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tracing/histogram: Fix sorting on old "cpu" value
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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_synth.h"
23
24 #define ERRORS \
25 C(NONE, "No error"), \
26 C(DUPLICATE_VAR, "Variable already defined"), \
27 C(VAR_NOT_UNIQUE, "Variable name not unique, need to use fully qualified name (subsys.event.var) for variable"), \
28 C(TOO_MANY_VARS, "Too many variables defined"), \
29 C(MALFORMED_ASSIGNMENT, "Malformed assignment"), \
30 C(NAMED_MISMATCH, "Named hist trigger doesn't match existing named trigger (includes variables)"), \
31 C(TRIGGER_EEXIST, "Hist trigger already exists"), \
32 C(TRIGGER_ENOENT_CLEAR, "Can't clear or continue a nonexistent hist trigger"), \
33 C(SET_CLOCK_FAIL, "Couldn't set trace_clock"), \
34 C(BAD_FIELD_MODIFIER, "Invalid field modifier"), \
35 C(TOO_MANY_SUBEXPR, "Too many subexpressions (3 max)"), \
36 C(TIMESTAMP_MISMATCH, "Timestamp units in expression don't match"), \
37 C(TOO_MANY_FIELD_VARS, "Too many field variables defined"), \
38 C(EVENT_FILE_NOT_FOUND, "Event file not found"), \
39 C(HIST_NOT_FOUND, "Matching event histogram not found"), \
40 C(HIST_CREATE_FAIL, "Couldn't create histogram for field"), \
41 C(SYNTH_VAR_NOT_FOUND, "Couldn't find synthetic variable"), \
42 C(SYNTH_EVENT_NOT_FOUND,"Couldn't find synthetic event"), \
43 C(SYNTH_TYPE_MISMATCH, "Param type doesn't match synthetic event field type"), \
44 C(SYNTH_COUNT_MISMATCH, "Param count doesn't match synthetic event field count"), \
45 C(FIELD_VAR_PARSE_FAIL, "Couldn't parse field variable"), \
46 C(VAR_CREATE_FIND_FAIL, "Couldn't create or find variable"), \
47 C(ONX_NOT_VAR, "For onmax(x) or onchange(x), x must be a variable"), \
48 C(ONX_VAR_NOT_FOUND, "Couldn't find onmax or onchange variable"), \
49 C(ONX_VAR_CREATE_FAIL, "Couldn't create onmax or onchange variable"), \
50 C(FIELD_VAR_CREATE_FAIL,"Couldn't create field variable"), \
51 C(TOO_MANY_PARAMS, "Too many action params"), \
52 C(PARAM_NOT_FOUND, "Couldn't find param"), \
53 C(INVALID_PARAM, "Invalid action param"), \
54 C(ACTION_NOT_FOUND, "No action found"), \
55 C(NO_SAVE_PARAMS, "No params found for save()"), \
56 C(TOO_MANY_SAVE_ACTIONS,"Can't have more than one save() action per hist"), \
57 C(ACTION_MISMATCH, "Handler doesn't support action"), \
58 C(NO_CLOSING_PAREN, "No closing paren found"), \
59 C(SUBSYS_NOT_FOUND, "Missing subsystem"), \
60 C(INVALID_SUBSYS_EVENT, "Invalid subsystem or event name"), \
61 C(INVALID_REF_KEY, "Using variable references in keys not supported"), \
62 C(VAR_NOT_FOUND, "Couldn't find variable"), \
63 C(FIELD_NOT_FOUND, "Couldn't find field"), \
64 C(EMPTY_ASSIGNMENT, "Empty assignment"), \
65 C(INVALID_SORT_MODIFIER,"Invalid sort modifier"), \
66 C(EMPTY_SORT_FIELD, "Empty sort field"), \
67 C(TOO_MANY_SORT_FIELDS, "Too many sort fields (Max = 2)"), \
68 C(INVALID_SORT_FIELD, "Sort field must be a key or a val"), \
69 C(INVALID_STR_OPERAND, "String type can not be an operand in expression"),
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 trace_buffer *buffer,
86 struct ring_buffer_event *rbe,
87 void *event);
88
89 #define HIST_FIELD_OPERANDS_MAX 2
90 #define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
91 #define HIST_ACTIONS_MAX 8
92
93 enum field_op_id {
94 FIELD_OP_NONE,
95 FIELD_OP_PLUS,
96 FIELD_OP_MINUS,
97 FIELD_OP_UNARY_MINUS,
98 };
99
100 /*
101 * A hist_var (histogram variable) contains variable information for
102 * hist_fields having the HIST_FIELD_FL_VAR or HIST_FIELD_FL_VAR_REF
103 * flag set. A hist_var has a variable name e.g. ts0, and is
104 * associated with a given histogram trigger, as specified by
105 * hist_data. The hist_var idx is the unique index assigned to the
106 * variable by the hist trigger's tracing_map. The idx is what is
107 * used to set a variable's value and, by a variable reference, to
108 * retrieve it.
109 */
110 struct hist_var {
111 char *name;
112 struct hist_trigger_data *hist_data;
113 unsigned int idx;
114 };
115
116 struct hist_field {
117 struct ftrace_event_field *field;
118 unsigned long flags;
119 hist_field_fn_t fn;
120 unsigned int ref;
121 unsigned int size;
122 unsigned int offset;
123 unsigned int is_signed;
124 unsigned long buckets;
125 const char *type;
126 struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
127 struct hist_trigger_data *hist_data;
128
129 /*
130 * Variable fields contain variable-specific info in var.
131 */
132 struct hist_var var;
133 enum field_op_id operator;
134 char *system;
135 char *event_name;
136
137 /*
138 * The name field is used for EXPR and VAR_REF fields. VAR
139 * fields contain the variable name in var.name.
140 */
141 char *name;
142
143 /*
144 * When a histogram trigger is hit, if it has any references
145 * to variables, the values of those variables are collected
146 * into a var_ref_vals array by resolve_var_refs(). The
147 * current value of each variable is read from the tracing_map
148 * using the hist field's hist_var.idx and entered into the
149 * var_ref_idx entry i.e. var_ref_vals[var_ref_idx].
150 */
151 unsigned int var_ref_idx;
152 bool read_once;
153
154 unsigned int var_str_idx;
155 };
156
157 static u64 hist_field_none(struct hist_field *field,
158 struct tracing_map_elt *elt,
159 struct trace_buffer *buffer,
160 struct ring_buffer_event *rbe,
161 void *event)
162 {
163 return 0;
164 }
165
166 static u64 hist_field_counter(struct hist_field *field,
167 struct tracing_map_elt *elt,
168 struct trace_buffer *buffer,
169 struct ring_buffer_event *rbe,
170 void *event)
171 {
172 return 1;
173 }
174
175 static u64 hist_field_string(struct hist_field *hist_field,
176 struct tracing_map_elt *elt,
177 struct trace_buffer *buffer,
178 struct ring_buffer_event *rbe,
179 void *event)
180 {
181 char *addr = (char *)(event + hist_field->field->offset);
182
183 return (u64)(unsigned long)addr;
184 }
185
186 static u64 hist_field_dynstring(struct hist_field *hist_field,
187 struct tracing_map_elt *elt,
188 struct trace_buffer *buffer,
189 struct ring_buffer_event *rbe,
190 void *event)
191 {
192 u32 str_item = *(u32 *)(event + hist_field->field->offset);
193 int str_loc = str_item & 0xffff;
194 char *addr = (char *)(event + str_loc);
195
196 return (u64)(unsigned long)addr;
197 }
198
199 static u64 hist_field_pstring(struct hist_field *hist_field,
200 struct tracing_map_elt *elt,
201 struct trace_buffer *buffer,
202 struct ring_buffer_event *rbe,
203 void *event)
204 {
205 char **addr = (char **)(event + hist_field->field->offset);
206
207 return (u64)(unsigned long)*addr;
208 }
209
210 static u64 hist_field_log2(struct hist_field *hist_field,
211 struct tracing_map_elt *elt,
212 struct trace_buffer *buffer,
213 struct ring_buffer_event *rbe,
214 void *event)
215 {
216 struct hist_field *operand = hist_field->operands[0];
217
218 u64 val = operand->fn(operand, elt, buffer, rbe, event);
219
220 return (u64) ilog2(roundup_pow_of_two(val));
221 }
222
223 static u64 hist_field_bucket(struct hist_field *hist_field,
224 struct tracing_map_elt *elt,
225 struct trace_buffer *buffer,
226 struct ring_buffer_event *rbe,
227 void *event)
228 {
229 struct hist_field *operand = hist_field->operands[0];
230 unsigned long buckets = hist_field->buckets;
231
232 u64 val = operand->fn(operand, elt, buffer, rbe, event);
233
234 if (WARN_ON_ONCE(!buckets))
235 return val;
236
237 if (val >= LONG_MAX)
238 val = div64_ul(val, buckets);
239 else
240 val = (u64)((unsigned long)val / buckets);
241 return val * buckets;
242 }
243
244 static u64 hist_field_plus(struct hist_field *hist_field,
245 struct tracing_map_elt *elt,
246 struct trace_buffer *buffer,
247 struct ring_buffer_event *rbe,
248 void *event)
249 {
250 struct hist_field *operand1 = hist_field->operands[0];
251 struct hist_field *operand2 = hist_field->operands[1];
252
253 u64 val1 = operand1->fn(operand1, elt, buffer, rbe, event);
254 u64 val2 = operand2->fn(operand2, elt, buffer, rbe, event);
255
256 return val1 + val2;
257 }
258
259 static u64 hist_field_minus(struct hist_field *hist_field,
260 struct tracing_map_elt *elt,
261 struct trace_buffer *buffer,
262 struct ring_buffer_event *rbe,
263 void *event)
264 {
265 struct hist_field *operand1 = hist_field->operands[0];
266 struct hist_field *operand2 = hist_field->operands[1];
267
268 u64 val1 = operand1->fn(operand1, elt, buffer, rbe, event);
269 u64 val2 = operand2->fn(operand2, elt, buffer, rbe, event);
270
271 return val1 - val2;
272 }
273
274 static u64 hist_field_unary_minus(struct hist_field *hist_field,
275 struct tracing_map_elt *elt,
276 struct trace_buffer *buffer,
277 struct ring_buffer_event *rbe,
278 void *event)
279 {
280 struct hist_field *operand = hist_field->operands[0];
281
282 s64 sval = (s64)operand->fn(operand, elt, buffer, rbe, event);
283 u64 val = (u64)-sval;
284
285 return val;
286 }
287
288 #define DEFINE_HIST_FIELD_FN(type) \
289 static u64 hist_field_##type(struct hist_field *hist_field, \
290 struct tracing_map_elt *elt, \
291 struct trace_buffer *buffer, \
292 struct ring_buffer_event *rbe, \
293 void *event) \
294 { \
295 type *addr = (type *)(event + hist_field->field->offset); \
296 \
297 return (u64)(unsigned long)*addr; \
298 }
299
300 DEFINE_HIST_FIELD_FN(s64);
301 DEFINE_HIST_FIELD_FN(u64);
302 DEFINE_HIST_FIELD_FN(s32);
303 DEFINE_HIST_FIELD_FN(u32);
304 DEFINE_HIST_FIELD_FN(s16);
305 DEFINE_HIST_FIELD_FN(u16);
306 DEFINE_HIST_FIELD_FN(s8);
307 DEFINE_HIST_FIELD_FN(u8);
308
309 #define for_each_hist_field(i, hist_data) \
310 for ((i) = 0; (i) < (hist_data)->n_fields; (i)++)
311
312 #define for_each_hist_val_field(i, hist_data) \
313 for ((i) = 0; (i) < (hist_data)->n_vals; (i)++)
314
315 #define for_each_hist_key_field(i, hist_data) \
316 for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++)
317
318 #define HIST_STACKTRACE_DEPTH 16
319 #define HIST_STACKTRACE_SIZE (HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
320 #define HIST_STACKTRACE_SKIP 5
321
322 #define HITCOUNT_IDX 0
323 #define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE)
324
325 enum hist_field_flags {
326 HIST_FIELD_FL_HITCOUNT = 1 << 0,
327 HIST_FIELD_FL_KEY = 1 << 1,
328 HIST_FIELD_FL_STRING = 1 << 2,
329 HIST_FIELD_FL_HEX = 1 << 3,
330 HIST_FIELD_FL_SYM = 1 << 4,
331 HIST_FIELD_FL_SYM_OFFSET = 1 << 5,
332 HIST_FIELD_FL_EXECNAME = 1 << 6,
333 HIST_FIELD_FL_SYSCALL = 1 << 7,
334 HIST_FIELD_FL_STACKTRACE = 1 << 8,
335 HIST_FIELD_FL_LOG2 = 1 << 9,
336 HIST_FIELD_FL_TIMESTAMP = 1 << 10,
337 HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11,
338 HIST_FIELD_FL_VAR = 1 << 12,
339 HIST_FIELD_FL_EXPR = 1 << 13,
340 HIST_FIELD_FL_VAR_REF = 1 << 14,
341 HIST_FIELD_FL_CPU = 1 << 15,
342 HIST_FIELD_FL_ALIAS = 1 << 16,
343 HIST_FIELD_FL_BUCKET = 1 << 17,
344 };
345
346 struct var_defs {
347 unsigned int n_vars;
348 char *name[TRACING_MAP_VARS_MAX];
349 char *expr[TRACING_MAP_VARS_MAX];
350 };
351
352 struct hist_trigger_attrs {
353 char *keys_str;
354 char *vals_str;
355 char *sort_key_str;
356 char *name;
357 char *clock;
358 bool pause;
359 bool cont;
360 bool clear;
361 bool ts_in_usecs;
362 unsigned int map_bits;
363
364 char *assignment_str[TRACING_MAP_VARS_MAX];
365 unsigned int n_assignments;
366
367 char *action_str[HIST_ACTIONS_MAX];
368 unsigned int n_actions;
369
370 struct var_defs var_defs;
371 };
372
373 struct field_var {
374 struct hist_field *var;
375 struct hist_field *val;
376 };
377
378 struct field_var_hist {
379 struct hist_trigger_data *hist_data;
380 char *cmd;
381 };
382
383 struct hist_trigger_data {
384 struct hist_field *fields[HIST_FIELDS_MAX];
385 unsigned int n_vals;
386 unsigned int n_keys;
387 unsigned int n_fields;
388 unsigned int n_vars;
389 unsigned int n_var_str;
390 unsigned int key_size;
391 struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX];
392 unsigned int n_sort_keys;
393 struct trace_event_file *event_file;
394 struct hist_trigger_attrs *attrs;
395 struct tracing_map *map;
396 bool enable_timestamps;
397 bool remove;
398 struct hist_field *var_refs[TRACING_MAP_VARS_MAX];
399 unsigned int n_var_refs;
400
401 struct action_data *actions[HIST_ACTIONS_MAX];
402 unsigned int n_actions;
403
404 struct field_var *field_vars[SYNTH_FIELDS_MAX];
405 unsigned int n_field_vars;
406 unsigned int n_field_var_str;
407 struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX];
408 unsigned int n_field_var_hists;
409
410 struct field_var *save_vars[SYNTH_FIELDS_MAX];
411 unsigned int n_save_vars;
412 unsigned int n_save_var_str;
413 };
414
415 struct action_data;
416
417 typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
418 struct tracing_map_elt *elt,
419 struct trace_buffer *buffer, void *rec,
420 struct ring_buffer_event *rbe, void *key,
421 struct action_data *data, u64 *var_ref_vals);
422
423 typedef bool (*check_track_val_fn_t) (u64 track_val, u64 var_val);
424
425 enum handler_id {
426 HANDLER_ONMATCH = 1,
427 HANDLER_ONMAX,
428 HANDLER_ONCHANGE,
429 };
430
431 enum action_id {
432 ACTION_SAVE = 1,
433 ACTION_TRACE,
434 ACTION_SNAPSHOT,
435 };
436
437 struct action_data {
438 enum handler_id handler;
439 enum action_id action;
440 char *action_name;
441 action_fn_t fn;
442
443 unsigned int n_params;
444 char *params[SYNTH_FIELDS_MAX];
445
446 /*
447 * When a histogram trigger is hit, the values of any
448 * references to variables, including variables being passed
449 * as parameters to synthetic events, are collected into a
450 * var_ref_vals array. This var_ref_idx array is an array of
451 * indices into the var_ref_vals array, one for each synthetic
452 * event param, and is passed to the synthetic event
453 * invocation.
454 */
455 unsigned int var_ref_idx[TRACING_MAP_VARS_MAX];
456 struct synth_event *synth_event;
457 bool use_trace_keyword;
458 char *synth_event_name;
459
460 union {
461 struct {
462 char *event;
463 char *event_system;
464 } match_data;
465
466 struct {
467 /*
468 * var_str contains the $-unstripped variable
469 * name referenced by var_ref, and used when
470 * printing the action. Because var_ref
471 * creation is deferred to create_actions(),
472 * we need a per-action way to save it until
473 * then, thus var_str.
474 */
475 char *var_str;
476
477 /*
478 * var_ref refers to the variable being
479 * tracked e.g onmax($var).
480 */
481 struct hist_field *var_ref;
482
483 /*
484 * track_var contains the 'invisible' tracking
485 * variable created to keep the current
486 * e.g. max value.
487 */
488 struct hist_field *track_var;
489
490 check_track_val_fn_t check_val;
491 action_fn_t save_data;
492 } track_data;
493 };
494 };
495
496 struct track_data {
497 u64 track_val;
498 bool updated;
499
500 unsigned int key_len;
501 void *key;
502 struct tracing_map_elt elt;
503
504 struct action_data *action_data;
505 struct hist_trigger_data *hist_data;
506 };
507
508 struct hist_elt_data {
509 char *comm;
510 u64 *var_ref_vals;
511 char **field_var_str;
512 int n_field_var_str;
513 };
514
515 struct snapshot_context {
516 struct tracing_map_elt *elt;
517 void *key;
518 };
519
520 static void track_data_free(struct track_data *track_data)
521 {
522 struct hist_elt_data *elt_data;
523
524 if (!track_data)
525 return;
526
527 kfree(track_data->key);
528
529 elt_data = track_data->elt.private_data;
530 if (elt_data) {
531 kfree(elt_data->comm);
532 kfree(elt_data);
533 }
534
535 kfree(track_data);
536 }
537
538 static struct track_data *track_data_alloc(unsigned int key_len,
539 struct action_data *action_data,
540 struct hist_trigger_data *hist_data)
541 {
542 struct track_data *data = kzalloc(sizeof(*data), GFP_KERNEL);
543 struct hist_elt_data *elt_data;
544
545 if (!data)
546 return ERR_PTR(-ENOMEM);
547
548 data->key = kzalloc(key_len, GFP_KERNEL);
549 if (!data->key) {
550 track_data_free(data);
551 return ERR_PTR(-ENOMEM);
552 }
553
554 data->key_len = key_len;
555 data->action_data = action_data;
556 data->hist_data = hist_data;
557
558 elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
559 if (!elt_data) {
560 track_data_free(data);
561 return ERR_PTR(-ENOMEM);
562 }
563
564 data->elt.private_data = elt_data;
565
566 elt_data->comm = kzalloc(TASK_COMM_LEN, GFP_KERNEL);
567 if (!elt_data->comm) {
568 track_data_free(data);
569 return ERR_PTR(-ENOMEM);
570 }
571
572 return data;
573 }
574
575 static char last_cmd[MAX_FILTER_STR_VAL];
576 static char last_cmd_loc[MAX_FILTER_STR_VAL];
577
578 static int errpos(char *str)
579 {
580 return err_pos(last_cmd, str);
581 }
582
583 static void last_cmd_set(struct trace_event_file *file, char *str)
584 {
585 const char *system = NULL, *name = NULL;
586 struct trace_event_call *call;
587
588 if (!str)
589 return;
590
591 strcpy(last_cmd, "hist:");
592 strncat(last_cmd, str, MAX_FILTER_STR_VAL - 1 - sizeof("hist:"));
593
594 if (file) {
595 call = file->event_call;
596 system = call->class->system;
597 if (system) {
598 name = trace_event_name(call);
599 if (!name)
600 system = NULL;
601 }
602 }
603
604 if (system)
605 snprintf(last_cmd_loc, MAX_FILTER_STR_VAL, "hist:%s:%s", system, name);
606 }
607
608 static void hist_err(struct trace_array *tr, u8 err_type, u8 err_pos)
609 {
610 tracing_log_err(tr, last_cmd_loc, last_cmd, err_text,
611 err_type, err_pos);
612 }
613
614 static void hist_err_clear(void)
615 {
616 last_cmd[0] = '\0';
617 last_cmd_loc[0] = '\0';
618 }
619
620 typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
621 unsigned int *var_ref_idx);
622
623 static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
624 unsigned int *var_ref_idx)
625 {
626 struct tracepoint *tp = event->tp;
627
628 if (unlikely(atomic_read(&tp->key.enabled) > 0)) {
629 struct tracepoint_func *probe_func_ptr;
630 synth_probe_func_t probe_func;
631 void *__data;
632
633 if (!(cpu_online(raw_smp_processor_id())))
634 return;
635
636 probe_func_ptr = rcu_dereference_sched((tp)->funcs);
637 if (probe_func_ptr) {
638 do {
639 probe_func = probe_func_ptr->func;
640 __data = probe_func_ptr->data;
641 probe_func(__data, var_ref_vals, var_ref_idx);
642 } while ((++probe_func_ptr)->func);
643 }
644 }
645 }
646
647 static void action_trace(struct hist_trigger_data *hist_data,
648 struct tracing_map_elt *elt,
649 struct trace_buffer *buffer, void *rec,
650 struct ring_buffer_event *rbe, void *key,
651 struct action_data *data, u64 *var_ref_vals)
652 {
653 struct synth_event *event = data->synth_event;
654
655 trace_synth(event, var_ref_vals, data->var_ref_idx);
656 }
657
658 struct hist_var_data {
659 struct list_head list;
660 struct hist_trigger_data *hist_data;
661 };
662
663 static u64 hist_field_timestamp(struct hist_field *hist_field,
664 struct tracing_map_elt *elt,
665 struct trace_buffer *buffer,
666 struct ring_buffer_event *rbe,
667 void *event)
668 {
669 struct hist_trigger_data *hist_data = hist_field->hist_data;
670 struct trace_array *tr = hist_data->event_file->tr;
671
672 u64 ts = ring_buffer_event_time_stamp(buffer, rbe);
673
674 if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr))
675 ts = ns2usecs(ts);
676
677 return ts;
678 }
679
680 static u64 hist_field_cpu(struct hist_field *hist_field,
681 struct tracing_map_elt *elt,
682 struct trace_buffer *buffer,
683 struct ring_buffer_event *rbe,
684 void *event)
685 {
686 int cpu = smp_processor_id();
687
688 return cpu;
689 }
690
691 /**
692 * check_field_for_var_ref - Check if a VAR_REF field references a variable
693 * @hist_field: The VAR_REF field to check
694 * @var_data: The hist trigger that owns the variable
695 * @var_idx: The trigger variable identifier
696 *
697 * Check the given VAR_REF field to see whether or not it references
698 * the given variable associated with the given trigger.
699 *
700 * Return: The VAR_REF field if it does reference the variable, NULL if not
701 */
702 static struct hist_field *
703 check_field_for_var_ref(struct hist_field *hist_field,
704 struct hist_trigger_data *var_data,
705 unsigned int var_idx)
706 {
707 WARN_ON(!(hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF));
708
709 if (hist_field && hist_field->var.idx == var_idx &&
710 hist_field->var.hist_data == var_data)
711 return hist_field;
712
713 return NULL;
714 }
715
716 /**
717 * find_var_ref - Check if a trigger has a reference to a trigger variable
718 * @hist_data: The hist trigger that might have a reference to the variable
719 * @var_data: The hist trigger that owns the variable
720 * @var_idx: The trigger variable identifier
721 *
722 * Check the list of var_refs[] on the first hist trigger to see
723 * whether any of them are references to the variable on the second
724 * trigger.
725 *
726 * Return: The VAR_REF field referencing the variable if so, NULL if not
727 */
728 static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data,
729 struct hist_trigger_data *var_data,
730 unsigned int var_idx)
731 {
732 struct hist_field *hist_field;
733 unsigned int i;
734
735 for (i = 0; i < hist_data->n_var_refs; i++) {
736 hist_field = hist_data->var_refs[i];
737 if (check_field_for_var_ref(hist_field, var_data, var_idx))
738 return hist_field;
739 }
740
741 return NULL;
742 }
743
744 /**
745 * find_any_var_ref - Check if there is a reference to a given trigger variable
746 * @hist_data: The hist trigger
747 * @var_idx: The trigger variable identifier
748 *
749 * Check to see whether the given variable is currently referenced by
750 * any other trigger.
751 *
752 * The trigger the variable is defined on is explicitly excluded - the
753 * assumption being that a self-reference doesn't prevent a trigger
754 * from being removed.
755 *
756 * Return: The VAR_REF field referencing the variable if so, NULL if not
757 */
758 static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data,
759 unsigned int var_idx)
760 {
761 struct trace_array *tr = hist_data->event_file->tr;
762 struct hist_field *found = NULL;
763 struct hist_var_data *var_data;
764
765 list_for_each_entry(var_data, &tr->hist_vars, list) {
766 if (var_data->hist_data == hist_data)
767 continue;
768 found = find_var_ref(var_data->hist_data, hist_data, var_idx);
769 if (found)
770 break;
771 }
772
773 return found;
774 }
775
776 /**
777 * check_var_refs - Check if there is a reference to any of trigger's variables
778 * @hist_data: The hist trigger
779 *
780 * A trigger can define one or more variables. If any one of them is
781 * currently referenced by any other trigger, this function will
782 * determine that.
783
784 * Typically used to determine whether or not a trigger can be removed
785 * - if there are any references to a trigger's variables, it cannot.
786 *
787 * Return: True if there is a reference to any of trigger's variables
788 */
789 static bool check_var_refs(struct hist_trigger_data *hist_data)
790 {
791 struct hist_field *field;
792 bool found = false;
793 int i;
794
795 for_each_hist_field(i, hist_data) {
796 field = hist_data->fields[i];
797 if (field && field->flags & HIST_FIELD_FL_VAR) {
798 if (find_any_var_ref(hist_data, field->var.idx)) {
799 found = true;
800 break;
801 }
802 }
803 }
804
805 return found;
806 }
807
808 static struct hist_var_data *find_hist_vars(struct hist_trigger_data *hist_data)
809 {
810 struct trace_array *tr = hist_data->event_file->tr;
811 struct hist_var_data *var_data, *found = NULL;
812
813 list_for_each_entry(var_data, &tr->hist_vars, list) {
814 if (var_data->hist_data == hist_data) {
815 found = var_data;
816 break;
817 }
818 }
819
820 return found;
821 }
822
823 static bool field_has_hist_vars(struct hist_field *hist_field,
824 unsigned int level)
825 {
826 int i;
827
828 if (level > 3)
829 return false;
830
831 if (!hist_field)
832 return false;
833
834 if (hist_field->flags & HIST_FIELD_FL_VAR ||
835 hist_field->flags & HIST_FIELD_FL_VAR_REF)
836 return true;
837
838 for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) {
839 struct hist_field *operand;
840
841 operand = hist_field->operands[i];
842 if (field_has_hist_vars(operand, level + 1))
843 return true;
844 }
845
846 return false;
847 }
848
849 static bool has_hist_vars(struct hist_trigger_data *hist_data)
850 {
851 struct hist_field *hist_field;
852 int i;
853
854 for_each_hist_field(i, hist_data) {
855 hist_field = hist_data->fields[i];
856 if (field_has_hist_vars(hist_field, 0))
857 return true;
858 }
859
860 return false;
861 }
862
863 static int save_hist_vars(struct hist_trigger_data *hist_data)
864 {
865 struct trace_array *tr = hist_data->event_file->tr;
866 struct hist_var_data *var_data;
867
868 var_data = find_hist_vars(hist_data);
869 if (var_data)
870 return 0;
871
872 if (tracing_check_open_get_tr(tr))
873 return -ENODEV;
874
875 var_data = kzalloc(sizeof(*var_data), GFP_KERNEL);
876 if (!var_data) {
877 trace_array_put(tr);
878 return -ENOMEM;
879 }
880
881 var_data->hist_data = hist_data;
882 list_add(&var_data->list, &tr->hist_vars);
883
884 return 0;
885 }
886
887 static void remove_hist_vars(struct hist_trigger_data *hist_data)
888 {
889 struct trace_array *tr = hist_data->event_file->tr;
890 struct hist_var_data *var_data;
891
892 var_data = find_hist_vars(hist_data);
893 if (!var_data)
894 return;
895
896 if (WARN_ON(check_var_refs(hist_data)))
897 return;
898
899 list_del(&var_data->list);
900
901 kfree(var_data);
902
903 trace_array_put(tr);
904 }
905
906 static struct hist_field *find_var_field(struct hist_trigger_data *hist_data,
907 const char *var_name)
908 {
909 struct hist_field *hist_field, *found = NULL;
910 int i;
911
912 for_each_hist_field(i, hist_data) {
913 hist_field = hist_data->fields[i];
914 if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR &&
915 strcmp(hist_field->var.name, var_name) == 0) {
916 found = hist_field;
917 break;
918 }
919 }
920
921 return found;
922 }
923
924 static struct hist_field *find_var(struct hist_trigger_data *hist_data,
925 struct trace_event_file *file,
926 const char *var_name)
927 {
928 struct hist_trigger_data *test_data;
929 struct event_trigger_data *test;
930 struct hist_field *hist_field;
931
932 lockdep_assert_held(&event_mutex);
933
934 hist_field = find_var_field(hist_data, var_name);
935 if (hist_field)
936 return hist_field;
937
938 list_for_each_entry(test, &file->triggers, list) {
939 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
940 test_data = test->private_data;
941 hist_field = find_var_field(test_data, var_name);
942 if (hist_field)
943 return hist_field;
944 }
945 }
946
947 return NULL;
948 }
949
950 static struct trace_event_file *find_var_file(struct trace_array *tr,
951 char *system,
952 char *event_name,
953 char *var_name)
954 {
955 struct hist_trigger_data *var_hist_data;
956 struct hist_var_data *var_data;
957 struct trace_event_file *file, *found = NULL;
958
959 if (system)
960 return find_event_file(tr, system, event_name);
961
962 list_for_each_entry(var_data, &tr->hist_vars, list) {
963 var_hist_data = var_data->hist_data;
964 file = var_hist_data->event_file;
965 if (file == found)
966 continue;
967
968 if (find_var_field(var_hist_data, var_name)) {
969 if (found) {
970 hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE, errpos(var_name));
971 return NULL;
972 }
973
974 found = file;
975 }
976 }
977
978 return found;
979 }
980
981 static struct hist_field *find_file_var(struct trace_event_file *file,
982 const char *var_name)
983 {
984 struct hist_trigger_data *test_data;
985 struct event_trigger_data *test;
986 struct hist_field *hist_field;
987
988 lockdep_assert_held(&event_mutex);
989
990 list_for_each_entry(test, &file->triggers, list) {
991 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
992 test_data = test->private_data;
993 hist_field = find_var_field(test_data, var_name);
994 if (hist_field)
995 return hist_field;
996 }
997 }
998
999 return NULL;
1000 }
1001
1002 static struct hist_field *
1003 find_match_var(struct hist_trigger_data *hist_data, char *var_name)
1004 {
1005 struct trace_array *tr = hist_data->event_file->tr;
1006 struct hist_field *hist_field, *found = NULL;
1007 struct trace_event_file *file;
1008 unsigned int i;
1009
1010 for (i = 0; i < hist_data->n_actions; i++) {
1011 struct action_data *data = hist_data->actions[i];
1012
1013 if (data->handler == HANDLER_ONMATCH) {
1014 char *system = data->match_data.event_system;
1015 char *event_name = data->match_data.event;
1016
1017 file = find_var_file(tr, system, event_name, var_name);
1018 if (!file)
1019 continue;
1020 hist_field = find_file_var(file, var_name);
1021 if (hist_field) {
1022 if (found) {
1023 hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE,
1024 errpos(var_name));
1025 return ERR_PTR(-EINVAL);
1026 }
1027
1028 found = hist_field;
1029 }
1030 }
1031 }
1032 return found;
1033 }
1034
1035 static struct hist_field *find_event_var(struct hist_trigger_data *hist_data,
1036 char *system,
1037 char *event_name,
1038 char *var_name)
1039 {
1040 struct trace_array *tr = hist_data->event_file->tr;
1041 struct hist_field *hist_field = NULL;
1042 struct trace_event_file *file;
1043
1044 if (!system || !event_name) {
1045 hist_field = find_match_var(hist_data, var_name);
1046 if (IS_ERR(hist_field))
1047 return NULL;
1048 if (hist_field)
1049 return hist_field;
1050 }
1051
1052 file = find_var_file(tr, system, event_name, var_name);
1053 if (!file)
1054 return NULL;
1055
1056 hist_field = find_file_var(file, var_name);
1057
1058 return hist_field;
1059 }
1060
1061 static u64 hist_field_var_ref(struct hist_field *hist_field,
1062 struct tracing_map_elt *elt,
1063 struct trace_buffer *buffer,
1064 struct ring_buffer_event *rbe,
1065 void *event)
1066 {
1067 struct hist_elt_data *elt_data;
1068 u64 var_val = 0;
1069
1070 if (WARN_ON_ONCE(!elt))
1071 return var_val;
1072
1073 elt_data = elt->private_data;
1074 var_val = elt_data->var_ref_vals[hist_field->var_ref_idx];
1075
1076 return var_val;
1077 }
1078
1079 static bool resolve_var_refs(struct hist_trigger_data *hist_data, void *key,
1080 u64 *var_ref_vals, bool self)
1081 {
1082 struct hist_trigger_data *var_data;
1083 struct tracing_map_elt *var_elt;
1084 struct hist_field *hist_field;
1085 unsigned int i, var_idx;
1086 bool resolved = true;
1087 u64 var_val = 0;
1088
1089 for (i = 0; i < hist_data->n_var_refs; i++) {
1090 hist_field = hist_data->var_refs[i];
1091 var_idx = hist_field->var.idx;
1092 var_data = hist_field->var.hist_data;
1093
1094 if (var_data == NULL) {
1095 resolved = false;
1096 break;
1097 }
1098
1099 if ((self && var_data != hist_data) ||
1100 (!self && var_data == hist_data))
1101 continue;
1102
1103 var_elt = tracing_map_lookup(var_data->map, key);
1104 if (!var_elt) {
1105 resolved = false;
1106 break;
1107 }
1108
1109 if (!tracing_map_var_set(var_elt, var_idx)) {
1110 resolved = false;
1111 break;
1112 }
1113
1114 if (self || !hist_field->read_once)
1115 var_val = tracing_map_read_var(var_elt, var_idx);
1116 else
1117 var_val = tracing_map_read_var_once(var_elt, var_idx);
1118
1119 var_ref_vals[i] = var_val;
1120 }
1121
1122 return resolved;
1123 }
1124
1125 static const char *hist_field_name(struct hist_field *field,
1126 unsigned int level)
1127 {
1128 const char *field_name = "";
1129
1130 if (level > 1)
1131 return field_name;
1132
1133 if (field->field)
1134 field_name = field->field->name;
1135 else if (field->flags & HIST_FIELD_FL_LOG2 ||
1136 field->flags & HIST_FIELD_FL_ALIAS ||
1137 field->flags & HIST_FIELD_FL_BUCKET)
1138 field_name = hist_field_name(field->operands[0], ++level);
1139 else if (field->flags & HIST_FIELD_FL_CPU)
1140 field_name = "common_cpu";
1141 else if (field->flags & HIST_FIELD_FL_EXPR ||
1142 field->flags & HIST_FIELD_FL_VAR_REF) {
1143 if (field->system) {
1144 static char full_name[MAX_FILTER_STR_VAL];
1145
1146 strcat(full_name, field->system);
1147 strcat(full_name, ".");
1148 strcat(full_name, field->event_name);
1149 strcat(full_name, ".");
1150 strcat(full_name, field->name);
1151 field_name = full_name;
1152 } else
1153 field_name = field->name;
1154 } else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
1155 field_name = "common_timestamp";
1156
1157 if (field_name == NULL)
1158 field_name = "";
1159
1160 return field_name;
1161 }
1162
1163 static hist_field_fn_t select_value_fn(int field_size, int field_is_signed)
1164 {
1165 hist_field_fn_t fn = NULL;
1166
1167 switch (field_size) {
1168 case 8:
1169 if (field_is_signed)
1170 fn = hist_field_s64;
1171 else
1172 fn = hist_field_u64;
1173 break;
1174 case 4:
1175 if (field_is_signed)
1176 fn = hist_field_s32;
1177 else
1178 fn = hist_field_u32;
1179 break;
1180 case 2:
1181 if (field_is_signed)
1182 fn = hist_field_s16;
1183 else
1184 fn = hist_field_u16;
1185 break;
1186 case 1:
1187 if (field_is_signed)
1188 fn = hist_field_s8;
1189 else
1190 fn = hist_field_u8;
1191 break;
1192 }
1193
1194 return fn;
1195 }
1196
1197 static int parse_map_size(char *str)
1198 {
1199 unsigned long size, map_bits;
1200 int ret;
1201
1202 ret = kstrtoul(str, 0, &size);
1203 if (ret)
1204 goto out;
1205
1206 map_bits = ilog2(roundup_pow_of_two(size));
1207 if (map_bits < TRACING_MAP_BITS_MIN ||
1208 map_bits > TRACING_MAP_BITS_MAX)
1209 ret = -EINVAL;
1210 else
1211 ret = map_bits;
1212 out:
1213 return ret;
1214 }
1215
1216 static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
1217 {
1218 unsigned int i;
1219
1220 if (!attrs)
1221 return;
1222
1223 for (i = 0; i < attrs->n_assignments; i++)
1224 kfree(attrs->assignment_str[i]);
1225
1226 for (i = 0; i < attrs->n_actions; i++)
1227 kfree(attrs->action_str[i]);
1228
1229 kfree(attrs->name);
1230 kfree(attrs->sort_key_str);
1231 kfree(attrs->keys_str);
1232 kfree(attrs->vals_str);
1233 kfree(attrs->clock);
1234 kfree(attrs);
1235 }
1236
1237 static int parse_action(char *str, struct hist_trigger_attrs *attrs)
1238 {
1239 int ret = -EINVAL;
1240
1241 if (attrs->n_actions >= HIST_ACTIONS_MAX)
1242 return ret;
1243
1244 if ((str_has_prefix(str, "onmatch(")) ||
1245 (str_has_prefix(str, "onmax(")) ||
1246 (str_has_prefix(str, "onchange("))) {
1247 attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL);
1248 if (!attrs->action_str[attrs->n_actions]) {
1249 ret = -ENOMEM;
1250 return ret;
1251 }
1252 attrs->n_actions++;
1253 ret = 0;
1254 }
1255 return ret;
1256 }
1257
1258 static int parse_assignment(struct trace_array *tr,
1259 char *str, struct hist_trigger_attrs *attrs)
1260 {
1261 int len, ret = 0;
1262
1263 if ((len = str_has_prefix(str, "key=")) ||
1264 (len = str_has_prefix(str, "keys="))) {
1265 attrs->keys_str = kstrdup(str + len, GFP_KERNEL);
1266 if (!attrs->keys_str) {
1267 ret = -ENOMEM;
1268 goto out;
1269 }
1270 } else if ((len = str_has_prefix(str, "val=")) ||
1271 (len = str_has_prefix(str, "vals=")) ||
1272 (len = str_has_prefix(str, "values="))) {
1273 attrs->vals_str = kstrdup(str + len, GFP_KERNEL);
1274 if (!attrs->vals_str) {
1275 ret = -ENOMEM;
1276 goto out;
1277 }
1278 } else if ((len = str_has_prefix(str, "sort="))) {
1279 attrs->sort_key_str = kstrdup(str + len, GFP_KERNEL);
1280 if (!attrs->sort_key_str) {
1281 ret = -ENOMEM;
1282 goto out;
1283 }
1284 } else if (str_has_prefix(str, "name=")) {
1285 attrs->name = kstrdup(str, GFP_KERNEL);
1286 if (!attrs->name) {
1287 ret = -ENOMEM;
1288 goto out;
1289 }
1290 } else if ((len = str_has_prefix(str, "clock="))) {
1291 str += len;
1292
1293 str = strstrip(str);
1294 attrs->clock = kstrdup(str, GFP_KERNEL);
1295 if (!attrs->clock) {
1296 ret = -ENOMEM;
1297 goto out;
1298 }
1299 } else if ((len = str_has_prefix(str, "size="))) {
1300 int map_bits = parse_map_size(str + len);
1301
1302 if (map_bits < 0) {
1303 ret = map_bits;
1304 goto out;
1305 }
1306 attrs->map_bits = map_bits;
1307 } else {
1308 char *assignment;
1309
1310 if (attrs->n_assignments == TRACING_MAP_VARS_MAX) {
1311 hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(str));
1312 ret = -EINVAL;
1313 goto out;
1314 }
1315
1316 assignment = kstrdup(str, GFP_KERNEL);
1317 if (!assignment) {
1318 ret = -ENOMEM;
1319 goto out;
1320 }
1321
1322 attrs->assignment_str[attrs->n_assignments++] = assignment;
1323 }
1324 out:
1325 return ret;
1326 }
1327
1328 static struct hist_trigger_attrs *
1329 parse_hist_trigger_attrs(struct trace_array *tr, char *trigger_str)
1330 {
1331 struct hist_trigger_attrs *attrs;
1332 int ret = 0;
1333
1334 attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
1335 if (!attrs)
1336 return ERR_PTR(-ENOMEM);
1337
1338 while (trigger_str) {
1339 char *str = strsep(&trigger_str, ":");
1340 char *rhs;
1341
1342 rhs = strchr(str, '=');
1343 if (rhs) {
1344 if (!strlen(++rhs)) {
1345 ret = -EINVAL;
1346 hist_err(tr, HIST_ERR_EMPTY_ASSIGNMENT, errpos(str));
1347 goto free;
1348 }
1349 ret = parse_assignment(tr, str, attrs);
1350 if (ret)
1351 goto free;
1352 } else if (strcmp(str, "pause") == 0)
1353 attrs->pause = true;
1354 else if ((strcmp(str, "cont") == 0) ||
1355 (strcmp(str, "continue") == 0))
1356 attrs->cont = true;
1357 else if (strcmp(str, "clear") == 0)
1358 attrs->clear = true;
1359 else {
1360 ret = parse_action(str, attrs);
1361 if (ret)
1362 goto free;
1363 }
1364 }
1365
1366 if (!attrs->keys_str) {
1367 ret = -EINVAL;
1368 goto free;
1369 }
1370
1371 if (!attrs->clock) {
1372 attrs->clock = kstrdup("global", GFP_KERNEL);
1373 if (!attrs->clock) {
1374 ret = -ENOMEM;
1375 goto free;
1376 }
1377 }
1378
1379 return attrs;
1380 free:
1381 destroy_hist_trigger_attrs(attrs);
1382
1383 return ERR_PTR(ret);
1384 }
1385
1386 static inline void save_comm(char *comm, struct task_struct *task)
1387 {
1388 if (!task->pid) {
1389 strcpy(comm, "<idle>");
1390 return;
1391 }
1392
1393 if (WARN_ON_ONCE(task->pid < 0)) {
1394 strcpy(comm, "<XXX>");
1395 return;
1396 }
1397
1398 strncpy(comm, task->comm, TASK_COMM_LEN);
1399 }
1400
1401 static void hist_elt_data_free(struct hist_elt_data *elt_data)
1402 {
1403 unsigned int i;
1404
1405 for (i = 0; i < elt_data->n_field_var_str; i++)
1406 kfree(elt_data->field_var_str[i]);
1407
1408 kfree(elt_data->field_var_str);
1409
1410 kfree(elt_data->comm);
1411 kfree(elt_data);
1412 }
1413
1414 static void hist_trigger_elt_data_free(struct tracing_map_elt *elt)
1415 {
1416 struct hist_elt_data *elt_data = elt->private_data;
1417
1418 hist_elt_data_free(elt_data);
1419 }
1420
1421 static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
1422 {
1423 struct hist_trigger_data *hist_data = elt->map->private_data;
1424 unsigned int size = TASK_COMM_LEN;
1425 struct hist_elt_data *elt_data;
1426 struct hist_field *hist_field;
1427 unsigned int i, n_str;
1428
1429 elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
1430 if (!elt_data)
1431 return -ENOMEM;
1432
1433 for_each_hist_field(i, hist_data) {
1434 hist_field = hist_data->fields[i];
1435
1436 if (hist_field->flags & HIST_FIELD_FL_EXECNAME) {
1437 elt_data->comm = kzalloc(size, GFP_KERNEL);
1438 if (!elt_data->comm) {
1439 kfree(elt_data);
1440 return -ENOMEM;
1441 }
1442 break;
1443 }
1444 }
1445
1446 n_str = hist_data->n_field_var_str + hist_data->n_save_var_str +
1447 hist_data->n_var_str;
1448 if (n_str > SYNTH_FIELDS_MAX) {
1449 hist_elt_data_free(elt_data);
1450 return -EINVAL;
1451 }
1452
1453 BUILD_BUG_ON(STR_VAR_LEN_MAX & (sizeof(u64) - 1));
1454
1455 size = STR_VAR_LEN_MAX;
1456
1457 elt_data->field_var_str = kcalloc(n_str, sizeof(char *), GFP_KERNEL);
1458 if (!elt_data->field_var_str) {
1459 hist_elt_data_free(elt_data);
1460 return -EINVAL;
1461 }
1462 elt_data->n_field_var_str = n_str;
1463
1464 for (i = 0; i < n_str; i++) {
1465 elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL);
1466 if (!elt_data->field_var_str[i]) {
1467 hist_elt_data_free(elt_data);
1468 return -ENOMEM;
1469 }
1470 }
1471
1472 elt->private_data = elt_data;
1473
1474 return 0;
1475 }
1476
1477 static void hist_trigger_elt_data_init(struct tracing_map_elt *elt)
1478 {
1479 struct hist_elt_data *elt_data = elt->private_data;
1480
1481 if (elt_data->comm)
1482 save_comm(elt_data->comm, current);
1483 }
1484
1485 static const struct tracing_map_ops hist_trigger_elt_data_ops = {
1486 .elt_alloc = hist_trigger_elt_data_alloc,
1487 .elt_free = hist_trigger_elt_data_free,
1488 .elt_init = hist_trigger_elt_data_init,
1489 };
1490
1491 static const char *get_hist_field_flags(struct hist_field *hist_field)
1492 {
1493 const char *flags_str = NULL;
1494
1495 if (hist_field->flags & HIST_FIELD_FL_HEX)
1496 flags_str = "hex";
1497 else if (hist_field->flags & HIST_FIELD_FL_SYM)
1498 flags_str = "sym";
1499 else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
1500 flags_str = "sym-offset";
1501 else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
1502 flags_str = "execname";
1503 else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
1504 flags_str = "syscall";
1505 else if (hist_field->flags & HIST_FIELD_FL_LOG2)
1506 flags_str = "log2";
1507 else if (hist_field->flags & HIST_FIELD_FL_BUCKET)
1508 flags_str = "buckets";
1509 else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS)
1510 flags_str = "usecs";
1511
1512 return flags_str;
1513 }
1514
1515 static void expr_field_str(struct hist_field *field, char *expr)
1516 {
1517 if (field->flags & HIST_FIELD_FL_VAR_REF)
1518 strcat(expr, "$");
1519
1520 strcat(expr, hist_field_name(field, 0));
1521
1522 if (field->flags && !(field->flags & HIST_FIELD_FL_VAR_REF)) {
1523 const char *flags_str = get_hist_field_flags(field);
1524
1525 if (flags_str) {
1526 strcat(expr, ".");
1527 strcat(expr, flags_str);
1528 }
1529 }
1530 }
1531
1532 static char *expr_str(struct hist_field *field, unsigned int level)
1533 {
1534 char *expr;
1535
1536 if (level > 1)
1537 return NULL;
1538
1539 expr = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
1540 if (!expr)
1541 return NULL;
1542
1543 if (!field->operands[0]) {
1544 expr_field_str(field, expr);
1545 return expr;
1546 }
1547
1548 if (field->operator == FIELD_OP_UNARY_MINUS) {
1549 char *subexpr;
1550
1551 strcat(expr, "-(");
1552 subexpr = expr_str(field->operands[0], ++level);
1553 if (!subexpr) {
1554 kfree(expr);
1555 return NULL;
1556 }
1557 strcat(expr, subexpr);
1558 strcat(expr, ")");
1559
1560 kfree(subexpr);
1561
1562 return expr;
1563 }
1564
1565 expr_field_str(field->operands[0], expr);
1566
1567 switch (field->operator) {
1568 case FIELD_OP_MINUS:
1569 strcat(expr, "-");
1570 break;
1571 case FIELD_OP_PLUS:
1572 strcat(expr, "+");
1573 break;
1574 default:
1575 kfree(expr);
1576 return NULL;
1577 }
1578
1579 expr_field_str(field->operands[1], expr);
1580
1581 return expr;
1582 }
1583
1584 static int contains_operator(char *str)
1585 {
1586 enum field_op_id field_op = FIELD_OP_NONE;
1587 char *op;
1588
1589 op = strpbrk(str, "+-");
1590 if (!op)
1591 return FIELD_OP_NONE;
1592
1593 switch (*op) {
1594 case '-':
1595 /*
1596 * Unfortunately, the modifier ".sym-offset"
1597 * can confuse things.
1598 */
1599 if (op - str >= 4 && !strncmp(op - 4, ".sym-offset", 11))
1600 return FIELD_OP_NONE;
1601
1602 if (*str == '-')
1603 field_op = FIELD_OP_UNARY_MINUS;
1604 else
1605 field_op = FIELD_OP_MINUS;
1606 break;
1607 case '+':
1608 field_op = FIELD_OP_PLUS;
1609 break;
1610 default:
1611 break;
1612 }
1613
1614 return field_op;
1615 }
1616
1617 static void get_hist_field(struct hist_field *hist_field)
1618 {
1619 hist_field->ref++;
1620 }
1621
1622 static void __destroy_hist_field(struct hist_field *hist_field)
1623 {
1624 if (--hist_field->ref > 1)
1625 return;
1626
1627 kfree(hist_field->var.name);
1628 kfree(hist_field->name);
1629
1630 /* Can likely be a const */
1631 kfree_const(hist_field->type);
1632
1633 kfree(hist_field->system);
1634 kfree(hist_field->event_name);
1635
1636 kfree(hist_field);
1637 }
1638
1639 static void destroy_hist_field(struct hist_field *hist_field,
1640 unsigned int level)
1641 {
1642 unsigned int i;
1643
1644 if (level > 3)
1645 return;
1646
1647 if (!hist_field)
1648 return;
1649
1650 if (hist_field->flags & HIST_FIELD_FL_VAR_REF)
1651 return; /* var refs will be destroyed separately */
1652
1653 for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
1654 destroy_hist_field(hist_field->operands[i], level + 1);
1655
1656 __destroy_hist_field(hist_field);
1657 }
1658
1659 static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
1660 struct ftrace_event_field *field,
1661 unsigned long flags,
1662 char *var_name)
1663 {
1664 struct hist_field *hist_field;
1665
1666 if (field && is_function_field(field))
1667 return NULL;
1668
1669 hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
1670 if (!hist_field)
1671 return NULL;
1672
1673 hist_field->ref = 1;
1674
1675 hist_field->hist_data = hist_data;
1676
1677 if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS)
1678 goto out; /* caller will populate */
1679
1680 if (flags & HIST_FIELD_FL_VAR_REF) {
1681 hist_field->fn = hist_field_var_ref;
1682 goto out;
1683 }
1684
1685 if (flags & HIST_FIELD_FL_HITCOUNT) {
1686 hist_field->fn = hist_field_counter;
1687 hist_field->size = sizeof(u64);
1688 hist_field->type = "u64";
1689 goto out;
1690 }
1691
1692 if (flags & HIST_FIELD_FL_STACKTRACE) {
1693 hist_field->fn = hist_field_none;
1694 goto out;
1695 }
1696
1697 if (flags & (HIST_FIELD_FL_LOG2 | HIST_FIELD_FL_BUCKET)) {
1698 unsigned long fl = flags & ~(HIST_FIELD_FL_LOG2 | HIST_FIELD_FL_BUCKET);
1699 hist_field->fn = flags & HIST_FIELD_FL_LOG2 ? hist_field_log2 :
1700 hist_field_bucket;
1701 hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
1702 hist_field->size = hist_field->operands[0]->size;
1703 hist_field->type = kstrdup_const(hist_field->operands[0]->type, GFP_KERNEL);
1704 if (!hist_field->type)
1705 goto free;
1706 goto out;
1707 }
1708
1709 if (flags & HIST_FIELD_FL_TIMESTAMP) {
1710 hist_field->fn = hist_field_timestamp;
1711 hist_field->size = sizeof(u64);
1712 hist_field->type = "u64";
1713 goto out;
1714 }
1715
1716 if (flags & HIST_FIELD_FL_CPU) {
1717 hist_field->fn = hist_field_cpu;
1718 hist_field->size = sizeof(int);
1719 hist_field->type = "unsigned int";
1720 goto out;
1721 }
1722
1723 if (WARN_ON_ONCE(!field))
1724 goto out;
1725
1726 /* Pointers to strings are just pointers and dangerous to dereference */
1727 if (is_string_field(field) &&
1728 (field->filter_type != FILTER_PTR_STRING)) {
1729 flags |= HIST_FIELD_FL_STRING;
1730
1731 hist_field->size = MAX_FILTER_STR_VAL;
1732 hist_field->type = kstrdup_const(field->type, GFP_KERNEL);
1733 if (!hist_field->type)
1734 goto free;
1735
1736 if (field->filter_type == FILTER_STATIC_STRING) {
1737 hist_field->fn = hist_field_string;
1738 hist_field->size = field->size;
1739 } else if (field->filter_type == FILTER_DYN_STRING)
1740 hist_field->fn = hist_field_dynstring;
1741 else
1742 hist_field->fn = hist_field_pstring;
1743 } else {
1744 hist_field->size = field->size;
1745 hist_field->is_signed = field->is_signed;
1746 hist_field->type = kstrdup_const(field->type, GFP_KERNEL);
1747 if (!hist_field->type)
1748 goto free;
1749
1750 hist_field->fn = select_value_fn(field->size,
1751 field->is_signed);
1752 if (!hist_field->fn) {
1753 destroy_hist_field(hist_field, 0);
1754 return NULL;
1755 }
1756 }
1757 out:
1758 hist_field->field = field;
1759 hist_field->flags = flags;
1760
1761 if (var_name) {
1762 hist_field->var.name = kstrdup(var_name, GFP_KERNEL);
1763 if (!hist_field->var.name)
1764 goto free;
1765 }
1766
1767 return hist_field;
1768 free:
1769 destroy_hist_field(hist_field, 0);
1770 return NULL;
1771 }
1772
1773 static void destroy_hist_fields(struct hist_trigger_data *hist_data)
1774 {
1775 unsigned int i;
1776
1777 for (i = 0; i < HIST_FIELDS_MAX; i++) {
1778 if (hist_data->fields[i]) {
1779 destroy_hist_field(hist_data->fields[i], 0);
1780 hist_data->fields[i] = NULL;
1781 }
1782 }
1783
1784 for (i = 0; i < hist_data->n_var_refs; i++) {
1785 WARN_ON(!(hist_data->var_refs[i]->flags & HIST_FIELD_FL_VAR_REF));
1786 __destroy_hist_field(hist_data->var_refs[i]);
1787 hist_data->var_refs[i] = NULL;
1788 }
1789 }
1790
1791 static int init_var_ref(struct hist_field *ref_field,
1792 struct hist_field *var_field,
1793 char *system, char *event_name)
1794 {
1795 int err = 0;
1796
1797 ref_field->var.idx = var_field->var.idx;
1798 ref_field->var.hist_data = var_field->hist_data;
1799 ref_field->size = var_field->size;
1800 ref_field->is_signed = var_field->is_signed;
1801 ref_field->flags |= var_field->flags &
1802 (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
1803
1804 if (system) {
1805 ref_field->system = kstrdup(system, GFP_KERNEL);
1806 if (!ref_field->system)
1807 return -ENOMEM;
1808 }
1809
1810 if (event_name) {
1811 ref_field->event_name = kstrdup(event_name, GFP_KERNEL);
1812 if (!ref_field->event_name) {
1813 err = -ENOMEM;
1814 goto free;
1815 }
1816 }
1817
1818 if (var_field->var.name) {
1819 ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL);
1820 if (!ref_field->name) {
1821 err = -ENOMEM;
1822 goto free;
1823 }
1824 } else if (var_field->name) {
1825 ref_field->name = kstrdup(var_field->name, GFP_KERNEL);
1826 if (!ref_field->name) {
1827 err = -ENOMEM;
1828 goto free;
1829 }
1830 }
1831
1832 ref_field->type = kstrdup_const(var_field->type, GFP_KERNEL);
1833 if (!ref_field->type) {
1834 err = -ENOMEM;
1835 goto free;
1836 }
1837 out:
1838 return err;
1839 free:
1840 kfree(ref_field->system);
1841 kfree(ref_field->event_name);
1842 kfree(ref_field->name);
1843
1844 goto out;
1845 }
1846
1847 static int find_var_ref_idx(struct hist_trigger_data *hist_data,
1848 struct hist_field *var_field)
1849 {
1850 struct hist_field *ref_field;
1851 int i;
1852
1853 for (i = 0; i < hist_data->n_var_refs; i++) {
1854 ref_field = hist_data->var_refs[i];
1855 if (ref_field->var.idx == var_field->var.idx &&
1856 ref_field->var.hist_data == var_field->hist_data)
1857 return i;
1858 }
1859
1860 return -ENOENT;
1861 }
1862
1863 /**
1864 * create_var_ref - Create a variable reference and attach it to trigger
1865 * @hist_data: The trigger that will be referencing the variable
1866 * @var_field: The VAR field to create a reference to
1867 * @system: The optional system string
1868 * @event_name: The optional event_name string
1869 *
1870 * Given a variable hist_field, create a VAR_REF hist_field that
1871 * represents a reference to it.
1872 *
1873 * This function also adds the reference to the trigger that
1874 * now references the variable.
1875 *
1876 * Return: The VAR_REF field if successful, NULL if not
1877 */
1878 static struct hist_field *create_var_ref(struct hist_trigger_data *hist_data,
1879 struct hist_field *var_field,
1880 char *system, char *event_name)
1881 {
1882 unsigned long flags = HIST_FIELD_FL_VAR_REF;
1883 struct hist_field *ref_field;
1884 int i;
1885
1886 /* Check if the variable already exists */
1887 for (i = 0; i < hist_data->n_var_refs; i++) {
1888 ref_field = hist_data->var_refs[i];
1889 if (ref_field->var.idx == var_field->var.idx &&
1890 ref_field->var.hist_data == var_field->hist_data) {
1891 get_hist_field(ref_field);
1892 return ref_field;
1893 }
1894 }
1895
1896 ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL);
1897 if (ref_field) {
1898 if (init_var_ref(ref_field, var_field, system, event_name)) {
1899 destroy_hist_field(ref_field, 0);
1900 return NULL;
1901 }
1902
1903 hist_data->var_refs[hist_data->n_var_refs] = ref_field;
1904 ref_field->var_ref_idx = hist_data->n_var_refs++;
1905 }
1906
1907 return ref_field;
1908 }
1909
1910 static bool is_var_ref(char *var_name)
1911 {
1912 if (!var_name || strlen(var_name) < 2 || var_name[0] != '$')
1913 return false;
1914
1915 return true;
1916 }
1917
1918 static char *field_name_from_var(struct hist_trigger_data *hist_data,
1919 char *var_name)
1920 {
1921 char *name, *field;
1922 unsigned int i;
1923
1924 for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
1925 name = hist_data->attrs->var_defs.name[i];
1926
1927 if (strcmp(var_name, name) == 0) {
1928 field = hist_data->attrs->var_defs.expr[i];
1929 if (contains_operator(field) || is_var_ref(field))
1930 continue;
1931 return field;
1932 }
1933 }
1934
1935 return NULL;
1936 }
1937
1938 static char *local_field_var_ref(struct hist_trigger_data *hist_data,
1939 char *system, char *event_name,
1940 char *var_name)
1941 {
1942 struct trace_event_call *call;
1943
1944 if (system && event_name) {
1945 call = hist_data->event_file->event_call;
1946
1947 if (strcmp(system, call->class->system) != 0)
1948 return NULL;
1949
1950 if (strcmp(event_name, trace_event_name(call)) != 0)
1951 return NULL;
1952 }
1953
1954 if (!!system != !!event_name)
1955 return NULL;
1956
1957 if (!is_var_ref(var_name))
1958 return NULL;
1959
1960 var_name++;
1961
1962 return field_name_from_var(hist_data, var_name);
1963 }
1964
1965 static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data,
1966 char *system, char *event_name,
1967 char *var_name)
1968 {
1969 struct hist_field *var_field = NULL, *ref_field = NULL;
1970 struct trace_array *tr = hist_data->event_file->tr;
1971
1972 if (!is_var_ref(var_name))
1973 return NULL;
1974
1975 var_name++;
1976
1977 var_field = find_event_var(hist_data, system, event_name, var_name);
1978 if (var_field)
1979 ref_field = create_var_ref(hist_data, var_field,
1980 system, event_name);
1981
1982 if (!ref_field)
1983 hist_err(tr, HIST_ERR_VAR_NOT_FOUND, errpos(var_name));
1984
1985 return ref_field;
1986 }
1987
1988 static struct ftrace_event_field *
1989 parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
1990 char *field_str, unsigned long *flags, unsigned long *buckets)
1991 {
1992 struct ftrace_event_field *field = NULL;
1993 char *field_name, *modifier, *str;
1994 struct trace_array *tr = file->tr;
1995
1996 modifier = str = kstrdup(field_str, GFP_KERNEL);
1997 if (!modifier)
1998 return ERR_PTR(-ENOMEM);
1999
2000 field_name = strsep(&modifier, ".");
2001 if (modifier) {
2002 if (strcmp(modifier, "hex") == 0)
2003 *flags |= HIST_FIELD_FL_HEX;
2004 else if (strcmp(modifier, "sym") == 0)
2005 *flags |= HIST_FIELD_FL_SYM;
2006 else if (strcmp(modifier, "sym-offset") == 0)
2007 *flags |= HIST_FIELD_FL_SYM_OFFSET;
2008 else if ((strcmp(modifier, "execname") == 0) &&
2009 (strcmp(field_name, "common_pid") == 0))
2010 *flags |= HIST_FIELD_FL_EXECNAME;
2011 else if (strcmp(modifier, "syscall") == 0)
2012 *flags |= HIST_FIELD_FL_SYSCALL;
2013 else if (strcmp(modifier, "log2") == 0)
2014 *flags |= HIST_FIELD_FL_LOG2;
2015 else if (strcmp(modifier, "usecs") == 0)
2016 *flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
2017 else if (strncmp(modifier, "bucket", 6) == 0) {
2018 int ret;
2019
2020 modifier += 6;
2021
2022 if (*modifier == 's')
2023 modifier++;
2024 if (*modifier != '=')
2025 goto error;
2026 modifier++;
2027 ret = kstrtoul(modifier, 0, buckets);
2028 if (ret || !(*buckets))
2029 goto error;
2030 *flags |= HIST_FIELD_FL_BUCKET;
2031 } else {
2032 error:
2033 hist_err(tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(modifier));
2034 field = ERR_PTR(-EINVAL);
2035 goto out;
2036 }
2037 }
2038
2039 if (strcmp(field_name, "common_timestamp") == 0) {
2040 *flags |= HIST_FIELD_FL_TIMESTAMP;
2041 hist_data->enable_timestamps = true;
2042 if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS)
2043 hist_data->attrs->ts_in_usecs = true;
2044 } else if (strcmp(field_name, "common_cpu") == 0)
2045 *flags |= HIST_FIELD_FL_CPU;
2046 else {
2047 field = trace_find_event_field(file->event_call, field_name);
2048 if (!field || !field->size) {
2049 /*
2050 * For backward compatibility, if field_name
2051 * was "cpu", then we treat this the same as
2052 * common_cpu. This also works for "CPU".
2053 */
2054 if (field && field->filter_type == FILTER_CPU) {
2055 *flags |= HIST_FIELD_FL_CPU;
2056 } else {
2057 hist_err(tr, HIST_ERR_FIELD_NOT_FOUND,
2058 errpos(field_name));
2059 field = ERR_PTR(-EINVAL);
2060 goto out;
2061 }
2062 }
2063 }
2064 out:
2065 kfree(str);
2066
2067 return field;
2068 }
2069
2070 static struct hist_field *create_alias(struct hist_trigger_data *hist_data,
2071 struct hist_field *var_ref,
2072 char *var_name)
2073 {
2074 struct hist_field *alias = NULL;
2075 unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR;
2076
2077 alias = create_hist_field(hist_data, NULL, flags, var_name);
2078 if (!alias)
2079 return NULL;
2080
2081 alias->fn = var_ref->fn;
2082 alias->operands[0] = var_ref;
2083
2084 if (init_var_ref(alias, var_ref, var_ref->system, var_ref->event_name)) {
2085 destroy_hist_field(alias, 0);
2086 return NULL;
2087 }
2088
2089 alias->var_ref_idx = var_ref->var_ref_idx;
2090
2091 return alias;
2092 }
2093
2094 static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
2095 struct trace_event_file *file, char *str,
2096 unsigned long *flags, char *var_name)
2097 {
2098 char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str;
2099 struct ftrace_event_field *field = NULL;
2100 struct hist_field *hist_field = NULL;
2101 unsigned long buckets = 0;
2102 int ret = 0;
2103
2104 s = strchr(str, '.');
2105 if (s) {
2106 s = strchr(++s, '.');
2107 if (s) {
2108 ref_system = strsep(&str, ".");
2109 if (!str) {
2110 ret = -EINVAL;
2111 goto out;
2112 }
2113 ref_event = strsep(&str, ".");
2114 if (!str) {
2115 ret = -EINVAL;
2116 goto out;
2117 }
2118 ref_var = str;
2119 }
2120 }
2121
2122 s = local_field_var_ref(hist_data, ref_system, ref_event, ref_var);
2123 if (!s) {
2124 hist_field = parse_var_ref(hist_data, ref_system,
2125 ref_event, ref_var);
2126 if (hist_field) {
2127 if (var_name) {
2128 hist_field = create_alias(hist_data, hist_field, var_name);
2129 if (!hist_field) {
2130 ret = -ENOMEM;
2131 goto out;
2132 }
2133 }
2134 return hist_field;
2135 }
2136 } else
2137 str = s;
2138
2139 field = parse_field(hist_data, file, str, flags, &buckets);
2140 if (IS_ERR(field)) {
2141 ret = PTR_ERR(field);
2142 goto out;
2143 }
2144
2145 hist_field = create_hist_field(hist_data, field, *flags, var_name);
2146 if (!hist_field) {
2147 ret = -ENOMEM;
2148 goto out;
2149 }
2150 hist_field->buckets = buckets;
2151
2152 return hist_field;
2153 out:
2154 return ERR_PTR(ret);
2155 }
2156
2157 static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
2158 struct trace_event_file *file,
2159 char *str, unsigned long flags,
2160 char *var_name, unsigned int level);
2161
2162 static struct hist_field *parse_unary(struct hist_trigger_data *hist_data,
2163 struct trace_event_file *file,
2164 char *str, unsigned long flags,
2165 char *var_name, unsigned int level)
2166 {
2167 struct hist_field *operand1, *expr = NULL;
2168 unsigned long operand_flags;
2169 int ret = 0;
2170 char *s;
2171
2172 /* we support only -(xxx) i.e. explicit parens required */
2173
2174 if (level > 3) {
2175 hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str));
2176 ret = -EINVAL;
2177 goto free;
2178 }
2179
2180 str++; /* skip leading '-' */
2181
2182 s = strchr(str, '(');
2183 if (s)
2184 str++;
2185 else {
2186 ret = -EINVAL;
2187 goto free;
2188 }
2189
2190 s = strrchr(str, ')');
2191 if (s)
2192 *s = '\0';
2193 else {
2194 ret = -EINVAL; /* no closing ')' */
2195 goto free;
2196 }
2197
2198 flags |= HIST_FIELD_FL_EXPR;
2199 expr = create_hist_field(hist_data, NULL, flags, var_name);
2200 if (!expr) {
2201 ret = -ENOMEM;
2202 goto free;
2203 }
2204
2205 operand_flags = 0;
2206 operand1 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
2207 if (IS_ERR(operand1)) {
2208 ret = PTR_ERR(operand1);
2209 goto free;
2210 }
2211 if (operand1->flags & HIST_FIELD_FL_STRING) {
2212 /* String type can not be the operand of unary operator. */
2213 hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str));
2214 destroy_hist_field(operand1, 0);
2215 ret = -EINVAL;
2216 goto free;
2217 }
2218
2219 expr->flags |= operand1->flags &
2220 (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
2221 expr->fn = hist_field_unary_minus;
2222 expr->operands[0] = operand1;
2223 expr->size = operand1->size;
2224 expr->is_signed = operand1->is_signed;
2225 expr->operator = FIELD_OP_UNARY_MINUS;
2226 expr->name = expr_str(expr, 0);
2227 expr->type = kstrdup_const(operand1->type, GFP_KERNEL);
2228 if (!expr->type) {
2229 ret = -ENOMEM;
2230 goto free;
2231 }
2232
2233 return expr;
2234 free:
2235 destroy_hist_field(expr, 0);
2236 return ERR_PTR(ret);
2237 }
2238
2239 static int check_expr_operands(struct trace_array *tr,
2240 struct hist_field *operand1,
2241 struct hist_field *operand2)
2242 {
2243 unsigned long operand1_flags = operand1->flags;
2244 unsigned long operand2_flags = operand2->flags;
2245
2246 if ((operand1_flags & HIST_FIELD_FL_VAR_REF) ||
2247 (operand1_flags & HIST_FIELD_FL_ALIAS)) {
2248 struct hist_field *var;
2249
2250 var = find_var_field(operand1->var.hist_data, operand1->name);
2251 if (!var)
2252 return -EINVAL;
2253 operand1_flags = var->flags;
2254 }
2255
2256 if ((operand2_flags & HIST_FIELD_FL_VAR_REF) ||
2257 (operand2_flags & HIST_FIELD_FL_ALIAS)) {
2258 struct hist_field *var;
2259
2260 var = find_var_field(operand2->var.hist_data, operand2->name);
2261 if (!var)
2262 return -EINVAL;
2263 operand2_flags = var->flags;
2264 }
2265
2266 if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) !=
2267 (operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS)) {
2268 hist_err(tr, HIST_ERR_TIMESTAMP_MISMATCH, 0);
2269 return -EINVAL;
2270 }
2271
2272 return 0;
2273 }
2274
2275 static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
2276 struct trace_event_file *file,
2277 char *str, unsigned long flags,
2278 char *var_name, unsigned int level)
2279 {
2280 struct hist_field *operand1 = NULL, *operand2 = NULL, *expr = NULL;
2281 unsigned long operand_flags;
2282 int field_op, ret = -EINVAL;
2283 char *sep, *operand1_str;
2284
2285 if (level > 3) {
2286 hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str));
2287 return ERR_PTR(-EINVAL);
2288 }
2289
2290 field_op = contains_operator(str);
2291
2292 if (field_op == FIELD_OP_NONE)
2293 return parse_atom(hist_data, file, str, &flags, var_name);
2294
2295 if (field_op == FIELD_OP_UNARY_MINUS)
2296 return parse_unary(hist_data, file, str, flags, var_name, ++level);
2297
2298 switch (field_op) {
2299 case FIELD_OP_MINUS:
2300 sep = "-";
2301 break;
2302 case FIELD_OP_PLUS:
2303 sep = "+";
2304 break;
2305 default:
2306 goto free;
2307 }
2308
2309 operand1_str = strsep(&str, sep);
2310 if (!operand1_str || !str)
2311 goto free;
2312
2313 operand_flags = 0;
2314 operand1 = parse_atom(hist_data, file, operand1_str,
2315 &operand_flags, NULL);
2316 if (IS_ERR(operand1)) {
2317 ret = PTR_ERR(operand1);
2318 operand1 = NULL;
2319 goto free;
2320 }
2321 if (operand1->flags & HIST_FIELD_FL_STRING) {
2322 hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(operand1_str));
2323 ret = -EINVAL;
2324 goto free;
2325 }
2326
2327 /* rest of string could be another expression e.g. b+c in a+b+c */
2328 operand_flags = 0;
2329 operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
2330 if (IS_ERR(operand2)) {
2331 ret = PTR_ERR(operand2);
2332 operand2 = NULL;
2333 goto free;
2334 }
2335 if (operand2->flags & HIST_FIELD_FL_STRING) {
2336 hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str));
2337 ret = -EINVAL;
2338 goto free;
2339 }
2340
2341 ret = check_expr_operands(file->tr, operand1, operand2);
2342 if (ret)
2343 goto free;
2344
2345 flags |= HIST_FIELD_FL_EXPR;
2346
2347 flags |= operand1->flags &
2348 (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
2349
2350 expr = create_hist_field(hist_data, NULL, flags, var_name);
2351 if (!expr) {
2352 ret = -ENOMEM;
2353 goto free;
2354 }
2355
2356 operand1->read_once = true;
2357 operand2->read_once = true;
2358
2359 expr->operands[0] = operand1;
2360 expr->operands[1] = operand2;
2361
2362 /* The operand sizes should be the same, so just pick one */
2363 expr->size = operand1->size;
2364 expr->is_signed = operand1->is_signed;
2365
2366 expr->operator = field_op;
2367 expr->name = expr_str(expr, 0);
2368 expr->type = kstrdup_const(operand1->type, GFP_KERNEL);
2369 if (!expr->type) {
2370 ret = -ENOMEM;
2371 goto free;
2372 }
2373
2374 switch (field_op) {
2375 case FIELD_OP_MINUS:
2376 expr->fn = hist_field_minus;
2377 break;
2378 case FIELD_OP_PLUS:
2379 expr->fn = hist_field_plus;
2380 break;
2381 default:
2382 ret = -EINVAL;
2383 goto free;
2384 }
2385
2386 return expr;
2387 free:
2388 destroy_hist_field(operand1, 0);
2389 destroy_hist_field(operand2, 0);
2390 destroy_hist_field(expr, 0);
2391
2392 return ERR_PTR(ret);
2393 }
2394
2395 static char *find_trigger_filter(struct hist_trigger_data *hist_data,
2396 struct trace_event_file *file)
2397 {
2398 struct event_trigger_data *test;
2399
2400 lockdep_assert_held(&event_mutex);
2401
2402 list_for_each_entry(test, &file->triggers, list) {
2403 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
2404 if (test->private_data == hist_data)
2405 return test->filter_str;
2406 }
2407 }
2408
2409 return NULL;
2410 }
2411
2412 static struct event_command trigger_hist_cmd;
2413 static int event_hist_trigger_func(struct event_command *cmd_ops,
2414 struct trace_event_file *file,
2415 char *glob, char *cmd, char *param);
2416
2417 static bool compatible_keys(struct hist_trigger_data *target_hist_data,
2418 struct hist_trigger_data *hist_data,
2419 unsigned int n_keys)
2420 {
2421 struct hist_field *target_hist_field, *hist_field;
2422 unsigned int n, i, j;
2423
2424 if (hist_data->n_fields - hist_data->n_vals != n_keys)
2425 return false;
2426
2427 i = hist_data->n_vals;
2428 j = target_hist_data->n_vals;
2429
2430 for (n = 0; n < n_keys; n++) {
2431 hist_field = hist_data->fields[i + n];
2432 target_hist_field = target_hist_data->fields[j + n];
2433
2434 if (strcmp(hist_field->type, target_hist_field->type) != 0)
2435 return false;
2436 if (hist_field->size != target_hist_field->size)
2437 return false;
2438 if (hist_field->is_signed != target_hist_field->is_signed)
2439 return false;
2440 }
2441
2442 return true;
2443 }
2444
2445 static struct hist_trigger_data *
2446 find_compatible_hist(struct hist_trigger_data *target_hist_data,
2447 struct trace_event_file *file)
2448 {
2449 struct hist_trigger_data *hist_data;
2450 struct event_trigger_data *test;
2451 unsigned int n_keys;
2452
2453 lockdep_assert_held(&event_mutex);
2454
2455 n_keys = target_hist_data->n_fields - target_hist_data->n_vals;
2456
2457 list_for_each_entry(test, &file->triggers, list) {
2458 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
2459 hist_data = test->private_data;
2460
2461 if (compatible_keys(target_hist_data, hist_data, n_keys))
2462 return hist_data;
2463 }
2464 }
2465
2466 return NULL;
2467 }
2468
2469 static struct trace_event_file *event_file(struct trace_array *tr,
2470 char *system, char *event_name)
2471 {
2472 struct trace_event_file *file;
2473
2474 file = __find_event_file(tr, system, event_name);
2475 if (!file)
2476 return ERR_PTR(-EINVAL);
2477
2478 return file;
2479 }
2480
2481 static struct hist_field *
2482 find_synthetic_field_var(struct hist_trigger_data *target_hist_data,
2483 char *system, char *event_name, char *field_name)
2484 {
2485 struct hist_field *event_var;
2486 char *synthetic_name;
2487
2488 synthetic_name = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
2489 if (!synthetic_name)
2490 return ERR_PTR(-ENOMEM);
2491
2492 strcpy(synthetic_name, "synthetic_");
2493 strcat(synthetic_name, field_name);
2494
2495 event_var = find_event_var(target_hist_data, system, event_name, synthetic_name);
2496
2497 kfree(synthetic_name);
2498
2499 return event_var;
2500 }
2501
2502 /**
2503 * create_field_var_hist - Automatically create a histogram and var for a field
2504 * @target_hist_data: The target hist trigger
2505 * @subsys_name: Optional subsystem name
2506 * @event_name: Optional event name
2507 * @field_name: The name of the field (and the resulting variable)
2508 *
2509 * Hist trigger actions fetch data from variables, not directly from
2510 * events. However, for convenience, users are allowed to directly
2511 * specify an event field in an action, which will be automatically
2512 * converted into a variable on their behalf.
2513 *
2514 * If a user specifies a field on an event that isn't the event the
2515 * histogram currently being defined (the target event histogram), the
2516 * only way that can be accomplished is if a new hist trigger is
2517 * created and the field variable defined on that.
2518 *
2519 * This function creates a new histogram compatible with the target
2520 * event (meaning a histogram with the same key as the target
2521 * histogram), and creates a variable for the specified field, but
2522 * with 'synthetic_' prepended to the variable name in order to avoid
2523 * collision with normal field variables.
2524 *
2525 * Return: The variable created for the field.
2526 */
2527 static struct hist_field *
2528 create_field_var_hist(struct hist_trigger_data *target_hist_data,
2529 char *subsys_name, char *event_name, char *field_name)
2530 {
2531 struct trace_array *tr = target_hist_data->event_file->tr;
2532 struct hist_trigger_data *hist_data;
2533 unsigned int i, n, first = true;
2534 struct field_var_hist *var_hist;
2535 struct trace_event_file *file;
2536 struct hist_field *key_field;
2537 struct hist_field *event_var;
2538 char *saved_filter;
2539 char *cmd;
2540 int ret;
2541
2542 if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) {
2543 hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name));
2544 return ERR_PTR(-EINVAL);
2545 }
2546
2547 file = event_file(tr, subsys_name, event_name);
2548
2549 if (IS_ERR(file)) {
2550 hist_err(tr, HIST_ERR_EVENT_FILE_NOT_FOUND, errpos(field_name));
2551 ret = PTR_ERR(file);
2552 return ERR_PTR(ret);
2553 }
2554
2555 /*
2556 * Look for a histogram compatible with target. We'll use the
2557 * found histogram specification to create a new matching
2558 * histogram with our variable on it. target_hist_data is not
2559 * yet a registered histogram so we can't use that.
2560 */
2561 hist_data = find_compatible_hist(target_hist_data, file);
2562 if (!hist_data) {
2563 hist_err(tr, HIST_ERR_HIST_NOT_FOUND, errpos(field_name));
2564 return ERR_PTR(-EINVAL);
2565 }
2566
2567 /* See if a synthetic field variable has already been created */
2568 event_var = find_synthetic_field_var(target_hist_data, subsys_name,
2569 event_name, field_name);
2570 if (!IS_ERR_OR_NULL(event_var))
2571 return event_var;
2572
2573 var_hist = kzalloc(sizeof(*var_hist), GFP_KERNEL);
2574 if (!var_hist)
2575 return ERR_PTR(-ENOMEM);
2576
2577 cmd = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
2578 if (!cmd) {
2579 kfree(var_hist);
2580 return ERR_PTR(-ENOMEM);
2581 }
2582
2583 /* Use the same keys as the compatible histogram */
2584 strcat(cmd, "keys=");
2585
2586 for_each_hist_key_field(i, hist_data) {
2587 key_field = hist_data->fields[i];
2588 if (!first)
2589 strcat(cmd, ",");
2590 strcat(cmd, key_field->field->name);
2591 first = false;
2592 }
2593
2594 /* Create the synthetic field variable specification */
2595 strcat(cmd, ":synthetic_");
2596 strcat(cmd, field_name);
2597 strcat(cmd, "=");
2598 strcat(cmd, field_name);
2599
2600 /* Use the same filter as the compatible histogram */
2601 saved_filter = find_trigger_filter(hist_data, file);
2602 if (saved_filter) {
2603 strcat(cmd, " if ");
2604 strcat(cmd, saved_filter);
2605 }
2606
2607 var_hist->cmd = kstrdup(cmd, GFP_KERNEL);
2608 if (!var_hist->cmd) {
2609 kfree(cmd);
2610 kfree(var_hist);
2611 return ERR_PTR(-ENOMEM);
2612 }
2613
2614 /* Save the compatible histogram information */
2615 var_hist->hist_data = hist_data;
2616
2617 /* Create the new histogram with our variable */
2618 ret = event_hist_trigger_func(&trigger_hist_cmd, file,
2619 "", "hist", cmd);
2620 if (ret) {
2621 kfree(cmd);
2622 kfree(var_hist->cmd);
2623 kfree(var_hist);
2624 hist_err(tr, HIST_ERR_HIST_CREATE_FAIL, errpos(field_name));
2625 return ERR_PTR(ret);
2626 }
2627
2628 kfree(cmd);
2629
2630 /* If we can't find the variable, something went wrong */
2631 event_var = find_synthetic_field_var(target_hist_data, subsys_name,
2632 event_name, field_name);
2633 if (IS_ERR_OR_NULL(event_var)) {
2634 kfree(var_hist->cmd);
2635 kfree(var_hist);
2636 hist_err(tr, HIST_ERR_SYNTH_VAR_NOT_FOUND, errpos(field_name));
2637 return ERR_PTR(-EINVAL);
2638 }
2639
2640 n = target_hist_data->n_field_var_hists;
2641 target_hist_data->field_var_hists[n] = var_hist;
2642 target_hist_data->n_field_var_hists++;
2643
2644 return event_var;
2645 }
2646
2647 static struct hist_field *
2648 find_target_event_var(struct hist_trigger_data *hist_data,
2649 char *subsys_name, char *event_name, char *var_name)
2650 {
2651 struct trace_event_file *file = hist_data->event_file;
2652 struct hist_field *hist_field = NULL;
2653
2654 if (subsys_name) {
2655 struct trace_event_call *call;
2656
2657 if (!event_name)
2658 return NULL;
2659
2660 call = file->event_call;
2661
2662 if (strcmp(subsys_name, call->class->system) != 0)
2663 return NULL;
2664
2665 if (strcmp(event_name, trace_event_name(call)) != 0)
2666 return NULL;
2667 }
2668
2669 hist_field = find_var_field(hist_data, var_name);
2670
2671 return hist_field;
2672 }
2673
2674 static inline void __update_field_vars(struct tracing_map_elt *elt,
2675 struct trace_buffer *buffer,
2676 struct ring_buffer_event *rbe,
2677 void *rec,
2678 struct field_var **field_vars,
2679 unsigned int n_field_vars,
2680 unsigned int field_var_str_start)
2681 {
2682 struct hist_elt_data *elt_data = elt->private_data;
2683 unsigned int i, j, var_idx;
2684 u64 var_val;
2685
2686 for (i = 0, j = field_var_str_start; i < n_field_vars; i++) {
2687 struct field_var *field_var = field_vars[i];
2688 struct hist_field *var = field_var->var;
2689 struct hist_field *val = field_var->val;
2690
2691 var_val = val->fn(val, elt, buffer, rbe, rec);
2692 var_idx = var->var.idx;
2693
2694 if (val->flags & HIST_FIELD_FL_STRING) {
2695 char *str = elt_data->field_var_str[j++];
2696 char *val_str = (char *)(uintptr_t)var_val;
2697 unsigned int size;
2698
2699 size = min(val->size, STR_VAR_LEN_MAX);
2700 strscpy(str, val_str, size);
2701 var_val = (u64)(uintptr_t)str;
2702 }
2703 tracing_map_set_var(elt, var_idx, var_val);
2704 }
2705 }
2706
2707 static void update_field_vars(struct hist_trigger_data *hist_data,
2708 struct tracing_map_elt *elt,
2709 struct trace_buffer *buffer,
2710 struct ring_buffer_event *rbe,
2711 void *rec)
2712 {
2713 __update_field_vars(elt, buffer, rbe, rec, hist_data->field_vars,
2714 hist_data->n_field_vars, 0);
2715 }
2716
2717 static void save_track_data_vars(struct hist_trigger_data *hist_data,
2718 struct tracing_map_elt *elt,
2719 struct trace_buffer *buffer, void *rec,
2720 struct ring_buffer_event *rbe, void *key,
2721 struct action_data *data, u64 *var_ref_vals)
2722 {
2723 __update_field_vars(elt, buffer, rbe, rec, hist_data->save_vars,
2724 hist_data->n_save_vars, hist_data->n_field_var_str);
2725 }
2726
2727 static struct hist_field *create_var(struct hist_trigger_data *hist_data,
2728 struct trace_event_file *file,
2729 char *name, int size, const char *type)
2730 {
2731 struct hist_field *var;
2732 int idx;
2733
2734 if (find_var(hist_data, file, name) && !hist_data->remove) {
2735 var = ERR_PTR(-EINVAL);
2736 goto out;
2737 }
2738
2739 var = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
2740 if (!var) {
2741 var = ERR_PTR(-ENOMEM);
2742 goto out;
2743 }
2744
2745 idx = tracing_map_add_var(hist_data->map);
2746 if (idx < 0) {
2747 kfree(var);
2748 var = ERR_PTR(-EINVAL);
2749 goto out;
2750 }
2751
2752 var->ref = 1;
2753 var->flags = HIST_FIELD_FL_VAR;
2754 var->var.idx = idx;
2755 var->var.hist_data = var->hist_data = hist_data;
2756 var->size = size;
2757 var->var.name = kstrdup(name, GFP_KERNEL);
2758 var->type = kstrdup_const(type, GFP_KERNEL);
2759 if (!var->var.name || !var->type) {
2760 kfree_const(var->type);
2761 kfree(var->var.name);
2762 kfree(var);
2763 var = ERR_PTR(-ENOMEM);
2764 }
2765 out:
2766 return var;
2767 }
2768
2769 static struct field_var *create_field_var(struct hist_trigger_data *hist_data,
2770 struct trace_event_file *file,
2771 char *field_name)
2772 {
2773 struct hist_field *val = NULL, *var = NULL;
2774 unsigned long flags = HIST_FIELD_FL_VAR;
2775 struct trace_array *tr = file->tr;
2776 struct field_var *field_var;
2777 int ret = 0;
2778
2779 if (hist_data->n_field_vars >= SYNTH_FIELDS_MAX) {
2780 hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name));
2781 ret = -EINVAL;
2782 goto err;
2783 }
2784
2785 val = parse_atom(hist_data, file, field_name, &flags, NULL);
2786 if (IS_ERR(val)) {
2787 hist_err(tr, HIST_ERR_FIELD_VAR_PARSE_FAIL, errpos(field_name));
2788 ret = PTR_ERR(val);
2789 goto err;
2790 }
2791
2792 var = create_var(hist_data, file, field_name, val->size, val->type);
2793 if (IS_ERR(var)) {
2794 hist_err(tr, HIST_ERR_VAR_CREATE_FIND_FAIL, errpos(field_name));
2795 kfree(val);
2796 ret = PTR_ERR(var);
2797 goto err;
2798 }
2799
2800 field_var = kzalloc(sizeof(struct field_var), GFP_KERNEL);
2801 if (!field_var) {
2802 kfree(val);
2803 kfree(var);
2804 ret = -ENOMEM;
2805 goto err;
2806 }
2807
2808 field_var->var = var;
2809 field_var->val = val;
2810 out:
2811 return field_var;
2812 err:
2813 field_var = ERR_PTR(ret);
2814 goto out;
2815 }
2816
2817 /**
2818 * create_target_field_var - Automatically create a variable for a field
2819 * @target_hist_data: The target hist trigger
2820 * @subsys_name: Optional subsystem name
2821 * @event_name: Optional event name
2822 * @var_name: The name of the field (and the resulting variable)
2823 *
2824 * Hist trigger actions fetch data from variables, not directly from
2825 * events. However, for convenience, users are allowed to directly
2826 * specify an event field in an action, which will be automatically
2827 * converted into a variable on their behalf.
2828
2829 * This function creates a field variable with the name var_name on
2830 * the hist trigger currently being defined on the target event. If
2831 * subsys_name and event_name are specified, this function simply
2832 * verifies that they do in fact match the target event subsystem and
2833 * event name.
2834 *
2835 * Return: The variable created for the field.
2836 */
2837 static struct field_var *
2838 create_target_field_var(struct hist_trigger_data *target_hist_data,
2839 char *subsys_name, char *event_name, char *var_name)
2840 {
2841 struct trace_event_file *file = target_hist_data->event_file;
2842
2843 if (subsys_name) {
2844 struct trace_event_call *call;
2845
2846 if (!event_name)
2847 return NULL;
2848
2849 call = file->event_call;
2850
2851 if (strcmp(subsys_name, call->class->system) != 0)
2852 return NULL;
2853
2854 if (strcmp(event_name, trace_event_name(call)) != 0)
2855 return NULL;
2856 }
2857
2858 return create_field_var(target_hist_data, file, var_name);
2859 }
2860
2861 static bool check_track_val_max(u64 track_val, u64 var_val)
2862 {
2863 if (var_val <= track_val)
2864 return false;
2865
2866 return true;
2867 }
2868
2869 static bool check_track_val_changed(u64 track_val, u64 var_val)
2870 {
2871 if (var_val == track_val)
2872 return false;
2873
2874 return true;
2875 }
2876
2877 static u64 get_track_val(struct hist_trigger_data *hist_data,
2878 struct tracing_map_elt *elt,
2879 struct action_data *data)
2880 {
2881 unsigned int track_var_idx = data->track_data.track_var->var.idx;
2882 u64 track_val;
2883
2884 track_val = tracing_map_read_var(elt, track_var_idx);
2885
2886 return track_val;
2887 }
2888
2889 static void save_track_val(struct hist_trigger_data *hist_data,
2890 struct tracing_map_elt *elt,
2891 struct action_data *data, u64 var_val)
2892 {
2893 unsigned int track_var_idx = data->track_data.track_var->var.idx;
2894
2895 tracing_map_set_var(elt, track_var_idx, var_val);
2896 }
2897
2898 static void save_track_data(struct hist_trigger_data *hist_data,
2899 struct tracing_map_elt *elt,
2900 struct trace_buffer *buffer, void *rec,
2901 struct ring_buffer_event *rbe, void *key,
2902 struct action_data *data, u64 *var_ref_vals)
2903 {
2904 if (data->track_data.save_data)
2905 data->track_data.save_data(hist_data, elt, buffer, rec, rbe,
2906 key, data, var_ref_vals);
2907 }
2908
2909 static bool check_track_val(struct tracing_map_elt *elt,
2910 struct action_data *data,
2911 u64 var_val)
2912 {
2913 struct hist_trigger_data *hist_data;
2914 u64 track_val;
2915
2916 hist_data = data->track_data.track_var->hist_data;
2917 track_val = get_track_val(hist_data, elt, data);
2918
2919 return data->track_data.check_val(track_val, var_val);
2920 }
2921
2922 #ifdef CONFIG_TRACER_SNAPSHOT
2923 static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
2924 {
2925 /* called with tr->max_lock held */
2926 struct track_data *track_data = tr->cond_snapshot->cond_data;
2927 struct hist_elt_data *elt_data, *track_elt_data;
2928 struct snapshot_context *context = cond_data;
2929 struct action_data *action;
2930 u64 track_val;
2931
2932 if (!track_data)
2933 return false;
2934
2935 action = track_data->action_data;
2936
2937 track_val = get_track_val(track_data->hist_data, context->elt,
2938 track_data->action_data);
2939
2940 if (!action->track_data.check_val(track_data->track_val, track_val))
2941 return false;
2942
2943 track_data->track_val = track_val;
2944 memcpy(track_data->key, context->key, track_data->key_len);
2945
2946 elt_data = context->elt->private_data;
2947 track_elt_data = track_data->elt.private_data;
2948 if (elt_data->comm)
2949 strncpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN);
2950
2951 track_data->updated = true;
2952
2953 return true;
2954 }
2955
2956 static void save_track_data_snapshot(struct hist_trigger_data *hist_data,
2957 struct tracing_map_elt *elt,
2958 struct trace_buffer *buffer, void *rec,
2959 struct ring_buffer_event *rbe, void *key,
2960 struct action_data *data,
2961 u64 *var_ref_vals)
2962 {
2963 struct trace_event_file *file = hist_data->event_file;
2964 struct snapshot_context context;
2965
2966 context.elt = elt;
2967 context.key = key;
2968
2969 tracing_snapshot_cond(file->tr, &context);
2970 }
2971
2972 static void hist_trigger_print_key(struct seq_file *m,
2973 struct hist_trigger_data *hist_data,
2974 void *key,
2975 struct tracing_map_elt *elt);
2976
2977 static struct action_data *snapshot_action(struct hist_trigger_data *hist_data)
2978 {
2979 unsigned int i;
2980
2981 if (!hist_data->n_actions)
2982 return NULL;
2983
2984 for (i = 0; i < hist_data->n_actions; i++) {
2985 struct action_data *data = hist_data->actions[i];
2986
2987 if (data->action == ACTION_SNAPSHOT)
2988 return data;
2989 }
2990
2991 return NULL;
2992 }
2993
2994 static void track_data_snapshot_print(struct seq_file *m,
2995 struct hist_trigger_data *hist_data)
2996 {
2997 struct trace_event_file *file = hist_data->event_file;
2998 struct track_data *track_data;
2999 struct action_data *action;
3000
3001 track_data = tracing_cond_snapshot_data(file->tr);
3002 if (!track_data)
3003 return;
3004
3005 if (!track_data->updated)
3006 return;
3007
3008 action = snapshot_action(hist_data);
3009 if (!action)
3010 return;
3011
3012 seq_puts(m, "\nSnapshot taken (see tracing/snapshot). Details:\n");
3013 seq_printf(m, "\ttriggering value { %s(%s) }: %10llu",
3014 action->handler == HANDLER_ONMAX ? "onmax" : "onchange",
3015 action->track_data.var_str, track_data->track_val);
3016
3017 seq_puts(m, "\ttriggered by event with key: ");
3018 hist_trigger_print_key(m, hist_data, track_data->key, &track_data->elt);
3019 seq_putc(m, '\n');
3020 }
3021 #else
3022 static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
3023 {
3024 return false;
3025 }
3026 static void save_track_data_snapshot(struct hist_trigger_data *hist_data,
3027 struct tracing_map_elt *elt,
3028 struct trace_buffer *buffer, void *rec,
3029 struct ring_buffer_event *rbe, void *key,
3030 struct action_data *data,
3031 u64 *var_ref_vals) {}
3032 static void track_data_snapshot_print(struct seq_file *m,
3033 struct hist_trigger_data *hist_data) {}
3034 #endif /* CONFIG_TRACER_SNAPSHOT */
3035
3036 static void track_data_print(struct seq_file *m,
3037 struct hist_trigger_data *hist_data,
3038 struct tracing_map_elt *elt,
3039 struct action_data *data)
3040 {
3041 u64 track_val = get_track_val(hist_data, elt, data);
3042 unsigned int i, save_var_idx;
3043
3044 if (data->handler == HANDLER_ONMAX)
3045 seq_printf(m, "\n\tmax: %10llu", track_val);
3046 else if (data->handler == HANDLER_ONCHANGE)
3047 seq_printf(m, "\n\tchanged: %10llu", track_val);
3048
3049 if (data->action == ACTION_SNAPSHOT)
3050 return;
3051
3052 for (i = 0; i < hist_data->n_save_vars; i++) {
3053 struct hist_field *save_val = hist_data->save_vars[i]->val;
3054 struct hist_field *save_var = hist_data->save_vars[i]->var;
3055 u64 val;
3056
3057 save_var_idx = save_var->var.idx;
3058
3059 val = tracing_map_read_var(elt, save_var_idx);
3060
3061 if (save_val->flags & HIST_FIELD_FL_STRING) {
3062 seq_printf(m, " %s: %-32s", save_var->var.name,
3063 (char *)(uintptr_t)(val));
3064 } else
3065 seq_printf(m, " %s: %10llu", save_var->var.name, val);
3066 }
3067 }
3068
3069 static void ontrack_action(struct hist_trigger_data *hist_data,
3070 struct tracing_map_elt *elt,
3071 struct trace_buffer *buffer, void *rec,
3072 struct ring_buffer_event *rbe, void *key,
3073 struct action_data *data, u64 *var_ref_vals)
3074 {
3075 u64 var_val = var_ref_vals[data->track_data.var_ref->var_ref_idx];
3076
3077 if (check_track_val(elt, data, var_val)) {
3078 save_track_val(hist_data, elt, data, var_val);
3079 save_track_data(hist_data, elt, buffer, rec, rbe,
3080 key, data, var_ref_vals);
3081 }
3082 }
3083
3084 static void action_data_destroy(struct action_data *data)
3085 {
3086 unsigned int i;
3087
3088 lockdep_assert_held(&event_mutex);
3089
3090 kfree(data->action_name);
3091
3092 for (i = 0; i < data->n_params; i++)
3093 kfree(data->params[i]);
3094
3095 if (data->synth_event)
3096 data->synth_event->ref--;
3097
3098 kfree(data->synth_event_name);
3099
3100 kfree(data);
3101 }
3102
3103 static void track_data_destroy(struct hist_trigger_data *hist_data,
3104 struct action_data *data)
3105 {
3106 struct trace_event_file *file = hist_data->event_file;
3107
3108 destroy_hist_field(data->track_data.track_var, 0);
3109
3110 if (data->action == ACTION_SNAPSHOT) {
3111 struct track_data *track_data;
3112
3113 track_data = tracing_cond_snapshot_data(file->tr);
3114 if (track_data && track_data->hist_data == hist_data) {
3115 tracing_snapshot_cond_disable(file->tr);
3116 track_data_free(track_data);
3117 }
3118 }
3119
3120 kfree(data->track_data.var_str);
3121
3122 action_data_destroy(data);
3123 }
3124
3125 static int action_create(struct hist_trigger_data *hist_data,
3126 struct action_data *data);
3127
3128 static int track_data_create(struct hist_trigger_data *hist_data,
3129 struct action_data *data)
3130 {
3131 struct hist_field *var_field, *ref_field, *track_var = NULL;
3132 struct trace_event_file *file = hist_data->event_file;
3133 struct trace_array *tr = file->tr;
3134 char *track_data_var_str;
3135 int ret = 0;
3136
3137 track_data_var_str = data->track_data.var_str;
3138 if (track_data_var_str[0] != '$') {
3139 hist_err(tr, HIST_ERR_ONX_NOT_VAR, errpos(track_data_var_str));
3140 return -EINVAL;
3141 }
3142 track_data_var_str++;
3143
3144 var_field = find_target_event_var(hist_data, NULL, NULL, track_data_var_str);
3145 if (!var_field) {
3146 hist_err(tr, HIST_ERR_ONX_VAR_NOT_FOUND, errpos(track_data_var_str));
3147 return -EINVAL;
3148 }
3149
3150 ref_field = create_var_ref(hist_data, var_field, NULL, NULL);
3151 if (!ref_field)
3152 return -ENOMEM;
3153
3154 data->track_data.var_ref = ref_field;
3155
3156 if (data->handler == HANDLER_ONMAX)
3157 track_var = create_var(hist_data, file, "__max", sizeof(u64), "u64");
3158 if (IS_ERR(track_var)) {
3159 hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0);
3160 ret = PTR_ERR(track_var);
3161 goto out;
3162 }
3163
3164 if (data->handler == HANDLER_ONCHANGE)
3165 track_var = create_var(hist_data, file, "__change", sizeof(u64), "u64");
3166 if (IS_ERR(track_var)) {
3167 hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0);
3168 ret = PTR_ERR(track_var);
3169 goto out;
3170 }
3171 data->track_data.track_var = track_var;
3172
3173 ret = action_create(hist_data, data);
3174 out:
3175 return ret;
3176 }
3177
3178 static int parse_action_params(struct trace_array *tr, char *params,
3179 struct action_data *data)
3180 {
3181 char *param, *saved_param;
3182 bool first_param = true;
3183 int ret = 0;
3184
3185 while (params) {
3186 if (data->n_params >= SYNTH_FIELDS_MAX) {
3187 hist_err(tr, HIST_ERR_TOO_MANY_PARAMS, 0);
3188 goto out;
3189 }
3190
3191 param = strsep(&params, ",");
3192 if (!param) {
3193 hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, 0);
3194 ret = -EINVAL;
3195 goto out;
3196 }
3197
3198 param = strstrip(param);
3199 if (strlen(param) < 2) {
3200 hist_err(tr, HIST_ERR_INVALID_PARAM, errpos(param));
3201 ret = -EINVAL;
3202 goto out;
3203 }
3204
3205 saved_param = kstrdup(param, GFP_KERNEL);
3206 if (!saved_param) {
3207 ret = -ENOMEM;
3208 goto out;
3209 }
3210
3211 if (first_param && data->use_trace_keyword) {
3212 data->synth_event_name = saved_param;
3213 first_param = false;
3214 continue;
3215 }
3216 first_param = false;
3217
3218 data->params[data->n_params++] = saved_param;
3219 }
3220 out:
3221 return ret;
3222 }
3223
3224 static int action_parse(struct trace_array *tr, char *str, struct action_data *data,
3225 enum handler_id handler)
3226 {
3227 char *action_name;
3228 int ret = 0;
3229
3230 strsep(&str, ".");
3231 if (!str) {
3232 hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0);
3233 ret = -EINVAL;
3234 goto out;
3235 }
3236
3237 action_name = strsep(&str, "(");
3238 if (!action_name || !str) {
3239 hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0);
3240 ret = -EINVAL;
3241 goto out;
3242 }
3243
3244 if (str_has_prefix(action_name, "save")) {
3245 char *params = strsep(&str, ")");
3246
3247 if (!params) {
3248 hist_err(tr, HIST_ERR_NO_SAVE_PARAMS, 0);
3249 ret = -EINVAL;
3250 goto out;
3251 }
3252
3253 ret = parse_action_params(tr, params, data);
3254 if (ret)
3255 goto out;
3256
3257 if (handler == HANDLER_ONMAX)
3258 data->track_data.check_val = check_track_val_max;
3259 else if (handler == HANDLER_ONCHANGE)
3260 data->track_data.check_val = check_track_val_changed;
3261 else {
3262 hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name));
3263 ret = -EINVAL;
3264 goto out;
3265 }
3266
3267 data->track_data.save_data = save_track_data_vars;
3268 data->fn = ontrack_action;
3269 data->action = ACTION_SAVE;
3270 } else if (str_has_prefix(action_name, "snapshot")) {
3271 char *params = strsep(&str, ")");
3272
3273 if (!str) {
3274 hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(params));
3275 ret = -EINVAL;
3276 goto out;
3277 }
3278
3279 if (handler == HANDLER_ONMAX)
3280 data->track_data.check_val = check_track_val_max;
3281 else if (handler == HANDLER_ONCHANGE)
3282 data->track_data.check_val = check_track_val_changed;
3283 else {
3284 hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name));
3285 ret = -EINVAL;
3286 goto out;
3287 }
3288
3289 data->track_data.save_data = save_track_data_snapshot;
3290 data->fn = ontrack_action;
3291 data->action = ACTION_SNAPSHOT;
3292 } else {
3293 char *params = strsep(&str, ")");
3294
3295 if (str_has_prefix(action_name, "trace"))
3296 data->use_trace_keyword = true;
3297
3298 if (params) {
3299 ret = parse_action_params(tr, params, data);
3300 if (ret)
3301 goto out;
3302 }
3303
3304 if (handler == HANDLER_ONMAX)
3305 data->track_data.check_val = check_track_val_max;
3306 else if (handler == HANDLER_ONCHANGE)
3307 data->track_data.check_val = check_track_val_changed;
3308
3309 if (handler != HANDLER_ONMATCH) {
3310 data->track_data.save_data = action_trace;
3311 data->fn = ontrack_action;
3312 } else
3313 data->fn = action_trace;
3314
3315 data->action = ACTION_TRACE;
3316 }
3317
3318 data->action_name = kstrdup(action_name, GFP_KERNEL);
3319 if (!data->action_name) {
3320 ret = -ENOMEM;
3321 goto out;
3322 }
3323
3324 data->handler = handler;
3325 out:
3326 return ret;
3327 }
3328
3329 static struct action_data *track_data_parse(struct hist_trigger_data *hist_data,
3330 char *str, enum handler_id handler)
3331 {
3332 struct action_data *data;
3333 int ret = -EINVAL;
3334 char *var_str;
3335
3336 data = kzalloc(sizeof(*data), GFP_KERNEL);
3337 if (!data)
3338 return ERR_PTR(-ENOMEM);
3339
3340 var_str = strsep(&str, ")");
3341 if (!var_str || !str) {
3342 ret = -EINVAL;
3343 goto free;
3344 }
3345
3346 data->track_data.var_str = kstrdup(var_str, GFP_KERNEL);
3347 if (!data->track_data.var_str) {
3348 ret = -ENOMEM;
3349 goto free;
3350 }
3351
3352 ret = action_parse(hist_data->event_file->tr, str, data, handler);
3353 if (ret)
3354 goto free;
3355 out:
3356 return data;
3357 free:
3358 track_data_destroy(hist_data, data);
3359 data = ERR_PTR(ret);
3360 goto out;
3361 }
3362
3363 static void onmatch_destroy(struct action_data *data)
3364 {
3365 kfree(data->match_data.event);
3366 kfree(data->match_data.event_system);
3367
3368 action_data_destroy(data);
3369 }
3370
3371 static void destroy_field_var(struct field_var *field_var)
3372 {
3373 if (!field_var)
3374 return;
3375
3376 destroy_hist_field(field_var->var, 0);
3377 destroy_hist_field(field_var->val, 0);
3378
3379 kfree(field_var);
3380 }
3381
3382 static void destroy_field_vars(struct hist_trigger_data *hist_data)
3383 {
3384 unsigned int i;
3385
3386 for (i = 0; i < hist_data->n_field_vars; i++)
3387 destroy_field_var(hist_data->field_vars[i]);
3388
3389 for (i = 0; i < hist_data->n_save_vars; i++)
3390 destroy_field_var(hist_data->save_vars[i]);
3391 }
3392
3393 static void save_field_var(struct hist_trigger_data *hist_data,
3394 struct field_var *field_var)
3395 {
3396 hist_data->field_vars[hist_data->n_field_vars++] = field_var;
3397
3398 if (field_var->val->flags & HIST_FIELD_FL_STRING)
3399 hist_data->n_field_var_str++;
3400 }
3401
3402
3403 static int check_synth_field(struct synth_event *event,
3404 struct hist_field *hist_field,
3405 unsigned int field_pos)
3406 {
3407 struct synth_field *field;
3408
3409 if (field_pos >= event->n_fields)
3410 return -EINVAL;
3411
3412 field = event->fields[field_pos];
3413
3414 /*
3415 * A dynamic string synth field can accept static or
3416 * dynamic. A static string synth field can only accept a
3417 * same-sized static string, which is checked for later.
3418 */
3419 if (strstr(hist_field->type, "char[") && field->is_string
3420 && field->is_dynamic)
3421 return 0;
3422
3423 if (strcmp(field->type, hist_field->type) != 0) {
3424 if (field->size != hist_field->size ||
3425 (!field->is_string && field->is_signed != hist_field->is_signed))
3426 return -EINVAL;
3427 }
3428
3429 return 0;
3430 }
3431
3432 static struct hist_field *
3433 trace_action_find_var(struct hist_trigger_data *hist_data,
3434 struct action_data *data,
3435 char *system, char *event, char *var)
3436 {
3437 struct trace_array *tr = hist_data->event_file->tr;
3438 struct hist_field *hist_field;
3439
3440 var++; /* skip '$' */
3441
3442 hist_field = find_target_event_var(hist_data, system, event, var);
3443 if (!hist_field) {
3444 if (!system && data->handler == HANDLER_ONMATCH) {
3445 system = data->match_data.event_system;
3446 event = data->match_data.event;
3447 }
3448
3449 hist_field = find_event_var(hist_data, system, event, var);
3450 }
3451
3452 if (!hist_field)
3453 hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, errpos(var));
3454
3455 return hist_field;
3456 }
3457
3458 static struct hist_field *
3459 trace_action_create_field_var(struct hist_trigger_data *hist_data,
3460 struct action_data *data, char *system,
3461 char *event, char *var)
3462 {
3463 struct hist_field *hist_field = NULL;
3464 struct field_var *field_var;
3465
3466 /*
3467 * First try to create a field var on the target event (the
3468 * currently being defined). This will create a variable for
3469 * unqualified fields on the target event, or if qualified,
3470 * target fields that have qualified names matching the target.
3471 */
3472 field_var = create_target_field_var(hist_data, system, event, var);
3473
3474 if (field_var && !IS_ERR(field_var)) {
3475 save_field_var(hist_data, field_var);
3476 hist_field = field_var->var;
3477 } else {
3478 field_var = NULL;
3479 /*
3480 * If no explicit system.event is specified, default to
3481 * looking for fields on the onmatch(system.event.xxx)
3482 * event.
3483 */
3484 if (!system && data->handler == HANDLER_ONMATCH) {
3485 system = data->match_data.event_system;
3486 event = data->match_data.event;
3487 }
3488
3489 if (!event)
3490 goto free;
3491 /*
3492 * At this point, we're looking at a field on another
3493 * event. Because we can't modify a hist trigger on
3494 * another event to add a variable for a field, we need
3495 * to create a new trigger on that event and create the
3496 * variable at the same time.
3497 */
3498 hist_field = create_field_var_hist(hist_data, system, event, var);
3499 if (IS_ERR(hist_field))
3500 goto free;
3501 }
3502 out:
3503 return hist_field;
3504 free:
3505 destroy_field_var(field_var);
3506 hist_field = NULL;
3507 goto out;
3508 }
3509
3510 static int trace_action_create(struct hist_trigger_data *hist_data,
3511 struct action_data *data)
3512 {
3513 struct trace_array *tr = hist_data->event_file->tr;
3514 char *event_name, *param, *system = NULL;
3515 struct hist_field *hist_field, *var_ref;
3516 unsigned int i;
3517 unsigned int field_pos = 0;
3518 struct synth_event *event;
3519 char *synth_event_name;
3520 int var_ref_idx, ret = 0;
3521
3522 lockdep_assert_held(&event_mutex);
3523
3524 if (data->use_trace_keyword)
3525 synth_event_name = data->synth_event_name;
3526 else
3527 synth_event_name = data->action_name;
3528
3529 event = find_synth_event(synth_event_name);
3530 if (!event) {
3531 hist_err(tr, HIST_ERR_SYNTH_EVENT_NOT_FOUND, errpos(synth_event_name));
3532 return -EINVAL;
3533 }
3534
3535 event->ref++;
3536
3537 for (i = 0; i < data->n_params; i++) {
3538 char *p;
3539
3540 p = param = kstrdup(data->params[i], GFP_KERNEL);
3541 if (!param) {
3542 ret = -ENOMEM;
3543 goto err;
3544 }
3545
3546 system = strsep(&param, ".");
3547 if (!param) {
3548 param = (char *)system;
3549 system = event_name = NULL;
3550 } else {
3551 event_name = strsep(&param, ".");
3552 if (!param) {
3553 kfree(p);
3554 ret = -EINVAL;
3555 goto err;
3556 }
3557 }
3558
3559 if (param[0] == '$')
3560 hist_field = trace_action_find_var(hist_data, data,
3561 system, event_name,
3562 param);
3563 else
3564 hist_field = trace_action_create_field_var(hist_data,
3565 data,
3566 system,
3567 event_name,
3568 param);
3569
3570 if (!hist_field) {
3571 kfree(p);
3572 ret = -EINVAL;
3573 goto err;
3574 }
3575
3576 if (check_synth_field(event, hist_field, field_pos) == 0) {
3577 var_ref = create_var_ref(hist_data, hist_field,
3578 system, event_name);
3579 if (!var_ref) {
3580 kfree(p);
3581 ret = -ENOMEM;
3582 goto err;
3583 }
3584
3585 var_ref_idx = find_var_ref_idx(hist_data, var_ref);
3586 if (WARN_ON(var_ref_idx < 0)) {
3587 kfree(p);
3588 ret = var_ref_idx;
3589 goto err;
3590 }
3591
3592 data->var_ref_idx[i] = var_ref_idx;
3593
3594 field_pos++;
3595 kfree(p);
3596 continue;
3597 }
3598
3599 hist_err(tr, HIST_ERR_SYNTH_TYPE_MISMATCH, errpos(param));
3600 kfree(p);
3601 ret = -EINVAL;
3602 goto err;
3603 }
3604
3605 if (field_pos != event->n_fields) {
3606 hist_err(tr, HIST_ERR_SYNTH_COUNT_MISMATCH, errpos(event->name));
3607 ret = -EINVAL;
3608 goto err;
3609 }
3610
3611 data->synth_event = event;
3612 out:
3613 return ret;
3614 err:
3615 event->ref--;
3616
3617 goto out;
3618 }
3619
3620 static int action_create(struct hist_trigger_data *hist_data,
3621 struct action_data *data)
3622 {
3623 struct trace_event_file *file = hist_data->event_file;
3624 struct trace_array *tr = file->tr;
3625 struct track_data *track_data;
3626 struct field_var *field_var;
3627 unsigned int i;
3628 char *param;
3629 int ret = 0;
3630
3631 if (data->action == ACTION_TRACE)
3632 return trace_action_create(hist_data, data);
3633
3634 if (data->action == ACTION_SNAPSHOT) {
3635 track_data = track_data_alloc(hist_data->key_size, data, hist_data);
3636 if (IS_ERR(track_data)) {
3637 ret = PTR_ERR(track_data);
3638 goto out;
3639 }
3640
3641 ret = tracing_snapshot_cond_enable(file->tr, track_data,
3642 cond_snapshot_update);
3643 if (ret)
3644 track_data_free(track_data);
3645
3646 goto out;
3647 }
3648
3649 if (data->action == ACTION_SAVE) {
3650 if (hist_data->n_save_vars) {
3651 ret = -EEXIST;
3652 hist_err(tr, HIST_ERR_TOO_MANY_SAVE_ACTIONS, 0);
3653 goto out;
3654 }
3655
3656 for (i = 0; i < data->n_params; i++) {
3657 param = kstrdup(data->params[i], GFP_KERNEL);
3658 if (!param) {
3659 ret = -ENOMEM;
3660 goto out;
3661 }
3662
3663 field_var = create_target_field_var(hist_data, NULL, NULL, param);
3664 if (IS_ERR(field_var)) {
3665 hist_err(tr, HIST_ERR_FIELD_VAR_CREATE_FAIL,
3666 errpos(param));
3667 ret = PTR_ERR(field_var);
3668 kfree(param);
3669 goto out;
3670 }
3671
3672 hist_data->save_vars[hist_data->n_save_vars++] = field_var;
3673 if (field_var->val->flags & HIST_FIELD_FL_STRING)
3674 hist_data->n_save_var_str++;
3675 kfree(param);
3676 }
3677 }
3678 out:
3679 return ret;
3680 }
3681
3682 static int onmatch_create(struct hist_trigger_data *hist_data,
3683 struct action_data *data)
3684 {
3685 return action_create(hist_data, data);
3686 }
3687
3688 static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
3689 {
3690 char *match_event, *match_event_system;
3691 struct action_data *data;
3692 int ret = -EINVAL;
3693
3694 data = kzalloc(sizeof(*data), GFP_KERNEL);
3695 if (!data)
3696 return ERR_PTR(-ENOMEM);
3697
3698 match_event = strsep(&str, ")");
3699 if (!match_event || !str) {
3700 hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(match_event));
3701 goto free;
3702 }
3703
3704 match_event_system = strsep(&match_event, ".");
3705 if (!match_event) {
3706 hist_err(tr, HIST_ERR_SUBSYS_NOT_FOUND, errpos(match_event_system));
3707 goto free;
3708 }
3709
3710 if (IS_ERR(event_file(tr, match_event_system, match_event))) {
3711 hist_err(tr, HIST_ERR_INVALID_SUBSYS_EVENT, errpos(match_event));
3712 goto free;
3713 }
3714
3715 data->match_data.event = kstrdup(match_event, GFP_KERNEL);
3716 if (!data->match_data.event) {
3717 ret = -ENOMEM;
3718 goto free;
3719 }
3720
3721 data->match_data.event_system = kstrdup(match_event_system, GFP_KERNEL);
3722 if (!data->match_data.event_system) {
3723 ret = -ENOMEM;
3724 goto free;
3725 }
3726
3727 ret = action_parse(tr, str, data, HANDLER_ONMATCH);
3728 if (ret)
3729 goto free;
3730 out:
3731 return data;
3732 free:
3733 onmatch_destroy(data);
3734 data = ERR_PTR(ret);
3735 goto out;
3736 }
3737
3738 static int create_hitcount_val(struct hist_trigger_data *hist_data)
3739 {
3740 hist_data->fields[HITCOUNT_IDX] =
3741 create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL);
3742 if (!hist_data->fields[HITCOUNT_IDX])
3743 return -ENOMEM;
3744
3745 hist_data->n_vals++;
3746 hist_data->n_fields++;
3747
3748 if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
3749 return -EINVAL;
3750
3751 return 0;
3752 }
3753
3754 static int __create_val_field(struct hist_trigger_data *hist_data,
3755 unsigned int val_idx,
3756 struct trace_event_file *file,
3757 char *var_name, char *field_str,
3758 unsigned long flags)
3759 {
3760 struct hist_field *hist_field;
3761 int ret = 0;
3762
3763 hist_field = parse_expr(hist_data, file, field_str, flags, var_name, 0);
3764 if (IS_ERR(hist_field)) {
3765 ret = PTR_ERR(hist_field);
3766 goto out;
3767 }
3768
3769 hist_data->fields[val_idx] = hist_field;
3770
3771 ++hist_data->n_vals;
3772 ++hist_data->n_fields;
3773
3774 if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
3775 ret = -EINVAL;
3776 out:
3777 return ret;
3778 }
3779
3780 static int create_val_field(struct hist_trigger_data *hist_data,
3781 unsigned int val_idx,
3782 struct trace_event_file *file,
3783 char *field_str)
3784 {
3785 if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
3786 return -EINVAL;
3787
3788 return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0);
3789 }
3790
3791 static const char *no_comm = "(no comm)";
3792
3793 static u64 hist_field_execname(struct hist_field *hist_field,
3794 struct tracing_map_elt *elt,
3795 struct trace_buffer *buffer,
3796 struct ring_buffer_event *rbe,
3797 void *event)
3798 {
3799 struct hist_elt_data *elt_data;
3800
3801 if (WARN_ON_ONCE(!elt))
3802 return (u64)(unsigned long)no_comm;
3803
3804 elt_data = elt->private_data;
3805
3806 if (WARN_ON_ONCE(!elt_data->comm))
3807 return (u64)(unsigned long)no_comm;
3808
3809 return (u64)(unsigned long)(elt_data->comm);
3810 }
3811
3812 /* Convert a var that points to common_pid.execname to a string */
3813 static void update_var_execname(struct hist_field *hist_field)
3814 {
3815 hist_field->flags = HIST_FIELD_FL_STRING | HIST_FIELD_FL_VAR |
3816 HIST_FIELD_FL_EXECNAME;
3817 hist_field->size = MAX_FILTER_STR_VAL;
3818 hist_field->is_signed = 0;
3819
3820 kfree_const(hist_field->type);
3821 hist_field->type = "char[]";
3822
3823 hist_field->fn = hist_field_execname;
3824 }
3825
3826 static int create_var_field(struct hist_trigger_data *hist_data,
3827 unsigned int val_idx,
3828 struct trace_event_file *file,
3829 char *var_name, char *expr_str)
3830 {
3831 struct trace_array *tr = hist_data->event_file->tr;
3832 unsigned long flags = 0;
3833 int ret;
3834
3835 if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
3836 return -EINVAL;
3837
3838 if (find_var(hist_data, file, var_name) && !hist_data->remove) {
3839 hist_err(tr, HIST_ERR_DUPLICATE_VAR, errpos(var_name));
3840 return -EINVAL;
3841 }
3842
3843 flags |= HIST_FIELD_FL_VAR;
3844 hist_data->n_vars++;
3845 if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX))
3846 return -EINVAL;
3847
3848 ret = __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);
3849
3850 if (!ret && hist_data->fields[val_idx]->flags & HIST_FIELD_FL_EXECNAME)
3851 update_var_execname(hist_data->fields[val_idx]);
3852
3853 if (!ret && hist_data->fields[val_idx]->flags & HIST_FIELD_FL_STRING)
3854 hist_data->fields[val_idx]->var_str_idx = hist_data->n_var_str++;
3855
3856 return ret;
3857 }
3858
3859 static int create_val_fields(struct hist_trigger_data *hist_data,
3860 struct trace_event_file *file)
3861 {
3862 char *fields_str, *field_str;
3863 unsigned int i, j = 1;
3864 int ret;
3865
3866 ret = create_hitcount_val(hist_data);
3867 if (ret)
3868 goto out;
3869
3870 fields_str = hist_data->attrs->vals_str;
3871 if (!fields_str)
3872 goto out;
3873
3874 for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
3875 j < TRACING_MAP_VALS_MAX; i++) {
3876 field_str = strsep(&fields_str, ",");
3877 if (!field_str)
3878 break;
3879
3880 if (strcmp(field_str, "hitcount") == 0)
3881 continue;
3882
3883 ret = create_val_field(hist_data, j++, file, field_str);
3884 if (ret)
3885 goto out;
3886 }
3887
3888 if (fields_str && (strcmp(fields_str, "hitcount") != 0))
3889 ret = -EINVAL;
3890 out:
3891 return ret;
3892 }
3893
3894 static int create_key_field(struct hist_trigger_data *hist_data,
3895 unsigned int key_idx,
3896 unsigned int key_offset,
3897 struct trace_event_file *file,
3898 char *field_str)
3899 {
3900 struct trace_array *tr = hist_data->event_file->tr;
3901 struct hist_field *hist_field = NULL;
3902 unsigned long flags = 0;
3903 unsigned int key_size;
3904 int ret = 0;
3905
3906 if (WARN_ON(key_idx >= HIST_FIELDS_MAX))
3907 return -EINVAL;
3908
3909 flags |= HIST_FIELD_FL_KEY;
3910
3911 if (strcmp(field_str, "stacktrace") == 0) {
3912 flags |= HIST_FIELD_FL_STACKTRACE;
3913 key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
3914 hist_field = create_hist_field(hist_data, NULL, flags, NULL);
3915 } else {
3916 hist_field = parse_expr(hist_data, file, field_str, flags,
3917 NULL, 0);
3918 if (IS_ERR(hist_field)) {
3919 ret = PTR_ERR(hist_field);
3920 goto out;
3921 }
3922
3923 if (field_has_hist_vars(hist_field, 0)) {
3924 hist_err(tr, HIST_ERR_INVALID_REF_KEY, errpos(field_str));
3925 destroy_hist_field(hist_field, 0);
3926 ret = -EINVAL;
3927 goto out;
3928 }
3929
3930 key_size = hist_field->size;
3931 }
3932
3933 hist_data->fields[key_idx] = hist_field;
3934
3935 key_size = ALIGN(key_size, sizeof(u64));
3936 hist_data->fields[key_idx]->size = key_size;
3937 hist_data->fields[key_idx]->offset = key_offset;
3938
3939 hist_data->key_size += key_size;
3940
3941 if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
3942 ret = -EINVAL;
3943 goto out;
3944 }
3945
3946 hist_data->n_keys++;
3947 hist_data->n_fields++;
3948
3949 if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
3950 return -EINVAL;
3951
3952 ret = key_size;
3953 out:
3954 return ret;
3955 }
3956
3957 static int create_key_fields(struct hist_trigger_data *hist_data,
3958 struct trace_event_file *file)
3959 {
3960 unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
3961 char *fields_str, *field_str;
3962 int ret = -EINVAL;
3963
3964 fields_str = hist_data->attrs->keys_str;
3965 if (!fields_str)
3966 goto out;
3967
3968 for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
3969 field_str = strsep(&fields_str, ",");
3970 if (!field_str)
3971 break;
3972 ret = create_key_field(hist_data, i, key_offset,
3973 file, field_str);
3974 if (ret < 0)
3975 goto out;
3976 key_offset += ret;
3977 }
3978 if (fields_str) {
3979 ret = -EINVAL;
3980 goto out;
3981 }
3982 ret = 0;
3983 out:
3984 return ret;
3985 }
3986
3987 static int create_var_fields(struct hist_trigger_data *hist_data,
3988 struct trace_event_file *file)
3989 {
3990 unsigned int i, j = hist_data->n_vals;
3991 int ret = 0;
3992
3993 unsigned int n_vars = hist_data->attrs->var_defs.n_vars;
3994
3995 for (i = 0; i < n_vars; i++) {
3996 char *var_name = hist_data->attrs->var_defs.name[i];
3997 char *expr = hist_data->attrs->var_defs.expr[i];
3998
3999 ret = create_var_field(hist_data, j++, file, var_name, expr);
4000 if (ret)
4001 goto out;
4002 }
4003 out:
4004 return ret;
4005 }
4006
4007 static void free_var_defs(struct hist_trigger_data *hist_data)
4008 {
4009 unsigned int i;
4010
4011 for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
4012 kfree(hist_data->attrs->var_defs.name[i]);
4013 kfree(hist_data->attrs->var_defs.expr[i]);
4014 }
4015
4016 hist_data->attrs->var_defs.n_vars = 0;
4017 }
4018
4019 static int parse_var_defs(struct hist_trigger_data *hist_data)
4020 {
4021 struct trace_array *tr = hist_data->event_file->tr;
4022 char *s, *str, *var_name, *field_str;
4023 unsigned int i, j, n_vars = 0;
4024 int ret = 0;
4025
4026 for (i = 0; i < hist_data->attrs->n_assignments; i++) {
4027 str = hist_data->attrs->assignment_str[i];
4028 for (j = 0; j < TRACING_MAP_VARS_MAX; j++) {
4029 field_str = strsep(&str, ",");
4030 if (!field_str)
4031 break;
4032
4033 var_name = strsep(&field_str, "=");
4034 if (!var_name || !field_str) {
4035 hist_err(tr, HIST_ERR_MALFORMED_ASSIGNMENT,
4036 errpos(var_name));
4037 ret = -EINVAL;
4038 goto free;
4039 }
4040
4041 if (n_vars == TRACING_MAP_VARS_MAX) {
4042 hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(var_name));
4043 ret = -EINVAL;
4044 goto free;
4045 }
4046
4047 s = kstrdup(var_name, GFP_KERNEL);
4048 if (!s) {
4049 ret = -ENOMEM;
4050 goto free;
4051 }
4052 hist_data->attrs->var_defs.name[n_vars] = s;
4053
4054 s = kstrdup(field_str, GFP_KERNEL);
4055 if (!s) {
4056 ret = -ENOMEM;
4057 goto free;
4058 }
4059 hist_data->attrs->var_defs.expr[n_vars++] = s;
4060
4061 hist_data->attrs->var_defs.n_vars = n_vars;
4062 }
4063 }
4064
4065 return ret;
4066 free:
4067 free_var_defs(hist_data);
4068
4069 return ret;
4070 }
4071
4072 static int create_hist_fields(struct hist_trigger_data *hist_data,
4073 struct trace_event_file *file)
4074 {
4075 int ret;
4076
4077 ret = parse_var_defs(hist_data);
4078 if (ret)
4079 goto out;
4080
4081 ret = create_val_fields(hist_data, file);
4082 if (ret)
4083 goto out;
4084
4085 ret = create_var_fields(hist_data, file);
4086 if (ret)
4087 goto out;
4088
4089 ret = create_key_fields(hist_data, file);
4090 if (ret)
4091 goto out;
4092 out:
4093 free_var_defs(hist_data);
4094
4095 return ret;
4096 }
4097
4098 static int is_descending(struct trace_array *tr, const char *str)
4099 {
4100 if (!str)
4101 return 0;
4102
4103 if (strcmp(str, "descending") == 0)
4104 return 1;
4105
4106 if (strcmp(str, "ascending") == 0)
4107 return 0;
4108
4109 hist_err(tr, HIST_ERR_INVALID_SORT_MODIFIER, errpos((char *)str));
4110
4111 return -EINVAL;
4112 }
4113
4114 static int create_sort_keys(struct hist_trigger_data *hist_data)
4115 {
4116 struct trace_array *tr = hist_data->event_file->tr;
4117 char *fields_str = hist_data->attrs->sort_key_str;
4118 struct tracing_map_sort_key *sort_key;
4119 int descending, ret = 0;
4120 unsigned int i, j, k;
4121
4122 hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
4123
4124 if (!fields_str)
4125 goto out;
4126
4127 for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
4128 struct hist_field *hist_field;
4129 char *field_str, *field_name;
4130 const char *test_name;
4131
4132 sort_key = &hist_data->sort_keys[i];
4133
4134 field_str = strsep(&fields_str, ",");
4135 if (!field_str)
4136 break;
4137
4138 if (!*field_str) {
4139 ret = -EINVAL;
4140 hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
4141 break;
4142 }
4143
4144 if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
4145 hist_err(tr, HIST_ERR_TOO_MANY_SORT_FIELDS, errpos("sort="));
4146 ret = -EINVAL;
4147 break;
4148 }
4149
4150 field_name = strsep(&field_str, ".");
4151 if (!field_name || !*field_name) {
4152 ret = -EINVAL;
4153 hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
4154 break;
4155 }
4156
4157 if (strcmp(field_name, "hitcount") == 0) {
4158 descending = is_descending(tr, field_str);
4159 if (descending < 0) {
4160 ret = descending;
4161 break;
4162 }
4163 sort_key->descending = descending;
4164 continue;
4165 }
4166
4167 for (j = 1, k = 1; j < hist_data->n_fields; j++) {
4168 unsigned int idx;
4169
4170 hist_field = hist_data->fields[j];
4171 if (hist_field->flags & HIST_FIELD_FL_VAR)
4172 continue;
4173
4174 idx = k++;
4175
4176 test_name = hist_field_name(hist_field, 0);
4177
4178 if (strcmp(field_name, test_name) == 0) {
4179 sort_key->field_idx = idx;
4180 descending = is_descending(tr, field_str);
4181 if (descending < 0) {
4182 ret = descending;
4183 goto out;
4184 }
4185 sort_key->descending = descending;
4186 break;
4187 }
4188 }
4189 if (j == hist_data->n_fields) {
4190 ret = -EINVAL;
4191 hist_err(tr, HIST_ERR_INVALID_SORT_FIELD, errpos(field_name));
4192 break;
4193 }
4194 }
4195
4196 hist_data->n_sort_keys = i;
4197 out:
4198 return ret;
4199 }
4200
4201 static void destroy_actions(struct hist_trigger_data *hist_data)
4202 {
4203 unsigned int i;
4204
4205 for (i = 0; i < hist_data->n_actions; i++) {
4206 struct action_data *data = hist_data->actions[i];
4207
4208 if (data->handler == HANDLER_ONMATCH)
4209 onmatch_destroy(data);
4210 else if (data->handler == HANDLER_ONMAX ||
4211 data->handler == HANDLER_ONCHANGE)
4212 track_data_destroy(hist_data, data);
4213 else
4214 kfree(data);
4215 }
4216 }
4217
4218 static int parse_actions(struct hist_trigger_data *hist_data)
4219 {
4220 struct trace_array *tr = hist_data->event_file->tr;
4221 struct action_data *data;
4222 unsigned int i;
4223 int ret = 0;
4224 char *str;
4225 int len;
4226
4227 for (i = 0; i < hist_data->attrs->n_actions; i++) {
4228 str = hist_data->attrs->action_str[i];
4229
4230 if ((len = str_has_prefix(str, "onmatch("))) {
4231 char *action_str = str + len;
4232
4233 data = onmatch_parse(tr, action_str);
4234 if (IS_ERR(data)) {
4235 ret = PTR_ERR(data);
4236 break;
4237 }
4238 } else if ((len = str_has_prefix(str, "onmax("))) {
4239 char *action_str = str + len;
4240
4241 data = track_data_parse(hist_data, action_str,
4242 HANDLER_ONMAX);
4243 if (IS_ERR(data)) {
4244 ret = PTR_ERR(data);
4245 break;
4246 }
4247 } else if ((len = str_has_prefix(str, "onchange("))) {
4248 char *action_str = str + len;
4249
4250 data = track_data_parse(hist_data, action_str,
4251 HANDLER_ONCHANGE);
4252 if (IS_ERR(data)) {
4253 ret = PTR_ERR(data);
4254 break;
4255 }
4256 } else {
4257 ret = -EINVAL;
4258 break;
4259 }
4260
4261 hist_data->actions[hist_data->n_actions++] = data;
4262 }
4263
4264 return ret;
4265 }
4266
4267 static int create_actions(struct hist_trigger_data *hist_data)
4268 {
4269 struct action_data *data;
4270 unsigned int i;
4271 int ret = 0;
4272
4273 for (i = 0; i < hist_data->attrs->n_actions; i++) {
4274 data = hist_data->actions[i];
4275
4276 if (data->handler == HANDLER_ONMATCH) {
4277 ret = onmatch_create(hist_data, data);
4278 if (ret)
4279 break;
4280 } else if (data->handler == HANDLER_ONMAX ||
4281 data->handler == HANDLER_ONCHANGE) {
4282 ret = track_data_create(hist_data, data);
4283 if (ret)
4284 break;
4285 } else {
4286 ret = -EINVAL;
4287 break;
4288 }
4289 }
4290
4291 return ret;
4292 }
4293
4294 static void print_actions(struct seq_file *m,
4295 struct hist_trigger_data *hist_data,
4296 struct tracing_map_elt *elt)
4297 {
4298 unsigned int i;
4299
4300 for (i = 0; i < hist_data->n_actions; i++) {
4301 struct action_data *data = hist_data->actions[i];
4302
4303 if (data->action == ACTION_SNAPSHOT)
4304 continue;
4305
4306 if (data->handler == HANDLER_ONMAX ||
4307 data->handler == HANDLER_ONCHANGE)
4308 track_data_print(m, hist_data, elt, data);
4309 }
4310 }
4311
4312 static void print_action_spec(struct seq_file *m,
4313 struct hist_trigger_data *hist_data,
4314 struct action_data *data)
4315 {
4316 unsigned int i;
4317
4318 if (data->action == ACTION_SAVE) {
4319 for (i = 0; i < hist_data->n_save_vars; i++) {
4320 seq_printf(m, "%s", hist_data->save_vars[i]->var->var.name);
4321 if (i < hist_data->n_save_vars - 1)
4322 seq_puts(m, ",");
4323 }
4324 } else if (data->action == ACTION_TRACE) {
4325 if (data->use_trace_keyword)
4326 seq_printf(m, "%s", data->synth_event_name);
4327 for (i = 0; i < data->n_params; i++) {
4328 if (i || data->use_trace_keyword)
4329 seq_puts(m, ",");
4330 seq_printf(m, "%s", data->params[i]);
4331 }
4332 }
4333 }
4334
4335 static void print_track_data_spec(struct seq_file *m,
4336 struct hist_trigger_data *hist_data,
4337 struct action_data *data)
4338 {
4339 if (data->handler == HANDLER_ONMAX)
4340 seq_puts(m, ":onmax(");
4341 else if (data->handler == HANDLER_ONCHANGE)
4342 seq_puts(m, ":onchange(");
4343 seq_printf(m, "%s", data->track_data.var_str);
4344 seq_printf(m, ").%s(", data->action_name);
4345
4346 print_action_spec(m, hist_data, data);
4347
4348 seq_puts(m, ")");
4349 }
4350
4351 static void print_onmatch_spec(struct seq_file *m,
4352 struct hist_trigger_data *hist_data,
4353 struct action_data *data)
4354 {
4355 seq_printf(m, ":onmatch(%s.%s).", data->match_data.event_system,
4356 data->match_data.event);
4357
4358 seq_printf(m, "%s(", data->action_name);
4359
4360 print_action_spec(m, hist_data, data);
4361
4362 seq_puts(m, ")");
4363 }
4364
4365 static bool actions_match(struct hist_trigger_data *hist_data,
4366 struct hist_trigger_data *hist_data_test)
4367 {
4368 unsigned int i, j;
4369
4370 if (hist_data->n_actions != hist_data_test->n_actions)
4371 return false;
4372
4373 for (i = 0; i < hist_data->n_actions; i++) {
4374 struct action_data *data = hist_data->actions[i];
4375 struct action_data *data_test = hist_data_test->actions[i];
4376 char *action_name, *action_name_test;
4377
4378 if (data->handler != data_test->handler)
4379 return false;
4380 if (data->action != data_test->action)
4381 return false;
4382
4383 if (data->n_params != data_test->n_params)
4384 return false;
4385
4386 for (j = 0; j < data->n_params; j++) {
4387 if (strcmp(data->params[j], data_test->params[j]) != 0)
4388 return false;
4389 }
4390
4391 if (data->use_trace_keyword)
4392 action_name = data->synth_event_name;
4393 else
4394 action_name = data->action_name;
4395
4396 if (data_test->use_trace_keyword)
4397 action_name_test = data_test->synth_event_name;
4398 else
4399 action_name_test = data_test->action_name;
4400
4401 if (strcmp(action_name, action_name_test) != 0)
4402 return false;
4403
4404 if (data->handler == HANDLER_ONMATCH) {
4405 if (strcmp(data->match_data.event_system,
4406 data_test->match_data.event_system) != 0)
4407 return false;
4408 if (strcmp(data->match_data.event,
4409 data_test->match_data.event) != 0)
4410 return false;
4411 } else if (data->handler == HANDLER_ONMAX ||
4412 data->handler == HANDLER_ONCHANGE) {
4413 if (strcmp(data->track_data.var_str,
4414 data_test->track_data.var_str) != 0)
4415 return false;
4416 }
4417 }
4418
4419 return true;
4420 }
4421
4422
4423 static void print_actions_spec(struct seq_file *m,
4424 struct hist_trigger_data *hist_data)
4425 {
4426 unsigned int i;
4427
4428 for (i = 0; i < hist_data->n_actions; i++) {
4429 struct action_data *data = hist_data->actions[i];
4430
4431 if (data->handler == HANDLER_ONMATCH)
4432 print_onmatch_spec(m, hist_data, data);
4433 else if (data->handler == HANDLER_ONMAX ||
4434 data->handler == HANDLER_ONCHANGE)
4435 print_track_data_spec(m, hist_data, data);
4436 }
4437 }
4438
4439 static void destroy_field_var_hists(struct hist_trigger_data *hist_data)
4440 {
4441 unsigned int i;
4442
4443 for (i = 0; i < hist_data->n_field_var_hists; i++) {
4444 kfree(hist_data->field_var_hists[i]->cmd);
4445 kfree(hist_data->field_var_hists[i]);
4446 }
4447 }
4448
4449 static void destroy_hist_data(struct hist_trigger_data *hist_data)
4450 {
4451 if (!hist_data)
4452 return;
4453
4454 destroy_hist_trigger_attrs(hist_data->attrs);
4455 destroy_hist_fields(hist_data);
4456 tracing_map_destroy(hist_data->map);
4457
4458 destroy_actions(hist_data);
4459 destroy_field_vars(hist_data);
4460 destroy_field_var_hists(hist_data);
4461
4462 kfree(hist_data);
4463 }
4464
4465 static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
4466 {
4467 struct tracing_map *map = hist_data->map;
4468 struct ftrace_event_field *field;
4469 struct hist_field *hist_field;
4470 int i, idx = 0;
4471
4472 for_each_hist_field(i, hist_data) {
4473 hist_field = hist_data->fields[i];
4474 if (hist_field->flags & HIST_FIELD_FL_KEY) {
4475 tracing_map_cmp_fn_t cmp_fn;
4476
4477 field = hist_field->field;
4478
4479 if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
4480 cmp_fn = tracing_map_cmp_none;
4481 else if (!field || hist_field->flags & HIST_FIELD_FL_CPU)
4482 cmp_fn = tracing_map_cmp_num(hist_field->size,
4483 hist_field->is_signed);
4484 else if (is_string_field(field))
4485 cmp_fn = tracing_map_cmp_string;
4486 else
4487 cmp_fn = tracing_map_cmp_num(field->size,
4488 field->is_signed);
4489 idx = tracing_map_add_key_field(map,
4490 hist_field->offset,
4491 cmp_fn);
4492 } else if (!(hist_field->flags & HIST_FIELD_FL_VAR))
4493 idx = tracing_map_add_sum_field(map);
4494
4495 if (idx < 0)
4496 return idx;
4497
4498 if (hist_field->flags & HIST_FIELD_FL_VAR) {
4499 idx = tracing_map_add_var(map);
4500 if (idx < 0)
4501 return idx;
4502 hist_field->var.idx = idx;
4503 hist_field->var.hist_data = hist_data;
4504 }
4505 }
4506
4507 return 0;
4508 }
4509
4510 static struct hist_trigger_data *
4511 create_hist_data(unsigned int map_bits,
4512 struct hist_trigger_attrs *attrs,
4513 struct trace_event_file *file,
4514 bool remove)
4515 {
4516 const struct tracing_map_ops *map_ops = NULL;
4517 struct hist_trigger_data *hist_data;
4518 int ret = 0;
4519
4520 hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL);
4521 if (!hist_data)
4522 return ERR_PTR(-ENOMEM);
4523
4524 hist_data->attrs = attrs;
4525 hist_data->remove = remove;
4526 hist_data->event_file = file;
4527
4528 ret = parse_actions(hist_data);
4529 if (ret)
4530 goto free;
4531
4532 ret = create_hist_fields(hist_data, file);
4533 if (ret)
4534 goto free;
4535
4536 ret = create_sort_keys(hist_data);
4537 if (ret)
4538 goto free;
4539
4540 map_ops = &hist_trigger_elt_data_ops;
4541
4542 hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
4543 map_ops, hist_data);
4544 if (IS_ERR(hist_data->map)) {
4545 ret = PTR_ERR(hist_data->map);
4546 hist_data->map = NULL;
4547 goto free;
4548 }
4549
4550 ret = create_tracing_map_fields(hist_data);
4551 if (ret)
4552 goto free;
4553 out:
4554 return hist_data;
4555 free:
4556 hist_data->attrs = NULL;
4557
4558 destroy_hist_data(hist_data);
4559
4560 hist_data = ERR_PTR(ret);
4561
4562 goto out;
4563 }
4564
4565 static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
4566 struct tracing_map_elt *elt,
4567 struct trace_buffer *buffer, void *rec,
4568 struct ring_buffer_event *rbe,
4569 u64 *var_ref_vals)
4570 {
4571 struct hist_elt_data *elt_data;
4572 struct hist_field *hist_field;
4573 unsigned int i, var_idx;
4574 u64 hist_val;
4575
4576 elt_data = elt->private_data;
4577 elt_data->var_ref_vals = var_ref_vals;
4578
4579 for_each_hist_val_field(i, hist_data) {
4580 hist_field = hist_data->fields[i];
4581 hist_val = hist_field->fn(hist_field, elt, buffer, rbe, rec);
4582 if (hist_field->flags & HIST_FIELD_FL_VAR) {
4583 var_idx = hist_field->var.idx;
4584
4585 if (hist_field->flags & HIST_FIELD_FL_STRING) {
4586 unsigned int str_start, var_str_idx, idx;
4587 char *str, *val_str;
4588 unsigned int size;
4589
4590 str_start = hist_data->n_field_var_str +
4591 hist_data->n_save_var_str;
4592 var_str_idx = hist_field->var_str_idx;
4593 idx = str_start + var_str_idx;
4594
4595 str = elt_data->field_var_str[idx];
4596 val_str = (char *)(uintptr_t)hist_val;
4597
4598 size = min(hist_field->size, STR_VAR_LEN_MAX);
4599 strscpy(str, val_str, size);
4600
4601 hist_val = (u64)(uintptr_t)str;
4602 }
4603 tracing_map_set_var(elt, var_idx, hist_val);
4604 continue;
4605 }
4606 tracing_map_update_sum(elt, i, hist_val);
4607 }
4608
4609 for_each_hist_key_field(i, hist_data) {
4610 hist_field = hist_data->fields[i];
4611 if (hist_field->flags & HIST_FIELD_FL_VAR) {
4612 hist_val = hist_field->fn(hist_field, elt, buffer, rbe, rec);
4613 var_idx = hist_field->var.idx;
4614 tracing_map_set_var(elt, var_idx, hist_val);
4615 }
4616 }
4617
4618 update_field_vars(hist_data, elt, buffer, rbe, rec);
4619 }
4620
4621 static inline void add_to_key(char *compound_key, void *key,
4622 struct hist_field *key_field, void *rec)
4623 {
4624 size_t size = key_field->size;
4625
4626 if (key_field->flags & HIST_FIELD_FL_STRING) {
4627 struct ftrace_event_field *field;
4628
4629 field = key_field->field;
4630 if (field->filter_type == FILTER_DYN_STRING)
4631 size = *(u32 *)(rec + field->offset) >> 16;
4632 else if (field->filter_type == FILTER_STATIC_STRING)
4633 size = field->size;
4634
4635 /* ensure NULL-termination */
4636 if (size > key_field->size - 1)
4637 size = key_field->size - 1;
4638
4639 strncpy(compound_key + key_field->offset, (char *)key, size);
4640 } else
4641 memcpy(compound_key + key_field->offset, key, size);
4642 }
4643
4644 static void
4645 hist_trigger_actions(struct hist_trigger_data *hist_data,
4646 struct tracing_map_elt *elt,
4647 struct trace_buffer *buffer, void *rec,
4648 struct ring_buffer_event *rbe, void *key,
4649 u64 *var_ref_vals)
4650 {
4651 struct action_data *data;
4652 unsigned int i;
4653
4654 for (i = 0; i < hist_data->n_actions; i++) {
4655 data = hist_data->actions[i];
4656 data->fn(hist_data, elt, buffer, rec, rbe, key, data, var_ref_vals);
4657 }
4658 }
4659
4660 static void event_hist_trigger(struct event_trigger_data *data,
4661 struct trace_buffer *buffer, void *rec,
4662 struct ring_buffer_event *rbe)
4663 {
4664 struct hist_trigger_data *hist_data = data->private_data;
4665 bool use_compound_key = (hist_data->n_keys > 1);
4666 unsigned long entries[HIST_STACKTRACE_DEPTH];
4667 u64 var_ref_vals[TRACING_MAP_VARS_MAX];
4668 char compound_key[HIST_KEY_SIZE_MAX];
4669 struct tracing_map_elt *elt = NULL;
4670 struct hist_field *key_field;
4671 u64 field_contents;
4672 void *key = NULL;
4673 unsigned int i;
4674
4675 memset(compound_key, 0, hist_data->key_size);
4676
4677 for_each_hist_key_field(i, hist_data) {
4678 key_field = hist_data->fields[i];
4679
4680 if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
4681 memset(entries, 0, HIST_STACKTRACE_SIZE);
4682 stack_trace_save(entries, HIST_STACKTRACE_DEPTH,
4683 HIST_STACKTRACE_SKIP);
4684 key = entries;
4685 } else {
4686 field_contents = key_field->fn(key_field, elt, buffer, rbe, rec);
4687 if (key_field->flags & HIST_FIELD_FL_STRING) {
4688 key = (void *)(unsigned long)field_contents;
4689 use_compound_key = true;
4690 } else
4691 key = (void *)&field_contents;
4692 }
4693
4694 if (use_compound_key)
4695 add_to_key(compound_key, key, key_field, rec);
4696 }
4697
4698 if (use_compound_key)
4699 key = compound_key;
4700
4701 if (hist_data->n_var_refs &&
4702 !resolve_var_refs(hist_data, key, var_ref_vals, false))
4703 return;
4704
4705 elt = tracing_map_insert(hist_data->map, key);
4706 if (!elt)
4707 return;
4708
4709 hist_trigger_elt_update(hist_data, elt, buffer, rec, rbe, var_ref_vals);
4710
4711 if (resolve_var_refs(hist_data, key, var_ref_vals, true))
4712 hist_trigger_actions(hist_data, elt, buffer, rec, rbe, key, var_ref_vals);
4713 }
4714
4715 static void hist_trigger_stacktrace_print(struct seq_file *m,
4716 unsigned long *stacktrace_entries,
4717 unsigned int max_entries)
4718 {
4719 char str[KSYM_SYMBOL_LEN];
4720 unsigned int spaces = 8;
4721 unsigned int i;
4722
4723 for (i = 0; i < max_entries; i++) {
4724 if (!stacktrace_entries[i])
4725 return;
4726
4727 seq_printf(m, "%*c", 1 + spaces, ' ');
4728 sprint_symbol(str, stacktrace_entries[i]);
4729 seq_printf(m, "%s\n", str);
4730 }
4731 }
4732
4733 static void hist_trigger_print_key(struct seq_file *m,
4734 struct hist_trigger_data *hist_data,
4735 void *key,
4736 struct tracing_map_elt *elt)
4737 {
4738 struct hist_field *key_field;
4739 char str[KSYM_SYMBOL_LEN];
4740 bool multiline = false;
4741 const char *field_name;
4742 unsigned int i;
4743 u64 uval;
4744
4745 seq_puts(m, "{ ");
4746
4747 for_each_hist_key_field(i, hist_data) {
4748 key_field = hist_data->fields[i];
4749
4750 if (i > hist_data->n_vals)
4751 seq_puts(m, ", ");
4752
4753 field_name = hist_field_name(key_field, 0);
4754
4755 if (key_field->flags & HIST_FIELD_FL_HEX) {
4756 uval = *(u64 *)(key + key_field->offset);
4757 seq_printf(m, "%s: %llx", field_name, uval);
4758 } else if (key_field->flags & HIST_FIELD_FL_SYM) {
4759 uval = *(u64 *)(key + key_field->offset);
4760 sprint_symbol_no_offset(str, uval);
4761 seq_printf(m, "%s: [%llx] %-45s", field_name,
4762 uval, str);
4763 } else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
4764 uval = *(u64 *)(key + key_field->offset);
4765 sprint_symbol(str, uval);
4766 seq_printf(m, "%s: [%llx] %-55s", field_name,
4767 uval, str);
4768 } else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
4769 struct hist_elt_data *elt_data = elt->private_data;
4770 char *comm;
4771
4772 if (WARN_ON_ONCE(!elt_data))
4773 return;
4774
4775 comm = elt_data->comm;
4776
4777 uval = *(u64 *)(key + key_field->offset);
4778 seq_printf(m, "%s: %-16s[%10llu]", field_name,
4779 comm, uval);
4780 } else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
4781 const char *syscall_name;
4782
4783 uval = *(u64 *)(key + key_field->offset);
4784 syscall_name = get_syscall_name(uval);
4785 if (!syscall_name)
4786 syscall_name = "unknown_syscall";
4787
4788 seq_printf(m, "%s: %-30s[%3llu]", field_name,
4789 syscall_name, uval);
4790 } else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
4791 seq_puts(m, "stacktrace:\n");
4792 hist_trigger_stacktrace_print(m,
4793 key + key_field->offset,
4794 HIST_STACKTRACE_DEPTH);
4795 multiline = true;
4796 } else if (key_field->flags & HIST_FIELD_FL_LOG2) {
4797 seq_printf(m, "%s: ~ 2^%-2llu", field_name,
4798 *(u64 *)(key + key_field->offset));
4799 } else if (key_field->flags & HIST_FIELD_FL_BUCKET) {
4800 unsigned long buckets = key_field->buckets;
4801 uval = *(u64 *)(key + key_field->offset);
4802 seq_printf(m, "%s: ~ %llu-%llu", field_name,
4803 uval, uval + buckets -1);
4804 } else if (key_field->flags & HIST_FIELD_FL_STRING) {
4805 seq_printf(m, "%s: %-50s", field_name,
4806 (char *)(key + key_field->offset));
4807 } else {
4808 uval = *(u64 *)(key + key_field->offset);
4809 seq_printf(m, "%s: %10llu", field_name, uval);
4810 }
4811 }
4812
4813 if (!multiline)
4814 seq_puts(m, " ");
4815
4816 seq_puts(m, "}");
4817 }
4818
4819 static void hist_trigger_entry_print(struct seq_file *m,
4820 struct hist_trigger_data *hist_data,
4821 void *key,
4822 struct tracing_map_elt *elt)
4823 {
4824 const char *field_name;
4825 unsigned int i;
4826
4827 hist_trigger_print_key(m, hist_data, key, elt);
4828
4829 seq_printf(m, " hitcount: %10llu",
4830 tracing_map_read_sum(elt, HITCOUNT_IDX));
4831
4832 for (i = 1; i < hist_data->n_vals; i++) {
4833 field_name = hist_field_name(hist_data->fields[i], 0);
4834
4835 if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR ||
4836 hist_data->fields[i]->flags & HIST_FIELD_FL_EXPR)
4837 continue;
4838
4839 if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
4840 seq_printf(m, " %s: %10llx", field_name,
4841 tracing_map_read_sum(elt, i));
4842 } else {
4843 seq_printf(m, " %s: %10llu", field_name,
4844 tracing_map_read_sum(elt, i));
4845 }
4846 }
4847
4848 print_actions(m, hist_data, elt);
4849
4850 seq_puts(m, "\n");
4851 }
4852
4853 static int print_entries(struct seq_file *m,
4854 struct hist_trigger_data *hist_data)
4855 {
4856 struct tracing_map_sort_entry **sort_entries = NULL;
4857 struct tracing_map *map = hist_data->map;
4858 int i, n_entries;
4859
4860 n_entries = tracing_map_sort_entries(map, hist_data->sort_keys,
4861 hist_data->n_sort_keys,
4862 &sort_entries);
4863 if (n_entries < 0)
4864 return n_entries;
4865
4866 for (i = 0; i < n_entries; i++)
4867 hist_trigger_entry_print(m, hist_data,
4868 sort_entries[i]->key,
4869 sort_entries[i]->elt);
4870
4871 tracing_map_destroy_sort_entries(sort_entries, n_entries);
4872
4873 return n_entries;
4874 }
4875
4876 static void hist_trigger_show(struct seq_file *m,
4877 struct event_trigger_data *data, int n)
4878 {
4879 struct hist_trigger_data *hist_data;
4880 int n_entries;
4881
4882 if (n > 0)
4883 seq_puts(m, "\n\n");
4884
4885 seq_puts(m, "# event histogram\n#\n# trigger info: ");
4886 data->ops->print(m, data->ops, data);
4887 seq_puts(m, "#\n\n");
4888
4889 hist_data = data->private_data;
4890 n_entries = print_entries(m, hist_data);
4891 if (n_entries < 0)
4892 n_entries = 0;
4893
4894 track_data_snapshot_print(m, hist_data);
4895
4896 seq_printf(m, "\nTotals:\n Hits: %llu\n Entries: %u\n Dropped: %llu\n",
4897 (u64)atomic64_read(&hist_data->map->hits),
4898 n_entries, (u64)atomic64_read(&hist_data->map->drops));
4899 }
4900
4901 static int hist_show(struct seq_file *m, void *v)
4902 {
4903 struct event_trigger_data *data;
4904 struct trace_event_file *event_file;
4905 int n = 0, ret = 0;
4906
4907 mutex_lock(&event_mutex);
4908
4909 event_file = event_file_data(m->private);
4910 if (unlikely(!event_file)) {
4911 ret = -ENODEV;
4912 goto out_unlock;
4913 }
4914
4915 list_for_each_entry(data, &event_file->triggers, list) {
4916 if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
4917 hist_trigger_show(m, data, n++);
4918 }
4919
4920 out_unlock:
4921 mutex_unlock(&event_mutex);
4922
4923 return ret;
4924 }
4925
4926 static int event_hist_open(struct inode *inode, struct file *file)
4927 {
4928 int ret;
4929
4930 ret = security_locked_down(LOCKDOWN_TRACEFS);
4931 if (ret)
4932 return ret;
4933
4934 return single_open(file, hist_show, file);
4935 }
4936
4937 const struct file_operations event_hist_fops = {
4938 .open = event_hist_open,
4939 .read = seq_read,
4940 .llseek = seq_lseek,
4941 .release = single_release,
4942 };
4943
4944 #ifdef CONFIG_HIST_TRIGGERS_DEBUG
4945 static void hist_field_debug_show_flags(struct seq_file *m,
4946 unsigned long flags)
4947 {
4948 seq_puts(m, " flags:\n");
4949
4950 if (flags & HIST_FIELD_FL_KEY)
4951 seq_puts(m, " HIST_FIELD_FL_KEY\n");
4952 else if (flags & HIST_FIELD_FL_HITCOUNT)
4953 seq_puts(m, " VAL: HIST_FIELD_FL_HITCOUNT\n");
4954 else if (flags & HIST_FIELD_FL_VAR)
4955 seq_puts(m, " HIST_FIELD_FL_VAR\n");
4956 else if (flags & HIST_FIELD_FL_VAR_REF)
4957 seq_puts(m, " HIST_FIELD_FL_VAR_REF\n");
4958 else
4959 seq_puts(m, " VAL: normal u64 value\n");
4960
4961 if (flags & HIST_FIELD_FL_ALIAS)
4962 seq_puts(m, " HIST_FIELD_FL_ALIAS\n");
4963 }
4964
4965 static int hist_field_debug_show(struct seq_file *m,
4966 struct hist_field *field, unsigned long flags)
4967 {
4968 if ((field->flags & flags) != flags) {
4969 seq_printf(m, "ERROR: bad flags - %lx\n", flags);
4970 return -EINVAL;
4971 }
4972
4973 hist_field_debug_show_flags(m, field->flags);
4974 if (field->field)
4975 seq_printf(m, " ftrace_event_field name: %s\n",
4976 field->field->name);
4977
4978 if (field->flags & HIST_FIELD_FL_VAR) {
4979 seq_printf(m, " var.name: %s\n", field->var.name);
4980 seq_printf(m, " var.idx (into tracing_map_elt.vars[]): %u\n",
4981 field->var.idx);
4982 }
4983
4984 if (field->flags & HIST_FIELD_FL_ALIAS)
4985 seq_printf(m, " var_ref_idx (into hist_data->var_refs[]): %u\n",
4986 field->var_ref_idx);
4987
4988 if (field->flags & HIST_FIELD_FL_VAR_REF) {
4989 seq_printf(m, " name: %s\n", field->name);
4990 seq_printf(m, " var.idx (into tracing_map_elt.vars[]): %u\n",
4991 field->var.idx);
4992 seq_printf(m, " var.hist_data: %p\n", field->var.hist_data);
4993 seq_printf(m, " var_ref_idx (into hist_data->var_refs[]): %u\n",
4994 field->var_ref_idx);
4995 if (field->system)
4996 seq_printf(m, " system: %s\n", field->system);
4997 if (field->event_name)
4998 seq_printf(m, " event_name: %s\n", field->event_name);
4999 }
5000
5001 seq_printf(m, " type: %s\n", field->type);
5002 seq_printf(m, " size: %u\n", field->size);
5003 seq_printf(m, " is_signed: %u\n", field->is_signed);
5004
5005 return 0;
5006 }
5007
5008 static int field_var_debug_show(struct seq_file *m,
5009 struct field_var *field_var, unsigned int i,
5010 bool save_vars)
5011 {
5012 const char *vars_name = save_vars ? "save_vars" : "field_vars";
5013 struct hist_field *field;
5014 int ret = 0;
5015
5016 seq_printf(m, "\n hist_data->%s[%d]:\n", vars_name, i);
5017
5018 field = field_var->var;
5019
5020 seq_printf(m, "\n %s[%d].var:\n", vars_name, i);
5021
5022 hist_field_debug_show_flags(m, field->flags);
5023 seq_printf(m, " var.name: %s\n", field->var.name);
5024 seq_printf(m, " var.idx (into tracing_map_elt.vars[]): %u\n",
5025 field->var.idx);
5026
5027 field = field_var->val;
5028
5029 seq_printf(m, "\n %s[%d].val:\n", vars_name, i);
5030 if (field->field)
5031 seq_printf(m, " ftrace_event_field name: %s\n",
5032 field->field->name);
5033 else {
5034 ret = -EINVAL;
5035 goto out;
5036 }
5037
5038 seq_printf(m, " type: %s\n", field->type);
5039 seq_printf(m, " size: %u\n", field->size);
5040 seq_printf(m, " is_signed: %u\n", field->is_signed);
5041 out:
5042 return ret;
5043 }
5044
5045 static int hist_action_debug_show(struct seq_file *m,
5046 struct action_data *data, int i)
5047 {
5048 int ret = 0;
5049
5050 if (data->handler == HANDLER_ONMAX ||
5051 data->handler == HANDLER_ONCHANGE) {
5052 seq_printf(m, "\n hist_data->actions[%d].track_data.var_ref:\n", i);
5053 ret = hist_field_debug_show(m, data->track_data.var_ref,
5054 HIST_FIELD_FL_VAR_REF);
5055 if (ret)
5056 goto out;
5057
5058 seq_printf(m, "\n hist_data->actions[%d].track_data.track_var:\n", i);
5059 ret = hist_field_debug_show(m, data->track_data.track_var,
5060 HIST_FIELD_FL_VAR);
5061 if (ret)
5062 goto out;
5063 }
5064
5065 if (data->handler == HANDLER_ONMATCH) {
5066 seq_printf(m, "\n hist_data->actions[%d].match_data.event_system: %s\n",
5067 i, data->match_data.event_system);
5068 seq_printf(m, " hist_data->actions[%d].match_data.event: %s\n",
5069 i, data->match_data.event);
5070 }
5071 out:
5072 return ret;
5073 }
5074
5075 static int hist_actions_debug_show(struct seq_file *m,
5076 struct hist_trigger_data *hist_data)
5077 {
5078 int i, ret = 0;
5079
5080 if (hist_data->n_actions)
5081 seq_puts(m, "\n action tracking variables (for onmax()/onchange()/onmatch()):\n");
5082
5083 for (i = 0; i < hist_data->n_actions; i++) {
5084 struct action_data *action = hist_data->actions[i];
5085
5086 ret = hist_action_debug_show(m, action, i);
5087 if (ret)
5088 goto out;
5089 }
5090
5091 if (hist_data->n_save_vars)
5092 seq_puts(m, "\n save action variables (save() params):\n");
5093
5094 for (i = 0; i < hist_data->n_save_vars; i++) {
5095 ret = field_var_debug_show(m, hist_data->save_vars[i], i, true);
5096 if (ret)
5097 goto out;
5098 }
5099 out:
5100 return ret;
5101 }
5102
5103 static void hist_trigger_debug_show(struct seq_file *m,
5104 struct event_trigger_data *data, int n)
5105 {
5106 struct hist_trigger_data *hist_data;
5107 int i, ret;
5108
5109 if (n > 0)
5110 seq_puts(m, "\n\n");
5111
5112 seq_puts(m, "# event histogram\n#\n# trigger info: ");
5113 data->ops->print(m, data->ops, data);
5114 seq_puts(m, "#\n\n");
5115
5116 hist_data = data->private_data;
5117
5118 seq_printf(m, "hist_data: %p\n\n", hist_data);
5119 seq_printf(m, " n_vals: %u\n", hist_data->n_vals);
5120 seq_printf(m, " n_keys: %u\n", hist_data->n_keys);
5121 seq_printf(m, " n_fields: %u\n", hist_data->n_fields);
5122
5123 seq_puts(m, "\n val fields:\n\n");
5124
5125 seq_puts(m, " hist_data->fields[0]:\n");
5126 ret = hist_field_debug_show(m, hist_data->fields[0],
5127 HIST_FIELD_FL_HITCOUNT);
5128 if (ret)
5129 return;
5130
5131 for (i = 1; i < hist_data->n_vals; i++) {
5132 seq_printf(m, "\n hist_data->fields[%d]:\n", i);
5133 ret = hist_field_debug_show(m, hist_data->fields[i], 0);
5134 if (ret)
5135 return;
5136 }
5137
5138 seq_puts(m, "\n key fields:\n");
5139
5140 for (i = hist_data->n_vals; i < hist_data->n_fields; i++) {
5141 seq_printf(m, "\n hist_data->fields[%d]:\n", i);
5142 ret = hist_field_debug_show(m, hist_data->fields[i],
5143 HIST_FIELD_FL_KEY);
5144 if (ret)
5145 return;
5146 }
5147
5148 if (hist_data->n_var_refs)
5149 seq_puts(m, "\n variable reference fields:\n");
5150
5151 for (i = 0; i < hist_data->n_var_refs; i++) {
5152 seq_printf(m, "\n hist_data->var_refs[%d]:\n", i);
5153 ret = hist_field_debug_show(m, hist_data->var_refs[i],
5154 HIST_FIELD_FL_VAR_REF);
5155 if (ret)
5156 return;
5157 }
5158
5159 if (hist_data->n_field_vars)
5160 seq_puts(m, "\n field variables:\n");
5161
5162 for (i = 0; i < hist_data->n_field_vars; i++) {
5163 ret = field_var_debug_show(m, hist_data->field_vars[i], i, false);
5164 if (ret)
5165 return;
5166 }
5167
5168 ret = hist_actions_debug_show(m, hist_data);
5169 if (ret)
5170 return;
5171 }
5172
5173 static int hist_debug_show(struct seq_file *m, void *v)
5174 {
5175 struct event_trigger_data *data;
5176 struct trace_event_file *event_file;
5177 int n = 0, ret = 0;
5178
5179 mutex_lock(&event_mutex);
5180
5181 event_file = event_file_data(m->private);
5182 if (unlikely(!event_file)) {
5183 ret = -ENODEV;
5184 goto out_unlock;
5185 }
5186
5187 list_for_each_entry(data, &event_file->triggers, list) {
5188 if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
5189 hist_trigger_debug_show(m, data, n++);
5190 }
5191
5192 out_unlock:
5193 mutex_unlock(&event_mutex);
5194
5195 return ret;
5196 }
5197
5198 static int event_hist_debug_open(struct inode *inode, struct file *file)
5199 {
5200 int ret;
5201
5202 ret = security_locked_down(LOCKDOWN_TRACEFS);
5203 if (ret)
5204 return ret;
5205
5206 return single_open(file, hist_debug_show, file);
5207 }
5208
5209 const struct file_operations event_hist_debug_fops = {
5210 .open = event_hist_debug_open,
5211 .read = seq_read,
5212 .llseek = seq_lseek,
5213 .release = single_release,
5214 };
5215 #endif
5216
5217 static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
5218 {
5219 const char *field_name = hist_field_name(hist_field, 0);
5220
5221 if (hist_field->var.name)
5222 seq_printf(m, "%s=", hist_field->var.name);
5223
5224 if (hist_field->flags & HIST_FIELD_FL_CPU)
5225 seq_puts(m, "common_cpu");
5226 else if (field_name) {
5227 if (hist_field->flags & HIST_FIELD_FL_VAR_REF ||
5228 hist_field->flags & HIST_FIELD_FL_ALIAS)
5229 seq_putc(m, '$');
5230 seq_printf(m, "%s", field_name);
5231 } else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP)
5232 seq_puts(m, "common_timestamp");
5233
5234 if (hist_field->flags) {
5235 if (!(hist_field->flags & HIST_FIELD_FL_VAR_REF) &&
5236 !(hist_field->flags & HIST_FIELD_FL_EXPR)) {
5237 const char *flags = get_hist_field_flags(hist_field);
5238
5239 if (flags)
5240 seq_printf(m, ".%s", flags);
5241 }
5242 }
5243 if (hist_field->buckets)
5244 seq_printf(m, "=%ld", hist_field->buckets);
5245 }
5246
5247 static int event_hist_trigger_print(struct seq_file *m,
5248 struct event_trigger_ops *ops,
5249 struct event_trigger_data *data)
5250 {
5251 struct hist_trigger_data *hist_data = data->private_data;
5252 struct hist_field *field;
5253 bool have_var = false;
5254 unsigned int i;
5255
5256 seq_puts(m, "hist:");
5257
5258 if (data->name)
5259 seq_printf(m, "%s:", data->name);
5260
5261 seq_puts(m, "keys=");
5262
5263 for_each_hist_key_field(i, hist_data) {
5264 field = hist_data->fields[i];
5265
5266 if (i > hist_data->n_vals)
5267 seq_puts(m, ",");
5268
5269 if (field->flags & HIST_FIELD_FL_STACKTRACE)
5270 seq_puts(m, "stacktrace");
5271 else
5272 hist_field_print(m, field);
5273 }
5274
5275 seq_puts(m, ":vals=");
5276
5277 for_each_hist_val_field(i, hist_data) {
5278 field = hist_data->fields[i];
5279 if (field->flags & HIST_FIELD_FL_VAR) {
5280 have_var = true;
5281 continue;
5282 }
5283
5284 if (i == HITCOUNT_IDX)
5285 seq_puts(m, "hitcount");
5286 else {
5287 seq_puts(m, ",");
5288 hist_field_print(m, field);
5289 }
5290 }
5291
5292 if (have_var) {
5293 unsigned int n = 0;
5294
5295 seq_puts(m, ":");
5296
5297 for_each_hist_val_field(i, hist_data) {
5298 field = hist_data->fields[i];
5299
5300 if (field->flags & HIST_FIELD_FL_VAR) {
5301 if (n++)
5302 seq_puts(m, ",");
5303 hist_field_print(m, field);
5304 }
5305 }
5306 }
5307
5308 seq_puts(m, ":sort=");
5309
5310 for (i = 0; i < hist_data->n_sort_keys; i++) {
5311 struct tracing_map_sort_key *sort_key;
5312 unsigned int idx, first_key_idx;
5313
5314 /* skip VAR vals */
5315 first_key_idx = hist_data->n_vals - hist_data->n_vars;
5316
5317 sort_key = &hist_data->sort_keys[i];
5318 idx = sort_key->field_idx;
5319
5320 if (WARN_ON(idx >= HIST_FIELDS_MAX))
5321 return -EINVAL;
5322
5323 if (i > 0)
5324 seq_puts(m, ",");
5325
5326 if (idx == HITCOUNT_IDX)
5327 seq_puts(m, "hitcount");
5328 else {
5329 if (idx >= first_key_idx)
5330 idx += hist_data->n_vars;
5331 hist_field_print(m, hist_data->fields[idx]);
5332 }
5333
5334 if (sort_key->descending)
5335 seq_puts(m, ".descending");
5336 }
5337 seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
5338 if (hist_data->enable_timestamps)
5339 seq_printf(m, ":clock=%s", hist_data->attrs->clock);
5340
5341 print_actions_spec(m, hist_data);
5342
5343 if (data->filter_str)
5344 seq_printf(m, " if %s", data->filter_str);
5345
5346 if (data->paused)
5347 seq_puts(m, " [paused]");
5348 else
5349 seq_puts(m, " [active]");
5350
5351 seq_putc(m, '\n');
5352
5353 return 0;
5354 }
5355
5356 static int event_hist_trigger_init(struct event_trigger_ops *ops,
5357 struct event_trigger_data *data)
5358 {
5359 struct hist_trigger_data *hist_data = data->private_data;
5360
5361 if (!data->ref && hist_data->attrs->name)
5362 save_named_trigger(hist_data->attrs->name, data);
5363
5364 data->ref++;
5365
5366 return 0;
5367 }
5368
5369 static void unregister_field_var_hists(struct hist_trigger_data *hist_data)
5370 {
5371 struct trace_event_file *file;
5372 unsigned int i;
5373 char *cmd;
5374 int ret;
5375
5376 for (i = 0; i < hist_data->n_field_var_hists; i++) {
5377 file = hist_data->field_var_hists[i]->hist_data->event_file;
5378 cmd = hist_data->field_var_hists[i]->cmd;
5379 ret = event_hist_trigger_func(&trigger_hist_cmd, file,
5380 "!hist", "hist", cmd);
5381 WARN_ON_ONCE(ret < 0);
5382 }
5383 }
5384
5385 static void event_hist_trigger_free(struct event_trigger_ops *ops,
5386 struct event_trigger_data *data)
5387 {
5388 struct hist_trigger_data *hist_data = data->private_data;
5389
5390 if (WARN_ON_ONCE(data->ref <= 0))
5391 return;
5392
5393 data->ref--;
5394 if (!data->ref) {
5395 if (data->name)
5396 del_named_trigger(data);
5397
5398 trigger_data_free(data);
5399
5400 remove_hist_vars(hist_data);
5401
5402 unregister_field_var_hists(hist_data);
5403
5404 destroy_hist_data(hist_data);
5405 }
5406 }
5407
5408 static struct event_trigger_ops event_hist_trigger_ops = {
5409 .func = event_hist_trigger,
5410 .print = event_hist_trigger_print,
5411 .init = event_hist_trigger_init,
5412 .free = event_hist_trigger_free,
5413 };
5414
5415 static int event_hist_trigger_named_init(struct event_trigger_ops *ops,
5416 struct event_trigger_data *data)
5417 {
5418 data->ref++;
5419
5420 save_named_trigger(data->named_data->name, data);
5421
5422 event_hist_trigger_init(ops, data->named_data);
5423
5424 return 0;
5425 }
5426
5427 static void event_hist_trigger_named_free(struct event_trigger_ops *ops,
5428 struct event_trigger_data *data)
5429 {
5430 if (WARN_ON_ONCE(data->ref <= 0))
5431 return;
5432
5433 event_hist_trigger_free(ops, data->named_data);
5434
5435 data->ref--;
5436 if (!data->ref) {
5437 del_named_trigger(data);
5438 trigger_data_free(data);
5439 }
5440 }
5441
5442 static struct event_trigger_ops event_hist_trigger_named_ops = {
5443 .func = event_hist_trigger,
5444 .print = event_hist_trigger_print,
5445 .init = event_hist_trigger_named_init,
5446 .free = event_hist_trigger_named_free,
5447 };
5448
5449 static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
5450 char *param)
5451 {
5452 return &event_hist_trigger_ops;
5453 }
5454
5455 static void hist_clear(struct event_trigger_data *data)
5456 {
5457 struct hist_trigger_data *hist_data = data->private_data;
5458
5459 if (data->name)
5460 pause_named_trigger(data);
5461
5462 tracepoint_synchronize_unregister();
5463
5464 tracing_map_clear(hist_data->map);
5465
5466 if (data->name)
5467 unpause_named_trigger(data);
5468 }
5469
5470 static bool compatible_field(struct ftrace_event_field *field,
5471 struct ftrace_event_field *test_field)
5472 {
5473 if (field == test_field)
5474 return true;
5475 if (field == NULL || test_field == NULL)
5476 return false;
5477 if (strcmp(field->name, test_field->name) != 0)
5478 return false;
5479 if (strcmp(field->type, test_field->type) != 0)
5480 return false;
5481 if (field->size != test_field->size)
5482 return false;
5483 if (field->is_signed != test_field->is_signed)
5484 return false;
5485
5486 return true;
5487 }
5488
5489 static bool hist_trigger_match(struct event_trigger_data *data,
5490 struct event_trigger_data *data_test,
5491 struct event_trigger_data *named_data,
5492 bool ignore_filter)
5493 {
5494 struct tracing_map_sort_key *sort_key, *sort_key_test;
5495 struct hist_trigger_data *hist_data, *hist_data_test;
5496 struct hist_field *key_field, *key_field_test;
5497 unsigned int i;
5498
5499 if (named_data && (named_data != data_test) &&
5500 (named_data != data_test->named_data))
5501 return false;
5502
5503 if (!named_data && is_named_trigger(data_test))
5504 return false;
5505
5506 hist_data = data->private_data;
5507 hist_data_test = data_test->private_data;
5508
5509 if (hist_data->n_vals != hist_data_test->n_vals ||
5510 hist_data->n_fields != hist_data_test->n_fields ||
5511 hist_data->n_sort_keys != hist_data_test->n_sort_keys)
5512 return false;
5513
5514 if (!ignore_filter) {
5515 if ((data->filter_str && !data_test->filter_str) ||
5516 (!data->filter_str && data_test->filter_str))
5517 return false;
5518 }
5519
5520 for_each_hist_field(i, hist_data) {
5521 key_field = hist_data->fields[i];
5522 key_field_test = hist_data_test->fields[i];
5523
5524 if (key_field->flags != key_field_test->flags)
5525 return false;
5526 if (!compatible_field(key_field->field, key_field_test->field))
5527 return false;
5528 if (key_field->offset != key_field_test->offset)
5529 return false;
5530 if (key_field->size != key_field_test->size)
5531 return false;
5532 if (key_field->is_signed != key_field_test->is_signed)
5533 return false;
5534 if (!!key_field->var.name != !!key_field_test->var.name)
5535 return false;
5536 if (key_field->var.name &&
5537 strcmp(key_field->var.name, key_field_test->var.name) != 0)
5538 return false;
5539 }
5540
5541 for (i = 0; i < hist_data->n_sort_keys; i++) {
5542 sort_key = &hist_data->sort_keys[i];
5543 sort_key_test = &hist_data_test->sort_keys[i];
5544
5545 if (sort_key->field_idx != sort_key_test->field_idx ||
5546 sort_key->descending != sort_key_test->descending)
5547 return false;
5548 }
5549
5550 if (!ignore_filter && data->filter_str &&
5551 (strcmp(data->filter_str, data_test->filter_str) != 0))
5552 return false;
5553
5554 if (!actions_match(hist_data, hist_data_test))
5555 return false;
5556
5557 return true;
5558 }
5559
5560 static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
5561 struct event_trigger_data *data,
5562 struct trace_event_file *file)
5563 {
5564 struct hist_trigger_data *hist_data = data->private_data;
5565 struct event_trigger_data *test, *named_data = NULL;
5566 struct trace_array *tr = file->tr;
5567 int ret = 0;
5568
5569 if (hist_data->attrs->name) {
5570 named_data = find_named_trigger(hist_data->attrs->name);
5571 if (named_data) {
5572 if (!hist_trigger_match(data, named_data, named_data,
5573 true)) {
5574 hist_err(tr, HIST_ERR_NAMED_MISMATCH, errpos(hist_data->attrs->name));
5575 ret = -EINVAL;
5576 goto out;
5577 }
5578 }
5579 }
5580
5581 if (hist_data->attrs->name && !named_data)
5582 goto new;
5583
5584 lockdep_assert_held(&event_mutex);
5585
5586 list_for_each_entry(test, &file->triggers, list) {
5587 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
5588 if (!hist_trigger_match(data, test, named_data, false))
5589 continue;
5590 if (hist_data->attrs->pause)
5591 test->paused = true;
5592 else if (hist_data->attrs->cont)
5593 test->paused = false;
5594 else if (hist_data->attrs->clear)
5595 hist_clear(test);
5596 else {
5597 hist_err(tr, HIST_ERR_TRIGGER_EEXIST, 0);
5598 ret = -EEXIST;
5599 }
5600 goto out;
5601 }
5602 }
5603 new:
5604 if (hist_data->attrs->cont || hist_data->attrs->clear) {
5605 hist_err(tr, HIST_ERR_TRIGGER_ENOENT_CLEAR, 0);
5606 ret = -ENOENT;
5607 goto out;
5608 }
5609
5610 if (hist_data->attrs->pause)
5611 data->paused = true;
5612
5613 if (named_data) {
5614 data->private_data = named_data->private_data;
5615 set_named_trigger_data(data, named_data);
5616 data->ops = &event_hist_trigger_named_ops;
5617 }
5618
5619 if (data->ops->init) {
5620 ret = data->ops->init(data->ops, data);
5621 if (ret < 0)
5622 goto out;
5623 }
5624
5625 if (hist_data->enable_timestamps) {
5626 char *clock = hist_data->attrs->clock;
5627
5628 ret = tracing_set_clock(file->tr, hist_data->attrs->clock);
5629 if (ret) {
5630 hist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock));
5631 goto out;
5632 }
5633
5634 tracing_set_filter_buffering(file->tr, true);
5635 }
5636
5637 if (named_data)
5638 destroy_hist_data(hist_data);
5639
5640 ret++;
5641 out:
5642 return ret;
5643 }
5644
5645 static int hist_trigger_enable(struct event_trigger_data *data,
5646 struct trace_event_file *file)
5647 {
5648 int ret = 0;
5649
5650 list_add_tail_rcu(&data->list, &file->triggers);
5651
5652 update_cond_flag(file);
5653
5654 if (trace_event_trigger_enable_disable(file, 1) < 0) {
5655 list_del_rcu(&data->list);
5656 update_cond_flag(file);
5657 ret--;
5658 }
5659
5660 return ret;
5661 }
5662
5663 static bool have_hist_trigger_match(struct event_trigger_data *data,
5664 struct trace_event_file *file)
5665 {
5666 struct hist_trigger_data *hist_data = data->private_data;
5667 struct event_trigger_data *test, *named_data = NULL;
5668 bool match = false;
5669
5670 lockdep_assert_held(&event_mutex);
5671
5672 if (hist_data->attrs->name)
5673 named_data = find_named_trigger(hist_data->attrs->name);
5674
5675 list_for_each_entry(test, &file->triggers, list) {
5676 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
5677 if (hist_trigger_match(data, test, named_data, false)) {
5678 match = true;
5679 break;
5680 }
5681 }
5682 }
5683
5684 return match;
5685 }
5686
5687 static bool hist_trigger_check_refs(struct event_trigger_data *data,
5688 struct trace_event_file *file)
5689 {
5690 struct hist_trigger_data *hist_data = data->private_data;
5691 struct event_trigger_data *test, *named_data = NULL;
5692
5693 lockdep_assert_held(&event_mutex);
5694
5695 if (hist_data->attrs->name)
5696 named_data = find_named_trigger(hist_data->attrs->name);
5697
5698 list_for_each_entry(test, &file->triggers, list) {
5699 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
5700 if (!hist_trigger_match(data, test, named_data, false))
5701 continue;
5702 hist_data = test->private_data;
5703 if (check_var_refs(hist_data))
5704 return true;
5705 break;
5706 }
5707 }
5708
5709 return false;
5710 }
5711
5712 static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
5713 struct event_trigger_data *data,
5714 struct trace_event_file *file)
5715 {
5716 struct hist_trigger_data *hist_data = data->private_data;
5717 struct event_trigger_data *test, *named_data = NULL;
5718 bool unregistered = false;
5719
5720 lockdep_assert_held(&event_mutex);
5721
5722 if (hist_data->attrs->name)
5723 named_data = find_named_trigger(hist_data->attrs->name);
5724
5725 list_for_each_entry(test, &file->triggers, list) {
5726 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
5727 if (!hist_trigger_match(data, test, named_data, false))
5728 continue;
5729 unregistered = true;
5730 list_del_rcu(&test->list);
5731 trace_event_trigger_enable_disable(file, 0);
5732 update_cond_flag(file);
5733 break;
5734 }
5735 }
5736
5737 if (unregistered && test->ops->free)
5738 test->ops->free(test->ops, test);
5739
5740 if (hist_data->enable_timestamps) {
5741 if (!hist_data->remove || unregistered)
5742 tracing_set_filter_buffering(file->tr, false);
5743 }
5744 }
5745
5746 static bool hist_file_check_refs(struct trace_event_file *file)
5747 {
5748 struct hist_trigger_data *hist_data;
5749 struct event_trigger_data *test;
5750
5751 lockdep_assert_held(&event_mutex);
5752
5753 list_for_each_entry(test, &file->triggers, list) {
5754 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
5755 hist_data = test->private_data;
5756 if (check_var_refs(hist_data))
5757 return true;
5758 }
5759 }
5760
5761 return false;
5762 }
5763
5764 static void hist_unreg_all(struct trace_event_file *file)
5765 {
5766 struct event_trigger_data *test, *n;
5767 struct hist_trigger_data *hist_data;
5768 struct synth_event *se;
5769 const char *se_name;
5770
5771 lockdep_assert_held(&event_mutex);
5772
5773 if (hist_file_check_refs(file))
5774 return;
5775
5776 list_for_each_entry_safe(test, n, &file->triggers, list) {
5777 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
5778 hist_data = test->private_data;
5779 list_del_rcu(&test->list);
5780 trace_event_trigger_enable_disable(file, 0);
5781
5782 se_name = trace_event_name(file->event_call);
5783 se = find_synth_event(se_name);
5784 if (se)
5785 se->ref--;
5786
5787 update_cond_flag(file);
5788 if (hist_data->enable_timestamps)
5789 tracing_set_filter_buffering(file->tr, false);
5790 if (test->ops->free)
5791 test->ops->free(test->ops, test);
5792 }
5793 }
5794 }
5795
5796 static int event_hist_trigger_func(struct event_command *cmd_ops,
5797 struct trace_event_file *file,
5798 char *glob, char *cmd, char *param)
5799 {
5800 unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
5801 struct event_trigger_data *trigger_data;
5802 struct hist_trigger_attrs *attrs;
5803 struct event_trigger_ops *trigger_ops;
5804 struct hist_trigger_data *hist_data;
5805 struct synth_event *se;
5806 const char *se_name;
5807 bool remove = false;
5808 char *trigger, *p;
5809 int ret = 0;
5810
5811 lockdep_assert_held(&event_mutex);
5812
5813 if (glob && strlen(glob)) {
5814 hist_err_clear();
5815 last_cmd_set(file, param);
5816 }
5817
5818 if (!param)
5819 return -EINVAL;
5820
5821 if (glob[0] == '!')
5822 remove = true;
5823
5824 /*
5825 * separate the trigger from the filter (k:v [if filter])
5826 * allowing for whitespace in the trigger
5827 */
5828 p = trigger = param;
5829 do {
5830 p = strstr(p, "if");
5831 if (!p)
5832 break;
5833 if (p == param)
5834 return -EINVAL;
5835 if (*(p - 1) != ' ' && *(p - 1) != '\t') {
5836 p++;
5837 continue;
5838 }
5839 if (p >= param + strlen(param) - (sizeof("if") - 1) - 1)
5840 return -EINVAL;
5841 if (*(p + sizeof("if") - 1) != ' ' && *(p + sizeof("if") - 1) != '\t') {
5842 p++;
5843 continue;
5844 }
5845 break;
5846 } while (p);
5847
5848 if (!p)
5849 param = NULL;
5850 else {
5851 *(p - 1) = '\0';
5852 param = strstrip(p);
5853 trigger = strstrip(trigger);
5854 }
5855
5856 attrs = parse_hist_trigger_attrs(file->tr, trigger);
5857 if (IS_ERR(attrs))
5858 return PTR_ERR(attrs);
5859
5860 if (attrs->map_bits)
5861 hist_trigger_bits = attrs->map_bits;
5862
5863 hist_data = create_hist_data(hist_trigger_bits, attrs, file, remove);
5864 if (IS_ERR(hist_data)) {
5865 destroy_hist_trigger_attrs(attrs);
5866 return PTR_ERR(hist_data);
5867 }
5868
5869 trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
5870
5871 trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
5872 if (!trigger_data) {
5873 ret = -ENOMEM;
5874 goto out_free;
5875 }
5876
5877 trigger_data->count = -1;
5878 trigger_data->ops = trigger_ops;
5879 trigger_data->cmd_ops = cmd_ops;
5880
5881 INIT_LIST_HEAD(&trigger_data->list);
5882 RCU_INIT_POINTER(trigger_data->filter, NULL);
5883
5884 trigger_data->private_data = hist_data;
5885
5886 /* if param is non-empty, it's supposed to be a filter */
5887 if (param && cmd_ops->set_filter) {
5888 ret = cmd_ops->set_filter(param, trigger_data, file);
5889 if (ret < 0)
5890 goto out_free;
5891 }
5892
5893 if (remove) {
5894 if (!have_hist_trigger_match(trigger_data, file))
5895 goto out_free;
5896
5897 if (hist_trigger_check_refs(trigger_data, file)) {
5898 ret = -EBUSY;
5899 goto out_free;
5900 }
5901
5902 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
5903 se_name = trace_event_name(file->event_call);
5904 se = find_synth_event(se_name);
5905 if (se)
5906 se->ref--;
5907 ret = 0;
5908 goto out_free;
5909 }
5910
5911 ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
5912 /*
5913 * The above returns on success the # of triggers registered,
5914 * but if it didn't register any it returns zero. Consider no
5915 * triggers registered a failure too.
5916 */
5917 if (!ret) {
5918 if (!(attrs->pause || attrs->cont || attrs->clear))
5919 ret = -ENOENT;
5920 goto out_free;
5921 } else if (ret < 0)
5922 goto out_free;
5923
5924 if (get_named_trigger_data(trigger_data))
5925 goto enable;
5926
5927 if (has_hist_vars(hist_data))
5928 save_hist_vars(hist_data);
5929
5930 ret = create_actions(hist_data);
5931 if (ret)
5932 goto out_unreg;
5933
5934 ret = tracing_map_init(hist_data->map);
5935 if (ret)
5936 goto out_unreg;
5937 enable:
5938 ret = hist_trigger_enable(trigger_data, file);
5939 if (ret)
5940 goto out_unreg;
5941
5942 se_name = trace_event_name(file->event_call);
5943 se = find_synth_event(se_name);
5944 if (se)
5945 se->ref++;
5946 /* Just return zero, not the number of registered triggers */
5947 ret = 0;
5948 out:
5949 if (ret == 0)
5950 hist_err_clear();
5951
5952 return ret;
5953 out_unreg:
5954 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
5955 out_free:
5956 if (cmd_ops->set_filter)
5957 cmd_ops->set_filter(NULL, trigger_data, NULL);
5958
5959 remove_hist_vars(hist_data);
5960
5961 kfree(trigger_data);
5962
5963 destroy_hist_data(hist_data);
5964 goto out;
5965 }
5966
5967 static struct event_command trigger_hist_cmd = {
5968 .name = "hist",
5969 .trigger_type = ETT_EVENT_HIST,
5970 .flags = EVENT_CMD_FL_NEEDS_REC,
5971 .func = event_hist_trigger_func,
5972 .reg = hist_register_trigger,
5973 .unreg = hist_unregister_trigger,
5974 .unreg_all = hist_unreg_all,
5975 .get_trigger_ops = event_hist_get_trigger_ops,
5976 .set_filter = set_trigger_filter,
5977 };
5978
5979 __init int register_trigger_hist_cmd(void)
5980 {
5981 int ret;
5982
5983 ret = register_event_command(&trigger_hist_cmd);
5984 WARN_ON(ret < 0);
5985
5986 return ret;
5987 }
5988
5989 static void
5990 hist_enable_trigger(struct event_trigger_data *data,
5991 struct trace_buffer *buffer, void *rec,
5992 struct ring_buffer_event *event)
5993 {
5994 struct enable_trigger_data *enable_data = data->private_data;
5995 struct event_trigger_data *test;
5996
5997 list_for_each_entry_rcu(test, &enable_data->file->triggers, list,
5998 lockdep_is_held(&event_mutex)) {
5999 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
6000 if (enable_data->enable)
6001 test->paused = false;
6002 else
6003 test->paused = true;
6004 }
6005 }
6006 }
6007
6008 static void
6009 hist_enable_count_trigger(struct event_trigger_data *data,
6010 struct trace_buffer *buffer, void *rec,
6011 struct ring_buffer_event *event)
6012 {
6013 if (!data->count)
6014 return;
6015
6016 if (data->count != -1)
6017 (data->count)--;
6018
6019 hist_enable_trigger(data, buffer, rec, event);
6020 }
6021
6022 static struct event_trigger_ops hist_enable_trigger_ops = {
6023 .func = hist_enable_trigger,
6024 .print = event_enable_trigger_print,
6025 .init = event_trigger_init,
6026 .free = event_enable_trigger_free,
6027 };
6028
6029 static struct event_trigger_ops hist_enable_count_trigger_ops = {
6030 .func = hist_enable_count_trigger,
6031 .print = event_enable_trigger_print,
6032 .init = event_trigger_init,
6033 .free = event_enable_trigger_free,
6034 };
6035
6036 static struct event_trigger_ops hist_disable_trigger_ops = {
6037 .func = hist_enable_trigger,
6038 .print = event_enable_trigger_print,
6039 .init = event_trigger_init,
6040 .free = event_enable_trigger_free,
6041 };
6042
6043 static struct event_trigger_ops hist_disable_count_trigger_ops = {
6044 .func = hist_enable_count_trigger,
6045 .print = event_enable_trigger_print,
6046 .init = event_trigger_init,
6047 .free = event_enable_trigger_free,
6048 };
6049
6050 static struct event_trigger_ops *
6051 hist_enable_get_trigger_ops(char *cmd, char *param)
6052 {
6053 struct event_trigger_ops *ops;
6054 bool enable;
6055
6056 enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
6057
6058 if (enable)
6059 ops = param ? &hist_enable_count_trigger_ops :
6060 &hist_enable_trigger_ops;
6061 else
6062 ops = param ? &hist_disable_count_trigger_ops :
6063 &hist_disable_trigger_ops;
6064
6065 return ops;
6066 }
6067
6068 static void hist_enable_unreg_all(struct trace_event_file *file)
6069 {
6070 struct event_trigger_data *test, *n;
6071
6072 list_for_each_entry_safe(test, n, &file->triggers, list) {
6073 if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) {
6074 list_del_rcu(&test->list);
6075 update_cond_flag(file);
6076 trace_event_trigger_enable_disable(file, 0);
6077 if (test->ops->free)
6078 test->ops->free(test->ops, test);
6079 }
6080 }
6081 }
6082
6083 static struct event_command trigger_hist_enable_cmd = {
6084 .name = ENABLE_HIST_STR,
6085 .trigger_type = ETT_HIST_ENABLE,
6086 .func = event_enable_trigger_func,
6087 .reg = event_enable_register_trigger,
6088 .unreg = event_enable_unregister_trigger,
6089 .unreg_all = hist_enable_unreg_all,
6090 .get_trigger_ops = hist_enable_get_trigger_ops,
6091 .set_filter = set_trigger_filter,
6092 };
6093
6094 static struct event_command trigger_hist_disable_cmd = {
6095 .name = DISABLE_HIST_STR,
6096 .trigger_type = ETT_HIST_ENABLE,
6097 .func = event_enable_trigger_func,
6098 .reg = event_enable_register_trigger,
6099 .unreg = event_enable_unregister_trigger,
6100 .unreg_all = hist_enable_unreg_all,
6101 .get_trigger_ops = hist_enable_get_trigger_ops,
6102 .set_filter = set_trigger_filter,
6103 };
6104
6105 static __init void unregister_trigger_hist_enable_disable_cmds(void)
6106 {
6107 unregister_event_command(&trigger_hist_enable_cmd);
6108 unregister_event_command(&trigger_hist_disable_cmd);
6109 }
6110
6111 __init int register_trigger_hist_enable_disable_cmds(void)
6112 {
6113 int ret;
6114
6115 ret = register_event_command(&trigger_hist_enable_cmd);
6116 if (WARN_ON(ret < 0))
6117 return ret;
6118 ret = register_event_command(&trigger_hist_disable_cmd);
6119 if (WARN_ON(ret < 0))
6120 unregister_trigger_hist_enable_disable_cmds();
6121
6122 return ret;
6123 }
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