1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * trace_events_hist - trace event hist triggers
4 *
5 * Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com>
6 */
7
8 #include <linux/module.h>
9 #include <linux/kallsyms.h>
10 #include <linux/security.h>
11 #include <linux/mutex.h>
12 #include <linux/slab.h>
13 #include <linux/stacktrace.h>
14 #include <linux/rculist.h>
15 #include <linux/tracefs.h>
16
17 /* for gfp flag names */
18 #include <linux/trace_events.h>
19 #include <trace/events/mmflags.h>
20
21 #include "tracing_map.h"
22 #include "trace.h"
23 #include "trace_dynevent.h"
24
25 #define SYNTH_SYSTEM "synthetic"
26 #define SYNTH_FIELDS_MAX 32
27
28 #define STR_VAR_LEN_MAX 32 /* must be multiple of sizeof(u64) */
29
30 #define ERRORS \
31 C(NONE, "No error"), \
32 C(DUPLICATE_VAR, "Variable already defined"), \
33 C(VAR_NOT_UNIQUE, "Variable name not unique, need to use fully qualified name (subsys.event.var) for variable"), \
34 C(TOO_MANY_VARS, "Too many variables defined"), \
35 C(MALFORMED_ASSIGNMENT, "Malformed assignment"), \
36 C(NAMED_MISMATCH, "Named hist trigger doesn't match existing named trigger (includes variables)"), \
37 C(TRIGGER_EEXIST, "Hist trigger already exists"), \
38 C(TRIGGER_ENOENT_CLEAR, "Can't clear or continue a nonexistent hist trigger"), \
39 C(SET_CLOCK_FAIL, "Couldn't set trace_clock"), \
40 C(BAD_FIELD_MODIFIER, "Invalid field modifier"), \
41 C(TOO_MANY_SUBEXPR, "Too many subexpressions (3 max)"), \
42 C(TIMESTAMP_MISMATCH, "Timestamp units in expression don't match"), \
43 C(TOO_MANY_FIELD_VARS, "Too many field variables defined"), \
44 C(EVENT_FILE_NOT_FOUND, "Event file not found"), \
45 C(HIST_NOT_FOUND, "Matching event histogram not found"), \
46 C(HIST_CREATE_FAIL, "Couldn't create histogram for field"), \
47 C(SYNTH_VAR_NOT_FOUND, "Couldn't find synthetic variable"), \
48 C(SYNTH_EVENT_NOT_FOUND,"Couldn't find synthetic event"), \
49 C(SYNTH_TYPE_MISMATCH, "Param type doesn't match synthetic event field type"), \
50 C(SYNTH_COUNT_MISMATCH, "Param count doesn't match synthetic event field count"), \
51 C(FIELD_VAR_PARSE_FAIL, "Couldn't parse field variable"), \
52 C(VAR_CREATE_FIND_FAIL, "Couldn't create or find variable"), \
53 C(ONX_NOT_VAR, "For onmax(x) or onchange(x), x must be a variable"), \
54 C(ONX_VAR_NOT_FOUND, "Couldn't find onmax or onchange variable"), \
55 C(ONX_VAR_CREATE_FAIL, "Couldn't create onmax or onchange variable"), \
56 C(FIELD_VAR_CREATE_FAIL,"Couldn't create field variable"), \
57 C(TOO_MANY_PARAMS, "Too many action params"), \
58 C(PARAM_NOT_FOUND, "Couldn't find param"), \
59 C(INVALID_PARAM, "Invalid action param"), \
60 C(ACTION_NOT_FOUND, "No action found"), \
61 C(NO_SAVE_PARAMS, "No params found for save()"), \
62 C(TOO_MANY_SAVE_ACTIONS,"Can't have more than one save() action per hist"), \
63 C(ACTION_MISMATCH, "Handler doesn't support action"), \
64 C(NO_CLOSING_PAREN, "No closing paren found"), \
65 C(SUBSYS_NOT_FOUND, "Missing subsystem"), \
66 C(INVALID_SUBSYS_EVENT, "Invalid subsystem or event name"), \
67 C(INVALID_REF_KEY, "Using variable references in keys not supported"), \
68 C(VAR_NOT_FOUND, "Couldn't find variable"), \
69 C(FIELD_NOT_FOUND, "Couldn't find field"),
70
71 #undef C
72 #define C(a, b) HIST_ERR_##a
73
74 enum { ERRORS };
75
76 #undef C
77 #define C(a, b) b
78
79 static const char *err_text[] = { ERRORS };
80
81 struct hist_field;
82
83 typedef u64 (*hist_field_fn_t) (struct hist_field *field,
84 struct tracing_map_elt *elt,
85 struct ring_buffer_event *rbe,
86 void *event);
87
88 #define HIST_FIELD_OPERANDS_MAX 2
89 #define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
90 #define HIST_ACTIONS_MAX 8
91
92 enum field_op_id {
93 FIELD_OP_NONE,
94 FIELD_OP_PLUS,
95 FIELD_OP_MINUS,
96 FIELD_OP_UNARY_MINUS,
97 };
98
99 /*
100 * A hist_var (histogram variable) contains variable information for
101 * hist_fields having the HIST_FIELD_FL_VAR or HIST_FIELD_FL_VAR_REF
102 * flag set. A hist_var has a variable name e.g. ts0, and is
103 * associated with a given histogram trigger, as specified by
104 * hist_data. The hist_var idx is the unique index assigned to the
105 * variable by the hist trigger's tracing_map. The idx is what is
106 * used to set a variable's value and, by a variable reference, to
107 * retrieve it.
108 */
109 struct hist_var {
110 char *name;
111 struct hist_trigger_data *hist_data;
112 unsigned int idx;
113 };
114
115 struct hist_field {
116 struct ftrace_event_field *field;
117 unsigned long flags;
118 hist_field_fn_t fn;
119 unsigned int ref;
120 unsigned int size;
121 unsigned int offset;
122 unsigned int is_signed;
123 const char *type;
124 struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
125 struct hist_trigger_data *hist_data;
126
127 /*
128 * Variable fields contain variable-specific info in var.
129 */
130 struct hist_var var;
131 enum field_op_id operator;
132 char *system;
133 char *event_name;
134
135 /*
136 * The name field is used for EXPR and VAR_REF fields. VAR
137 * fields contain the variable name in var.name.
138 */
139 char *name;
140
141 /*
142 * When a histogram trigger is hit, if it has any references
143 * to variables, the values of those variables are collected
144 * into a var_ref_vals array by resolve_var_refs(). The
145 * current value of each variable is read from the tracing_map
146 * using the hist field's hist_var.idx and entered into the
147 * var_ref_idx entry i.e. var_ref_vals[var_ref_idx].
148 */
149 unsigned int var_ref_idx;
150 bool read_once;
151 };
152
153 static u64 hist_field_none(struct hist_field *field,
154 struct tracing_map_elt *elt,
155 struct ring_buffer_event *rbe,
156 void *event)
157 {
158 return 0;
159 }
160
161 static u64 hist_field_counter(struct hist_field *field,
162 struct tracing_map_elt *elt,
163 struct ring_buffer_event *rbe,
164 void *event)
165 {
166 return 1;
167 }
168
169 static u64 hist_field_string(struct hist_field *hist_field,
170 struct tracing_map_elt *elt,
171 struct ring_buffer_event *rbe,
172 void *event)
173 {
174 char *addr = (char *)(event + hist_field->field->offset);
175
176 return (u64)(unsigned long)addr;
177 }
178
179 static u64 hist_field_dynstring(struct hist_field *hist_field,
180 struct tracing_map_elt *elt,
181 struct ring_buffer_event *rbe,
182 void *event)
183 {
184 u32 str_item = *(u32 *)(event + hist_field->field->offset);
185 int str_loc = str_item & 0xffff;
186 char *addr = (char *)(event + str_loc);
187
188 return (u64)(unsigned long)addr;
189 }
190
191 static u64 hist_field_pstring(struct hist_field *hist_field,
192 struct tracing_map_elt *elt,
193 struct ring_buffer_event *rbe,
194 void *event)
195 {
196 char **addr = (char **)(event + hist_field->field->offset);
197
198 return (u64)(unsigned long)*addr;
199 }
200
201 static u64 hist_field_log2(struct hist_field *hist_field,
202 struct tracing_map_elt *elt,
203 struct ring_buffer_event *rbe,
204 void *event)
205 {
206 struct hist_field *operand = hist_field->operands[0];
207
208 u64 val = operand->fn(operand, elt, rbe, event);
209
210 return (u64) ilog2(roundup_pow_of_two(val));
211 }
212
213 static u64 hist_field_plus(struct hist_field *hist_field,
214 struct tracing_map_elt *elt,
215 struct ring_buffer_event *rbe,
216 void *event)
217 {
218 struct hist_field *operand1 = hist_field->operands[0];
219 struct hist_field *operand2 = hist_field->operands[1];
220
221 u64 val1 = operand1->fn(operand1, elt, rbe, event);
222 u64 val2 = operand2->fn(operand2, elt, rbe, event);
223
224 return val1 + val2;
225 }
226
227 static u64 hist_field_minus(struct hist_field *hist_field,
228 struct tracing_map_elt *elt,
229 struct ring_buffer_event *rbe,
230 void *event)
231 {
232 struct hist_field *operand1 = hist_field->operands[0];
233 struct hist_field *operand2 = hist_field->operands[1];
234
235 u64 val1 = operand1->fn(operand1, elt, rbe, event);
236 u64 val2 = operand2->fn(operand2, elt, rbe, event);
237
238 return val1 - val2;
239 }
240
241 static u64 hist_field_unary_minus(struct hist_field *hist_field,
242 struct tracing_map_elt *elt,
243 struct ring_buffer_event *rbe,
244 void *event)
245 {
246 struct hist_field *operand = hist_field->operands[0];
247
248 s64 sval = (s64)operand->fn(operand, elt, rbe, event);
249 u64 val = (u64)-sval;
250
251 return val;
252 }
253
254 #define DEFINE_HIST_FIELD_FN(type) \
255 static u64 hist_field_##type(struct hist_field *hist_field, \
256 struct tracing_map_elt *elt, \
257 struct ring_buffer_event *rbe, \
258 void *event) \
259 { \
260 type *addr = (type *)(event + hist_field->field->offset); \
261 \
262 return (u64)(unsigned long)*addr; \
263 }
264
265 DEFINE_HIST_FIELD_FN(s64);
266 DEFINE_HIST_FIELD_FN(u64);
267 DEFINE_HIST_FIELD_FN(s32);
268 DEFINE_HIST_FIELD_FN(u32);
269 DEFINE_HIST_FIELD_FN(s16);
270 DEFINE_HIST_FIELD_FN(u16);
271 DEFINE_HIST_FIELD_FN(s8);
272 DEFINE_HIST_FIELD_FN(u8);
273
274 #define for_each_hist_field(i, hist_data) \
275 for ((i) = 0; (i) < (hist_data)->n_fields; (i)++)
276
277 #define for_each_hist_val_field(i, hist_data) \
278 for ((i) = 0; (i) < (hist_data)->n_vals; (i)++)
279
280 #define for_each_hist_key_field(i, hist_data) \
281 for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++)
282
283 #define HIST_STACKTRACE_DEPTH 16
284 #define HIST_STACKTRACE_SIZE (HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
285 #define HIST_STACKTRACE_SKIP 5
286
287 #define HITCOUNT_IDX 0
288 #define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE)
289
290 enum hist_field_flags {
291 HIST_FIELD_FL_HITCOUNT = 1 << 0,
292 HIST_FIELD_FL_KEY = 1 << 1,
293 HIST_FIELD_FL_STRING = 1 << 2,
294 HIST_FIELD_FL_HEX = 1 << 3,
295 HIST_FIELD_FL_SYM = 1 << 4,
296 HIST_FIELD_FL_SYM_OFFSET = 1 << 5,
297 HIST_FIELD_FL_EXECNAME = 1 << 6,
298 HIST_FIELD_FL_SYSCALL = 1 << 7,
299 HIST_FIELD_FL_STACKTRACE = 1 << 8,
300 HIST_FIELD_FL_LOG2 = 1 << 9,
301 HIST_FIELD_FL_TIMESTAMP = 1 << 10,
302 HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11,
303 HIST_FIELD_FL_VAR = 1 << 12,
304 HIST_FIELD_FL_EXPR = 1 << 13,
305 HIST_FIELD_FL_VAR_REF = 1 << 14,
306 HIST_FIELD_FL_CPU = 1 << 15,
307 HIST_FIELD_FL_ALIAS = 1 << 16,
308 };
309
310 struct var_defs {
311 unsigned int n_vars;
312 char *name[TRACING_MAP_VARS_MAX];
313 char *expr[TRACING_MAP_VARS_MAX];
314 };
315
316 struct hist_trigger_attrs {
317 char *keys_str;
318 char *vals_str;
319 char *sort_key_str;
320 char *name;
321 char *clock;
322 bool pause;
323 bool cont;
324 bool clear;
325 bool ts_in_usecs;
326 unsigned int map_bits;
327
328 char *assignment_str[TRACING_MAP_VARS_MAX];
329 unsigned int n_assignments;
330
331 char *action_str[HIST_ACTIONS_MAX];
332 unsigned int n_actions;
333
334 struct var_defs var_defs;
335 };
336
337 struct field_var {
338 struct hist_field *var;
339 struct hist_field *val;
340 };
341
342 struct field_var_hist {
343 struct hist_trigger_data *hist_data;
344 char *cmd;
345 };
346
347 struct hist_trigger_data {
348 struct hist_field *fields[HIST_FIELDS_MAX];
349 unsigned int n_vals;
350 unsigned int n_keys;
351 unsigned int n_fields;
352 unsigned int n_vars;
353 unsigned int key_size;
354 struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX];
355 unsigned int n_sort_keys;
356 struct trace_event_file *event_file;
357 struct hist_trigger_attrs *attrs;
358 struct tracing_map *map;
359 bool enable_timestamps;
360 bool remove;
361 struct hist_field *var_refs[TRACING_MAP_VARS_MAX];
362 unsigned int n_var_refs;
363
364 struct action_data *actions[HIST_ACTIONS_MAX];
365 unsigned int n_actions;
366
367 struct field_var *field_vars[SYNTH_FIELDS_MAX];
368 unsigned int n_field_vars;
369 unsigned int n_field_var_str;
370 struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX];
371 unsigned int n_field_var_hists;
372
373 struct field_var *save_vars[SYNTH_FIELDS_MAX];
374 unsigned int n_save_vars;
375 unsigned int n_save_var_str;
376 };
377
378 static int synth_event_create(int argc, const char **argv);
379 static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
380 static int synth_event_release(struct dyn_event *ev);
381 static bool synth_event_is_busy(struct dyn_event *ev);
382 static bool synth_event_match(const char *system, const char *event,
383 int argc, const char **argv, struct dyn_event *ev);
384
385 static struct dyn_event_operations synth_event_ops = {
386 .create = synth_event_create,
387 .show = synth_event_show,
388 .is_busy = synth_event_is_busy,
389 .free = synth_event_release,
390 .match = synth_event_match,
391 };
392
393 struct synth_field {
394 char *type;
395 char *name;
396 size_t size;
397 bool is_signed;
398 bool is_string;
399 };
400
401 struct synth_event {
402 struct dyn_event devent;
403 int ref;
404 char *name;
405 struct synth_field **fields;
406 unsigned int n_fields;
407 unsigned int n_u64;
408 struct trace_event_class class;
409 struct trace_event_call call;
410 struct tracepoint *tp;
411 };
412
413 static bool is_synth_event(struct dyn_event *ev)
414 {
415 return ev->ops == &synth_event_ops;
416 }
417
418 static struct synth_event *to_synth_event(struct dyn_event *ev)
419 {
420 return container_of(ev, struct synth_event, devent);
421 }
422
423 static bool synth_event_is_busy(struct dyn_event *ev)
424 {
425 struct synth_event *event = to_synth_event(ev);
426
427 return event->ref != 0;
428 }
429
430 static bool synth_event_match(const char *system, const char *event,
431 int argc, const char **argv, struct dyn_event *ev)
432 {
433 struct synth_event *sev = to_synth_event(ev);
434
435 return strcmp(sev->name, event) == 0 &&
436 (!system || strcmp(system, SYNTH_SYSTEM) == 0);
437 }
438
439 struct action_data;
440
441 typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
442 struct tracing_map_elt *elt, void *rec,
443 struct ring_buffer_event *rbe, void *key,
444 struct action_data *data, u64 *var_ref_vals);
445
446 typedef bool (*check_track_val_fn_t) (u64 track_val, u64 var_val);
447
448 enum handler_id {
449 HANDLER_ONMATCH = 1,
450 HANDLER_ONMAX,
451 HANDLER_ONCHANGE,
452 };
453
454 enum action_id {
455 ACTION_SAVE = 1,
456 ACTION_TRACE,
457 ACTION_SNAPSHOT,
458 };
459
460 struct action_data {
461 enum handler_id handler;
462 enum action_id action;
463 char *action_name;
464 action_fn_t fn;
465
466 unsigned int n_params;
467 char *params[SYNTH_FIELDS_MAX];
468
469 /*
470 * When a histogram trigger is hit, the values of any
471 * references to variables, including variables being passed
472 * as parameters to synthetic events, are collected into a
473 * var_ref_vals array. This var_ref_idx array is an array of
474 * indices into the var_ref_vals array, one for each synthetic
475 * event param, and is passed to the synthetic event
476 * invocation.
477 */
478 unsigned int var_ref_idx[TRACING_MAP_VARS_MAX];
479 struct synth_event *synth_event;
480 bool use_trace_keyword;
481 char *synth_event_name;
482
483 union {
484 struct {
485 char *event;
486 char *event_system;
487 } match_data;
488
489 struct {
490 /*
491 * var_str contains the $-unstripped variable
492 * name referenced by var_ref, and used when
493 * printing the action. Because var_ref
494 * creation is deferred to create_actions(),
495 * we need a per-action way to save it until
496 * then, thus var_str.
497 */
498 char *var_str;
499
500 /*
501 * var_ref refers to the variable being
502 * tracked e.g onmax($var).
503 */
504 struct hist_field *var_ref;
505
506 /*
507 * track_var contains the 'invisible' tracking
508 * variable created to keep the current
509 * e.g. max value.
510 */
511 struct hist_field *track_var;
512
513 check_track_val_fn_t check_val;
514 action_fn_t save_data;
515 } track_data;
516 };
517 };
518
519 struct track_data {
520 u64 track_val;
521 bool updated;
522
523 unsigned int key_len;
524 void *key;
525 struct tracing_map_elt elt;
526
527 struct action_data *action_data;
528 struct hist_trigger_data *hist_data;
529 };
530
531 struct hist_elt_data {
532 char *comm;
533 u64 *var_ref_vals;
534 char *field_var_str[SYNTH_FIELDS_MAX];
535 };
536
537 struct snapshot_context {
538 struct tracing_map_elt *elt;
539 void *key;
540 };
541
542 static void track_data_free(struct track_data *track_data)
543 {
544 struct hist_elt_data *elt_data;
545
546 if (!track_data)
547 return;
548
549 kfree(track_data->key);
550
551 elt_data = track_data->elt.private_data;
552 if (elt_data) {
553 kfree(elt_data->comm);
554 kfree(elt_data);
555 }
556
557 kfree(track_data);
558 }
559
560 static struct track_data *track_data_alloc(unsigned int key_len,
561 struct action_data *action_data,
562 struct hist_trigger_data *hist_data)
563 {
564 struct track_data *data = kzalloc(sizeof(*data), GFP_KERNEL);
565 struct hist_elt_data *elt_data;
566
567 if (!data)
568 return ERR_PTR(-ENOMEM);
569
570 data->key = kzalloc(key_len, GFP_KERNEL);
571 if (!data->key) {
572 track_data_free(data);
573 return ERR_PTR(-ENOMEM);
574 }
575
576 data->key_len = key_len;
577 data->action_data = action_data;
578 data->hist_data = hist_data;
579
580 elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
581 if (!elt_data) {
582 track_data_free(data);
583 return ERR_PTR(-ENOMEM);
584 }
585 data->elt.private_data = elt_data;
586
587 elt_data->comm = kzalloc(TASK_COMM_LEN, GFP_KERNEL);
588 if (!elt_data->comm) {
589 track_data_free(data);
590 return ERR_PTR(-ENOMEM);
591 }
592
593 return data;
594 }
595
596 static char last_cmd[MAX_FILTER_STR_VAL];
597 static char last_cmd_loc[MAX_FILTER_STR_VAL];
598
599 static int errpos(char *str)
600 {
601 return err_pos(last_cmd, str);
602 }
603
604 static void last_cmd_set(struct trace_event_file *file, char *str)
605 {
606 const char *system = NULL, *name = NULL;
607 struct trace_event_call *call;
608
609 if (!str)
610 return;
611
612 strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1);
613
614 if (file) {
615 call = file->event_call;
616
617 system = call->class->system;
618 if (system) {
619 name = trace_event_name(call);
620 if (!name)
621 system = NULL;
622 }
623 }
624
625 if (system)
626 snprintf(last_cmd_loc, MAX_FILTER_STR_VAL, "hist:%s:%s", system, name);
627 }
628
629 static void hist_err(struct trace_array *tr, u8 err_type, u8 err_pos)
630 {
631 tracing_log_err(tr, last_cmd_loc, last_cmd, err_text,
632 err_type, err_pos);
633 }
634
635 static void hist_err_clear(void)
636 {
637 last_cmd[0] = '\0';
638 last_cmd_loc[0] = '\0';
639 }
640
641 struct synth_trace_event {
642 struct trace_entry ent;
643 u64 fields[];
644 };
645
646 static int synth_event_define_fields(struct trace_event_call *call)
647 {
648 struct synth_trace_event trace;
649 int offset = offsetof(typeof(trace), fields);
650 struct synth_event *event = call->data;
651 unsigned int i, size, n_u64;
652 char *name, *type;
653 bool is_signed;
654 int ret = 0;
655
656 for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
657 size = event->fields[i]->size;
658 is_signed = event->fields[i]->is_signed;
659 type = event->fields[i]->type;
660 name = event->fields[i]->name;
661 ret = trace_define_field(call, type, name, offset, size,
662 is_signed, FILTER_OTHER);
663 if (ret)
664 break;
665
666 if (event->fields[i]->is_string) {
667 offset += STR_VAR_LEN_MAX;
668 n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
669 } else {
670 offset += sizeof(u64);
671 n_u64++;
672 }
673 }
674
675 event->n_u64 = n_u64;
676
677 return ret;
678 }
679
680 static bool synth_field_signed(char *type)
681 {
682 if (str_has_prefix(type, "u"))
683 return false;
684 if (strcmp(type, "gfp_t") == 0)
685 return false;
686
687 return true;
688 }
689
690 static int synth_field_is_string(char *type)
691 {
692 if (strstr(type, "char[") != NULL)
693 return true;
694
695 return false;
696 }
697
698 static int synth_field_string_size(char *type)
699 {
700 char buf[4], *end, *start;
701 unsigned int len;
702 int size, err;
703
704 start = strstr(type, "char[");
705 if (start == NULL)
706 return -EINVAL;
707 start += sizeof("char[") - 1;
708
709 end = strchr(type, ']');
710 if (!end || end < start)
711 return -EINVAL;
712
713 len = end - start;
714 if (len > 3)
715 return -EINVAL;
716
717 strncpy(buf, start, len);
718 buf[len] = '\0';
719
720 err = kstrtouint(buf, 0, &size);
721 if (err)
722 return err;
723
724 if (size > STR_VAR_LEN_MAX)
725 return -EINVAL;
726
727 return size;
728 }
729
730 static int synth_field_size(char *type)
731 {
732 int size = 0;
733
734 if (strcmp(type, "s64") == 0)
735 size = sizeof(s64);
736 else if (strcmp(type, "u64") == 0)
737 size = sizeof(u64);
738 else if (strcmp(type, "s32") == 0)
739 size = sizeof(s32);
740 else if (strcmp(type, "u32") == 0)
741 size = sizeof(u32);
742 else if (strcmp(type, "s16") == 0)
743 size = sizeof(s16);
744 else if (strcmp(type, "u16") == 0)
745 size = sizeof(u16);
746 else if (strcmp(type, "s8") == 0)
747 size = sizeof(s8);
748 else if (strcmp(type, "u8") == 0)
749 size = sizeof(u8);
750 else if (strcmp(type, "char") == 0)
751 size = sizeof(char);
752 else if (strcmp(type, "unsigned char") == 0)
753 size = sizeof(unsigned char);
754 else if (strcmp(type, "int") == 0)
755 size = sizeof(int);
756 else if (strcmp(type, "unsigned int") == 0)
757 size = sizeof(unsigned int);
758 else if (strcmp(type, "long") == 0)
759 size = sizeof(long);
760 else if (strcmp(type, "unsigned long") == 0)
761 size = sizeof(unsigned long);
762 else if (strcmp(type, "pid_t") == 0)
763 size = sizeof(pid_t);
764 else if (strcmp(type, "gfp_t") == 0)
765 size = sizeof(gfp_t);
766 else if (synth_field_is_string(type))
767 size = synth_field_string_size(type);
768
769 return size;
770 }
771
772 static const char *synth_field_fmt(char *type)
773 {
774 const char *fmt = "%llu";
775
776 if (strcmp(type, "s64") == 0)
777 fmt = "%lld";
778 else if (strcmp(type, "u64") == 0)
779 fmt = "%llu";
780 else if (strcmp(type, "s32") == 0)
781 fmt = "%d";
782 else if (strcmp(type, "u32") == 0)
783 fmt = "%u";
784 else if (strcmp(type, "s16") == 0)
785 fmt = "%d";
786 else if (strcmp(type, "u16") == 0)
787 fmt = "%u";
788 else if (strcmp(type, "s8") == 0)
789 fmt = "%d";
790 else if (strcmp(type, "u8") == 0)
791 fmt = "%u";
792 else if (strcmp(type, "char") == 0)
793 fmt = "%d";
794 else if (strcmp(type, "unsigned char") == 0)
795 fmt = "%u";
796 else if (strcmp(type, "int") == 0)
797 fmt = "%d";
798 else if (strcmp(type, "unsigned int") == 0)
799 fmt = "%u";
800 else if (strcmp(type, "long") == 0)
801 fmt = "%ld";
802 else if (strcmp(type, "unsigned long") == 0)
803 fmt = "%lu";
804 else if (strcmp(type, "pid_t") == 0)
805 fmt = "%d";
806 else if (strcmp(type, "gfp_t") == 0)
807 fmt = "%x";
808 else if (synth_field_is_string(type))
809 fmt = "%s";
810
811 return fmt;
812 }
813
814 static void print_synth_event_num_val(struct trace_seq *s,
815 char *print_fmt, char *name,
816 int size, u64 val, char *space)
817 {
818 switch (size) {
819 case 1:
820 trace_seq_printf(s, print_fmt, name, (u8)val, space);
821 break;
822
823 case 2:
824 trace_seq_printf(s, print_fmt, name, (u16)val, space);
825 break;
826
827 case 4:
828 trace_seq_printf(s, print_fmt, name, (u32)val, space);
829 break;
830
831 default:
832 trace_seq_printf(s, print_fmt, name, val, space);
833 break;
834 }
835 }
836
837 static enum print_line_t print_synth_event(struct trace_iterator *iter,
838 int flags,
839 struct trace_event *event)
840 {
841 struct trace_array *tr = iter->tr;
842 struct trace_seq *s = &iter->seq;
843 struct synth_trace_event *entry;
844 struct synth_event *se;
845 unsigned int i, n_u64;
846 char print_fmt[32];
847 const char *fmt;
848
849 entry = (struct synth_trace_event *)iter->ent;
850 se = container_of(event, struct synth_event, call.event);
851
852 trace_seq_printf(s, "%s: ", se->name);
853
854 for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
855 if (trace_seq_has_overflowed(s))
856 goto end;
857
858 fmt = synth_field_fmt(se->fields[i]->type);
859
860 /* parameter types */
861 if (tr->trace_flags & TRACE_ITER_VERBOSE)
862 trace_seq_printf(s, "%s ", fmt);
863
864 snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
865
866 /* parameter values */
867 if (se->fields[i]->is_string) {
868 trace_seq_printf(s, print_fmt, se->fields[i]->name,
869 (char *)&entry->fields[n_u64],
870 i == se->n_fields - 1 ? "" : " ");
871 n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
872 } else {
873 struct trace_print_flags __flags[] = {
874 __def_gfpflag_names, {-1, NULL} };
875 char *space = (i == se->n_fields - 1 ? "" : " ");
876
877 print_synth_event_num_val(s, print_fmt,
878 se->fields[i]->name,
879 se->fields[i]->size,
880 entry->fields[n_u64],
881 space);
882
883 if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
884 trace_seq_puts(s, " (");
885 trace_print_flags_seq(s, "|",
886 entry->fields[n_u64],
887 __flags);
888 trace_seq_putc(s, ')');
889 }
890 n_u64++;
891 }
892 }
893 end:
894 trace_seq_putc(s, '\n');
895
896 return trace_handle_return(s);
897 }
898
899 static struct trace_event_functions synth_event_funcs = {
900 .trace = print_synth_event
901 };
902
903 static notrace void trace_event_raw_event_synth(void *__data,
904 u64 *var_ref_vals,
905 unsigned int *var_ref_idx)
906 {
907 struct trace_event_file *trace_file = __data;
908 struct synth_trace_event *entry;
909 struct trace_event_buffer fbuffer;
910 struct ring_buffer *buffer;
911 struct synth_event *event;
912 unsigned int i, n_u64, val_idx;
913 int fields_size = 0;
914
915 event = trace_file->event_call->data;
916
917 if (trace_trigger_soft_disabled(trace_file))
918 return;
919
920 fields_size = event->n_u64 * sizeof(u64);
921
922 /*
923 * Avoid ring buffer recursion detection, as this event
924 * is being performed within another event.
925 */
926 buffer = trace_file->tr->trace_buffer.buffer;
927 ring_buffer_nest_start(buffer);
928
929 entry = trace_event_buffer_reserve(&fbuffer, trace_file,
930 sizeof(*entry) + fields_size);
931 if (!entry)
932 goto out;
933
934 for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
935 val_idx = var_ref_idx[i];
936 if (event->fields[i]->is_string) {
937 char *str_val = (char *)(long)var_ref_vals[val_idx];
938 char *str_field = (char *)&entry->fields[n_u64];
939
940 strscpy(str_field, str_val, STR_VAR_LEN_MAX);
941 n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
942 } else {
943 struct synth_field *field = event->fields[i];
944 u64 val = var_ref_vals[val_idx];
945
946 switch (field->size) {
947 case 1:
948 *(u8 *)&entry->fields[n_u64] = (u8)val;
949 break;
950
951 case 2:
952 *(u16 *)&entry->fields[n_u64] = (u16)val;
953 break;
954
955 case 4:
956 *(u32 *)&entry->fields[n_u64] = (u32)val;
957 break;
958
959 default:
960 entry->fields[n_u64] = val;
961 break;
962 }
963 n_u64++;
964 }
965 }
966
967 trace_event_buffer_commit(&fbuffer);
968 out:
969 ring_buffer_nest_end(buffer);
970 }
971
972 static void free_synth_event_print_fmt(struct trace_event_call *call)
973 {
974 if (call) {
975 kfree(call->print_fmt);
976 call->print_fmt = NULL;
977 }
978 }
979
980 static int __set_synth_event_print_fmt(struct synth_event *event,
981 char *buf, int len)
982 {
983 const char *fmt;
984 int pos = 0;
985 int i;
986
987 /* When len=0, we just calculate the needed length */
988 #define LEN_OR_ZERO (len ? len - pos : 0)
989
990 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
991 for (i = 0; i < event->n_fields; i++) {
992 fmt = synth_field_fmt(event->fields[i]->type);
993 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
994 event->fields[i]->name, fmt,
995 i == event->n_fields - 1 ? "" : ", ");
996 }
997 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
998
999 for (i = 0; i < event->n_fields; i++) {
1000 pos += snprintf(buf + pos, LEN_OR_ZERO,
1001 ", REC->%s", event->fields[i]->name);
1002 }
1003
1004 #undef LEN_OR_ZERO
1005
1006 /* return the length of print_fmt */
1007 return pos;
1008 }
1009
1010 static int set_synth_event_print_fmt(struct trace_event_call *call)
1011 {
1012 struct synth_event *event = call->data;
1013 char *print_fmt;
1014 int len;
1015
1016 /* First: called with 0 length to calculate the needed length */
1017 len = __set_synth_event_print_fmt(event, NULL, 0);
1018
1019 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1020 if (!print_fmt)
1021 return -ENOMEM;
1022
1023 /* Second: actually write the @print_fmt */
1024 __set_synth_event_print_fmt(event, print_fmt, len + 1);
1025 call->print_fmt = print_fmt;
1026
1027 return 0;
1028 }
1029
1030 static void free_synth_field(struct synth_field *field)
1031 {
1032 kfree(field->type);
1033 kfree(field->name);
1034 kfree(field);
1035 }
1036
1037 static struct synth_field *parse_synth_field(int argc, const char **argv,
1038 int *consumed)
1039 {
1040 struct synth_field *field;
1041 const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
1042 int len, ret = 0;
1043
1044 if (field_type[0] == ';')
1045 field_type++;
1046
1047 if (!strcmp(field_type, "unsigned")) {
1048 if (argc < 3)
1049 return ERR_PTR(-EINVAL);
1050 prefix = "unsigned ";
1051 field_type = argv[1];
1052 field_name = argv[2];
1053 *consumed = 3;
1054 } else {
1055 field_name = argv[1];
1056 *consumed = 2;
1057 }
1058
1059 field = kzalloc(sizeof(*field), GFP_KERNEL);
1060 if (!field)
1061 return ERR_PTR(-ENOMEM);
1062
1063 len = strlen(field_name);
1064 array = strchr(field_name, '[');
1065 if (array)
1066 len -= strlen(array);
1067 else if (field_name[len - 1] == ';')
1068 len--;
1069
1070 field->name = kmemdup_nul(field_name, len, GFP_KERNEL);
1071 if (!field->name) {
1072 ret = -ENOMEM;
1073 goto free;
1074 }
1075
1076 if (field_type[0] == ';')
1077 field_type++;
1078 len = strlen(field_type) + 1;
1079 if (array)
1080 len += strlen(array);
1081 if (prefix)
1082 len += strlen(prefix);
1083
1084 field->type = kzalloc(len, GFP_KERNEL);
1085 if (!field->type) {
1086 ret = -ENOMEM;
1087 goto free;
1088 }
1089 if (prefix)
1090 strcat(field->type, prefix);
1091 strcat(field->type, field_type);
1092 if (array) {
1093 strcat(field->type, array);
1094 if (field->type[len - 1] == ';')
1095 field->type[len - 1] = '\0';
1096 }
1097
1098 field->size = synth_field_size(field->type);
1099 if (!field->size) {
1100 ret = -EINVAL;
1101 goto free;
1102 }
1103
1104 if (synth_field_is_string(field->type))
1105 field->is_string = true;
1106
1107 field->is_signed = synth_field_signed(field->type);
1108
1109 out:
1110 return field;
1111 free:
1112 free_synth_field(field);
1113 field = ERR_PTR(ret);
1114 goto out;
1115 }
1116
1117 static void free_synth_tracepoint(struct tracepoint *tp)
1118 {
1119 if (!tp)
1120 return;
1121
1122 kfree(tp->name);
1123 kfree(tp);
1124 }
1125
1126 static struct tracepoint *alloc_synth_tracepoint(char *name)
1127 {
1128 struct tracepoint *tp;
1129
1130 tp = kzalloc(sizeof(*tp), GFP_KERNEL);
1131 if (!tp)
1132 return ERR_PTR(-ENOMEM);
1133
1134 tp->name = kstrdup(name, GFP_KERNEL);
1135 if (!tp->name) {
1136 kfree(tp);
1137 return ERR_PTR(-ENOMEM);
1138 }
1139
1140 return tp;
1141 }
1142
1143 typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
1144 unsigned int *var_ref_idx);
1145
1146 static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
1147 unsigned int *var_ref_idx)
1148 {
1149 struct tracepoint *tp = event->tp;
1150
1151 if (unlikely(atomic_read(&tp->key.enabled) > 0)) {
1152 struct tracepoint_func *probe_func_ptr;
1153 synth_probe_func_t probe_func;
1154 void *__data;
1155
1156 if (!(cpu_online(raw_smp_processor_id())))
1157 return;
1158
1159 probe_func_ptr = rcu_dereference_sched((tp)->funcs);
1160 if (probe_func_ptr) {
1161 do {
1162 probe_func = probe_func_ptr->func;
1163 __data = probe_func_ptr->data;
1164 probe_func(__data, var_ref_vals, var_ref_idx);
1165 } while ((++probe_func_ptr)->func);
1166 }
1167 }
1168 }
1169
1170 static struct synth_event *find_synth_event(const char *name)
1171 {
1172 struct dyn_event *pos;
1173 struct synth_event *event;
1174
1175 for_each_dyn_event(pos) {
1176 if (!is_synth_event(pos))
1177 continue;
1178 event = to_synth_event(pos);
1179 if (strcmp(event->name, name) == 0)
1180 return event;
1181 }
1182
1183 return NULL;
1184 }
1185
1186 static int register_synth_event(struct synth_event *event)
1187 {
1188 struct trace_event_call *call = &event->call;
1189 int ret = 0;
1190
1191 event->call.class = &event->class;
1192 event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
1193 if (!event->class.system) {
1194 ret = -ENOMEM;
1195 goto out;
1196 }
1197
1198 event->tp = alloc_synth_tracepoint(event->name);
1199 if (IS_ERR(event->tp)) {
1200 ret = PTR_ERR(event->tp);
1201 event->tp = NULL;
1202 goto out;
1203 }
1204
1205 INIT_LIST_HEAD(&call->class->fields);
1206 call->event.funcs = &synth_event_funcs;
1207 call->class->define_fields = synth_event_define_fields;
1208
1209 ret = register_trace_event(&call->event);
1210 if (!ret) {
1211 ret = -ENODEV;
1212 goto out;
1213 }
1214 call->flags = TRACE_EVENT_FL_TRACEPOINT;
1215 call->class->reg = trace_event_reg;
1216 call->class->probe = trace_event_raw_event_synth;
1217 call->data = event;
1218 call->tp = event->tp;
1219
1220 ret = trace_add_event_call(call);
1221 if (ret) {
1222 pr_warn("Failed to register synthetic event: %s\n",
1223 trace_event_name(call));
1224 goto err;
1225 }
1226
1227 ret = set_synth_event_print_fmt(call);
1228 if (ret < 0) {
1229 trace_remove_event_call(call);
1230 goto err;
1231 }
1232 out:
1233 return ret;
1234 err:
1235 unregister_trace_event(&call->event);
1236 goto out;
1237 }
1238
1239 static int unregister_synth_event(struct synth_event *event)
1240 {
1241 struct trace_event_call *call = &event->call;
1242 int ret;
1243
1244 ret = trace_remove_event_call(call);
1245
1246 return ret;
1247 }
1248
1249 static void free_synth_event(struct synth_event *event)
1250 {
1251 unsigned int i;
1252
1253 if (!event)
1254 return;
1255
1256 for (i = 0; i < event->n_fields; i++)
1257 free_synth_field(event->fields[i]);
1258
1259 kfree(event->fields);
1260 kfree(event->name);
1261 kfree(event->class.system);
1262 free_synth_tracepoint(event->tp);
1263 free_synth_event_print_fmt(&event->call);
1264 kfree(event);
1265 }
1266
1267 static struct synth_event *alloc_synth_event(const char *name, int n_fields,
1268 struct synth_field **fields)
1269 {
1270 struct synth_event *event;
1271 unsigned int i;
1272
1273 event = kzalloc(sizeof(*event), GFP_KERNEL);
1274 if (!event) {
1275 event = ERR_PTR(-ENOMEM);
1276 goto out;
1277 }
1278
1279 event->name = kstrdup(name, GFP_KERNEL);
1280 if (!event->name) {
1281 kfree(event);
1282 event = ERR_PTR(-ENOMEM);
1283 goto out;
1284 }
1285
1286 event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
1287 if (!event->fields) {
1288 free_synth_event(event);
1289 event = ERR_PTR(-ENOMEM);
1290 goto out;
1291 }
1292
1293 dyn_event_init(&event->devent, &synth_event_ops);
1294
1295 for (i = 0; i < n_fields; i++)
1296 event->fields[i] = fields[i];
1297
1298 event->n_fields = n_fields;
1299 out:
1300 return event;
1301 }
1302
1303 static void action_trace(struct hist_trigger_data *hist_data,
1304 struct tracing_map_elt *elt, void *rec,
1305 struct ring_buffer_event *rbe, void *key,
1306 struct action_data *data, u64 *var_ref_vals)
1307 {
1308 struct synth_event *event = data->synth_event;
1309
1310 trace_synth(event, var_ref_vals, data->var_ref_idx);
1311 }
1312
1313 struct hist_var_data {
1314 struct list_head list;
1315 struct hist_trigger_data *hist_data;
1316 };
1317
1318 static int __create_synth_event(int argc, const char *name, const char **argv)
1319 {
1320 struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
1321 struct synth_event *event = NULL;
1322 int i, consumed = 0, n_fields = 0, ret = 0;
1323
1324 /*
1325 * Argument syntax:
1326 * - Add synthetic event: <event_name> field[;field] ...
1327 * - Remove synthetic event: !<event_name> field[;field] ...
1328 * where 'field' = type field_name
1329 */
1330
1331 if (name[0] == '\0' || argc < 1)
1332 return -EINVAL;
1333
1334 mutex_lock(&event_mutex);
1335
1336 event = find_synth_event(name);
1337 if (event) {
1338 ret = -EEXIST;
1339 goto out;
1340 }
1341
1342 for (i = 0; i < argc - 1; i++) {
1343 if (strcmp(argv[i], ";") == 0)
1344 continue;
1345 if (n_fields == SYNTH_FIELDS_MAX) {
1346 ret = -EINVAL;
1347 goto err;
1348 }
1349
1350 field = parse_synth_field(argc - i, &argv[i], &consumed);
1351 if (IS_ERR(field)) {
1352 ret = PTR_ERR(field);
1353 goto err;
1354 }
1355 fields[n_fields++] = field;
1356 i += consumed - 1;
1357 }
1358
1359 if (i < argc && strcmp(argv[i], ";") != 0) {
1360 ret = -EINVAL;
1361 goto err;
1362 }
1363
1364 event = alloc_synth_event(name, n_fields, fields);
1365 if (IS_ERR(event)) {
1366 ret = PTR_ERR(event);
1367 event = NULL;
1368 goto err;
1369 }
1370 ret = register_synth_event(event);
1371 if (!ret)
1372 dyn_event_add(&event->devent);
1373 else
1374 free_synth_event(event);
1375 out:
1376 mutex_unlock(&event_mutex);
1377
1378 return ret;
1379 err:
1380 for (i = 0; i < n_fields; i++)
1381 free_synth_field(fields[i]);
1382
1383 goto out;
1384 }
1385
1386 static int create_or_delete_synth_event(int argc, char **argv)
1387 {
1388 const char *name = argv[0];
1389 struct synth_event *event = NULL;
1390 int ret;
1391
1392 /* trace_run_command() ensures argc != 0 */
1393 if (name[0] == '!') {
1394 mutex_lock(&event_mutex);
1395 event = find_synth_event(name + 1);
1396 if (event) {
1397 if (event->ref)
1398 ret = -EBUSY;
1399 else {
1400 ret = unregister_synth_event(event);
1401 if (!ret) {
1402 dyn_event_remove(&event->devent);
1403 free_synth_event(event);
1404 }
1405 }
1406 } else
1407 ret = -ENOENT;
1408 mutex_unlock(&event_mutex);
1409 return ret;
1410 }
1411
1412 ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
1413 return ret == -ECANCELED ? -EINVAL : ret;
1414 }
1415
1416 static int synth_event_create(int argc, const char **argv)
1417 {
1418 const char *name = argv[0];
1419 int len;
1420
1421 if (name[0] != 's' || name[1] != ':')
1422 return -ECANCELED;
1423 name += 2;
1424
1425 /* This interface accepts group name prefix */
1426 if (strchr(name, '/')) {
1427 len = str_has_prefix(name, SYNTH_SYSTEM "/");
1428 if (len == 0)
1429 return -EINVAL;
1430 name += len;
1431 }
1432 return __create_synth_event(argc - 1, name, argv + 1);
1433 }
1434
1435 static int synth_event_release(struct dyn_event *ev)
1436 {
1437 struct synth_event *event = to_synth_event(ev);
1438 int ret;
1439
1440 if (event->ref)
1441 return -EBUSY;
1442
1443 ret = unregister_synth_event(event);
1444 if (ret)
1445 return ret;
1446
1447 dyn_event_remove(ev);
1448 free_synth_event(event);
1449 return 0;
1450 }
1451
1452 static int __synth_event_show(struct seq_file *m, struct synth_event *event)
1453 {
1454 struct synth_field *field;
1455 unsigned int i;
1456
1457 seq_printf(m, "%s\t", event->name);
1458
1459 for (i = 0; i < event->n_fields; i++) {
1460 field = event->fields[i];
1461
1462 /* parameter values */
1463 seq_printf(m, "%s %s%s", field->type, field->name,
1464 i == event->n_fields - 1 ? "" : "; ");
1465 }
1466
1467 seq_putc(m, '\n');
1468
1469 return 0;
1470 }
1471
1472 static int synth_event_show(struct seq_file *m, struct dyn_event *ev)
1473 {
1474 struct synth_event *event = to_synth_event(ev);
1475
1476 seq_printf(m, "s:%s/", event->class.system);
1477
1478 return __synth_event_show(m, event);
1479 }
1480
1481 static int synth_events_seq_show(struct seq_file *m, void *v)
1482 {
1483 struct dyn_event *ev = v;
1484
1485 if (!is_synth_event(ev))
1486 return 0;
1487
1488 return __synth_event_show(m, to_synth_event(ev));
1489 }
1490
1491 static const struct seq_operations synth_events_seq_op = {
1492 .start = dyn_event_seq_start,
1493 .next = dyn_event_seq_next,
1494 .stop = dyn_event_seq_stop,
1495 .show = synth_events_seq_show,
1496 };
1497
1498 static int synth_events_open(struct inode *inode, struct file *file)
1499 {
1500 int ret;
1501
1502 ret = security_locked_down(LOCKDOWN_TRACEFS);
1503 if (ret)
1504 return ret;
1505
1506 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1507 ret = dyn_events_release_all(&synth_event_ops);
1508 if (ret < 0)
1509 return ret;
1510 }
1511
1512 return seq_open(file, &synth_events_seq_op);
1513 }
1514
1515 static ssize_t synth_events_write(struct file *file,
1516 const char __user *buffer,
1517 size_t count, loff_t *ppos)
1518 {
1519 return trace_parse_run_command(file, buffer, count, ppos,
1520 create_or_delete_synth_event);
1521 }
1522
1523 static const struct file_operations synth_events_fops = {
1524 .open = synth_events_open,
1525 .write = synth_events_write,
1526 .read = seq_read,
1527 .llseek = seq_lseek,
1528 .release = seq_release,
1529 };
1530
1531 static u64 hist_field_timestamp(struct hist_field *hist_field,
1532 struct tracing_map_elt *elt,
1533 struct ring_buffer_event *rbe,
1534 void *event)
1535 {
1536 struct hist_trigger_data *hist_data = hist_field->hist_data;
1537 struct trace_array *tr = hist_data->event_file->tr;
1538
1539 u64 ts = ring_buffer_event_time_stamp(rbe);
1540
1541 if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr))
1542 ts = ns2usecs(ts);
1543
1544 return ts;
1545 }
1546
1547 static u64 hist_field_cpu(struct hist_field *hist_field,
1548 struct tracing_map_elt *elt,
1549 struct ring_buffer_event *rbe,
1550 void *event)
1551 {
1552 int cpu = smp_processor_id();
1553
1554 return cpu;
1555 }
1556
1557 /**
1558 * check_field_for_var_ref - Check if a VAR_REF field references a variable
1559 * @hist_field: The VAR_REF field to check
1560 * @var_data: The hist trigger that owns the variable
1561 * @var_idx: The trigger variable identifier
1562 *
1563 * Check the given VAR_REF field to see whether or not it references
1564 * the given variable associated with the given trigger.
1565 *
1566 * Return: The VAR_REF field if it does reference the variable, NULL if not
1567 */
1568 static struct hist_field *
1569 check_field_for_var_ref(struct hist_field *hist_field,
1570 struct hist_trigger_data *var_data,
1571 unsigned int var_idx)
1572 {
1573 WARN_ON(!(hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF));
1574
1575 if (hist_field && hist_field->var.idx == var_idx &&
1576 hist_field->var.hist_data == var_data)
1577 return hist_field;
1578
1579 return NULL;
1580 }
1581
1582 /**
1583 * find_var_ref - Check if a trigger has a reference to a trigger variable
1584 * @hist_data: The hist trigger that might have a reference to the variable
1585 * @var_data: The hist trigger that owns the variable
1586 * @var_idx: The trigger variable identifier
1587 *
1588 * Check the list of var_refs[] on the first hist trigger to see
1589 * whether any of them are references to the variable on the second
1590 * trigger.
1591 *
1592 * Return: The VAR_REF field referencing the variable if so, NULL if not
1593 */
1594 static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data,
1595 struct hist_trigger_data *var_data,
1596 unsigned int var_idx)
1597 {
1598 struct hist_field *hist_field;
1599 unsigned int i;
1600
1601 for (i = 0; i < hist_data->n_var_refs; i++) {
1602 hist_field = hist_data->var_refs[i];
1603 if (check_field_for_var_ref(hist_field, var_data, var_idx))
1604 return hist_field;
1605 }
1606
1607 return NULL;
1608 }
1609
1610 /**
1611 * find_any_var_ref - Check if there is a reference to a given trigger variable
1612 * @hist_data: The hist trigger
1613 * @var_idx: The trigger variable identifier
1614 *
1615 * Check to see whether the given variable is currently referenced by
1616 * any other trigger.
1617 *
1618 * The trigger the variable is defined on is explicitly excluded - the
1619 * assumption being that a self-reference doesn't prevent a trigger
1620 * from being removed.
1621 *
1622 * Return: The VAR_REF field referencing the variable if so, NULL if not
1623 */
1624 static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data,
1625 unsigned int var_idx)
1626 {
1627 struct trace_array *tr = hist_data->event_file->tr;
1628 struct hist_field *found = NULL;
1629 struct hist_var_data *var_data;
1630
1631 list_for_each_entry(var_data, &tr->hist_vars, list) {
1632 if (var_data->hist_data == hist_data)
1633 continue;
1634 found = find_var_ref(var_data->hist_data, hist_data, var_idx);
1635 if (found)
1636 break;
1637 }
1638
1639 return found;
1640 }
1641
1642 /**
1643 * check_var_refs - Check if there is a reference to any of trigger's variables
1644 * @hist_data: The hist trigger
1645 *
1646 * A trigger can define one or more variables. If any one of them is
1647 * currently referenced by any other trigger, this function will
1648 * determine that.
1649
1650 * Typically used to determine whether or not a trigger can be removed
1651 * - if there are any references to a trigger's variables, it cannot.
1652 *
1653 * Return: True if there is a reference to any of trigger's variables
1654 */
1655 static bool check_var_refs(struct hist_trigger_data *hist_data)
1656 {
1657 struct hist_field *field;
1658 bool found = false;
1659 int i;
1660
1661 for_each_hist_field(i, hist_data) {
1662 field = hist_data->fields[i];
1663 if (field && field->flags & HIST_FIELD_FL_VAR) {
1664 if (find_any_var_ref(hist_data, field->var.idx)) {
1665 found = true;
1666 break;
1667 }
1668 }
1669 }
1670
1671 return found;
1672 }
1673
1674 static struct hist_var_data *find_hist_vars(struct hist_trigger_data *hist_data)
1675 {
1676 struct trace_array *tr = hist_data->event_file->tr;
1677 struct hist_var_data *var_data, *found = NULL;
1678
1679 list_for_each_entry(var_data, &tr->hist_vars, list) {
1680 if (var_data->hist_data == hist_data) {
1681 found = var_data;
1682 break;
1683 }
1684 }
1685
1686 return found;
1687 }
1688
1689 static bool field_has_hist_vars(struct hist_field *hist_field,
1690 unsigned int level)
1691 {
1692 int i;
1693
1694 if (level > 3)
1695 return false;
1696
1697 if (!hist_field)
1698 return false;
1699
1700 if (hist_field->flags & HIST_FIELD_FL_VAR ||
1701 hist_field->flags & HIST_FIELD_FL_VAR_REF)
1702 return true;
1703
1704 for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) {
1705 struct hist_field *operand;
1706
1707 operand = hist_field->operands[i];
1708 if (field_has_hist_vars(operand, level + 1))
1709 return true;
1710 }
1711
1712 return false;
1713 }
1714
1715 static bool has_hist_vars(struct hist_trigger_data *hist_data)
1716 {
1717 struct hist_field *hist_field;
1718 int i;
1719
1720 for_each_hist_field(i, hist_data) {
1721 hist_field = hist_data->fields[i];
1722 if (field_has_hist_vars(hist_field, 0))
1723 return true;
1724 }
1725
1726 return false;
1727 }
1728
1729 static int save_hist_vars(struct hist_trigger_data *hist_data)
1730 {
1731 struct trace_array *tr = hist_data->event_file->tr;
1732 struct hist_var_data *var_data;
1733
1734 var_data = find_hist_vars(hist_data);
1735 if (var_data)
1736 return 0;
1737
1738 if (tracing_check_open_get_tr(tr))
1739 return -ENODEV;
1740
1741 var_data = kzalloc(sizeof(*var_data), GFP_KERNEL);
1742 if (!var_data) {
1743 trace_array_put(tr);
1744 return -ENOMEM;
1745 }
1746
1747 var_data->hist_data = hist_data;
1748 list_add(&var_data->list, &tr->hist_vars);
1749
1750 return 0;
1751 }
1752
1753 static void remove_hist_vars(struct hist_trigger_data *hist_data)
1754 {
1755 struct trace_array *tr = hist_data->event_file->tr;
1756 struct hist_var_data *var_data;
1757
1758 var_data = find_hist_vars(hist_data);
1759 if (!var_data)
1760 return;
1761
1762 if (WARN_ON(check_var_refs(hist_data)))
1763 return;
1764
1765 list_del(&var_data->list);
1766
1767 kfree(var_data);
1768
1769 trace_array_put(tr);
1770 }
1771
1772 static struct hist_field *find_var_field(struct hist_trigger_data *hist_data,
1773 const char *var_name)
1774 {
1775 struct hist_field *hist_field, *found = NULL;
1776 int i;
1777
1778 for_each_hist_field(i, hist_data) {
1779 hist_field = hist_data->fields[i];
1780 if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR &&
1781 strcmp(hist_field->var.name, var_name) == 0) {
1782 found = hist_field;
1783 break;
1784 }
1785 }
1786
1787 return found;
1788 }
1789
1790 static struct hist_field *find_var(struct hist_trigger_data *hist_data,
1791 struct trace_event_file *file,
1792 const char *var_name)
1793 {
1794 struct hist_trigger_data *test_data;
1795 struct event_trigger_data *test;
1796 struct hist_field *hist_field;
1797
1798 lockdep_assert_held(&event_mutex);
1799
1800 hist_field = find_var_field(hist_data, var_name);
1801 if (hist_field)
1802 return hist_field;
1803
1804 list_for_each_entry(test, &file->triggers, list) {
1805 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1806 test_data = test->private_data;
1807 hist_field = find_var_field(test_data, var_name);
1808 if (hist_field)
1809 return hist_field;
1810 }
1811 }
1812
1813 return NULL;
1814 }
1815
1816 static struct trace_event_file *find_var_file(struct trace_array *tr,
1817 char *system,
1818 char *event_name,
1819 char *var_name)
1820 {
1821 struct hist_trigger_data *var_hist_data;
1822 struct hist_var_data *var_data;
1823 struct trace_event_file *file, *found = NULL;
1824
1825 if (system)
1826 return find_event_file(tr, system, event_name);
1827
1828 list_for_each_entry(var_data, &tr->hist_vars, list) {
1829 var_hist_data = var_data->hist_data;
1830 file = var_hist_data->event_file;
1831 if (file == found)
1832 continue;
1833
1834 if (find_var_field(var_hist_data, var_name)) {
1835 if (found) {
1836 hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE, errpos(var_name));
1837 return NULL;
1838 }
1839
1840 found = file;
1841 }
1842 }
1843
1844 return found;
1845 }
1846
1847 static struct hist_field *find_file_var(struct trace_event_file *file,
1848 const char *var_name)
1849 {
1850 struct hist_trigger_data *test_data;
1851 struct event_trigger_data *test;
1852 struct hist_field *hist_field;
1853
1854 lockdep_assert_held(&event_mutex);
1855
1856 list_for_each_entry(test, &file->triggers, list) {
1857 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1858 test_data = test->private_data;
1859 hist_field = find_var_field(test_data, var_name);
1860 if (hist_field)
1861 return hist_field;
1862 }
1863 }
1864
1865 return NULL;
1866 }
1867
1868 static struct hist_field *
1869 find_match_var(struct hist_trigger_data *hist_data, char *var_name)
1870 {
1871 struct trace_array *tr = hist_data->event_file->tr;
1872 struct hist_field *hist_field, *found = NULL;
1873 struct trace_event_file *file;
1874 unsigned int i;
1875
1876 for (i = 0; i < hist_data->n_actions; i++) {
1877 struct action_data *data = hist_data->actions[i];
1878
1879 if (data->handler == HANDLER_ONMATCH) {
1880 char *system = data->match_data.event_system;
1881 char *event_name = data->match_data.event;
1882
1883 file = find_var_file(tr, system, event_name, var_name);
1884 if (!file)
1885 continue;
1886 hist_field = find_file_var(file, var_name);
1887 if (hist_field) {
1888 if (found) {
1889 hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE,
1890 errpos(var_name));
1891 return ERR_PTR(-EINVAL);
1892 }
1893
1894 found = hist_field;
1895 }
1896 }
1897 }
1898 return found;
1899 }
1900
1901 static struct hist_field *find_event_var(struct hist_trigger_data *hist_data,
1902 char *system,
1903 char *event_name,
1904 char *var_name)
1905 {
1906 struct trace_array *tr = hist_data->event_file->tr;
1907 struct hist_field *hist_field = NULL;
1908 struct trace_event_file *file;
1909
1910 if (!system || !event_name) {
1911 hist_field = find_match_var(hist_data, var_name);
1912 if (IS_ERR(hist_field))
1913 return NULL;
1914 if (hist_field)
1915 return hist_field;
1916 }
1917
1918 file = find_var_file(tr, system, event_name, var_name);
1919 if (!file)
1920 return NULL;
1921
1922 hist_field = find_file_var(file, var_name);
1923
1924 return hist_field;
1925 }
1926
1927 static u64 hist_field_var_ref(struct hist_field *hist_field,
1928 struct tracing_map_elt *elt,
1929 struct ring_buffer_event *rbe,
1930 void *event)
1931 {
1932 struct hist_elt_data *elt_data;
1933 u64 var_val = 0;
1934
1935 if (WARN_ON_ONCE(!elt))
1936 return var_val;
1937
1938 elt_data = elt->private_data;
1939 var_val = elt_data->var_ref_vals[hist_field->var_ref_idx];
1940
1941 return var_val;
1942 }
1943
1944 static bool resolve_var_refs(struct hist_trigger_data *hist_data, void *key,
1945 u64 *var_ref_vals, bool self)
1946 {
1947 struct hist_trigger_data *var_data;
1948 struct tracing_map_elt *var_elt;
1949 struct hist_field *hist_field;
1950 unsigned int i, var_idx;
1951 bool resolved = true;
1952 u64 var_val = 0;
1953
1954 for (i = 0; i < hist_data->n_var_refs; i++) {
1955 hist_field = hist_data->var_refs[i];
1956 var_idx = hist_field->var.idx;
1957 var_data = hist_field->var.hist_data;
1958
1959 if (var_data == NULL) {
1960 resolved = false;
1961 break;
1962 }
1963
1964 if ((self && var_data != hist_data) ||
1965 (!self && var_data == hist_data))
1966 continue;
1967
1968 var_elt = tracing_map_lookup(var_data->map, key);
1969 if (!var_elt) {
1970 resolved = false;
1971 break;
1972 }
1973
1974 if (!tracing_map_var_set(var_elt, var_idx)) {
1975 resolved = false;
1976 break;
1977 }
1978
1979 if (self || !hist_field->read_once)
1980 var_val = tracing_map_read_var(var_elt, var_idx);
1981 else
1982 var_val = tracing_map_read_var_once(var_elt, var_idx);
1983
1984 var_ref_vals[i] = var_val;
1985 }
1986
1987 return resolved;
1988 }
1989
1990 static const char *hist_field_name(struct hist_field *field,
1991 unsigned int level)
1992 {
1993 const char *field_name = "";
1994
1995 if (level > 1)
1996 return field_name;
1997
1998 if (field->field)
1999 field_name = field->field->name;
2000 else if (field->flags & HIST_FIELD_FL_LOG2 ||
2001 field->flags & HIST_FIELD_FL_ALIAS)
2002 field_name = hist_field_name(field->operands[0], ++level);
2003 else if (field->flags & HIST_FIELD_FL_CPU)
2004 field_name = "cpu";
2005 else if (field->flags & HIST_FIELD_FL_EXPR ||
2006 field->flags & HIST_FIELD_FL_VAR_REF) {
2007 if (field->system) {
2008 static char full_name[MAX_FILTER_STR_VAL];
2009
2010 strcat(full_name, field->system);
2011 strcat(full_name, ".");
2012 strcat(full_name, field->event_name);
2013 strcat(full_name, ".");
2014 strcat(full_name, field->name);
2015 field_name = full_name;
2016 } else
2017 field_name = field->name;
2018 } else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
2019 field_name = "common_timestamp";
2020
2021 if (field_name == NULL)
2022 field_name = "";
2023
2024 return field_name;
2025 }
2026
2027 static hist_field_fn_t select_value_fn(int field_size, int field_is_signed)
2028 {
2029 hist_field_fn_t fn = NULL;
2030
2031 switch (field_size) {
2032 case 8:
2033 if (field_is_signed)
2034 fn = hist_field_s64;
2035 else
2036 fn = hist_field_u64;
2037 break;
2038 case 4:
2039 if (field_is_signed)
2040 fn = hist_field_s32;
2041 else
2042 fn = hist_field_u32;
2043 break;
2044 case 2:
2045 if (field_is_signed)
2046 fn = hist_field_s16;
2047 else
2048 fn = hist_field_u16;
2049 break;
2050 case 1:
2051 if (field_is_signed)
2052 fn = hist_field_s8;
2053 else
2054 fn = hist_field_u8;
2055 break;
2056 }
2057
2058 return fn;
2059 }
2060
2061 static int parse_map_size(char *str)
2062 {
2063 unsigned long size, map_bits;
2064 int ret;
2065
2066 ret = kstrtoul(str, 0, &size);
2067 if (ret)
2068 goto out;
2069
2070 map_bits = ilog2(roundup_pow_of_two(size));
2071 if (map_bits < TRACING_MAP_BITS_MIN ||
2072 map_bits > TRACING_MAP_BITS_MAX)
2073 ret = -EINVAL;
2074 else
2075 ret = map_bits;
2076 out:
2077 return ret;
2078 }
2079
2080 static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
2081 {
2082 unsigned int i;
2083
2084 if (!attrs)
2085 return;
2086
2087 for (i = 0; i < attrs->n_assignments; i++)
2088 kfree(attrs->assignment_str[i]);
2089
2090 for (i = 0; i < attrs->n_actions; i++)
2091 kfree(attrs->action_str[i]);
2092
2093 kfree(attrs->name);
2094 kfree(attrs->sort_key_str);
2095 kfree(attrs->keys_str);
2096 kfree(attrs->vals_str);
2097 kfree(attrs->clock);
2098 kfree(attrs);
2099 }
2100
2101 static int parse_action(char *str, struct hist_trigger_attrs *attrs)
2102 {
2103 int ret = -EINVAL;
2104
2105 if (attrs->n_actions >= HIST_ACTIONS_MAX)
2106 return ret;
2107
2108 if ((str_has_prefix(str, "onmatch(")) ||
2109 (str_has_prefix(str, "onmax(")) ||
2110 (str_has_prefix(str, "onchange("))) {
2111 attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL);
2112 if (!attrs->action_str[attrs->n_actions]) {
2113 ret = -ENOMEM;
2114 return ret;
2115 }
2116 attrs->n_actions++;
2117 ret = 0;
2118 }
2119 return ret;
2120 }
2121
2122 static int parse_assignment(struct trace_array *tr,
2123 char *str, struct hist_trigger_attrs *attrs)
2124 {
2125 int len, ret = 0;
2126
2127 if ((len = str_has_prefix(str, "key=")) ||
2128 (len = str_has_prefix(str, "keys="))) {
2129 attrs->keys_str = kstrdup(str + len, GFP_KERNEL);
2130 if (!attrs->keys_str) {
2131 ret = -ENOMEM;
2132 goto out;
2133 }
2134 } else if ((len = str_has_prefix(str, "val=")) ||
2135 (len = str_has_prefix(str, "vals=")) ||
2136 (len = str_has_prefix(str, "values="))) {
2137 attrs->vals_str = kstrdup(str + len, GFP_KERNEL);
2138 if (!attrs->vals_str) {
2139 ret = -ENOMEM;
2140 goto out;
2141 }
2142 } else if ((len = str_has_prefix(str, "sort="))) {
2143 attrs->sort_key_str = kstrdup(str + len, GFP_KERNEL);
2144 if (!attrs->sort_key_str) {
2145 ret = -ENOMEM;
2146 goto out;
2147 }
2148 } else if (str_has_prefix(str, "name=")) {
2149 attrs->name = kstrdup(str, GFP_KERNEL);
2150 if (!attrs->name) {
2151 ret = -ENOMEM;
2152 goto out;
2153 }
2154 } else if ((len = str_has_prefix(str, "clock="))) {
2155 str += len;
2156
2157 str = strstrip(str);
2158 attrs->clock = kstrdup(str, GFP_KERNEL);
2159 if (!attrs->clock) {
2160 ret = -ENOMEM;
2161 goto out;
2162 }
2163 } else if ((len = str_has_prefix(str, "size="))) {
2164 int map_bits = parse_map_size(str + len);
2165
2166 if (map_bits < 0) {
2167 ret = map_bits;
2168 goto out;
2169 }
2170 attrs->map_bits = map_bits;
2171 } else {
2172 char *assignment;
2173
2174 if (attrs->n_assignments == TRACING_MAP_VARS_MAX) {
2175 hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(str));
2176 ret = -EINVAL;
2177 goto out;
2178 }
2179
2180 assignment = kstrdup(str, GFP_KERNEL);
2181 if (!assignment) {
2182 ret = -ENOMEM;
2183 goto out;
2184 }
2185
2186 attrs->assignment_str[attrs->n_assignments++] = assignment;
2187 }
2188 out:
2189 return ret;
2190 }
2191
2192 static struct hist_trigger_attrs *
2193 parse_hist_trigger_attrs(struct trace_array *tr, char *trigger_str)
2194 {
2195 struct hist_trigger_attrs *attrs;
2196 int ret = 0;
2197
2198 attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
2199 if (!attrs)
2200 return ERR_PTR(-ENOMEM);
2201
2202 while (trigger_str) {
2203 char *str = strsep(&trigger_str, ":");
2204 char *rhs;
2205
2206 rhs = strchr(str, '=');
2207 if (rhs) {
2208 if (!strlen(++rhs)) {
2209 ret = -EINVAL;
2210 goto free;
2211 }
2212 ret = parse_assignment(tr, str, attrs);
2213 if (ret)
2214 goto free;
2215 } else if (strcmp(str, "pause") == 0)
2216 attrs->pause = true;
2217 else if ((strcmp(str, "cont") == 0) ||
2218 (strcmp(str, "continue") == 0))
2219 attrs->cont = true;
2220 else if (strcmp(str, "clear") == 0)
2221 attrs->clear = true;
2222 else {
2223 ret = parse_action(str, attrs);
2224 if (ret)
2225 goto free;
2226 }
2227 }
2228
2229 if (!attrs->keys_str) {
2230 ret = -EINVAL;
2231 goto free;
2232 }
2233
2234 if (!attrs->clock) {
2235 attrs->clock = kstrdup("global", GFP_KERNEL);
2236 if (!attrs->clock) {
2237 ret = -ENOMEM;
2238 goto free;
2239 }
2240 }
2241
2242 return attrs;
2243 free:
2244 destroy_hist_trigger_attrs(attrs);
2245
2246 return ERR_PTR(ret);
2247 }
2248
2249 static inline void save_comm(char *comm, struct task_struct *task)
2250 {
2251 if (!task->pid) {
2252 strcpy(comm, "<idle>");
2253 return;
2254 }
2255
2256 if (WARN_ON_ONCE(task->pid < 0)) {
2257 strcpy(comm, "<XXX>");
2258 return;
2259 }
2260
2261 strncpy(comm, task->comm, TASK_COMM_LEN);
2262 }
2263
2264 static void hist_elt_data_free(struct hist_elt_data *elt_data)
2265 {
2266 unsigned int i;
2267
2268 for (i = 0; i < SYNTH_FIELDS_MAX; i++)
2269 kfree(elt_data->field_var_str[i]);
2270
2271 kfree(elt_data->comm);
2272 kfree(elt_data);
2273 }
2274
2275 static void hist_trigger_elt_data_free(struct tracing_map_elt *elt)
2276 {
2277 struct hist_elt_data *elt_data = elt->private_data;
2278
2279 hist_elt_data_free(elt_data);
2280 }
2281
2282 static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
2283 {
2284 struct hist_trigger_data *hist_data = elt->map->private_data;
2285 unsigned int size = TASK_COMM_LEN;
2286 struct hist_elt_data *elt_data;
2287 struct hist_field *key_field;
2288 unsigned int i, n_str;
2289
2290 elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
2291 if (!elt_data)
2292 return -ENOMEM;
2293
2294 for_each_hist_key_field(i, hist_data) {
2295 key_field = hist_data->fields[i];
2296
2297 if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
2298 elt_data->comm = kzalloc(size, GFP_KERNEL);
2299 if (!elt_data->comm) {
2300 kfree(elt_data);
2301 return -ENOMEM;
2302 }
2303 break;
2304 }
2305 }
2306
2307 n_str = hist_data->n_field_var_str + hist_data->n_save_var_str;
2308
2309 size = STR_VAR_LEN_MAX;
2310
2311 for (i = 0; i < n_str; i++) {
2312 elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL);
2313 if (!elt_data->field_var_str[i]) {
2314 hist_elt_data_free(elt_data);
2315 return -ENOMEM;
2316 }
2317 }
2318
2319 elt->private_data = elt_data;
2320
2321 return 0;
2322 }
2323
2324 static void hist_trigger_elt_data_init(struct tracing_map_elt *elt)
2325 {
2326 struct hist_elt_data *elt_data = elt->private_data;
2327
2328 if (elt_data->comm)
2329 save_comm(elt_data->comm, current);
2330 }
2331
2332 static const struct tracing_map_ops hist_trigger_elt_data_ops = {
2333 .elt_alloc = hist_trigger_elt_data_alloc,
2334 .elt_free = hist_trigger_elt_data_free,
2335 .elt_init = hist_trigger_elt_data_init,
2336 };
2337
2338 static const char *get_hist_field_flags(struct hist_field *hist_field)
2339 {
2340 const char *flags_str = NULL;
2341
2342 if (hist_field->flags & HIST_FIELD_FL_HEX)
2343 flags_str = "hex";
2344 else if (hist_field->flags & HIST_FIELD_FL_SYM)
2345 flags_str = "sym";
2346 else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
2347 flags_str = "sym-offset";
2348 else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
2349 flags_str = "execname";
2350 else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
2351 flags_str = "syscall";
2352 else if (hist_field->flags & HIST_FIELD_FL_LOG2)
2353 flags_str = "log2";
2354 else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS)
2355 flags_str = "usecs";
2356
2357 return flags_str;
2358 }
2359
2360 static void expr_field_str(struct hist_field *field, char *expr)
2361 {
2362 if (field->flags & HIST_FIELD_FL_VAR_REF)
2363 strcat(expr, "$");
2364
2365 strcat(expr, hist_field_name(field, 0));
2366
2367 if (field->flags && !(field->flags & HIST_FIELD_FL_VAR_REF)) {
2368 const char *flags_str = get_hist_field_flags(field);
2369
2370 if (flags_str) {
2371 strcat(expr, ".");
2372 strcat(expr, flags_str);
2373 }
2374 }
2375 }
2376
2377 static char *expr_str(struct hist_field *field, unsigned int level)
2378 {
2379 char *expr;
2380
2381 if (level > 1)
2382 return NULL;
2383
2384 expr = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
2385 if (!expr)
2386 return NULL;
2387
2388 if (!field->operands[0]) {
2389 expr_field_str(field, expr);
2390 return expr;
2391 }
2392
2393 if (field->operator == FIELD_OP_UNARY_MINUS) {
2394 char *subexpr;
2395
2396 strcat(expr, "-(");
2397 subexpr = expr_str(field->operands[0], ++level);
2398 if (!subexpr) {
2399 kfree(expr);
2400 return NULL;
2401 }
2402 strcat(expr, subexpr);
2403 strcat(expr, ")");
2404
2405 kfree(subexpr);
2406
2407 return expr;
2408 }
2409
2410 expr_field_str(field->operands[0], expr);
2411
2412 switch (field->operator) {
2413 case FIELD_OP_MINUS:
2414 strcat(expr, "-");
2415 break;
2416 case FIELD_OP_PLUS:
2417 strcat(expr, "+");
2418 break;
2419 default:
2420 kfree(expr);
2421 return NULL;
2422 }
2423
2424 expr_field_str(field->operands[1], expr);
2425
2426 return expr;
2427 }
2428
2429 static int contains_operator(char *str)
2430 {
2431 enum field_op_id field_op = FIELD_OP_NONE;
2432 char *op;
2433
2434 op = strpbrk(str, "+-");
2435 if (!op)
2436 return FIELD_OP_NONE;
2437
2438 switch (*op) {
2439 case '-':
2440 if (*str == '-')
2441 field_op = FIELD_OP_UNARY_MINUS;
2442 else
2443 field_op = FIELD_OP_MINUS;
2444 break;
2445 case '+':
2446 field_op = FIELD_OP_PLUS;
2447 break;
2448 default:
2449 break;
2450 }
2451
2452 return field_op;
2453 }
2454
2455 static void get_hist_field(struct hist_field *hist_field)
2456 {
2457 hist_field->ref++;
2458 }
2459
2460 static void __destroy_hist_field(struct hist_field *hist_field)
2461 {
2462 if (--hist_field->ref > 1)
2463 return;
2464
2465 kfree(hist_field->var.name);
2466 kfree(hist_field->name);
2467 kfree(hist_field->type);
2468
2469 kfree(hist_field);
2470 }
2471
2472 static void destroy_hist_field(struct hist_field *hist_field,
2473 unsigned int level)
2474 {
2475 unsigned int i;
2476
2477 if (level > 3)
2478 return;
2479
2480 if (!hist_field)
2481 return;
2482
2483 if (hist_field->flags & HIST_FIELD_FL_VAR_REF)
2484 return; /* var refs will be destroyed separately */
2485
2486 for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
2487 destroy_hist_field(hist_field->operands[i], level + 1);
2488
2489 __destroy_hist_field(hist_field);
2490 }
2491
2492 static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
2493 struct ftrace_event_field *field,
2494 unsigned long flags,
2495 char *var_name)
2496 {
2497 struct hist_field *hist_field;
2498
2499 if (field && is_function_field(field))
2500 return NULL;
2501
2502 hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
2503 if (!hist_field)
2504 return NULL;
2505
2506 hist_field->ref = 1;
2507
2508 hist_field->hist_data = hist_data;
2509
2510 if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS)
2511 goto out; /* caller will populate */
2512
2513 if (flags & HIST_FIELD_FL_VAR_REF) {
2514 hist_field->fn = hist_field_var_ref;
2515 goto out;
2516 }
2517
2518 if (flags & HIST_FIELD_FL_HITCOUNT) {
2519 hist_field->fn = hist_field_counter;
2520 hist_field->size = sizeof(u64);
2521 hist_field->type = kstrdup("u64", GFP_KERNEL);
2522 if (!hist_field->type)
2523 goto free;
2524 goto out;
2525 }
2526
2527 if (flags & HIST_FIELD_FL_STACKTRACE) {
2528 hist_field->fn = hist_field_none;
2529 goto out;
2530 }
2531
2532 if (flags & HIST_FIELD_FL_LOG2) {
2533 unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
2534 hist_field->fn = hist_field_log2;
2535 hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
2536 hist_field->size = hist_field->operands[0]->size;
2537 hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL);
2538 if (!hist_field->type)
2539 goto free;
2540 goto out;
2541 }
2542
2543 if (flags & HIST_FIELD_FL_TIMESTAMP) {
2544 hist_field->fn = hist_field_timestamp;
2545 hist_field->size = sizeof(u64);
2546 hist_field->type = kstrdup("u64", GFP_KERNEL);
2547 if (!hist_field->type)
2548 goto free;
2549 goto out;
2550 }
2551
2552 if (flags & HIST_FIELD_FL_CPU) {
2553 hist_field->fn = hist_field_cpu;
2554 hist_field->size = sizeof(int);
2555 hist_field->type = kstrdup("unsigned int", GFP_KERNEL);
2556 if (!hist_field->type)
2557 goto free;
2558 goto out;
2559 }
2560
2561 if (WARN_ON_ONCE(!field))
2562 goto out;
2563
2564 if (is_string_field(field)) {
2565 flags |= HIST_FIELD_FL_STRING;
2566
2567 hist_field->size = MAX_FILTER_STR_VAL;
2568 hist_field->type = kstrdup(field->type, GFP_KERNEL);
2569 if (!hist_field->type)
2570 goto free;
2571
2572 if (field->filter_type == FILTER_STATIC_STRING)
2573 hist_field->fn = hist_field_string;
2574 else if (field->filter_type == FILTER_DYN_STRING)
2575 hist_field->fn = hist_field_dynstring;
2576 else
2577 hist_field->fn = hist_field_pstring;
2578 } else {
2579 hist_field->size = field->size;
2580 hist_field->is_signed = field->is_signed;
2581 hist_field->type = kstrdup(field->type, GFP_KERNEL);
2582 if (!hist_field->type)
2583 goto free;
2584
2585 hist_field->fn = select_value_fn(field->size,
2586 field->is_signed);
2587 if (!hist_field->fn) {
2588 destroy_hist_field(hist_field, 0);
2589 return NULL;
2590 }
2591 }
2592 out:
2593 hist_field->field = field;
2594 hist_field->flags = flags;
2595
2596 if (var_name) {
2597 hist_field->var.name = kstrdup(var_name, GFP_KERNEL);
2598 if (!hist_field->var.name)
2599 goto free;
2600 }
2601
2602 return hist_field;
2603 free:
2604 destroy_hist_field(hist_field, 0);
2605 return NULL;
2606 }
2607
2608 static void destroy_hist_fields(struct hist_trigger_data *hist_data)
2609 {
2610 unsigned int i;
2611
2612 for (i = 0; i < HIST_FIELDS_MAX; i++) {
2613 if (hist_data->fields[i]) {
2614 destroy_hist_field(hist_data->fields[i], 0);
2615 hist_data->fields[i] = NULL;
2616 }
2617 }
2618
2619 for (i = 0; i < hist_data->n_var_refs; i++) {
2620 WARN_ON(!(hist_data->var_refs[i]->flags & HIST_FIELD_FL_VAR_REF));
2621 __destroy_hist_field(hist_data->var_refs[i]);
2622 hist_data->var_refs[i] = NULL;
2623 }
2624 }
2625
2626 static int init_var_ref(struct hist_field *ref_field,
2627 struct hist_field *var_field,
2628 char *system, char *event_name)
2629 {
2630 int err = 0;
2631
2632 ref_field->var.idx = var_field->var.idx;
2633 ref_field->var.hist_data = var_field->hist_data;
2634 ref_field->size = var_field->size;
2635 ref_field->is_signed = var_field->is_signed;
2636 ref_field->flags |= var_field->flags &
2637 (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
2638
2639 if (system) {
2640 ref_field->system = kstrdup(system, GFP_KERNEL);
2641 if (!ref_field->system)
2642 return -ENOMEM;
2643 }
2644
2645 if (event_name) {
2646 ref_field->event_name = kstrdup(event_name, GFP_KERNEL);
2647 if (!ref_field->event_name) {
2648 err = -ENOMEM;
2649 goto free;
2650 }
2651 }
2652
2653 if (var_field->var.name) {
2654 ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL);
2655 if (!ref_field->name) {
2656 err = -ENOMEM;
2657 goto free;
2658 }
2659 } else if (var_field->name) {
2660 ref_field->name = kstrdup(var_field->name, GFP_KERNEL);
2661 if (!ref_field->name) {
2662 err = -ENOMEM;
2663 goto free;
2664 }
2665 }
2666
2667 ref_field->type = kstrdup(var_field->type, GFP_KERNEL);
2668 if (!ref_field->type) {
2669 err = -ENOMEM;
2670 goto free;
2671 }
2672 out:
2673 return err;
2674 free:
2675 kfree(ref_field->system);
2676 kfree(ref_field->event_name);
2677 kfree(ref_field->name);
2678
2679 goto out;
2680 }
2681
2682 static int find_var_ref_idx(struct hist_trigger_data *hist_data,
2683 struct hist_field *var_field)
2684 {
2685 struct hist_field *ref_field;
2686 int i;
2687
2688 for (i = 0; i < hist_data->n_var_refs; i++) {
2689 ref_field = hist_data->var_refs[i];
2690 if (ref_field->var.idx == var_field->var.idx &&
2691 ref_field->var.hist_data == var_field->hist_data)
2692 return i;
2693 }
2694
2695 return -ENOENT;
2696 }
2697
2698 /**
2699 * create_var_ref - Create a variable reference and attach it to trigger
2700 * @hist_data: The trigger that will be referencing the variable
2701 * @var_field: The VAR field to create a reference to
2702 * @system: The optional system string
2703 * @event_name: The optional event_name string
2704 *
2705 * Given a variable hist_field, create a VAR_REF hist_field that
2706 * represents a reference to it.
2707 *
2708 * This function also adds the reference to the trigger that
2709 * now references the variable.
2710 *
2711 * Return: The VAR_REF field if successful, NULL if not
2712 */
2713 static struct hist_field *create_var_ref(struct hist_trigger_data *hist_data,
2714 struct hist_field *var_field,
2715 char *system, char *event_name)
2716 {
2717 unsigned long flags = HIST_FIELD_FL_VAR_REF;
2718 struct hist_field *ref_field;
2719 int i;
2720
2721 /* Check if the variable already exists */
2722 for (i = 0; i < hist_data->n_var_refs; i++) {
2723 ref_field = hist_data->var_refs[i];
2724 if (ref_field->var.idx == var_field->var.idx &&
2725 ref_field->var.hist_data == var_field->hist_data) {
2726 get_hist_field(ref_field);
2727 return ref_field;
2728 }
2729 }
2730
2731 ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL);
2732 if (ref_field) {
2733 if (init_var_ref(ref_field, var_field, system, event_name)) {
2734 destroy_hist_field(ref_field, 0);
2735 return NULL;
2736 }
2737
2738 hist_data->var_refs[hist_data->n_var_refs] = ref_field;
2739 ref_field->var_ref_idx = hist_data->n_var_refs++;
2740 }
2741
2742 return ref_field;
2743 }
2744
2745 static bool is_var_ref(char *var_name)
2746 {
2747 if (!var_name || strlen(var_name) < 2 || var_name[0] != '$')
2748 return false;
2749
2750 return true;
2751 }
2752
2753 static char *field_name_from_var(struct hist_trigger_data *hist_data,
2754 char *var_name)
2755 {
2756 char *name, *field;
2757 unsigned int i;
2758
2759 for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
2760 name = hist_data->attrs->var_defs.name[i];
2761
2762 if (strcmp(var_name, name) == 0) {
2763 field = hist_data->attrs->var_defs.expr[i];
2764 if (contains_operator(field) || is_var_ref(field))
2765 continue;
2766 return field;
2767 }
2768 }
2769
2770 return NULL;
2771 }
2772
2773 static char *local_field_var_ref(struct hist_trigger_data *hist_data,
2774 char *system, char *event_name,
2775 char *var_name)
2776 {
2777 struct trace_event_call *call;
2778
2779 if (system && event_name) {
2780 call = hist_data->event_file->event_call;
2781
2782 if (strcmp(system, call->class->system) != 0)
2783 return NULL;
2784
2785 if (strcmp(event_name, trace_event_name(call)) != 0)
2786 return NULL;
2787 }
2788
2789 if (!!system != !!event_name)
2790 return NULL;
2791
2792 if (!is_var_ref(var_name))
2793 return NULL;
2794
2795 var_name++;
2796
2797 return field_name_from_var(hist_data, var_name);
2798 }
2799
2800 static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data,
2801 char *system, char *event_name,
2802 char *var_name)
2803 {
2804 struct hist_field *var_field = NULL, *ref_field = NULL;
2805 struct trace_array *tr = hist_data->event_file->tr;
2806
2807 if (!is_var_ref(var_name))
2808 return NULL;
2809
2810 var_name++;
2811
2812 var_field = find_event_var(hist_data, system, event_name, var_name);
2813 if (var_field)
2814 ref_field = create_var_ref(hist_data, var_field,
2815 system, event_name);
2816
2817 if (!ref_field)
2818 hist_err(tr, HIST_ERR_VAR_NOT_FOUND, errpos(var_name));
2819
2820 return ref_field;
2821 }
2822
2823 static struct ftrace_event_field *
2824 parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
2825 char *field_str, unsigned long *flags)
2826 {
2827 struct ftrace_event_field *field = NULL;
2828 char *field_name, *modifier, *str;
2829 struct trace_array *tr = file->tr;
2830
2831 modifier = str = kstrdup(field_str, GFP_KERNEL);
2832 if (!modifier)
2833 return ERR_PTR(-ENOMEM);
2834
2835 field_name = strsep(&modifier, ".");
2836 if (modifier) {
2837 if (strcmp(modifier, "hex") == 0)
2838 *flags |= HIST_FIELD_FL_HEX;
2839 else if (strcmp(modifier, "sym") == 0)
2840 *flags |= HIST_FIELD_FL_SYM;
2841 else if (strcmp(modifier, "sym-offset") == 0)
2842 *flags |= HIST_FIELD_FL_SYM_OFFSET;
2843 else if ((strcmp(modifier, "execname") == 0) &&
2844 (strcmp(field_name, "common_pid") == 0))
2845 *flags |= HIST_FIELD_FL_EXECNAME;
2846 else if (strcmp(modifier, "syscall") == 0)
2847 *flags |= HIST_FIELD_FL_SYSCALL;
2848 else if (strcmp(modifier, "log2") == 0)
2849 *flags |= HIST_FIELD_FL_LOG2;
2850 else if (strcmp(modifier, "usecs") == 0)
2851 *flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
2852 else {
2853 hist_err(tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(modifier));
2854 field = ERR_PTR(-EINVAL);
2855 goto out;
2856 }
2857 }
2858
2859 if (strcmp(field_name, "common_timestamp") == 0) {
2860 *flags |= HIST_FIELD_FL_TIMESTAMP;
2861 hist_data->enable_timestamps = true;
2862 if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS)
2863 hist_data->attrs->ts_in_usecs = true;
2864 } else if (strcmp(field_name, "cpu") == 0)
2865 *flags |= HIST_FIELD_FL_CPU;
2866 else {
2867 field = trace_find_event_field(file->event_call, field_name);
2868 if (!field || !field->size) {
2869 hist_err(tr, HIST_ERR_FIELD_NOT_FOUND, errpos(field_name));
2870 field = ERR_PTR(-EINVAL);
2871 goto out;
2872 }
2873 }
2874 out:
2875 kfree(str);
2876
2877 return field;
2878 }
2879
2880 static struct hist_field *create_alias(struct hist_trigger_data *hist_data,
2881 struct hist_field *var_ref,
2882 char *var_name)
2883 {
2884 struct hist_field *alias = NULL;
2885 unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR;
2886
2887 alias = create_hist_field(hist_data, NULL, flags, var_name);
2888 if (!alias)
2889 return NULL;
2890
2891 alias->fn = var_ref->fn;
2892 alias->operands[0] = var_ref;
2893
2894 if (init_var_ref(alias, var_ref, var_ref->system, var_ref->event_name)) {
2895 destroy_hist_field(alias, 0);
2896 return NULL;
2897 }
2898
2899 alias->var_ref_idx = var_ref->var_ref_idx;
2900
2901 return alias;
2902 }
2903
2904 static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
2905 struct trace_event_file *file, char *str,
2906 unsigned long *flags, char *var_name)
2907 {
2908 char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str;
2909 struct ftrace_event_field *field = NULL;
2910 struct hist_field *hist_field = NULL;
2911 int ret = 0;
2912
2913 s = strchr(str, '.');
2914 if (s) {
2915 s = strchr(++s, '.');
2916 if (s) {
2917 ref_system = strsep(&str, ".");
2918 if (!str) {
2919 ret = -EINVAL;
2920 goto out;
2921 }
2922 ref_event = strsep(&str, ".");
2923 if (!str) {
2924 ret = -EINVAL;
2925 goto out;
2926 }
2927 ref_var = str;
2928 }
2929 }
2930
2931 s = local_field_var_ref(hist_data, ref_system, ref_event, ref_var);
2932 if (!s) {
2933 hist_field = parse_var_ref(hist_data, ref_system,
2934 ref_event, ref_var);
2935 if (hist_field) {
2936 if (var_name) {
2937 hist_field = create_alias(hist_data, hist_field, var_name);
2938 if (!hist_field) {
2939 ret = -ENOMEM;
2940 goto out;
2941 }
2942 }
2943 return hist_field;
2944 }
2945 } else
2946 str = s;
2947
2948 field = parse_field(hist_data, file, str, flags);
2949 if (IS_ERR(field)) {
2950 ret = PTR_ERR(field);
2951 goto out;
2952 }
2953
2954 hist_field = create_hist_field(hist_data, field, *flags, var_name);
2955 if (!hist_field) {
2956 ret = -ENOMEM;
2957 goto out;
2958 }
2959
2960 return hist_field;
2961 out:
2962 return ERR_PTR(ret);
2963 }
2964
2965 static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
2966 struct trace_event_file *file,
2967 char *str, unsigned long flags,
2968 char *var_name, unsigned int level);
2969
2970 static struct hist_field *parse_unary(struct hist_trigger_data *hist_data,
2971 struct trace_event_file *file,
2972 char *str, unsigned long flags,
2973 char *var_name, unsigned int level)
2974 {
2975 struct hist_field *operand1, *expr = NULL;
2976 unsigned long operand_flags;
2977 int ret = 0;
2978 char *s;
2979
2980 /* we support only -(xxx) i.e. explicit parens required */
2981
2982 if (level > 3) {
2983 hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str));
2984 ret = -EINVAL;
2985 goto free;
2986 }
2987
2988 str++; /* skip leading '-' */
2989
2990 s = strchr(str, '(');
2991 if (s)
2992 str++;
2993 else {
2994 ret = -EINVAL;
2995 goto free;
2996 }
2997
2998 s = strrchr(str, ')');
2999 if (s)
3000 *s = '\0';
3001 else {
3002 ret = -EINVAL; /* no closing ')' */
3003 goto free;
3004 }
3005
3006 flags |= HIST_FIELD_FL_EXPR;
3007 expr = create_hist_field(hist_data, NULL, flags, var_name);
3008 if (!expr) {
3009 ret = -ENOMEM;
3010 goto free;
3011 }
3012
3013 operand_flags = 0;
3014 operand1 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
3015 if (IS_ERR(operand1)) {
3016 ret = PTR_ERR(operand1);
3017 goto free;
3018 }
3019
3020 expr->flags |= operand1->flags &
3021 (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
3022 expr->fn = hist_field_unary_minus;
3023 expr->operands[0] = operand1;
3024 expr->operator = FIELD_OP_UNARY_MINUS;
3025 expr->name = expr_str(expr, 0);
3026 expr->type = kstrdup(operand1->type, GFP_KERNEL);
3027 if (!expr->type) {
3028 ret = -ENOMEM;
3029 goto free;
3030 }
3031
3032 return expr;
3033 free:
3034 destroy_hist_field(expr, 0);
3035 return ERR_PTR(ret);
3036 }
3037
3038 static int check_expr_operands(struct trace_array *tr,
3039 struct hist_field *operand1,
3040 struct hist_field *operand2)
3041 {
3042 unsigned long operand1_flags = operand1->flags;
3043 unsigned long operand2_flags = operand2->flags;
3044
3045 if ((operand1_flags & HIST_FIELD_FL_VAR_REF) ||
3046 (operand1_flags & HIST_FIELD_FL_ALIAS)) {
3047 struct hist_field *var;
3048
3049 var = find_var_field(operand1->var.hist_data, operand1->name);
3050 if (!var)
3051 return -EINVAL;
3052 operand1_flags = var->flags;
3053 }
3054
3055 if ((operand2_flags & HIST_FIELD_FL_VAR_REF) ||
3056 (operand2_flags & HIST_FIELD_FL_ALIAS)) {
3057 struct hist_field *var;
3058
3059 var = find_var_field(operand2->var.hist_data, operand2->name);
3060 if (!var)
3061 return -EINVAL;
3062 operand2_flags = var->flags;
3063 }
3064
3065 if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) !=
3066 (operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS)) {
3067 hist_err(tr, HIST_ERR_TIMESTAMP_MISMATCH, 0);
3068 return -EINVAL;
3069 }
3070
3071 return 0;
3072 }
3073
3074 static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
3075 struct trace_event_file *file,
3076 char *str, unsigned long flags,
3077 char *var_name, unsigned int level)
3078 {
3079 struct hist_field *operand1 = NULL, *operand2 = NULL, *expr = NULL;
3080 unsigned long operand_flags;
3081 int field_op, ret = -EINVAL;
3082 char *sep, *operand1_str;
3083
3084 if (level > 3) {
3085 hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str));
3086 return ERR_PTR(-EINVAL);
3087 }
3088
3089 field_op = contains_operator(str);
3090
3091 if (field_op == FIELD_OP_NONE)
3092 return parse_atom(hist_data, file, str, &flags, var_name);
3093
3094 if (field_op == FIELD_OP_UNARY_MINUS)
3095 return parse_unary(hist_data, file, str, flags, var_name, ++level);
3096
3097 switch (field_op) {
3098 case FIELD_OP_MINUS:
3099 sep = "-";
3100 break;
3101 case FIELD_OP_PLUS:
3102 sep = "+";
3103 break;
3104 default:
3105 goto free;
3106 }
3107
3108 operand1_str = strsep(&str, sep);
3109 if (!operand1_str || !str)
3110 goto free;
3111
3112 operand_flags = 0;
3113 operand1 = parse_atom(hist_data, file, operand1_str,
3114 &operand_flags, NULL);
3115 if (IS_ERR(operand1)) {
3116 ret = PTR_ERR(operand1);
3117 operand1 = NULL;
3118 goto free;
3119 }
3120
3121 /* rest of string could be another expression e.g. b+c in a+b+c */
3122 operand_flags = 0;
3123 operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
3124 if (IS_ERR(operand2)) {
3125 ret = PTR_ERR(operand2);
3126 operand2 = NULL;
3127 goto free;
3128 }
3129
3130 ret = check_expr_operands(file->tr, operand1, operand2);
3131 if (ret)
3132 goto free;
3133
3134 flags |= HIST_FIELD_FL_EXPR;
3135
3136 flags |= operand1->flags &
3137 (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
3138
3139 expr = create_hist_field(hist_data, NULL, flags, var_name);
3140 if (!expr) {
3141 ret = -ENOMEM;
3142 goto free;
3143 }
3144
3145 operand1->read_once = true;
3146 operand2->read_once = true;
3147
3148 expr->operands[0] = operand1;
3149 expr->operands[1] = operand2;
3150 expr->operator = field_op;
3151 expr->name = expr_str(expr, 0);
3152 expr->type = kstrdup(operand1->type, GFP_KERNEL);
3153 if (!expr->type) {
3154 ret = -ENOMEM;
3155 goto free;
3156 }
3157
3158 switch (field_op) {
3159 case FIELD_OP_MINUS:
3160 expr->fn = hist_field_minus;
3161 break;
3162 case FIELD_OP_PLUS:
3163 expr->fn = hist_field_plus;
3164 break;
3165 default:
3166 ret = -EINVAL;
3167 goto free;
3168 }
3169
3170 return expr;
3171 free:
3172 destroy_hist_field(operand1, 0);
3173 destroy_hist_field(operand2, 0);
3174 destroy_hist_field(expr, 0);
3175
3176 return ERR_PTR(ret);
3177 }
3178
3179 static char *find_trigger_filter(struct hist_trigger_data *hist_data,
3180 struct trace_event_file *file)
3181 {
3182 struct event_trigger_data *test;
3183
3184 lockdep_assert_held(&event_mutex);
3185
3186 list_for_each_entry(test, &file->triggers, list) {
3187 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
3188 if (test->private_data == hist_data)
3189 return test->filter_str;
3190 }
3191 }
3192
3193 return NULL;
3194 }
3195
3196 static struct event_command trigger_hist_cmd;
3197 static int event_hist_trigger_func(struct event_command *cmd_ops,
3198 struct trace_event_file *file,
3199 char *glob, char *cmd, char *param);
3200
3201 static bool compatible_keys(struct hist_trigger_data *target_hist_data,
3202 struct hist_trigger_data *hist_data,
3203 unsigned int n_keys)
3204 {
3205 struct hist_field *target_hist_field, *hist_field;
3206 unsigned int n, i, j;
3207
3208 if (hist_data->n_fields - hist_data->n_vals != n_keys)
3209 return false;
3210
3211 i = hist_data->n_vals;
3212 j = target_hist_data->n_vals;
3213
3214 for (n = 0; n < n_keys; n++) {
3215 hist_field = hist_data->fields[i + n];
3216 target_hist_field = target_hist_data->fields[j + n];
3217
3218 if (strcmp(hist_field->type, target_hist_field->type) != 0)
3219 return false;
3220 if (hist_field->size != target_hist_field->size)
3221 return false;
3222 if (hist_field->is_signed != target_hist_field->is_signed)
3223 return false;
3224 }
3225
3226 return true;
3227 }
3228
3229 static struct hist_trigger_data *
3230 find_compatible_hist(struct hist_trigger_data *target_hist_data,
3231 struct trace_event_file *file)
3232 {
3233 struct hist_trigger_data *hist_data;
3234 struct event_trigger_data *test;
3235 unsigned int n_keys;
3236
3237 lockdep_assert_held(&event_mutex);
3238
3239 n_keys = target_hist_data->n_fields - target_hist_data->n_vals;
3240
3241 list_for_each_entry(test, &file->triggers, list) {
3242 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
3243 hist_data = test->private_data;
3244
3245 if (compatible_keys(target_hist_data, hist_data, n_keys))
3246 return hist_data;
3247 }
3248 }
3249
3250 return NULL;
3251 }
3252
3253 static struct trace_event_file *event_file(struct trace_array *tr,
3254 char *system, char *event_name)
3255 {
3256 struct trace_event_file *file;
3257
3258 file = __find_event_file(tr, system, event_name);
3259 if (!file)
3260 return ERR_PTR(-EINVAL);
3261
3262 return file;
3263 }
3264
3265 static struct hist_field *
3266 find_synthetic_field_var(struct hist_trigger_data *target_hist_data,
3267 char *system, char *event_name, char *field_name)
3268 {
3269 struct hist_field *event_var;
3270 char *synthetic_name;
3271
3272 synthetic_name = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
3273 if (!synthetic_name)
3274 return ERR_PTR(-ENOMEM);
3275
3276 strcpy(synthetic_name, "synthetic_");
3277 strcat(synthetic_name, field_name);
3278
3279 event_var = find_event_var(target_hist_data, system, event_name, synthetic_name);
3280
3281 kfree(synthetic_name);
3282
3283 return event_var;
3284 }
3285
3286 /**
3287 * create_field_var_hist - Automatically create a histogram and var for a field
3288 * @target_hist_data: The target hist trigger
3289 * @subsys_name: Optional subsystem name
3290 * @event_name: Optional event name
3291 * @field_name: The name of the field (and the resulting variable)
3292 *
3293 * Hist trigger actions fetch data from variables, not directly from
3294 * events. However, for convenience, users are allowed to directly
3295 * specify an event field in an action, which will be automatically
3296 * converted into a variable on their behalf.
3297
3298 * If a user specifies a field on an event that isn't the event the
3299 * histogram currently being defined (the target event histogram), the
3300 * only way that can be accomplished is if a new hist trigger is
3301 * created and the field variable defined on that.
3302 *
3303 * This function creates a new histogram compatible with the target
3304 * event (meaning a histogram with the same key as the target
3305 * histogram), and creates a variable for the specified field, but
3306 * with 'synthetic_' prepended to the variable name in order to avoid
3307 * collision with normal field variables.
3308 *
3309 * Return: The variable created for the field.
3310 */
3311 static struct hist_field *
3312 create_field_var_hist(struct hist_trigger_data *target_hist_data,
3313 char *subsys_name, char *event_name, char *field_name)
3314 {
3315 struct trace_array *tr = target_hist_data->event_file->tr;
3316 struct hist_field *event_var = ERR_PTR(-EINVAL);
3317 struct hist_trigger_data *hist_data;
3318 unsigned int i, n, first = true;
3319 struct field_var_hist *var_hist;
3320 struct trace_event_file *file;
3321 struct hist_field *key_field;
3322 char *saved_filter;
3323 char *cmd;
3324 int ret;
3325
3326 if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) {
3327 hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name));
3328 return ERR_PTR(-EINVAL);
3329 }
3330
3331 file = event_file(tr, subsys_name, event_name);
3332
3333 if (IS_ERR(file)) {
3334 hist_err(tr, HIST_ERR_EVENT_FILE_NOT_FOUND, errpos(field_name));
3335 ret = PTR_ERR(file);
3336 return ERR_PTR(ret);
3337 }
3338
3339 /*
3340 * Look for a histogram compatible with target. We'll use the
3341 * found histogram specification to create a new matching
3342 * histogram with our variable on it. target_hist_data is not
3343 * yet a registered histogram so we can't use that.
3344 */
3345 hist_data = find_compatible_hist(target_hist_data, file);
3346 if (!hist_data) {
3347 hist_err(tr, HIST_ERR_HIST_NOT_FOUND, errpos(field_name));
3348 return ERR_PTR(-EINVAL);
3349 }
3350
3351 /* See if a synthetic field variable has already been created */
3352 event_var = find_synthetic_field_var(target_hist_data, subsys_name,
3353 event_name, field_name);
3354 if (!IS_ERR_OR_NULL(event_var))
3355 return event_var;
3356
3357 var_hist = kzalloc(sizeof(*var_hist), GFP_KERNEL);
3358 if (!var_hist)
3359 return ERR_PTR(-ENOMEM);
3360
3361 cmd = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
3362 if (!cmd) {
3363 kfree(var_hist);
3364 return ERR_PTR(-ENOMEM);
3365 }
3366
3367 /* Use the same keys as the compatible histogram */
3368 strcat(cmd, "keys=");
3369
3370 for_each_hist_key_field(i, hist_data) {
3371 key_field = hist_data->fields[i];
3372 if (!first)
3373 strcat(cmd, ",");
3374 strcat(cmd, key_field->field->name);
3375 first = false;
3376 }
3377
3378 /* Create the synthetic field variable specification */
3379 strcat(cmd, ":synthetic_");
3380 strcat(cmd, field_name);
3381 strcat(cmd, "=");
3382 strcat(cmd, field_name);
3383
3384 /* Use the same filter as the compatible histogram */
3385 saved_filter = find_trigger_filter(hist_data, file);
3386 if (saved_filter) {
3387 strcat(cmd, " if ");
3388 strcat(cmd, saved_filter);
3389 }
3390
3391 var_hist->cmd = kstrdup(cmd, GFP_KERNEL);
3392 if (!var_hist->cmd) {
3393 kfree(cmd);
3394 kfree(var_hist);
3395 return ERR_PTR(-ENOMEM);
3396 }
3397
3398 /* Save the compatible histogram information */
3399 var_hist->hist_data = hist_data;
3400
3401 /* Create the new histogram with our variable */
3402 ret = event_hist_trigger_func(&trigger_hist_cmd, file,
3403 "", "hist", cmd);
3404 if (ret) {
3405 kfree(cmd);
3406 kfree(var_hist->cmd);
3407 kfree(var_hist);
3408 hist_err(tr, HIST_ERR_HIST_CREATE_FAIL, errpos(field_name));
3409 return ERR_PTR(ret);
3410 }
3411
3412 kfree(cmd);
3413
3414 /* If we can't find the variable, something went wrong */
3415 event_var = find_synthetic_field_var(target_hist_data, subsys_name,
3416 event_name, field_name);
3417 if (IS_ERR_OR_NULL(event_var)) {
3418 kfree(var_hist->cmd);
3419 kfree(var_hist);
3420 hist_err(tr, HIST_ERR_SYNTH_VAR_NOT_FOUND, errpos(field_name));
3421 return ERR_PTR(-EINVAL);
3422 }
3423
3424 n = target_hist_data->n_field_var_hists;
3425 target_hist_data->field_var_hists[n] = var_hist;
3426 target_hist_data->n_field_var_hists++;
3427
3428 return event_var;
3429 }
3430
3431 static struct hist_field *
3432 find_target_event_var(struct hist_trigger_data *hist_data,
3433 char *subsys_name, char *event_name, char *var_name)
3434 {
3435 struct trace_event_file *file = hist_data->event_file;
3436 struct hist_field *hist_field = NULL;
3437
3438 if (subsys_name) {
3439 struct trace_event_call *call;
3440
3441 if (!event_name)
3442 return NULL;
3443
3444 call = file->event_call;
3445
3446 if (strcmp(subsys_name, call->class->system) != 0)
3447 return NULL;
3448
3449 if (strcmp(event_name, trace_event_name(call)) != 0)
3450 return NULL;
3451 }
3452
3453 hist_field = find_var_field(hist_data, var_name);
3454
3455 return hist_field;
3456 }
3457
3458 static inline void __update_field_vars(struct tracing_map_elt *elt,
3459 struct ring_buffer_event *rbe,
3460 void *rec,
3461 struct field_var **field_vars,
3462 unsigned int n_field_vars,
3463 unsigned int field_var_str_start)
3464 {
3465 struct hist_elt_data *elt_data = elt->private_data;
3466 unsigned int i, j, var_idx;
3467 u64 var_val;
3468
3469 for (i = 0, j = field_var_str_start; i < n_field_vars; i++) {
3470 struct field_var *field_var = field_vars[i];
3471 struct hist_field *var = field_var->var;
3472 struct hist_field *val = field_var->val;
3473
3474 var_val = val->fn(val, elt, rbe, rec);
3475 var_idx = var->var.idx;
3476
3477 if (val->flags & HIST_FIELD_FL_STRING) {
3478 char *str = elt_data->field_var_str[j++];
3479 char *val_str = (char *)(uintptr_t)var_val;
3480
3481 strscpy(str, val_str, STR_VAR_LEN_MAX);
3482 var_val = (u64)(uintptr_t)str;
3483 }
3484 tracing_map_set_var(elt, var_idx, var_val);
3485 }
3486 }
3487
3488 static void update_field_vars(struct hist_trigger_data *hist_data,
3489 struct tracing_map_elt *elt,
3490 struct ring_buffer_event *rbe,
3491 void *rec)
3492 {
3493 __update_field_vars(elt, rbe, rec, hist_data->field_vars,
3494 hist_data->n_field_vars, 0);
3495 }
3496
3497 static void save_track_data_vars(struct hist_trigger_data *hist_data,
3498 struct tracing_map_elt *elt, void *rec,
3499 struct ring_buffer_event *rbe, void *key,
3500 struct action_data *data, u64 *var_ref_vals)
3501 {
3502 __update_field_vars(elt, rbe, rec, hist_data->save_vars,
3503 hist_data->n_save_vars, hist_data->n_field_var_str);
3504 }
3505
3506 static struct hist_field *create_var(struct hist_trigger_data *hist_data,
3507 struct trace_event_file *file,
3508 char *name, int size, const char *type)
3509 {
3510 struct hist_field *var;
3511 int idx;
3512
3513 if (find_var(hist_data, file, name) && !hist_data->remove) {
3514 var = ERR_PTR(-EINVAL);
3515 goto out;
3516 }
3517
3518 var = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
3519 if (!var) {
3520 var = ERR_PTR(-ENOMEM);
3521 goto out;
3522 }
3523
3524 idx = tracing_map_add_var(hist_data->map);
3525 if (idx < 0) {
3526 kfree(var);
3527 var = ERR_PTR(-EINVAL);
3528 goto out;
3529 }
3530
3531 var->flags = HIST_FIELD_FL_VAR;
3532 var->var.idx = idx;
3533 var->var.hist_data = var->hist_data = hist_data;
3534 var->size = size;
3535 var->var.name = kstrdup(name, GFP_KERNEL);
3536 var->type = kstrdup(type, GFP_KERNEL);
3537 if (!var->var.name || !var->type) {
3538 kfree(var->var.name);
3539 kfree(var->type);
3540 kfree(var);
3541 var = ERR_PTR(-ENOMEM);
3542 }
3543 out:
3544 return var;
3545 }
3546
3547 static struct field_var *create_field_var(struct hist_trigger_data *hist_data,
3548 struct trace_event_file *file,
3549 char *field_name)
3550 {
3551 struct hist_field *val = NULL, *var = NULL;
3552 unsigned long flags = HIST_FIELD_FL_VAR;
3553 struct trace_array *tr = file->tr;
3554 struct field_var *field_var;
3555 int ret = 0;
3556
3557 if (hist_data->n_field_vars >= SYNTH_FIELDS_MAX) {
3558 hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name));
3559 ret = -EINVAL;
3560 goto err;
3561 }
3562
3563 val = parse_atom(hist_data, file, field_name, &flags, NULL);
3564 if (IS_ERR(val)) {
3565 hist_err(tr, HIST_ERR_FIELD_VAR_PARSE_FAIL, errpos(field_name));
3566 ret = PTR_ERR(val);
3567 goto err;
3568 }
3569
3570 var = create_var(hist_data, file, field_name, val->size, val->type);
3571 if (IS_ERR(var)) {
3572 hist_err(tr, HIST_ERR_VAR_CREATE_FIND_FAIL, errpos(field_name));
3573 kfree(val);
3574 ret = PTR_ERR(var);
3575 goto err;
3576 }
3577
3578 field_var = kzalloc(sizeof(struct field_var), GFP_KERNEL);
3579 if (!field_var) {
3580 kfree(val);
3581 kfree(var);
3582 ret = -ENOMEM;
3583 goto err;
3584 }
3585
3586 field_var->var = var;
3587 field_var->val = val;
3588 out:
3589 return field_var;
3590 err:
3591 field_var = ERR_PTR(ret);
3592 goto out;
3593 }
3594
3595 /**
3596 * create_target_field_var - Automatically create a variable for a field
3597 * @target_hist_data: The target hist trigger
3598 * @subsys_name: Optional subsystem name
3599 * @event_name: Optional event name
3600 * @var_name: The name of the field (and the resulting variable)
3601 *
3602 * Hist trigger actions fetch data from variables, not directly from
3603 * events. However, for convenience, users are allowed to directly
3604 * specify an event field in an action, which will be automatically
3605 * converted into a variable on their behalf.
3606
3607 * This function creates a field variable with the name var_name on
3608 * the hist trigger currently being defined on the target event. If
3609 * subsys_name and event_name are specified, this function simply
3610 * verifies that they do in fact match the target event subsystem and
3611 * event name.
3612 *
3613 * Return: The variable created for the field.
3614 */
3615 static struct field_var *
3616 create_target_field_var(struct hist_trigger_data *target_hist_data,
3617 char *subsys_name, char *event_name, char *var_name)
3618 {
3619 struct trace_event_file *file = target_hist_data->event_file;
3620
3621 if (subsys_name) {
3622 struct trace_event_call *call;
3623
3624 if (!event_name)
3625 return NULL;
3626
3627 call = file->event_call;
3628
3629 if (strcmp(subsys_name, call->class->system) != 0)
3630 return NULL;
3631
3632 if (strcmp(event_name, trace_event_name(call)) != 0)
3633 return NULL;
3634 }
3635
3636 return create_field_var(target_hist_data, file, var_name);
3637 }
3638
3639 static bool check_track_val_max(u64 track_val, u64 var_val)
3640 {
3641 if (var_val <= track_val)
3642 return false;
3643
3644 return true;
3645 }
3646
3647 static bool check_track_val_changed(u64 track_val, u64 var_val)
3648 {
3649 if (var_val == track_val)
3650 return false;
3651
3652 return true;
3653 }
3654
3655 static u64 get_track_val(struct hist_trigger_data *hist_data,
3656 struct tracing_map_elt *elt,
3657 struct action_data *data)
3658 {
3659 unsigned int track_var_idx = data->track_data.track_var->var.idx;
3660 u64 track_val;
3661
3662 track_val = tracing_map_read_var(elt, track_var_idx);
3663
3664 return track_val;
3665 }
3666
3667 static void save_track_val(struct hist_trigger_data *hist_data,
3668 struct tracing_map_elt *elt,
3669 struct action_data *data, u64 var_val)
3670 {
3671 unsigned int track_var_idx = data->track_data.track_var->var.idx;
3672
3673 tracing_map_set_var(elt, track_var_idx, var_val);
3674 }
3675
3676 static void save_track_data(struct hist_trigger_data *hist_data,
3677 struct tracing_map_elt *elt, void *rec,
3678 struct ring_buffer_event *rbe, void *key,
3679 struct action_data *data, u64 *var_ref_vals)
3680 {
3681 if (data->track_data.save_data)
3682 data->track_data.save_data(hist_data, elt, rec, rbe, key, data, var_ref_vals);
3683 }
3684
3685 static bool check_track_val(struct tracing_map_elt *elt,
3686 struct action_data *data,
3687 u64 var_val)
3688 {
3689 struct hist_trigger_data *hist_data;
3690 u64 track_val;
3691
3692 hist_data = data->track_data.track_var->hist_data;
3693 track_val = get_track_val(hist_data, elt, data);
3694
3695 return data->track_data.check_val(track_val, var_val);
3696 }
3697
3698 #ifdef CONFIG_TRACER_SNAPSHOT
3699 static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
3700 {
3701 /* called with tr->max_lock held */
3702 struct track_data *track_data = tr->cond_snapshot->cond_data;
3703 struct hist_elt_data *elt_data, *track_elt_data;
3704 struct snapshot_context *context = cond_data;
3705 struct action_data *action;
3706 u64 track_val;
3707
3708 if (!track_data)
3709 return false;
3710
3711 action = track_data->action_data;
3712
3713 track_val = get_track_val(track_data->hist_data, context->elt,
3714 track_data->action_data);
3715
3716 if (!action->track_data.check_val(track_data->track_val, track_val))
3717 return false;
3718
3719 track_data->track_val = track_val;
3720 memcpy(track_data->key, context->key, track_data->key_len);
3721
3722 elt_data = context->elt->private_data;
3723 track_elt_data = track_data->elt.private_data;
3724 if (elt_data->comm)
3725 strncpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN);
3726
3727 track_data->updated = true;
3728
3729 return true;
3730 }
3731
3732 static void save_track_data_snapshot(struct hist_trigger_data *hist_data,
3733 struct tracing_map_elt *elt, void *rec,
3734 struct ring_buffer_event *rbe, void *key,
3735 struct action_data *data,
3736 u64 *var_ref_vals)
3737 {
3738 struct trace_event_file *file = hist_data->event_file;
3739 struct snapshot_context context;
3740
3741 context.elt = elt;
3742 context.key = key;
3743
3744 tracing_snapshot_cond(file->tr, &context);
3745 }
3746
3747 static void hist_trigger_print_key(struct seq_file *m,
3748 struct hist_trigger_data *hist_data,
3749 void *key,
3750 struct tracing_map_elt *elt);
3751
3752 static struct action_data *snapshot_action(struct hist_trigger_data *hist_data)
3753 {
3754 unsigned int i;
3755
3756 if (!hist_data->n_actions)
3757 return NULL;
3758
3759 for (i = 0; i < hist_data->n_actions; i++) {
3760 struct action_data *data = hist_data->actions[i];
3761
3762 if (data->action == ACTION_SNAPSHOT)
3763 return data;
3764 }
3765
3766 return NULL;
3767 }
3768
3769 static void track_data_snapshot_print(struct seq_file *m,
3770 struct hist_trigger_data *hist_data)
3771 {
3772 struct trace_event_file *file = hist_data->event_file;
3773 struct track_data *track_data;
3774 struct action_data *action;
3775
3776 track_data = tracing_cond_snapshot_data(file->tr);
3777 if (!track_data)
3778 return;
3779
3780 if (!track_data->updated)
3781 return;
3782
3783 action = snapshot_action(hist_data);
3784 if (!action)
3785 return;
3786
3787 seq_puts(m, "\nSnapshot taken (see tracing/snapshot). Details:\n");
3788 seq_printf(m, "\ttriggering value { %s(%s) }: %10llu",
3789 action->handler == HANDLER_ONMAX ? "onmax" : "onchange",
3790 action->track_data.var_str, track_data->track_val);
3791
3792 seq_puts(m, "\ttriggered by event with key: ");
3793 hist_trigger_print_key(m, hist_data, track_data->key, &track_data->elt);
3794 seq_putc(m, '\n');
3795 }
3796 #else
3797 static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
3798 {
3799 return false;
3800 }
3801 static void save_track_data_snapshot(struct hist_trigger_data *hist_data,
3802 struct tracing_map_elt *elt, void *rec,
3803 struct ring_buffer_event *rbe, void *key,
3804 struct action_data *data,
3805 u64 *var_ref_vals) {}
3806 static void track_data_snapshot_print(struct seq_file *m,
3807 struct hist_trigger_data *hist_data) {}
3808 #endif /* CONFIG_TRACER_SNAPSHOT */
3809
3810 static void track_data_print(struct seq_file *m,
3811 struct hist_trigger_data *hist_data,
3812 struct tracing_map_elt *elt,
3813 struct action_data *data)
3814 {
3815 u64 track_val = get_track_val(hist_data, elt, data);
3816 unsigned int i, save_var_idx;
3817
3818 if (data->handler == HANDLER_ONMAX)
3819 seq_printf(m, "\n\tmax: %10llu", track_val);
3820 else if (data->handler == HANDLER_ONCHANGE)
3821 seq_printf(m, "\n\tchanged: %10llu", track_val);
3822
3823 if (data->action == ACTION_SNAPSHOT)
3824 return;
3825
3826 for (i = 0; i < hist_data->n_save_vars; i++) {
3827 struct hist_field *save_val = hist_data->save_vars[i]->val;
3828 struct hist_field *save_var = hist_data->save_vars[i]->var;
3829 u64 val;
3830
3831 save_var_idx = save_var->var.idx;
3832
3833 val = tracing_map_read_var(elt, save_var_idx);
3834
3835 if (save_val->flags & HIST_FIELD_FL_STRING) {
3836 seq_printf(m, " %s: %-32s", save_var->var.name,
3837 (char *)(uintptr_t)(val));
3838 } else
3839 seq_printf(m, " %s: %10llu", save_var->var.name, val);
3840 }
3841 }
3842
3843 static void ontrack_action(struct hist_trigger_data *hist_data,
3844 struct tracing_map_elt *elt, void *rec,
3845 struct ring_buffer_event *rbe, void *key,
3846 struct action_data *data, u64 *var_ref_vals)
3847 {
3848 u64 var_val = var_ref_vals[data->track_data.var_ref->var_ref_idx];
3849
3850 if (check_track_val(elt, data, var_val)) {
3851 save_track_val(hist_data, elt, data, var_val);
3852 save_track_data(hist_data, elt, rec, rbe, key, data, var_ref_vals);
3853 }
3854 }
3855
3856 static void action_data_destroy(struct action_data *data)
3857 {
3858 unsigned int i;
3859
3860 lockdep_assert_held(&event_mutex);
3861
3862 kfree(data->action_name);
3863
3864 for (i = 0; i < data->n_params; i++)
3865 kfree(data->params[i]);
3866
3867 if (data->synth_event)
3868 data->synth_event->ref--;
3869
3870 kfree(data->synth_event_name);
3871
3872 kfree(data);
3873 }
3874
3875 static void track_data_destroy(struct hist_trigger_data *hist_data,
3876 struct action_data *data)
3877 {
3878 struct trace_event_file *file = hist_data->event_file;
3879
3880 destroy_hist_field(data->track_data.track_var, 0);
3881
3882 if (data->action == ACTION_SNAPSHOT) {
3883 struct track_data *track_data;
3884
3885 track_data = tracing_cond_snapshot_data(file->tr);
3886 if (track_data && track_data->hist_data == hist_data) {
3887 tracing_snapshot_cond_disable(file->tr);
3888 track_data_free(track_data);
3889 }
3890 }
3891
3892 kfree(data->track_data.var_str);
3893
3894 action_data_destroy(data);
3895 }
3896
3897 static int action_create(struct hist_trigger_data *hist_data,
3898 struct action_data *data);
3899
3900 static int track_data_create(struct hist_trigger_data *hist_data,
3901 struct action_data *data)
3902 {
3903 struct hist_field *var_field, *ref_field, *track_var = NULL;
3904 struct trace_event_file *file = hist_data->event_file;
3905 struct trace_array *tr = file->tr;
3906 char *track_data_var_str;
3907 int ret = 0;
3908
3909 track_data_var_str = data->track_data.var_str;
3910 if (track_data_var_str[0] != '$') {
3911 hist_err(tr, HIST_ERR_ONX_NOT_VAR, errpos(track_data_var_str));
3912 return -EINVAL;
3913 }
3914 track_data_var_str++;
3915
3916 var_field = find_target_event_var(hist_data, NULL, NULL, track_data_var_str);
3917 if (!var_field) {
3918 hist_err(tr, HIST_ERR_ONX_VAR_NOT_FOUND, errpos(track_data_var_str));
3919 return -EINVAL;
3920 }
3921
3922 ref_field = create_var_ref(hist_data, var_field, NULL, NULL);
3923 if (!ref_field)
3924 return -ENOMEM;
3925
3926 data->track_data.var_ref = ref_field;
3927
3928 if (data->handler == HANDLER_ONMAX)
3929 track_var = create_var(hist_data, file, "__max", sizeof(u64), "u64");
3930 if (IS_ERR(track_var)) {
3931 hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0);
3932 ret = PTR_ERR(track_var);
3933 goto out;
3934 }
3935
3936 if (data->handler == HANDLER_ONCHANGE)
3937 track_var = create_var(hist_data, file, "__change", sizeof(u64), "u64");
3938 if (IS_ERR(track_var)) {
3939 hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0);
3940 ret = PTR_ERR(track_var);
3941 goto out;
3942 }
3943 data->track_data.track_var = track_var;
3944
3945 ret = action_create(hist_data, data);
3946 out:
3947 return ret;
3948 }
3949
3950 static int parse_action_params(struct trace_array *tr, char *params,
3951 struct action_data *data)
3952 {
3953 char *param, *saved_param;
3954 bool first_param = true;
3955 int ret = 0;
3956
3957 while (params) {
3958 if (data->n_params >= SYNTH_FIELDS_MAX) {
3959 hist_err(tr, HIST_ERR_TOO_MANY_PARAMS, 0);
3960 goto out;
3961 }
3962
3963 param = strsep(¶ms, ",");
3964 if (!param) {
3965 hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, 0);
3966 ret = -EINVAL;
3967 goto out;
3968 }
3969
3970 param = strstrip(param);
3971 if (strlen(param) < 2) {
3972 hist_err(tr, HIST_ERR_INVALID_PARAM, errpos(param));
3973 ret = -EINVAL;
3974 goto out;
3975 }
3976
3977 saved_param = kstrdup(param, GFP_KERNEL);
3978 if (!saved_param) {
3979 ret = -ENOMEM;
3980 goto out;
3981 }
3982
3983 if (first_param && data->use_trace_keyword) {
3984 data->synth_event_name = saved_param;
3985 first_param = false;
3986 continue;
3987 }
3988 first_param = false;
3989
3990 data->params[data->n_params++] = saved_param;
3991 }
3992 out:
3993 return ret;
3994 }
3995
3996 static int action_parse(struct trace_array *tr, char *str, struct action_data *data,
3997 enum handler_id handler)
3998 {
3999 char *action_name;
4000 int ret = 0;
4001
4002 strsep(&str, ".");
4003 if (!str) {
4004 hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0);
4005 ret = -EINVAL;
4006 goto out;
4007 }
4008
4009 action_name = strsep(&str, "(");
4010 if (!action_name || !str) {
4011 hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0);
4012 ret = -EINVAL;
4013 goto out;
4014 }
4015
4016 if (str_has_prefix(action_name, "save")) {
4017 char *params = strsep(&str, ")");
4018
4019 if (!params) {
4020 hist_err(tr, HIST_ERR_NO_SAVE_PARAMS, 0);
4021 ret = -EINVAL;
4022 goto out;
4023 }
4024
4025 ret = parse_action_params(tr, params, data);
4026 if (ret)
4027 goto out;
4028
4029 if (handler == HANDLER_ONMAX)
4030 data->track_data.check_val = check_track_val_max;
4031 else if (handler == HANDLER_ONCHANGE)
4032 data->track_data.check_val = check_track_val_changed;
4033 else {
4034 hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name));
4035 ret = -EINVAL;
4036 goto out;
4037 }
4038
4039 data->track_data.save_data = save_track_data_vars;
4040 data->fn = ontrack_action;
4041 data->action = ACTION_SAVE;
4042 } else if (str_has_prefix(action_name, "snapshot")) {
4043 char *params = strsep(&str, ")");
4044
4045 if (!str) {
4046 hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(params));
4047 ret = -EINVAL;
4048 goto out;
4049 }
4050
4051 if (handler == HANDLER_ONMAX)
4052 data->track_data.check_val = check_track_val_max;
4053 else if (handler == HANDLER_ONCHANGE)
4054 data->track_data.check_val = check_track_val_changed;
4055 else {
4056 hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name));
4057 ret = -EINVAL;
4058 goto out;
4059 }
4060
4061 data->track_data.save_data = save_track_data_snapshot;
4062 data->fn = ontrack_action;
4063 data->action = ACTION_SNAPSHOT;
4064 } else {
4065 char *params = strsep(&str, ")");
4066
4067 if (str_has_prefix(action_name, "trace"))
4068 data->use_trace_keyword = true;
4069
4070 if (params) {
4071 ret = parse_action_params(tr, params, data);
4072 if (ret)
4073 goto out;
4074 }
4075
4076 if (handler == HANDLER_ONMAX)
4077 data->track_data.check_val = check_track_val_max;
4078 else if (handler == HANDLER_ONCHANGE)
4079 data->track_data.check_val = check_track_val_changed;
4080
4081 if (handler != HANDLER_ONMATCH) {
4082 data->track_data.save_data = action_trace;
4083 data->fn = ontrack_action;
4084 } else
4085 data->fn = action_trace;
4086
4087 data->action = ACTION_TRACE;
4088 }
4089
4090 data->action_name = kstrdup(action_name, GFP_KERNEL);
4091 if (!data->action_name) {
4092 ret = -ENOMEM;
4093 goto out;
4094 }
4095
4096 data->handler = handler;
4097 out:
4098 return ret;
4099 }
4100
4101 static struct action_data *track_data_parse(struct hist_trigger_data *hist_data,
4102 char *str, enum handler_id handler)
4103 {
4104 struct action_data *data;
4105 int ret = -EINVAL;
4106 char *var_str;
4107
4108 data = kzalloc(sizeof(*data), GFP_KERNEL);
4109 if (!data)
4110 return ERR_PTR(-ENOMEM);
4111
4112 var_str = strsep(&str, ")");
4113 if (!var_str || !str) {
4114 ret = -EINVAL;
4115 goto free;
4116 }
4117
4118 data->track_data.var_str = kstrdup(var_str, GFP_KERNEL);
4119 if (!data->track_data.var_str) {
4120 ret = -ENOMEM;
4121 goto free;
4122 }
4123
4124 ret = action_parse(hist_data->event_file->tr, str, data, handler);
4125 if (ret)
4126 goto free;
4127 out:
4128 return data;
4129 free:
4130 track_data_destroy(hist_data, data);
4131 data = ERR_PTR(ret);
4132 goto out;
4133 }
4134
4135 static void onmatch_destroy(struct action_data *data)
4136 {
4137 kfree(data->match_data.event);
4138 kfree(data->match_data.event_system);
4139
4140 action_data_destroy(data);
4141 }
4142
4143 static void destroy_field_var(struct field_var *field_var)
4144 {
4145 if (!field_var)
4146 return;
4147
4148 destroy_hist_field(field_var->var, 0);
4149 destroy_hist_field(field_var->val, 0);
4150
4151 kfree(field_var);
4152 }
4153
4154 static void destroy_field_vars(struct hist_trigger_data *hist_data)
4155 {
4156 unsigned int i;
4157
4158 for (i = 0; i < hist_data->n_field_vars; i++)
4159 destroy_field_var(hist_data->field_vars[i]);
4160 }
4161
4162 static void save_field_var(struct hist_trigger_data *hist_data,
4163 struct field_var *field_var)
4164 {
4165 hist_data->field_vars[hist_data->n_field_vars++] = field_var;
4166
4167 if (field_var->val->flags & HIST_FIELD_FL_STRING)
4168 hist_data->n_field_var_str++;
4169 }
4170
4171
4172 static int check_synth_field(struct synth_event *event,
4173 struct hist_field *hist_field,
4174 unsigned int field_pos)
4175 {
4176 struct synth_field *field;
4177
4178 if (field_pos >= event->n_fields)
4179 return -EINVAL;
4180
4181 field = event->fields[field_pos];
4182
4183 if (strcmp(field->type, hist_field->type) != 0)
4184 return -EINVAL;
4185
4186 return 0;
4187 }
4188
4189 static struct hist_field *
4190 trace_action_find_var(struct hist_trigger_data *hist_data,
4191 struct action_data *data,
4192 char *system, char *event, char *var)
4193 {
4194 struct trace_array *tr = hist_data->event_file->tr;
4195 struct hist_field *hist_field;
4196
4197 var++; /* skip '$' */
4198
4199 hist_field = find_target_event_var(hist_data, system, event, var);
4200 if (!hist_field) {
4201 if (!system && data->handler == HANDLER_ONMATCH) {
4202 system = data->match_data.event_system;
4203 event = data->match_data.event;
4204 }
4205
4206 hist_field = find_event_var(hist_data, system, event, var);
4207 }
4208
4209 if (!hist_field)
4210 hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, errpos(var));
4211
4212 return hist_field;
4213 }
4214
4215 static struct hist_field *
4216 trace_action_create_field_var(struct hist_trigger_data *hist_data,
4217 struct action_data *data, char *system,
4218 char *event, char *var)
4219 {
4220 struct hist_field *hist_field = NULL;
4221 struct field_var *field_var;
4222
4223 /*
4224 * First try to create a field var on the target event (the
4225 * currently being defined). This will create a variable for
4226 * unqualified fields on the target event, or if qualified,
4227 * target fields that have qualified names matching the target.
4228 */
4229 field_var = create_target_field_var(hist_data, system, event, var);
4230
4231 if (field_var && !IS_ERR(field_var)) {
4232 save_field_var(hist_data, field_var);
4233 hist_field = field_var->var;
4234 } else {
4235 field_var = NULL;
4236 /*
4237 * If no explicit system.event is specfied, default to
4238 * looking for fields on the onmatch(system.event.xxx)
4239 * event.
4240 */
4241 if (!system && data->handler == HANDLER_ONMATCH) {
4242 system = data->match_data.event_system;
4243 event = data->match_data.event;
4244 }
4245
4246 /*
4247 * At this point, we're looking at a field on another
4248 * event. Because we can't modify a hist trigger on
4249 * another event to add a variable for a field, we need
4250 * to create a new trigger on that event and create the
4251 * variable at the same time.
4252 */
4253 hist_field = create_field_var_hist(hist_data, system, event, var);
4254 if (IS_ERR(hist_field))
4255 goto free;
4256 }
4257 out:
4258 return hist_field;
4259 free:
4260 destroy_field_var(field_var);
4261 hist_field = NULL;
4262 goto out;
4263 }
4264
4265 static int trace_action_create(struct hist_trigger_data *hist_data,
4266 struct action_data *data)
4267 {
4268 struct trace_array *tr = hist_data->event_file->tr;
4269 char *event_name, *param, *system = NULL;
4270 struct hist_field *hist_field, *var_ref;
4271 unsigned int i;
4272 unsigned int field_pos = 0;
4273 struct synth_event *event;
4274 char *synth_event_name;
4275 int var_ref_idx, ret = 0;
4276
4277 lockdep_assert_held(&event_mutex);
4278
4279 if (data->use_trace_keyword)
4280 synth_event_name = data->synth_event_name;
4281 else
4282 synth_event_name = data->action_name;
4283
4284 event = find_synth_event(synth_event_name);
4285 if (!event) {
4286 hist_err(tr, HIST_ERR_SYNTH_EVENT_NOT_FOUND, errpos(synth_event_name));
4287 return -EINVAL;
4288 }
4289
4290 event->ref++;
4291
4292 for (i = 0; i < data->n_params; i++) {
4293 char *p;
4294
4295 p = param = kstrdup(data->params[i], GFP_KERNEL);
4296 if (!param) {
4297 ret = -ENOMEM;
4298 goto err;
4299 }
4300
4301 system = strsep(¶m, ".");
4302 if (!param) {
4303 param = (char *)system;
4304 system = event_name = NULL;
4305 } else {
4306 event_name = strsep(¶m, ".");
4307 if (!param) {
4308 kfree(p);
4309 ret = -EINVAL;
4310 goto err;
4311 }
4312 }
4313
4314 if (param[0] == '$')
4315 hist_field = trace_action_find_var(hist_data, data,
4316 system, event_name,
4317 param);
4318 else
4319 hist_field = trace_action_create_field_var(hist_data,
4320 data,
4321 system,
4322 event_name,
4323 param);
4324
4325 if (!hist_field) {
4326 kfree(p);
4327 ret = -EINVAL;
4328 goto err;
4329 }
4330
4331 if (check_synth_field(event, hist_field, field_pos) == 0) {
4332 var_ref = create_var_ref(hist_data, hist_field,
4333 system, event_name);
4334 if (!var_ref) {
4335 kfree(p);
4336 ret = -ENOMEM;
4337 goto err;
4338 }
4339
4340 var_ref_idx = find_var_ref_idx(hist_data, var_ref);
4341 if (WARN_ON(var_ref_idx < 0)) {
4342 ret = var_ref_idx;
4343 goto err;
4344 }
4345
4346 data->var_ref_idx[i] = var_ref_idx;
4347
4348 field_pos++;
4349 kfree(p);
4350 continue;
4351 }
4352
4353 hist_err(tr, HIST_ERR_SYNTH_TYPE_MISMATCH, errpos(param));
4354 kfree(p);
4355 ret = -EINVAL;
4356 goto err;
4357 }
4358
4359 if (field_pos != event->n_fields) {
4360 hist_err(tr, HIST_ERR_SYNTH_COUNT_MISMATCH, errpos(event->name));
4361 ret = -EINVAL;
4362 goto err;
4363 }
4364
4365 data->synth_event = event;
4366 out:
4367 return ret;
4368 err:
4369 event->ref--;
4370
4371 goto out;
4372 }
4373
4374 static int action_create(struct hist_trigger_data *hist_data,
4375 struct action_data *data)
4376 {
4377 struct trace_event_file *file = hist_data->event_file;
4378 struct trace_array *tr = file->tr;
4379 struct track_data *track_data;
4380 struct field_var *field_var;
4381 unsigned int i;
4382 char *param;
4383 int ret = 0;
4384
4385 if (data->action == ACTION_TRACE)
4386 return trace_action_create(hist_data, data);
4387
4388 if (data->action == ACTION_SNAPSHOT) {
4389 track_data = track_data_alloc(hist_data->key_size, data, hist_data);
4390 if (IS_ERR(track_data)) {
4391 ret = PTR_ERR(track_data);
4392 goto out;
4393 }
4394
4395 ret = tracing_snapshot_cond_enable(file->tr, track_data,
4396 cond_snapshot_update);
4397 if (ret)
4398 track_data_free(track_data);
4399
4400 goto out;
4401 }
4402
4403 if (data->action == ACTION_SAVE) {
4404 if (hist_data->n_save_vars) {
4405 ret = -EEXIST;
4406 hist_err(tr, HIST_ERR_TOO_MANY_SAVE_ACTIONS, 0);
4407 goto out;
4408 }
4409
4410 for (i = 0; i < data->n_params; i++) {
4411 param = kstrdup(data->params[i], GFP_KERNEL);
4412 if (!param) {
4413 ret = -ENOMEM;
4414 goto out;
4415 }
4416
4417 field_var = create_target_field_var(hist_data, NULL, NULL, param);
4418 if (IS_ERR(field_var)) {
4419 hist_err(tr, HIST_ERR_FIELD_VAR_CREATE_FAIL,
4420 errpos(param));
4421 ret = PTR_ERR(field_var);
4422 kfree(param);
4423 goto out;
4424 }
4425
4426 hist_data->save_vars[hist_data->n_save_vars++] = field_var;
4427 if (field_var->val->flags & HIST_FIELD_FL_STRING)
4428 hist_data->n_save_var_str++;
4429 kfree(param);
4430 }
4431 }
4432 out:
4433 return ret;
4434 }
4435
4436 static int onmatch_create(struct hist_trigger_data *hist_data,
4437 struct action_data *data)
4438 {
4439 return action_create(hist_data, data);
4440 }
4441
4442 static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
4443 {
4444 char *match_event, *match_event_system;
4445 struct action_data *data;
4446 int ret = -EINVAL;
4447
4448 data = kzalloc(sizeof(*data), GFP_KERNEL);
4449 if (!data)
4450 return ERR_PTR(-ENOMEM);
4451
4452 match_event = strsep(&str, ")");
4453 if (!match_event || !str) {
4454 hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(match_event));
4455 goto free;
4456 }
4457
4458 match_event_system = strsep(&match_event, ".");
4459 if (!match_event) {
4460 hist_err(tr, HIST_ERR_SUBSYS_NOT_FOUND, errpos(match_event_system));
4461 goto free;
4462 }
4463
4464 if (IS_ERR(event_file(tr, match_event_system, match_event))) {
4465 hist_err(tr, HIST_ERR_INVALID_SUBSYS_EVENT, errpos(match_event));
4466 goto free;
4467 }
4468
4469 data->match_data.event = kstrdup(match_event, GFP_KERNEL);
4470 if (!data->match_data.event) {
4471 ret = -ENOMEM;
4472 goto free;
4473 }
4474
4475 data->match_data.event_system = kstrdup(match_event_system, GFP_KERNEL);
4476 if (!data->match_data.event_system) {
4477 ret = -ENOMEM;
4478 goto free;
4479 }
4480
4481 ret = action_parse(tr, str, data, HANDLER_ONMATCH);
4482 if (ret)
4483 goto free;
4484 out:
4485 return data;
4486 free:
4487 onmatch_destroy(data);
4488 data = ERR_PTR(ret);
4489 goto out;
4490 }
4491
4492 static int create_hitcount_val(struct hist_trigger_data *hist_data)
4493 {
4494 hist_data->fields[HITCOUNT_IDX] =
4495 create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL);
4496 if (!hist_data->fields[HITCOUNT_IDX])
4497 return -ENOMEM;
4498
4499 hist_data->n_vals++;
4500 hist_data->n_fields++;
4501
4502 if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
4503 return -EINVAL;
4504
4505 return 0;
4506 }
4507
4508 static int __create_val_field(struct hist_trigger_data *hist_data,
4509 unsigned int val_idx,
4510 struct trace_event_file *file,
4511 char *var_name, char *field_str,
4512 unsigned long flags)
4513 {
4514 struct hist_field *hist_field;
4515 int ret = 0;
4516
4517 hist_field = parse_expr(hist_data, file, field_str, flags, var_name, 0);
4518 if (IS_ERR(hist_field)) {
4519 ret = PTR_ERR(hist_field);
4520 goto out;
4521 }
4522
4523 hist_data->fields[val_idx] = hist_field;
4524
4525 ++hist_data->n_vals;
4526 ++hist_data->n_fields;
4527
4528 if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
4529 ret = -EINVAL;
4530 out:
4531 return ret;
4532 }
4533
4534 static int create_val_field(struct hist_trigger_data *hist_data,
4535 unsigned int val_idx,
4536 struct trace_event_file *file,
4537 char *field_str)
4538 {
4539 if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
4540 return -EINVAL;
4541
4542 return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0);
4543 }
4544
4545 static int create_var_field(struct hist_trigger_data *hist_data,
4546 unsigned int val_idx,
4547 struct trace_event_file *file,
4548 char *var_name, char *expr_str)
4549 {
4550 struct trace_array *tr = hist_data->event_file->tr;
4551 unsigned long flags = 0;
4552
4553 if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
4554 return -EINVAL;
4555
4556 if (find_var(hist_data, file, var_name) && !hist_data->remove) {
4557 hist_err(tr, HIST_ERR_DUPLICATE_VAR, errpos(var_name));
4558 return -EINVAL;
4559 }
4560
4561 flags |= HIST_FIELD_FL_VAR;
4562 hist_data->n_vars++;
4563 if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX))
4564 return -EINVAL;
4565
4566 return __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);
4567 }
4568
4569 static int create_val_fields(struct hist_trigger_data *hist_data,
4570 struct trace_event_file *file)
4571 {
4572 char *fields_str, *field_str;
4573 unsigned int i, j = 1;
4574 int ret;
4575
4576 ret = create_hitcount_val(hist_data);
4577 if (ret)
4578 goto out;
4579
4580 fields_str = hist_data->attrs->vals_str;
4581 if (!fields_str)
4582 goto out;
4583
4584 for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
4585 j < TRACING_MAP_VALS_MAX; i++) {
4586 field_str = strsep(&fields_str, ",");
4587 if (!field_str)
4588 break;
4589
4590 if (strcmp(field_str, "hitcount") == 0)
4591 continue;
4592
4593 ret = create_val_field(hist_data, j++, file, field_str);
4594 if (ret)
4595 goto out;
4596 }
4597
4598 if (fields_str && (strcmp(fields_str, "hitcount") != 0))
4599 ret = -EINVAL;
4600 out:
4601 return ret;
4602 }
4603
4604 static int create_key_field(struct hist_trigger_data *hist_data,
4605 unsigned int key_idx,
4606 unsigned int key_offset,
4607 struct trace_event_file *file,
4608 char *field_str)
4609 {
4610 struct trace_array *tr = hist_data->event_file->tr;
4611 struct hist_field *hist_field = NULL;
4612 unsigned long flags = 0;
4613 unsigned int key_size;
4614 int ret = 0;
4615
4616 if (WARN_ON(key_idx >= HIST_FIELDS_MAX))
4617 return -EINVAL;
4618
4619 flags |= HIST_FIELD_FL_KEY;
4620
4621 if (strcmp(field_str, "stacktrace") == 0) {
4622 flags |= HIST_FIELD_FL_STACKTRACE;
4623 key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
4624 hist_field = create_hist_field(hist_data, NULL, flags, NULL);
4625 } else {
4626 hist_field = parse_expr(hist_data, file, field_str, flags,
4627 NULL, 0);
4628 if (IS_ERR(hist_field)) {
4629 ret = PTR_ERR(hist_field);
4630 goto out;
4631 }
4632
4633 if (field_has_hist_vars(hist_field, 0)) {
4634 hist_err(tr, HIST_ERR_INVALID_REF_KEY, errpos(field_str));
4635 destroy_hist_field(hist_field, 0);
4636 ret = -EINVAL;
4637 goto out;
4638 }
4639
4640 key_size = hist_field->size;
4641 }
4642
4643 hist_data->fields[key_idx] = hist_field;
4644
4645 key_size = ALIGN(key_size, sizeof(u64));
4646 hist_data->fields[key_idx]->size = key_size;
4647 hist_data->fields[key_idx]->offset = key_offset;
4648
4649 hist_data->key_size += key_size;
4650
4651 if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
4652 ret = -EINVAL;
4653 goto out;
4654 }
4655
4656 hist_data->n_keys++;
4657 hist_data->n_fields++;
4658
4659 if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
4660 return -EINVAL;
4661
4662 ret = key_size;
4663 out:
4664 return ret;
4665 }
4666
4667 static int create_key_fields(struct hist_trigger_data *hist_data,
4668 struct trace_event_file *file)
4669 {
4670 unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
4671 char *fields_str, *field_str;
4672 int ret = -EINVAL;
4673
4674 fields_str = hist_data->attrs->keys_str;
4675 if (!fields_str)
4676 goto out;
4677
4678 for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
4679 field_str = strsep(&fields_str, ",");
4680 if (!field_str)
4681 break;
4682 ret = create_key_field(hist_data, i, key_offset,
4683 file, field_str);
4684 if (ret < 0)
4685 goto out;
4686 key_offset += ret;
4687 }
4688 if (fields_str) {
4689 ret = -EINVAL;
4690 goto out;
4691 }
4692 ret = 0;
4693 out:
4694 return ret;
4695 }
4696
4697 static int create_var_fields(struct hist_trigger_data *hist_data,
4698 struct trace_event_file *file)
4699 {
4700 unsigned int i, j = hist_data->n_vals;
4701 int ret = 0;
4702
4703 unsigned int n_vars = hist_data->attrs->var_defs.n_vars;
4704
4705 for (i = 0; i < n_vars; i++) {
4706 char *var_name = hist_data->attrs->var_defs.name[i];
4707 char *expr = hist_data->attrs->var_defs.expr[i];
4708
4709 ret = create_var_field(hist_data, j++, file, var_name, expr);
4710 if (ret)
4711 goto out;
4712 }
4713 out:
4714 return ret;
4715 }
4716
4717 static void free_var_defs(struct hist_trigger_data *hist_data)
4718 {
4719 unsigned int i;
4720
4721 for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
4722 kfree(hist_data->attrs->var_defs.name[i]);
4723 kfree(hist_data->attrs->var_defs.expr[i]);
4724 }
4725
4726 hist_data->attrs->var_defs.n_vars = 0;
4727 }
4728
4729 static int parse_var_defs(struct hist_trigger_data *hist_data)
4730 {
4731 struct trace_array *tr = hist_data->event_file->tr;
4732 char *s, *str, *var_name, *field_str;
4733 unsigned int i, j, n_vars = 0;
4734 int ret = 0;
4735
4736 for (i = 0; i < hist_data->attrs->n_assignments; i++) {
4737 str = hist_data->attrs->assignment_str[i];
4738 for (j = 0; j < TRACING_MAP_VARS_MAX; j++) {
4739 field_str = strsep(&str, ",");
4740 if (!field_str)
4741 break;
4742
4743 var_name = strsep(&field_str, "=");
4744 if (!var_name || !field_str) {
4745 hist_err(tr, HIST_ERR_MALFORMED_ASSIGNMENT,
4746 errpos(var_name));
4747 ret = -EINVAL;
4748 goto free;
4749 }
4750
4751 if (n_vars == TRACING_MAP_VARS_MAX) {
4752 hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(var_name));
4753 ret = -EINVAL;
4754 goto free;
4755 }
4756
4757 s = kstrdup(var_name, GFP_KERNEL);
4758 if (!s) {
4759 ret = -ENOMEM;
4760 goto free;
4761 }
4762 hist_data->attrs->var_defs.name[n_vars] = s;
4763
4764 s = kstrdup(field_str, GFP_KERNEL);
4765 if (!s) {
4766 kfree(hist_data->attrs->var_defs.name[n_vars]);
4767 ret = -ENOMEM;
4768 goto free;
4769 }
4770 hist_data->attrs->var_defs.expr[n_vars++] = s;
4771
4772 hist_data->attrs->var_defs.n_vars = n_vars;
4773 }
4774 }
4775
4776 return ret;
4777 free:
4778 free_var_defs(hist_data);
4779
4780 return ret;
4781 }
4782
4783 static int create_hist_fields(struct hist_trigger_data *hist_data,
4784 struct trace_event_file *file)
4785 {
4786 int ret;
4787
4788 ret = parse_var_defs(hist_data);
4789 if (ret)
4790 goto out;
4791
4792 ret = create_val_fields(hist_data, file);
4793 if (ret)
4794 goto out;
4795
4796 ret = create_var_fields(hist_data, file);
4797 if (ret)
4798 goto out;
4799
4800 ret = create_key_fields(hist_data, file);
4801 if (ret)
4802 goto out;
4803 out:
4804 free_var_defs(hist_data);
4805
4806 return ret;
4807 }
4808
4809 static int is_descending(const char *str)
4810 {
4811 if (!str)
4812 return 0;
4813
4814 if (strcmp(str, "descending") == 0)
4815 return 1;
4816
4817 if (strcmp(str, "ascending") == 0)
4818 return 0;
4819
4820 return -EINVAL;
4821 }
4822
4823 static int create_sort_keys(struct hist_trigger_data *hist_data)
4824 {
4825 char *fields_str = hist_data->attrs->sort_key_str;
4826 struct tracing_map_sort_key *sort_key;
4827 int descending, ret = 0;
4828 unsigned int i, j, k;
4829
4830 hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
4831
4832 if (!fields_str)
4833 goto out;
4834
4835 for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
4836 struct hist_field *hist_field;
4837 char *field_str, *field_name;
4838 const char *test_name;
4839
4840 sort_key = &hist_data->sort_keys[i];
4841
4842 field_str = strsep(&fields_str, ",");
4843 if (!field_str)
4844 break;
4845
4846 if (!*field_str) {
4847 ret = -EINVAL;
4848 break;
4849 }
4850
4851 if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
4852 ret = -EINVAL;
4853 break;
4854 }
4855
4856 field_name = strsep(&field_str, ".");
4857 if (!field_name || !*field_name) {
4858 ret = -EINVAL;
4859 break;
4860 }
4861
4862 if (strcmp(field_name, "hitcount") == 0) {
4863 descending = is_descending(field_str);
4864 if (descending < 0) {
4865 ret = descending;
4866 break;
4867 }
4868 sort_key->descending = descending;
4869 continue;
4870 }
4871
4872 for (j = 1, k = 1; j < hist_data->n_fields; j++) {
4873 unsigned int idx;
4874
4875 hist_field = hist_data->fields[j];
4876 if (hist_field->flags & HIST_FIELD_FL_VAR)
4877 continue;
4878
4879 idx = k++;
4880
4881 test_name = hist_field_name(hist_field, 0);
4882
4883 if (strcmp(field_name, test_name) == 0) {
4884 sort_key->field_idx = idx;
4885 descending = is_descending(field_str);
4886 if (descending < 0) {
4887 ret = descending;
4888 goto out;
4889 }
4890 sort_key->descending = descending;
4891 break;
4892 }
4893 }
4894 if (j == hist_data->n_fields) {
4895 ret = -EINVAL;
4896 break;
4897 }
4898 }
4899
4900 hist_data->n_sort_keys = i;
4901 out:
4902 return ret;
4903 }
4904
4905 static void destroy_actions(struct hist_trigger_data *hist_data)
4906 {
4907 unsigned int i;
4908
4909 for (i = 0; i < hist_data->n_actions; i++) {
4910 struct action_data *data = hist_data->actions[i];
4911
4912 if (data->handler == HANDLER_ONMATCH)
4913 onmatch_destroy(data);
4914 else if (data->handler == HANDLER_ONMAX ||
4915 data->handler == HANDLER_ONCHANGE)
4916 track_data_destroy(hist_data, data);
4917 else
4918 kfree(data);
4919 }
4920 }
4921
4922 static int parse_actions(struct hist_trigger_data *hist_data)
4923 {
4924 struct trace_array *tr = hist_data->event_file->tr;
4925 struct action_data *data;
4926 unsigned int i;
4927 int ret = 0;
4928 char *str;
4929 int len;
4930
4931 for (i = 0; i < hist_data->attrs->n_actions; i++) {
4932 str = hist_data->attrs->action_str[i];
4933
4934 if ((len = str_has_prefix(str, "onmatch("))) {
4935 char *action_str = str + len;
4936
4937 data = onmatch_parse(tr, action_str);
4938 if (IS_ERR(data)) {
4939 ret = PTR_ERR(data);
4940 break;
4941 }
4942 } else if ((len = str_has_prefix(str, "onmax("))) {
4943 char *action_str = str + len;
4944
4945 data = track_data_parse(hist_data, action_str,
4946 HANDLER_ONMAX);
4947 if (IS_ERR(data)) {
4948 ret = PTR_ERR(data);
4949 break;
4950 }
4951 } else if ((len = str_has_prefix(str, "onchange("))) {
4952 char *action_str = str + len;
4953
4954 data = track_data_parse(hist_data, action_str,
4955 HANDLER_ONCHANGE);
4956 if (IS_ERR(data)) {
4957 ret = PTR_ERR(data);
4958 break;
4959 }
4960 } else {
4961 ret = -EINVAL;
4962 break;
4963 }
4964
4965 hist_data->actions[hist_data->n_actions++] = data;
4966 }
4967
4968 return ret;
4969 }
4970
4971 static int create_actions(struct hist_trigger_data *hist_data)
4972 {
4973 struct action_data *data;
4974 unsigned int i;
4975 int ret = 0;
4976
4977 for (i = 0; i < hist_data->attrs->n_actions; i++) {
4978 data = hist_data->actions[i];
4979
4980 if (data->handler == HANDLER_ONMATCH) {
4981 ret = onmatch_create(hist_data, data);
4982 if (ret)
4983 break;
4984 } else if (data->handler == HANDLER_ONMAX ||
4985 data->handler == HANDLER_ONCHANGE) {
4986 ret = track_data_create(hist_data, data);
4987 if (ret)
4988 break;
4989 } else {
4990 ret = -EINVAL;
4991 break;
4992 }
4993 }
4994
4995 return ret;
4996 }
4997
4998 static void print_actions(struct seq_file *m,
4999 struct hist_trigger_data *hist_data,
5000 struct tracing_map_elt *elt)
5001 {
5002 unsigned int i;
5003
5004 for (i = 0; i < hist_data->n_actions; i++) {
5005 struct action_data *data = hist_data->actions[i];
5006
5007 if (data->action == ACTION_SNAPSHOT)
5008 continue;
5009
5010 if (data->handler == HANDLER_ONMAX ||
5011 data->handler == HANDLER_ONCHANGE)
5012 track_data_print(m, hist_data, elt, data);
5013 }
5014 }
5015
5016 static void print_action_spec(struct seq_file *m,
5017 struct hist_trigger_data *hist_data,
5018 struct action_data *data)
5019 {
5020 unsigned int i;
5021
5022 if (data->action == ACTION_SAVE) {
5023 for (i = 0; i < hist_data->n_save_vars; i++) {
5024 seq_printf(m, "%s", hist_data->save_vars[i]->var->var.name);
5025 if (i < hist_data->n_save_vars - 1)
5026 seq_puts(m, ",");
5027 }
5028 } else if (data->action == ACTION_TRACE) {
5029 if (data->use_trace_keyword)
5030 seq_printf(m, "%s", data->synth_event_name);
5031 for (i = 0; i < data->n_params; i++) {
5032 if (i || data->use_trace_keyword)
5033 seq_puts(m, ",");
5034 seq_printf(m, "%s", data->params[i]);
5035 }
5036 }
5037 }
5038
5039 static void print_track_data_spec(struct seq_file *m,
5040 struct hist_trigger_data *hist_data,
5041 struct action_data *data)
5042 {
5043 if (data->handler == HANDLER_ONMAX)
5044 seq_puts(m, ":onmax(");
5045 else if (data->handler == HANDLER_ONCHANGE)
5046 seq_puts(m, ":onchange(");
5047 seq_printf(m, "%s", data->track_data.var_str);
5048 seq_printf(m, ").%s(", data->action_name);
5049
5050 print_action_spec(m, hist_data, data);
5051
5052 seq_puts(m, ")");
5053 }
5054
5055 static void print_onmatch_spec(struct seq_file *m,
5056 struct hist_trigger_data *hist_data,
5057 struct action_data *data)
5058 {
5059 seq_printf(m, ":onmatch(%s.%s).", data->match_data.event_system,
5060 data->match_data.event);
5061
5062 seq_printf(m, "%s(", data->action_name);
5063
5064 print_action_spec(m, hist_data, data);
5065
5066 seq_puts(m, ")");
5067 }
5068
5069 static bool actions_match(struct hist_trigger_data *hist_data,
5070 struct hist_trigger_data *hist_data_test)
5071 {
5072 unsigned int i, j;
5073
5074 if (hist_data->n_actions != hist_data_test->n_actions)
5075 return false;
5076
5077 for (i = 0; i < hist_data->n_actions; i++) {
5078 struct action_data *data = hist_data->actions[i];
5079 struct action_data *data_test = hist_data_test->actions[i];
5080 char *action_name, *action_name_test;
5081
5082 if (data->handler != data_test->handler)
5083 return false;
5084 if (data->action != data_test->action)
5085 return false;
5086
5087 if (data->n_params != data_test->n_params)
5088 return false;
5089
5090 for (j = 0; j < data->n_params; j++) {
5091 if (strcmp(data->params[j], data_test->params[j]) != 0)
5092 return false;
5093 }
5094
5095 if (data->use_trace_keyword)
5096 action_name = data->synth_event_name;
5097 else
5098 action_name = data->action_name;
5099
5100 if (data_test->use_trace_keyword)
5101 action_name_test = data_test->synth_event_name;
5102 else
5103 action_name_test = data_test->action_name;
5104
5105 if (strcmp(action_name, action_name_test) != 0)
5106 return false;
5107
5108 if (data->handler == HANDLER_ONMATCH) {
5109 if (strcmp(data->match_data.event_system,
5110 data_test->match_data.event_system) != 0)
5111 return false;
5112 if (strcmp(data->match_data.event,
5113 data_test->match_data.event) != 0)
5114 return false;
5115 } else if (data->handler == HANDLER_ONMAX ||
5116 data->handler == HANDLER_ONCHANGE) {
5117 if (strcmp(data->track_data.var_str,
5118 data_test->track_data.var_str) != 0)
5119 return false;
5120 }
5121 }
5122
5123 return true;
5124 }
5125
5126
5127 static void print_actions_spec(struct seq_file *m,
5128 struct hist_trigger_data *hist_data)
5129 {
5130 unsigned int i;
5131
5132 for (i = 0; i < hist_data->n_actions; i++) {
5133 struct action_data *data = hist_data->actions[i];
5134
5135 if (data->handler == HANDLER_ONMATCH)
5136 print_onmatch_spec(m, hist_data, data);
5137 else if (data->handler == HANDLER_ONMAX ||
5138 data->handler == HANDLER_ONCHANGE)
5139 print_track_data_spec(m, hist_data, data);
5140 }
5141 }
5142
5143 static void destroy_field_var_hists(struct hist_trigger_data *hist_data)
5144 {
5145 unsigned int i;
5146
5147 for (i = 0; i < hist_data->n_field_var_hists; i++) {
5148 kfree(hist_data->field_var_hists[i]->cmd);
5149 kfree(hist_data->field_var_hists[i]);
5150 }
5151 }
5152
5153 static void destroy_hist_data(struct hist_trigger_data *hist_data)
5154 {
5155 if (!hist_data)
5156 return;
5157
5158 destroy_hist_trigger_attrs(hist_data->attrs);
5159 destroy_hist_fields(hist_data);
5160 tracing_map_destroy(hist_data->map);
5161
5162 destroy_actions(hist_data);
5163 destroy_field_vars(hist_data);
5164 destroy_field_var_hists(hist_data);
5165
5166 kfree(hist_data);
5167 }
5168
5169 static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
5170 {
5171 struct tracing_map *map = hist_data->map;
5172 struct ftrace_event_field *field;
5173 struct hist_field *hist_field;
5174 int i, idx = 0;
5175
5176 for_each_hist_field(i, hist_data) {
5177 hist_field = hist_data->fields[i];
5178 if (hist_field->flags & HIST_FIELD_FL_KEY) {
5179 tracing_map_cmp_fn_t cmp_fn;
5180
5181 field = hist_field->field;
5182
5183 if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
5184 cmp_fn = tracing_map_cmp_none;
5185 else if (!field)
5186 cmp_fn = tracing_map_cmp_num(hist_field->size,
5187 hist_field->is_signed);
5188 else if (is_string_field(field))
5189 cmp_fn = tracing_map_cmp_string;
5190 else
5191 cmp_fn = tracing_map_cmp_num(field->size,
5192 field->is_signed);
5193 idx = tracing_map_add_key_field(map,
5194 hist_field->offset,
5195 cmp_fn);
5196 } else if (!(hist_field->flags & HIST_FIELD_FL_VAR))
5197 idx = tracing_map_add_sum_field(map);
5198
5199 if (idx < 0)
5200 return idx;
5201
5202 if (hist_field->flags & HIST_FIELD_FL_VAR) {
5203 idx = tracing_map_add_var(map);
5204 if (idx < 0)
5205 return idx;
5206 hist_field->var.idx = idx;
5207 hist_field->var.hist_data = hist_data;
5208 }
5209 }
5210
5211 return 0;
5212 }
5213
5214 static struct hist_trigger_data *
5215 create_hist_data(unsigned int map_bits,
5216 struct hist_trigger_attrs *attrs,
5217 struct trace_event_file *file,
5218 bool remove)
5219 {
5220 const struct tracing_map_ops *map_ops = NULL;
5221 struct hist_trigger_data *hist_data;
5222 int ret = 0;
5223
5224 hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL);
5225 if (!hist_data)
5226 return ERR_PTR(-ENOMEM);
5227
5228 hist_data->attrs = attrs;
5229 hist_data->remove = remove;
5230 hist_data->event_file = file;
5231
5232 ret = parse_actions(hist_data);
5233 if (ret)
5234 goto free;
5235
5236 ret = create_hist_fields(hist_data, file);
5237 if (ret)
5238 goto free;
5239
5240 ret = create_sort_keys(hist_data);
5241 if (ret)
5242 goto free;
5243
5244 map_ops = &hist_trigger_elt_data_ops;
5245
5246 hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
5247 map_ops, hist_data);
5248 if (IS_ERR(hist_data->map)) {
5249 ret = PTR_ERR(hist_data->map);
5250 hist_data->map = NULL;
5251 goto free;
5252 }
5253
5254 ret = create_tracing_map_fields(hist_data);
5255 if (ret)
5256 goto free;
5257 out:
5258 return hist_data;
5259 free:
5260 hist_data->attrs = NULL;
5261
5262 destroy_hist_data(hist_data);
5263
5264 hist_data = ERR_PTR(ret);
5265
5266 goto out;