
1366 		return false;
1367 
1368 	if (!ignore_filter) {
1369 		if ((data->filter_str && !data_test->filter_str) ||
1370 		   (!data->filter_str && data_test->filter_str))
1371 			return false;
1372 	}
1373 
1374 	for_each_hist_field(i, hist_data) {
1375 		key_field = hist_data->fields[i];
1376 		key_field_test = hist_data_test->fields[i];
1377 
1378 		if (key_field->flags != key_field_test->flags)
1379 			return false;
1380 		if (!compatible_field(key_field->field, key_field_test->field))
1381 			return false;
1382 		if (key_field->offset != key_field_test->offset)
1383 			return false;
1384 	}
1385 
1386 	for (i = 0; i < hist_data->n_sort_keys; i++) {
1387 		sort_key = &hist_data->sort_keys[i];
1388 		sort_key_test = &hist_data_test->sort_keys[i];
1389 
1390 		if (sort_key->field_idx != sort_key_test->field_idx ||
1391 		    sort_key->descending != sort_key_test->descending)
1392 			return false;
1393 	}
1394 
1395 	if (!ignore_filter && data->filter_str &&
1396 	    (strcmp(data->filter_str, data_test->filter_str) != 0))
1397 		return false;
1398 
1399 	return true;
1400 }
1401 
1402 static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
1403 				 struct event_trigger_data *data,
1404 				 struct trace_event_file *file)
1405 {
1406 	struct hist_trigger_data *hist_data = data->private_data;
1407 	struct event_trigger_data *test, *named_data = NULL;
1408 	int ret = 0;
1409 
1410 	if (hist_data->attrs->name) {
1411 		named_data = find_named_trigger(hist_data->attrs->name);
1412 		if (named_data) {
1413 			if (!hist_trigger_match(data, named_data, named_data,
1414 						true)) {
1415 				ret = -EINVAL;
1416 				goto out;
1417 			}
1418 		}
1419 	}
1420 
1421 	if (hist_data->attrs->name && !named_data)
1422 		goto new;
1423 
1424 	list_for_each_entry_rcu(test, &file->triggers, list) {
1425 		if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1426 			if (!hist_trigger_match(data, test, named_data, false))
1427 				continue;
1428 			if (hist_data->attrs->pause)
1429 				test->paused = true;
1430 			else if (hist_data->attrs->cont)
1431 				test->paused = false;
1432 			else if (hist_data->attrs->clear)
1433 				hist_clear(test);
1434 			else
1435 				ret = -EEXIST;
1436 			goto out;
1437 		}
1438 	}
1439  new:
1440 	if (hist_data->attrs->cont || hist_data->attrs->clear) {
1441 		ret = -ENOENT;
1442 		goto out;
1443 	}
1444 
1445 	if (hist_data->attrs->pause)
1446 		data->paused = true;
1447 
1448 	if (named_data) {
1449 		destroy_hist_data(data->private_data);
1450 		data->private_data = named_data->private_data;
1451 		set_named_trigger_data(data, named_data);
1452 		data->ops = &event_hist_trigger_named_ops;
1453 	}
1454 
1455 	if (data->ops->init) {
1456 		ret = data->ops->init(data->ops, data);
1457 		if (ret < 0)
1458 			goto out;
1459 	}
1460 
1461 	list_add_rcu(&data->list, &file->triggers);
1462 	ret++;
1463 
1464 	update_cond_flag(file);
1465 
1466 	if (trace_event_trigger_enable_disable(file, 1) < 0) {
1467 		list_del_rcu(&data->list);
1468 		update_cond_flag(file);
1469 		ret--;
1470 	}
1471  out:
1472 	return ret;
1473 }
1474 
1475 static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
1476 				    struct event_trigger_data *data,
1477 				    struct trace_event_file *file)
1478 {
1479 	struct hist_trigger_data *hist_data = data->private_data;
1480 	struct event_trigger_data *test, *named_data = NULL;
1481 	bool unregistered = false;
1482 
1483 	if (hist_data->attrs->name)
1484 		named_data = find_named_trigger(hist_data->attrs->name);
1485 
1486 	list_for_each_entry_rcu(test, &file->triggers, list) {
1487 		if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1488 			if (!hist_trigger_match(data, test, named_data, false))
1489 				continue;
1490 			unregistered = true;
1491 			list_del_rcu(&test->list);
1492 			trace_event_trigger_enable_disable(file, 0);
1493 			update_cond_flag(file);
1494 			break;
1495 		}
1496 	}
1497 
1498 	if (unregistered && test->ops->free)
1499 		test->ops->free(test->ops, test);
1500 }
1501 
1502 static void hist_unreg_all(struct trace_event_file *file)
1503 {
1504 	struct event_trigger_data *test, *n;
1505 
1506 	list_for_each_entry_safe(test, n, &file->triggers, list) {
1507 		if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1508 			list_del_rcu(&test->list);
1509 			trace_event_trigger_enable_disable(file, 0);
1510 			update_cond_flag(file);
1511 			if (test->ops->free)
1512 				test->ops->free(test->ops, test);
1513 		}
1514 	}
1515 }
1516 
1517 static int event_hist_trigger_func(struct event_command *cmd_ops,
1518 				   struct trace_event_file *file,
1519 				   char *glob, char *cmd, char *param)
1520 {
1521 	unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
1522 	struct event_trigger_data *trigger_data;
1523 	struct hist_trigger_attrs *attrs;
1524 	struct event_trigger_ops *trigger_ops;
1525 	struct hist_trigger_data *hist_data;
1526 	char *trigger;
1527 	int ret = 0;
1528 
1529 	if (!param)
1530 		return -EINVAL;
1531 
1532 	/* separate the trigger from the filter (k:v [if filter]) */
1533 	trigger = strsep(&param, " \t");
1534 	if (!trigger)
1535 		return -EINVAL;
1536 
1537 	attrs = parse_hist_trigger_attrs(trigger);
1538 	if (IS_ERR(attrs))
1539 		return PTR_ERR(attrs);
1540 
1541 	if (attrs->map_bits)
1542 		hist_trigger_bits = attrs->map_bits;
1543 
1544 	hist_data = create_hist_data(hist_trigger_bits, attrs, file);
1545 	if (IS_ERR(hist_data)) {
1546 		destroy_hist_trigger_attrs(attrs);
1547 		return PTR_ERR(hist_data);
1548 	}
1549 
1550 	trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1551 
1552 	ret = -ENOMEM;
1553 	trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1554 	if (!trigger_data)
1555 		goto out_free;
1556 
1557 	trigger_data->count = -1;
1558 	trigger_data->ops = trigger_ops;
1559 	trigger_data->cmd_ops = cmd_ops;
1560 
1561 	INIT_LIST_HEAD(&trigger_data->list);
1562 	RCU_INIT_POINTER(trigger_data->filter, NULL);
1563 
1564 	trigger_data->private_data = hist_data;
1565 
1566 	/* if param is non-empty, it's supposed to be a filter */
1567 	if (param && cmd_ops->set_filter) {
1568 		ret = cmd_ops->set_filter(param, trigger_data, file);
1569 		if (ret < 0)
1570 			goto out_free;
1571 	}
1572 
1573 	if (glob[0] == '!') {
1574 		cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1575 		ret = 0;
1576 		goto out_free;
1577 	}
1578 
1579 	ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1580 	/*
1581 	 * The above returns on success the # of triggers registered,
1582 	 * but if it didn't register any it returns zero.  Consider no
1583 	 * triggers registered a failure too.
1584 	 */
1585 	if (!ret) {
1586 		if (!(attrs->pause || attrs->cont || attrs->clear))
1587 			ret = -ENOENT;
1588 		goto out_free;
1589 	} else if (ret < 0)
1590 		goto out_free;
1591 	/* Just return zero, not the number of registered triggers */
1592 	ret = 0;
1593  out:
1594 	return ret;
1595  out_free:
1596 	if (cmd_ops->set_filter)
1597 		cmd_ops->set_filter(NULL, trigger_data, NULL);
1598 
1599 	kfree(trigger_data);
1600 
1601 	destroy_hist_data(hist_data);
1602 	goto out;
1603 }
1604 
1605 static struct event_command trigger_hist_cmd = {
1606 	.name			= "hist",
1607 	.trigger_type		= ETT_EVENT_HIST,
1608 	.flags			= EVENT_CMD_FL_NEEDS_REC,
1609 	.func			= event_hist_trigger_func,
1610 	.reg			= hist_register_trigger,
1611 	.unreg			= hist_unregister_trigger,
1612 	.unreg_all		= hist_unreg_all,
1613 	.get_trigger_ops	= event_hist_get_trigger_ops,
1614 	.set_filter		= set_trigger_filter,
1615 };
1616 
1617 __init int register_trigger_hist_cmd(void)
1618 {
1619 	int ret;
1620 
1621 	ret = register_event_command(&trigger_hist_cmd);
1622 	WARN_ON(ret < 0);
1623 
1624 	return ret;
1625 }
1626 
1627 static void
1628 hist_enable_trigger(struct event_trigger_data *data, void *rec)
1629 {
1630 	struct enable_trigger_data *enable_data = data->private_data;
1631 	struct event_trigger_data *test;
1632 
1633 	list_for_each_entry_rcu(test, &enable_data->file->triggers, list) {
1634 		if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1635 			if (enable_data->enable)
1636 				test->paused = false;
1637 			else
1638 				test->paused = true;
1639 		}
1640 	}
1641 }
1642 
1643 static void
1644 hist_enable_count_trigger(struct event_trigger_data *data, void *rec)
1645 {
1646 	if (!data->count)
1647 		return;
1648 
1649 	if (data->count != -1)
1650 		(data->count)--;
1651 
1652 	hist_enable_trigger(data, rec);
1653 }
1654 
1655 static struct event_trigger_ops hist_enable_trigger_ops = {
1656 	.func			= hist_enable_trigger,
1657 	.print			= event_enable_trigger_print,
1658 	.init			= event_trigger_init,
1659 	.free			= event_enable_trigger_free,
1660 };
1661 
1662 static struct event_trigger_ops hist_enable_count_trigger_ops = {
1663 	.func			= hist_enable_count_trigger,
1664 	.print			= event_enable_trigger_print,
1665 	.init			= event_trigger_init,
1666 	.free			= event_enable_trigger_free,
1667 };
1668 
1669 static struct event_trigger_ops hist_disable_trigger_ops = {
1670 	.func			= hist_enable_trigger,
1671 	.print			= event_enable_trigger_print,
1672 	.init			= event_trigger_init,
1673 	.free			= event_enable_trigger_free,
1674 };
1675 
1676 static struct event_trigger_ops hist_disable_count_trigger_ops = {
1677 	.func			= hist_enable_count_trigger,
1678 	.print			= event_enable_trigger_print,
1679 	.init			= event_trigger_init,
1680 	.free			= event_enable_trigger_free,
1681 };
1682 
1683 static struct event_trigger_ops *
1684 hist_enable_get_trigger_ops(char *cmd, char *param)
1685 {
1686 	struct event_trigger_ops *ops;
1687 	bool enable;
1688 
1689 	enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
1690 
1691 	if (enable)
1692 		ops = param ? &hist_enable_count_trigger_ops :
1693 			&hist_enable_trigger_ops;
1694 	else
1695 		ops = param ? &hist_disable_count_trigger_ops :
1696 			&hist_disable_trigger_ops;
1697 
1698 	return ops;
1699 }
1700 
1701 static void hist_enable_unreg_all(struct trace_event_file *file)
1702 {
1703 	struct event_trigger_data *test, *n;
1704 
1705 	list_for_each_entry_safe(test, n, &file->triggers, list) {
1706 		if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) {
1707 			list_del_rcu(&test->list);
1708 			update_cond_flag(file);
1709 			trace_event_trigger_enable_disable(file, 0);
1710 			if (test->ops->free)
1711 				test->ops->free(test->ops, test);
1712 		}
1713 	}
1714 }
1715 
1716 static struct event_command trigger_hist_enable_cmd = {
1717 	.name			= ENABLE_HIST_STR,
1718 	.trigger_type		= ETT_HIST_ENABLE,
1719 	.func			= event_enable_trigger_func,
1720 	.reg			= event_enable_register_trigger,
1721 	.unreg			= event_enable_unregister_trigger,
1722 	.unreg_all		= hist_enable_unreg_all,
1723 	.get_trigger_ops	= hist_enable_get_trigger_ops,
1724 	.set_filter		= set_trigger_filter,
1725 };
1726 
1727 static struct event_command trigger_hist_disable_cmd = {
1728 	.name			= DISABLE_HIST_STR,
1729 	.trigger_type		= ETT_HIST_ENABLE,
1730 	.func			= event_enable_trigger_func,
1731 	.reg			= event_enable_register_trigger,
1732 	.unreg			= event_enable_unregister_trigger,
1733 	.unreg_all		= hist_enable_unreg_all,
1734 	.get_trigger_ops	= hist_enable_get_trigger_ops,
1735 	.set_filter		= set_trigger_filter,
1736 };
1737 
1738 static __init void unregister_trigger_hist_enable_disable_cmds(void)
1739 {
1740 	unregister_event_command(&trigger_hist_enable_cmd);
1741 	unregister_event_command(&trigger_hist_disable_cmd);
1742 }
1743 
1744 __init int register_trigger_hist_enable_disable_cmds(void)
1745 {
1746 	int ret;
1747 
1748 	ret = register_event_command(&trigger_hist_enable_cmd);
1749 	if (WARN_ON(ret < 0))
1750 		return ret;
1751 	ret = register_event_command(&trigger_hist_disable_cmd);
1752 	if (WARN_ON(ret < 0))
1753 		unregister_trigger_hist_enable_disable_cmds();
1754 
1755 	return ret;
1756 }
1757