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[thirdparty/linux.git] / kernel / trace / trace_events_hist.c
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 C(EXPECT_NUMBER, "Expecting numeric literal"), \
71 C(UNARY_MINUS_SUBEXPR, "Unary minus not supported in sub-expressions"), \
72 C(DIVISION_BY_ZERO, "Division by zero"), \
73 C(NEED_NOHC_VAL, "Non-hitcount value is required for 'nohitcount'"),
74
75 #undef C
76 #define C(a, b) HIST_ERR_##a
77
78 enum { ERRORS };
79
80 #undef C
81 #define C(a, b) b
82
83 static const char *err_text[] = { ERRORS };
84
85 struct hist_field;
86
87 typedef u64 (*hist_field_fn_t) (struct hist_field *field,
88 struct tracing_map_elt *elt,
89 struct trace_buffer *buffer,
90 struct ring_buffer_event *rbe,
91 void *event);
92
93 #define HIST_FIELD_OPERANDS_MAX 2
94 #define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
95 #define HIST_ACTIONS_MAX 8
96 #define HIST_CONST_DIGITS_MAX 21
97 #define HIST_DIV_SHIFT 20 /* For optimizing division by constants */
98
99 enum field_op_id {
100 FIELD_OP_NONE,
101 FIELD_OP_PLUS,
102 FIELD_OP_MINUS,
103 FIELD_OP_UNARY_MINUS,
104 FIELD_OP_DIV,
105 FIELD_OP_MULT,
106 };
107
108 enum hist_field_fn {
109 HIST_FIELD_FN_NOP,
110 HIST_FIELD_FN_VAR_REF,
111 HIST_FIELD_FN_COUNTER,
112 HIST_FIELD_FN_CONST,
113 HIST_FIELD_FN_LOG2,
114 HIST_FIELD_FN_BUCKET,
115 HIST_FIELD_FN_TIMESTAMP,
116 HIST_FIELD_FN_CPU,
117 HIST_FIELD_FN_COMM,
118 HIST_FIELD_FN_STRING,
119 HIST_FIELD_FN_DYNSTRING,
120 HIST_FIELD_FN_RELDYNSTRING,
121 HIST_FIELD_FN_PSTRING,
122 HIST_FIELD_FN_S64,
123 HIST_FIELD_FN_U64,
124 HIST_FIELD_FN_S32,
125 HIST_FIELD_FN_U32,
126 HIST_FIELD_FN_S16,
127 HIST_FIELD_FN_U16,
128 HIST_FIELD_FN_S8,
129 HIST_FIELD_FN_U8,
130 HIST_FIELD_FN_UMINUS,
131 HIST_FIELD_FN_MINUS,
132 HIST_FIELD_FN_PLUS,
133 HIST_FIELD_FN_DIV,
134 HIST_FIELD_FN_MULT,
135 HIST_FIELD_FN_DIV_POWER2,
136 HIST_FIELD_FN_DIV_NOT_POWER2,
137 HIST_FIELD_FN_DIV_MULT_SHIFT,
138 HIST_FIELD_FN_EXECNAME,
139 HIST_FIELD_FN_STACK,
140 };
141
142 /*
143 * A hist_var (histogram variable) contains variable information for
144 * hist_fields having the HIST_FIELD_FL_VAR or HIST_FIELD_FL_VAR_REF
145 * flag set. A hist_var has a variable name e.g. ts0, and is
146 * associated with a given histogram trigger, as specified by
147 * hist_data. The hist_var idx is the unique index assigned to the
148 * variable by the hist trigger's tracing_map. The idx is what is
149 * used to set a variable's value and, by a variable reference, to
150 * retrieve it.
151 */
152 struct hist_var {
153 char *name;
154 struct hist_trigger_data *hist_data;
155 unsigned int idx;
156 };
157
158 struct hist_field {
159 struct ftrace_event_field *field;
160 unsigned long flags;
161 unsigned long buckets;
162 const char *type;
163 struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
164 struct hist_trigger_data *hist_data;
165 enum hist_field_fn fn_num;
166 unsigned int ref;
167 unsigned int size;
168 unsigned int offset;
169 unsigned int is_signed;
170
171 /*
172 * Variable fields contain variable-specific info in var.
173 */
174 struct hist_var var;
175 enum field_op_id operator;
176 char *system;
177 char *event_name;
178
179 /*
180 * The name field is used for EXPR and VAR_REF fields. VAR
181 * fields contain the variable name in var.name.
182 */
183 char *name;
184
185 /*
186 * When a histogram trigger is hit, if it has any references
187 * to variables, the values of those variables are collected
188 * into a var_ref_vals array by resolve_var_refs(). The
189 * current value of each variable is read from the tracing_map
190 * using the hist field's hist_var.idx and entered into the
191 * var_ref_idx entry i.e. var_ref_vals[var_ref_idx].
192 */
193 unsigned int var_ref_idx;
194 bool read_once;
195
196 unsigned int var_str_idx;
197
198 /* Numeric literals are represented as u64 */
199 u64 constant;
200 /* Used to optimize division by constants */
201 u64 div_multiplier;
202 };
203
204 static u64 hist_fn_call(struct hist_field *hist_field,
205 struct tracing_map_elt *elt,
206 struct trace_buffer *buffer,
207 struct ring_buffer_event *rbe,
208 void *event);
209
210 static u64 hist_field_const(struct hist_field *field,
211 struct tracing_map_elt *elt,
212 struct trace_buffer *buffer,
213 struct ring_buffer_event *rbe,
214 void *event)
215 {
216 return field->constant;
217 }
218
219 static u64 hist_field_counter(struct hist_field *field,
220 struct tracing_map_elt *elt,
221 struct trace_buffer *buffer,
222 struct ring_buffer_event *rbe,
223 void *event)
224 {
225 return 1;
226 }
227
228 static u64 hist_field_string(struct hist_field *hist_field,
229 struct tracing_map_elt *elt,
230 struct trace_buffer *buffer,
231 struct ring_buffer_event *rbe,
232 void *event)
233 {
234 char *addr = (char *)(event + hist_field->field->offset);
235
236 return (u64)(unsigned long)addr;
237 }
238
239 static u64 hist_field_dynstring(struct hist_field *hist_field,
240 struct tracing_map_elt *elt,
241 struct trace_buffer *buffer,
242 struct ring_buffer_event *rbe,
243 void *event)
244 {
245 u32 str_item = *(u32 *)(event + hist_field->field->offset);
246 int str_loc = str_item & 0xffff;
247 char *addr = (char *)(event + str_loc);
248
249 return (u64)(unsigned long)addr;
250 }
251
252 static u64 hist_field_reldynstring(struct hist_field *hist_field,
253 struct tracing_map_elt *elt,
254 struct trace_buffer *buffer,
255 struct ring_buffer_event *rbe,
256 void *event)
257 {
258 u32 *item = event + hist_field->field->offset;
259 u32 str_item = *item;
260 int str_loc = str_item & 0xffff;
261 char *addr = (char *)&item[1] + str_loc;
262
263 return (u64)(unsigned long)addr;
264 }
265
266 static u64 hist_field_pstring(struct hist_field *hist_field,
267 struct tracing_map_elt *elt,
268 struct trace_buffer *buffer,
269 struct ring_buffer_event *rbe,
270 void *event)
271 {
272 char **addr = (char **)(event + hist_field->field->offset);
273
274 return (u64)(unsigned long)*addr;
275 }
276
277 static u64 hist_field_log2(struct hist_field *hist_field,
278 struct tracing_map_elt *elt,
279 struct trace_buffer *buffer,
280 struct ring_buffer_event *rbe,
281 void *event)
282 {
283 struct hist_field *operand = hist_field->operands[0];
284
285 u64 val = hist_fn_call(operand, elt, buffer, rbe, event);
286
287 return (u64) ilog2(roundup_pow_of_two(val));
288 }
289
290 static u64 hist_field_bucket(struct hist_field *hist_field,
291 struct tracing_map_elt *elt,
292 struct trace_buffer *buffer,
293 struct ring_buffer_event *rbe,
294 void *event)
295 {
296 struct hist_field *operand = hist_field->operands[0];
297 unsigned long buckets = hist_field->buckets;
298
299 u64 val = hist_fn_call(operand, elt, buffer, rbe, event);
300
301 if (WARN_ON_ONCE(!buckets))
302 return val;
303
304 if (val >= LONG_MAX)
305 val = div64_ul(val, buckets);
306 else
307 val = (u64)((unsigned long)val / buckets);
308 return val * buckets;
309 }
310
311 static u64 hist_field_plus(struct hist_field *hist_field,
312 struct tracing_map_elt *elt,
313 struct trace_buffer *buffer,
314 struct ring_buffer_event *rbe,
315 void *event)
316 {
317 struct hist_field *operand1 = hist_field->operands[0];
318 struct hist_field *operand2 = hist_field->operands[1];
319
320 u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event);
321 u64 val2 = hist_fn_call(operand2, elt, buffer, rbe, event);
322
323 return val1 + val2;
324 }
325
326 static u64 hist_field_minus(struct hist_field *hist_field,
327 struct tracing_map_elt *elt,
328 struct trace_buffer *buffer,
329 struct ring_buffer_event *rbe,
330 void *event)
331 {
332 struct hist_field *operand1 = hist_field->operands[0];
333 struct hist_field *operand2 = hist_field->operands[1];
334
335 u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event);
336 u64 val2 = hist_fn_call(operand2, elt, buffer, rbe, event);
337
338 return val1 - val2;
339 }
340
341 static u64 hist_field_div(struct hist_field *hist_field,
342 struct tracing_map_elt *elt,
343 struct trace_buffer *buffer,
344 struct ring_buffer_event *rbe,
345 void *event)
346 {
347 struct hist_field *operand1 = hist_field->operands[0];
348 struct hist_field *operand2 = hist_field->operands[1];
349
350 u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event);
351 u64 val2 = hist_fn_call(operand2, elt, buffer, rbe, event);
352
353 /* Return -1 for the undefined case */
354 if (!val2)
355 return -1;
356
357 /* Use shift if the divisor is a power of 2 */
358 if (!(val2 & (val2 - 1)))
359 return val1 >> __ffs64(val2);
360
361 return div64_u64(val1, val2);
362 }
363
364 static u64 div_by_power_of_two(struct hist_field *hist_field,
365 struct tracing_map_elt *elt,
366 struct trace_buffer *buffer,
367 struct ring_buffer_event *rbe,
368 void *event)
369 {
370 struct hist_field *operand1 = hist_field->operands[0];
371 struct hist_field *operand2 = hist_field->operands[1];
372
373 u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event);
374
375 return val1 >> __ffs64(operand2->constant);
376 }
377
378 static u64 div_by_not_power_of_two(struct hist_field *hist_field,
379 struct tracing_map_elt *elt,
380 struct trace_buffer *buffer,
381 struct ring_buffer_event *rbe,
382 void *event)
383 {
384 struct hist_field *operand1 = hist_field->operands[0];
385 struct hist_field *operand2 = hist_field->operands[1];
386
387 u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event);
388
389 return div64_u64(val1, operand2->constant);
390 }
391
392 static u64 div_by_mult_and_shift(struct hist_field *hist_field,
393 struct tracing_map_elt *elt,
394 struct trace_buffer *buffer,
395 struct ring_buffer_event *rbe,
396 void *event)
397 {
398 struct hist_field *operand1 = hist_field->operands[0];
399 struct hist_field *operand2 = hist_field->operands[1];
400
401 u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event);
402
403 /*
404 * If the divisor is a constant, do a multiplication and shift instead.
405 *
406 * Choose Z = some power of 2. If Y <= Z, then:
407 * X / Y = (X * (Z / Y)) / Z
408 *
409 * (Z / Y) is a constant (mult) which is calculated at parse time, so:
410 * X / Y = (X * mult) / Z
411 *
412 * The division by Z can be replaced by a shift since Z is a power of 2:
413 * X / Y = (X * mult) >> HIST_DIV_SHIFT
414 *
415 * As long, as X < Z the results will not be off by more than 1.
416 */
417 if (val1 < (1 << HIST_DIV_SHIFT)) {
418 u64 mult = operand2->div_multiplier;
419
420 return (val1 * mult + ((1 << HIST_DIV_SHIFT) - 1)) >> HIST_DIV_SHIFT;
421 }
422
423 return div64_u64(val1, operand2->constant);
424 }
425
426 static u64 hist_field_mult(struct hist_field *hist_field,
427 struct tracing_map_elt *elt,
428 struct trace_buffer *buffer,
429 struct ring_buffer_event *rbe,
430 void *event)
431 {
432 struct hist_field *operand1 = hist_field->operands[0];
433 struct hist_field *operand2 = hist_field->operands[1];
434
435 u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event);
436 u64 val2 = hist_fn_call(operand2, elt, buffer, rbe, event);
437
438 return val1 * val2;
439 }
440
441 static u64 hist_field_unary_minus(struct hist_field *hist_field,
442 struct tracing_map_elt *elt,
443 struct trace_buffer *buffer,
444 struct ring_buffer_event *rbe,
445 void *event)
446 {
447 struct hist_field *operand = hist_field->operands[0];
448
449 s64 sval = (s64)hist_fn_call(operand, elt, buffer, rbe, event);
450 u64 val = (u64)-sval;
451
452 return val;
453 }
454
455 #define DEFINE_HIST_FIELD_FN(type) \
456 static u64 hist_field_##type(struct hist_field *hist_field, \
457 struct tracing_map_elt *elt, \
458 struct trace_buffer *buffer, \
459 struct ring_buffer_event *rbe, \
460 void *event) \
461 { \
462 type *addr = (type *)(event + hist_field->field->offset); \
463 \
464 return (u64)(unsigned long)*addr; \
465 }
466
467 DEFINE_HIST_FIELD_FN(s64);
468 DEFINE_HIST_FIELD_FN(u64);
469 DEFINE_HIST_FIELD_FN(s32);
470 DEFINE_HIST_FIELD_FN(u32);
471 DEFINE_HIST_FIELD_FN(s16);
472 DEFINE_HIST_FIELD_FN(u16);
473 DEFINE_HIST_FIELD_FN(s8);
474 DEFINE_HIST_FIELD_FN(u8);
475
476 #define for_each_hist_field(i, hist_data) \
477 for ((i) = 0; (i) < (hist_data)->n_fields; (i)++)
478
479 #define for_each_hist_val_field(i, hist_data) \
480 for ((i) = 0; (i) < (hist_data)->n_vals; (i)++)
481
482 #define for_each_hist_key_field(i, hist_data) \
483 for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++)
484
485 #define HITCOUNT_IDX 0
486 #define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE)
487
488 enum hist_field_flags {
489 HIST_FIELD_FL_HITCOUNT = 1 << 0,
490 HIST_FIELD_FL_KEY = 1 << 1,
491 HIST_FIELD_FL_STRING = 1 << 2,
492 HIST_FIELD_FL_HEX = 1 << 3,
493 HIST_FIELD_FL_SYM = 1 << 4,
494 HIST_FIELD_FL_SYM_OFFSET = 1 << 5,
495 HIST_FIELD_FL_EXECNAME = 1 << 6,
496 HIST_FIELD_FL_SYSCALL = 1 << 7,
497 HIST_FIELD_FL_STACKTRACE = 1 << 8,
498 HIST_FIELD_FL_LOG2 = 1 << 9,
499 HIST_FIELD_FL_TIMESTAMP = 1 << 10,
500 HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11,
501 HIST_FIELD_FL_VAR = 1 << 12,
502 HIST_FIELD_FL_EXPR = 1 << 13,
503 HIST_FIELD_FL_VAR_REF = 1 << 14,
504 HIST_FIELD_FL_CPU = 1 << 15,
505 HIST_FIELD_FL_ALIAS = 1 << 16,
506 HIST_FIELD_FL_BUCKET = 1 << 17,
507 HIST_FIELD_FL_CONST = 1 << 18,
508 HIST_FIELD_FL_PERCENT = 1 << 19,
509 HIST_FIELD_FL_GRAPH = 1 << 20,
510 HIST_FIELD_FL_COMM = 1 << 21,
511 };
512
513 struct var_defs {
514 unsigned int n_vars;
515 char *name[TRACING_MAP_VARS_MAX];
516 char *expr[TRACING_MAP_VARS_MAX];
517 };
518
519 struct hist_trigger_attrs {
520 char *keys_str;
521 char *vals_str;
522 char *sort_key_str;
523 char *name;
524 char *clock;
525 bool pause;
526 bool cont;
527 bool clear;
528 bool ts_in_usecs;
529 bool no_hitcount;
530 unsigned int map_bits;
531
532 char *assignment_str[TRACING_MAP_VARS_MAX];
533 unsigned int n_assignments;
534
535 char *action_str[HIST_ACTIONS_MAX];
536 unsigned int n_actions;
537
538 struct var_defs var_defs;
539 };
540
541 struct field_var {
542 struct hist_field *var;
543 struct hist_field *val;
544 };
545
546 struct field_var_hist {
547 struct hist_trigger_data *hist_data;
548 char *cmd;
549 };
550
551 struct hist_trigger_data {
552 struct hist_field *fields[HIST_FIELDS_MAX];
553 unsigned int n_vals;
554 unsigned int n_keys;
555 unsigned int n_fields;
556 unsigned int n_vars;
557 unsigned int n_var_str;
558 unsigned int key_size;
559 struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX];
560 unsigned int n_sort_keys;
561 struct trace_event_file *event_file;
562 struct hist_trigger_attrs *attrs;
563 struct tracing_map *map;
564 bool enable_timestamps;
565 bool remove;
566 struct hist_field *var_refs[TRACING_MAP_VARS_MAX];
567 unsigned int n_var_refs;
568
569 struct action_data *actions[HIST_ACTIONS_MAX];
570 unsigned int n_actions;
571
572 struct field_var *field_vars[SYNTH_FIELDS_MAX];
573 unsigned int n_field_vars;
574 unsigned int n_field_var_str;
575 struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX];
576 unsigned int n_field_var_hists;
577
578 struct field_var *save_vars[SYNTH_FIELDS_MAX];
579 unsigned int n_save_vars;
580 unsigned int n_save_var_str;
581 };
582
583 struct action_data;
584
585 typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
586 struct tracing_map_elt *elt,
587 struct trace_buffer *buffer, void *rec,
588 struct ring_buffer_event *rbe, void *key,
589 struct action_data *data, u64 *var_ref_vals);
590
591 typedef bool (*check_track_val_fn_t) (u64 track_val, u64 var_val);
592
593 enum handler_id {
594 HANDLER_ONMATCH = 1,
595 HANDLER_ONMAX,
596 HANDLER_ONCHANGE,
597 };
598
599 enum action_id {
600 ACTION_SAVE = 1,
601 ACTION_TRACE,
602 ACTION_SNAPSHOT,
603 };
604
605 struct action_data {
606 enum handler_id handler;
607 enum action_id action;
608 char *action_name;
609 action_fn_t fn;
610
611 unsigned int n_params;
612 char *params[SYNTH_FIELDS_MAX];
613
614 /*
615 * When a histogram trigger is hit, the values of any
616 * references to variables, including variables being passed
617 * as parameters to synthetic events, are collected into a
618 * var_ref_vals array. This var_ref_idx array is an array of
619 * indices into the var_ref_vals array, one for each synthetic
620 * event param, and is passed to the synthetic event
621 * invocation.
622 */
623 unsigned int var_ref_idx[SYNTH_FIELDS_MAX];
624 struct synth_event *synth_event;
625 bool use_trace_keyword;
626 char *synth_event_name;
627
628 union {
629 struct {
630 char *event;
631 char *event_system;
632 } match_data;
633
634 struct {
635 /*
636 * var_str contains the $-unstripped variable
637 * name referenced by var_ref, and used when
638 * printing the action. Because var_ref
639 * creation is deferred to create_actions(),
640 * we need a per-action way to save it until
641 * then, thus var_str.
642 */
643 char *var_str;
644
645 /*
646 * var_ref refers to the variable being
647 * tracked e.g onmax($var).
648 */
649 struct hist_field *var_ref;
650
651 /*
652 * track_var contains the 'invisible' tracking
653 * variable created to keep the current
654 * e.g. max value.
655 */
656 struct hist_field *track_var;
657
658 check_track_val_fn_t check_val;
659 action_fn_t save_data;
660 } track_data;
661 };
662 };
663
664 struct track_data {
665 u64 track_val;
666 bool updated;
667
668 unsigned int key_len;
669 void *key;
670 struct tracing_map_elt elt;
671
672 struct action_data *action_data;
673 struct hist_trigger_data *hist_data;
674 };
675
676 struct hist_elt_data {
677 char *comm;
678 u64 *var_ref_vals;
679 char **field_var_str;
680 int n_field_var_str;
681 };
682
683 struct snapshot_context {
684 struct tracing_map_elt *elt;
685 void *key;
686 };
687
688 /*
689 * Returns the specific division function to use if the divisor
690 * is constant. This avoids extra branches when the trigger is hit.
691 */
692 static enum hist_field_fn hist_field_get_div_fn(struct hist_field *divisor)
693 {
694 u64 div = divisor->constant;
695
696 if (!(div & (div - 1)))
697 return HIST_FIELD_FN_DIV_POWER2;
698
699 /* If the divisor is too large, do a regular division */
700 if (div > (1 << HIST_DIV_SHIFT))
701 return HIST_FIELD_FN_DIV_NOT_POWER2;
702
703 divisor->div_multiplier = div64_u64((u64)(1 << HIST_DIV_SHIFT), div);
704 return HIST_FIELD_FN_DIV_MULT_SHIFT;
705 }
706
707 static void track_data_free(struct track_data *track_data)
708 {
709 struct hist_elt_data *elt_data;
710
711 if (!track_data)
712 return;
713
714 kfree(track_data->key);
715
716 elt_data = track_data->elt.private_data;
717 if (elt_data) {
718 kfree(elt_data->comm);
719 kfree(elt_data);
720 }
721
722 kfree(track_data);
723 }
724
725 static struct track_data *track_data_alloc(unsigned int key_len,
726 struct action_data *action_data,
727 struct hist_trigger_data *hist_data)
728 {
729 struct track_data *data = kzalloc(sizeof(*data), GFP_KERNEL);
730 struct hist_elt_data *elt_data;
731
732 if (!data)
733 return ERR_PTR(-ENOMEM);
734
735 data->key = kzalloc(key_len, GFP_KERNEL);
736 if (!data->key) {
737 track_data_free(data);
738 return ERR_PTR(-ENOMEM);
739 }
740
741 data->key_len = key_len;
742 data->action_data = action_data;
743 data->hist_data = hist_data;
744
745 elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
746 if (!elt_data) {
747 track_data_free(data);
748 return ERR_PTR(-ENOMEM);
749 }
750
751 data->elt.private_data = elt_data;
752
753 elt_data->comm = kzalloc(TASK_COMM_LEN, GFP_KERNEL);
754 if (!elt_data->comm) {
755 track_data_free(data);
756 return ERR_PTR(-ENOMEM);
757 }
758
759 return data;
760 }
761
762 #define HIST_PREFIX "hist:"
763
764 static char *last_cmd;
765 static char last_cmd_loc[MAX_FILTER_STR_VAL];
766
767 static int errpos(char *str)
768 {
769 if (!str || !last_cmd)
770 return 0;
771
772 return err_pos(last_cmd, str);
773 }
774
775 static void last_cmd_set(struct trace_event_file *file, char *str)
776 {
777 const char *system = NULL, *name = NULL;
778 struct trace_event_call *call;
779
780 if (!str)
781 return;
782
783 kfree(last_cmd);
784
785 last_cmd = kasprintf(GFP_KERNEL, HIST_PREFIX "%s", str);
786 if (!last_cmd)
787 return;
788
789 if (file) {
790 call = file->event_call;
791 system = call->class->system;
792 if (system) {
793 name = trace_event_name(call);
794 if (!name)
795 system = NULL;
796 }
797 }
798
799 if (system)
800 snprintf(last_cmd_loc, MAX_FILTER_STR_VAL, HIST_PREFIX "%s:%s", system, name);
801 }
802
803 static void hist_err(struct trace_array *tr, u8 err_type, u16 err_pos)
804 {
805 if (!last_cmd)
806 return;
807
808 tracing_log_err(tr, last_cmd_loc, last_cmd, err_text,
809 err_type, err_pos);
810 }
811
812 static void hist_err_clear(void)
813 {
814 if (last_cmd)
815 last_cmd[0] = '\0';
816 last_cmd_loc[0] = '\0';
817 }
818
819 typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
820 unsigned int *var_ref_idx);
821
822 static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
823 unsigned int *var_ref_idx)
824 {
825 struct tracepoint *tp = event->tp;
826
827 if (unlikely(static_key_enabled(&tp->key))) {
828 struct tracepoint_func *probe_func_ptr;
829 synth_probe_func_t probe_func;
830 void *__data;
831
832 if (!(cpu_online(raw_smp_processor_id())))
833 return;
834
835 probe_func_ptr = rcu_dereference_sched((tp)->funcs);
836 if (probe_func_ptr) {
837 do {
838 probe_func = probe_func_ptr->func;
839 __data = probe_func_ptr->data;
840 probe_func(__data, var_ref_vals, var_ref_idx);
841 } while ((++probe_func_ptr)->func);
842 }
843 }
844 }
845
846 static void action_trace(struct hist_trigger_data *hist_data,
847 struct tracing_map_elt *elt,
848 struct trace_buffer *buffer, void *rec,
849 struct ring_buffer_event *rbe, void *key,
850 struct action_data *data, u64 *var_ref_vals)
851 {
852 struct synth_event *event = data->synth_event;
853
854 trace_synth(event, var_ref_vals, data->var_ref_idx);
855 }
856
857 struct hist_var_data {
858 struct list_head list;
859 struct hist_trigger_data *hist_data;
860 };
861
862 static u64 hist_field_timestamp(struct hist_field *hist_field,
863 struct tracing_map_elt *elt,
864 struct trace_buffer *buffer,
865 struct ring_buffer_event *rbe,
866 void *event)
867 {
868 struct hist_trigger_data *hist_data = hist_field->hist_data;
869 struct trace_array *tr = hist_data->event_file->tr;
870
871 u64 ts = ring_buffer_event_time_stamp(buffer, rbe);
872
873 if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr))
874 ts = ns2usecs(ts);
875
876 return ts;
877 }
878
879 static u64 hist_field_cpu(struct hist_field *hist_field,
880 struct tracing_map_elt *elt,
881 struct trace_buffer *buffer,
882 struct ring_buffer_event *rbe,
883 void *event)
884 {
885 int cpu = smp_processor_id();
886
887 return cpu;
888 }
889
890 static u64 hist_field_comm(struct hist_field *hist_field,
891 struct tracing_map_elt *elt,
892 struct trace_buffer *buffer,
893 struct ring_buffer_event *rbe,
894 void *event)
895 {
896 return (u64)(unsigned long)current->comm;
897 }
898
899 /**
900 * check_field_for_var_ref - Check if a VAR_REF field references a variable
901 * @hist_field: The VAR_REF field to check
902 * @var_data: The hist trigger that owns the variable
903 * @var_idx: The trigger variable identifier
904 *
905 * Check the given VAR_REF field to see whether or not it references
906 * the given variable associated with the given trigger.
907 *
908 * Return: The VAR_REF field if it does reference the variable, NULL if not
909 */
910 static struct hist_field *
911 check_field_for_var_ref(struct hist_field *hist_field,
912 struct hist_trigger_data *var_data,
913 unsigned int var_idx)
914 {
915 WARN_ON(!(hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF));
916
917 if (hist_field && hist_field->var.idx == var_idx &&
918 hist_field->var.hist_data == var_data)
919 return hist_field;
920
921 return NULL;
922 }
923
924 /**
925 * find_var_ref - Check if a trigger has a reference to a trigger variable
926 * @hist_data: The hist trigger that might have a reference to the variable
927 * @var_data: The hist trigger that owns the variable
928 * @var_idx: The trigger variable identifier
929 *
930 * Check the list of var_refs[] on the first hist trigger to see
931 * whether any of them are references to the variable on the second
932 * trigger.
933 *
934 * Return: The VAR_REF field referencing the variable if so, NULL if not
935 */
936 static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data,
937 struct hist_trigger_data *var_data,
938 unsigned int var_idx)
939 {
940 struct hist_field *hist_field;
941 unsigned int i;
942
943 for (i = 0; i < hist_data->n_var_refs; i++) {
944 hist_field = hist_data->var_refs[i];
945 if (check_field_for_var_ref(hist_field, var_data, var_idx))
946 return hist_field;
947 }
948
949 return NULL;
950 }
951
952 /**
953 * find_any_var_ref - Check if there is a reference to a given trigger variable
954 * @hist_data: The hist trigger
955 * @var_idx: The trigger variable identifier
956 *
957 * Check to see whether the given variable is currently referenced by
958 * any other trigger.
959 *
960 * The trigger the variable is defined on is explicitly excluded - the
961 * assumption being that a self-reference doesn't prevent a trigger
962 * from being removed.
963 *
964 * Return: The VAR_REF field referencing the variable if so, NULL if not
965 */
966 static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data,
967 unsigned int var_idx)
968 {
969 struct trace_array *tr = hist_data->event_file->tr;
970 struct hist_field *found = NULL;
971 struct hist_var_data *var_data;
972
973 list_for_each_entry(var_data, &tr->hist_vars, list) {
974 if (var_data->hist_data == hist_data)
975 continue;
976 found = find_var_ref(var_data->hist_data, hist_data, var_idx);
977 if (found)
978 break;
979 }
980
981 return found;
982 }
983
984 /**
985 * check_var_refs - Check if there is a reference to any of trigger's variables
986 * @hist_data: The hist trigger
987 *
988 * A trigger can define one or more variables. If any one of them is
989 * currently referenced by any other trigger, this function will
990 * determine that.
991 *
992 * Typically used to determine whether or not a trigger can be removed
993 * - if there are any references to a trigger's variables, it cannot.
994 *
995 * Return: True if there is a reference to any of trigger's variables
996 */
997 static bool check_var_refs(struct hist_trigger_data *hist_data)
998 {
999 struct hist_field *field;
1000 bool found = false;
1001 int i;
1002
1003 for_each_hist_field(i, hist_data) {
1004 field = hist_data->fields[i];
1005 if (field && field->flags & HIST_FIELD_FL_VAR) {
1006 if (find_any_var_ref(hist_data, field->var.idx)) {
1007 found = true;
1008 break;
1009 }
1010 }
1011 }
1012
1013 return found;
1014 }
1015
1016 static struct hist_var_data *find_hist_vars(struct hist_trigger_data *hist_data)
1017 {
1018 struct trace_array *tr = hist_data->event_file->tr;
1019 struct hist_var_data *var_data, *found = NULL;
1020
1021 list_for_each_entry(var_data, &tr->hist_vars, list) {
1022 if (var_data->hist_data == hist_data) {
1023 found = var_data;
1024 break;
1025 }
1026 }
1027
1028 return found;
1029 }
1030
1031 static bool field_has_hist_vars(struct hist_field *hist_field,
1032 unsigned int level)
1033 {
1034 int i;
1035
1036 if (level > 3)
1037 return false;
1038
1039 if (!hist_field)
1040 return false;
1041
1042 if (hist_field->flags & HIST_FIELD_FL_VAR ||
1043 hist_field->flags & HIST_FIELD_FL_VAR_REF)
1044 return true;
1045
1046 for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) {
1047 struct hist_field *operand;
1048
1049 operand = hist_field->operands[i];
1050 if (field_has_hist_vars(operand, level + 1))
1051 return true;
1052 }
1053
1054 return false;
1055 }
1056
1057 static bool has_hist_vars(struct hist_trigger_data *hist_data)
1058 {
1059 struct hist_field *hist_field;
1060 int i;
1061
1062 for_each_hist_field(i, hist_data) {
1063 hist_field = hist_data->fields[i];
1064 if (field_has_hist_vars(hist_field, 0))
1065 return true;
1066 }
1067
1068 return false;
1069 }
1070
1071 static int save_hist_vars(struct hist_trigger_data *hist_data)
1072 {
1073 struct trace_array *tr = hist_data->event_file->tr;
1074 struct hist_var_data *var_data;
1075
1076 var_data = find_hist_vars(hist_data);
1077 if (var_data)
1078 return 0;
1079
1080 if (tracing_check_open_get_tr(tr))
1081 return -ENODEV;
1082
1083 var_data = kzalloc(sizeof(*var_data), GFP_KERNEL);
1084 if (!var_data) {
1085 trace_array_put(tr);
1086 return -ENOMEM;
1087 }
1088
1089 var_data->hist_data = hist_data;
1090 list_add(&var_data->list, &tr->hist_vars);
1091
1092 return 0;
1093 }
1094
1095 static void remove_hist_vars(struct hist_trigger_data *hist_data)
1096 {
1097 struct trace_array *tr = hist_data->event_file->tr;
1098 struct hist_var_data *var_data;
1099
1100 var_data = find_hist_vars(hist_data);
1101 if (!var_data)
1102 return;
1103
1104 if (WARN_ON(check_var_refs(hist_data)))
1105 return;
1106
1107 list_del(&var_data->list);
1108
1109 kfree(var_data);
1110
1111 trace_array_put(tr);
1112 }
1113
1114 static struct hist_field *find_var_field(struct hist_trigger_data *hist_data,
1115 const char *var_name)
1116 {
1117 struct hist_field *hist_field, *found = NULL;
1118 int i;
1119
1120 for_each_hist_field(i, hist_data) {
1121 hist_field = hist_data->fields[i];
1122 if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR &&
1123 strcmp(hist_field->var.name, var_name) == 0) {
1124 found = hist_field;
1125 break;
1126 }
1127 }
1128
1129 return found;
1130 }
1131
1132 static struct hist_field *find_var(struct hist_trigger_data *hist_data,
1133 struct trace_event_file *file,
1134 const char *var_name)
1135 {
1136 struct hist_trigger_data *test_data;
1137 struct event_trigger_data *test;
1138 struct hist_field *hist_field;
1139
1140 lockdep_assert_held(&event_mutex);
1141
1142 hist_field = find_var_field(hist_data, var_name);
1143 if (hist_field)
1144 return hist_field;
1145
1146 list_for_each_entry(test, &file->triggers, list) {
1147 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1148 test_data = test->private_data;
1149 hist_field = find_var_field(test_data, var_name);
1150 if (hist_field)
1151 return hist_field;
1152 }
1153 }
1154
1155 return NULL;
1156 }
1157
1158 static struct trace_event_file *find_var_file(struct trace_array *tr,
1159 char *system,
1160 char *event_name,
1161 char *var_name)
1162 {
1163 struct hist_trigger_data *var_hist_data;
1164 struct hist_var_data *var_data;
1165 struct trace_event_file *file, *found = NULL;
1166
1167 if (system)
1168 return find_event_file(tr, system, event_name);
1169
1170 list_for_each_entry(var_data, &tr->hist_vars, list) {
1171 var_hist_data = var_data->hist_data;
1172 file = var_hist_data->event_file;
1173 if (file == found)
1174 continue;
1175
1176 if (find_var_field(var_hist_data, var_name)) {
1177 if (found) {
1178 hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE, errpos(var_name));
1179 return NULL;
1180 }
1181
1182 found = file;
1183 }
1184 }
1185
1186 return found;
1187 }
1188
1189 static struct hist_field *find_file_var(struct trace_event_file *file,
1190 const char *var_name)
1191 {
1192 struct hist_trigger_data *test_data;
1193 struct event_trigger_data *test;
1194 struct hist_field *hist_field;
1195
1196 lockdep_assert_held(&event_mutex);
1197
1198 list_for_each_entry(test, &file->triggers, list) {
1199 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1200 test_data = test->private_data;
1201 hist_field = find_var_field(test_data, var_name);
1202 if (hist_field)
1203 return hist_field;
1204 }
1205 }
1206
1207 return NULL;
1208 }
1209
1210 static struct hist_field *
1211 find_match_var(struct hist_trigger_data *hist_data, char *var_name)
1212 {
1213 struct trace_array *tr = hist_data->event_file->tr;
1214 struct hist_field *hist_field, *found = NULL;
1215 struct trace_event_file *file;
1216 unsigned int i;
1217
1218 for (i = 0; i < hist_data->n_actions; i++) {
1219 struct action_data *data = hist_data->actions[i];
1220
1221 if (data->handler == HANDLER_ONMATCH) {
1222 char *system = data->match_data.event_system;
1223 char *event_name = data->match_data.event;
1224
1225 file = find_var_file(tr, system, event_name, var_name);
1226 if (!file)
1227 continue;
1228 hist_field = find_file_var(file, var_name);
1229 if (hist_field) {
1230 if (found) {
1231 hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE,
1232 errpos(var_name));
1233 return ERR_PTR(-EINVAL);
1234 }
1235
1236 found = hist_field;
1237 }
1238 }
1239 }
1240 return found;
1241 }
1242
1243 static struct hist_field *find_event_var(struct hist_trigger_data *hist_data,
1244 char *system,
1245 char *event_name,
1246 char *var_name)
1247 {
1248 struct trace_array *tr = hist_data->event_file->tr;
1249 struct hist_field *hist_field = NULL;
1250 struct trace_event_file *file;
1251
1252 if (!system || !event_name) {
1253 hist_field = find_match_var(hist_data, var_name);
1254 if (IS_ERR(hist_field))
1255 return NULL;
1256 if (hist_field)
1257 return hist_field;
1258 }
1259
1260 file = find_var_file(tr, system, event_name, var_name);
1261 if (!file)
1262 return NULL;
1263
1264 hist_field = find_file_var(file, var_name);
1265
1266 return hist_field;
1267 }
1268
1269 static u64 hist_field_var_ref(struct hist_field *hist_field,
1270 struct tracing_map_elt *elt,
1271 struct trace_buffer *buffer,
1272 struct ring_buffer_event *rbe,
1273 void *event)
1274 {
1275 struct hist_elt_data *elt_data;
1276 u64 var_val = 0;
1277
1278 if (WARN_ON_ONCE(!elt))
1279 return var_val;
1280
1281 elt_data = elt->private_data;
1282 var_val = elt_data->var_ref_vals[hist_field->var_ref_idx];
1283
1284 return var_val;
1285 }
1286
1287 static bool resolve_var_refs(struct hist_trigger_data *hist_data, void *key,
1288 u64 *var_ref_vals, bool self)
1289 {
1290 struct hist_trigger_data *var_data;
1291 struct tracing_map_elt *var_elt;
1292 struct hist_field *hist_field;
1293 unsigned int i, var_idx;
1294 bool resolved = true;
1295 u64 var_val = 0;
1296
1297 for (i = 0; i < hist_data->n_var_refs; i++) {
1298 hist_field = hist_data->var_refs[i];
1299 var_idx = hist_field->var.idx;
1300 var_data = hist_field->var.hist_data;
1301
1302 if (var_data == NULL) {
1303 resolved = false;
1304 break;
1305 }
1306
1307 if ((self && var_data != hist_data) ||
1308 (!self && var_data == hist_data))
1309 continue;
1310
1311 var_elt = tracing_map_lookup(var_data->map, key);
1312 if (!var_elt) {
1313 resolved = false;
1314 break;
1315 }
1316
1317 if (!tracing_map_var_set(var_elt, var_idx)) {
1318 resolved = false;
1319 break;
1320 }
1321
1322 if (self || !hist_field->read_once)
1323 var_val = tracing_map_read_var(var_elt, var_idx);
1324 else
1325 var_val = tracing_map_read_var_once(var_elt, var_idx);
1326
1327 var_ref_vals[i] = var_val;
1328 }
1329
1330 return resolved;
1331 }
1332
1333 static const char *hist_field_name(struct hist_field *field,
1334 unsigned int level)
1335 {
1336 const char *field_name = "";
1337
1338 if (WARN_ON_ONCE(!field))
1339 return field_name;
1340
1341 if (level > 1)
1342 return field_name;
1343
1344 if (field->field)
1345 field_name = field->field->name;
1346 else if (field->flags & HIST_FIELD_FL_LOG2 ||
1347 field->flags & HIST_FIELD_FL_ALIAS ||
1348 field->flags & HIST_FIELD_FL_BUCKET)
1349 field_name = hist_field_name(field->operands[0], ++level);
1350 else if (field->flags & HIST_FIELD_FL_CPU)
1351 field_name = "common_cpu";
1352 else if (field->flags & HIST_FIELD_FL_COMM)
1353 field_name = "common_comm";
1354 else if (field->flags & HIST_FIELD_FL_EXPR ||
1355 field->flags & HIST_FIELD_FL_VAR_REF) {
1356 if (field->system) {
1357 static char full_name[MAX_FILTER_STR_VAL];
1358
1359 strcat(full_name, field->system);
1360 strcat(full_name, ".");
1361 strcat(full_name, field->event_name);
1362 strcat(full_name, ".");
1363 strcat(full_name, field->name);
1364 field_name = full_name;
1365 } else
1366 field_name = field->name;
1367 } else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
1368 field_name = "common_timestamp";
1369 else if (field->flags & HIST_FIELD_FL_STACKTRACE) {
1370 field_name = "common_stacktrace";
1371 } else if (field->flags & HIST_FIELD_FL_HITCOUNT)
1372 field_name = "hitcount";
1373
1374 if (field_name == NULL)
1375 field_name = "";
1376
1377 return field_name;
1378 }
1379
1380 static enum hist_field_fn select_value_fn(int field_size, int field_is_signed)
1381 {
1382 switch (field_size) {
1383 case 8:
1384 if (field_is_signed)
1385 return HIST_FIELD_FN_S64;
1386 else
1387 return HIST_FIELD_FN_U64;
1388 case 4:
1389 if (field_is_signed)
1390 return HIST_FIELD_FN_S32;
1391 else
1392 return HIST_FIELD_FN_U32;
1393 case 2:
1394 if (field_is_signed)
1395 return HIST_FIELD_FN_S16;
1396 else
1397 return HIST_FIELD_FN_U16;
1398 case 1:
1399 if (field_is_signed)
1400 return HIST_FIELD_FN_S8;
1401 else
1402 return HIST_FIELD_FN_U8;
1403 }
1404
1405 return HIST_FIELD_FN_NOP;
1406 }
1407
1408 static int parse_map_size(char *str)
1409 {
1410 unsigned long size, map_bits;
1411 int ret;
1412
1413 ret = kstrtoul(str, 0, &size);
1414 if (ret)
1415 goto out;
1416
1417 map_bits = ilog2(roundup_pow_of_two(size));
1418 if (map_bits < TRACING_MAP_BITS_MIN ||
1419 map_bits > TRACING_MAP_BITS_MAX)
1420 ret = -EINVAL;
1421 else
1422 ret = map_bits;
1423 out:
1424 return ret;
1425 }
1426
1427 static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
1428 {
1429 unsigned int i;
1430
1431 if (!attrs)
1432 return;
1433
1434 for (i = 0; i < attrs->n_assignments; i++)
1435 kfree(attrs->assignment_str[i]);
1436
1437 for (i = 0; i < attrs->n_actions; i++)
1438 kfree(attrs->action_str[i]);
1439
1440 kfree(attrs->name);
1441 kfree(attrs->sort_key_str);
1442 kfree(attrs->keys_str);
1443 kfree(attrs->vals_str);
1444 kfree(attrs->clock);
1445 kfree(attrs);
1446 }
1447
1448 static int parse_action(char *str, struct hist_trigger_attrs *attrs)
1449 {
1450 int ret = -EINVAL;
1451
1452 if (attrs->n_actions >= HIST_ACTIONS_MAX)
1453 return ret;
1454
1455 if ((str_has_prefix(str, "onmatch(")) ||
1456 (str_has_prefix(str, "onmax(")) ||
1457 (str_has_prefix(str, "onchange("))) {
1458 attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL);
1459 if (!attrs->action_str[attrs->n_actions]) {
1460 ret = -ENOMEM;
1461 return ret;
1462 }
1463 attrs->n_actions++;
1464 ret = 0;
1465 }
1466 return ret;
1467 }
1468
1469 static int parse_assignment(struct trace_array *tr,
1470 char *str, struct hist_trigger_attrs *attrs)
1471 {
1472 int len, ret = 0;
1473
1474 if ((len = str_has_prefix(str, "key=")) ||
1475 (len = str_has_prefix(str, "keys="))) {
1476 attrs->keys_str = kstrdup(str + len, GFP_KERNEL);
1477 if (!attrs->keys_str) {
1478 ret = -ENOMEM;
1479 goto out;
1480 }
1481 } else if ((len = str_has_prefix(str, "val=")) ||
1482 (len = str_has_prefix(str, "vals=")) ||
1483 (len = str_has_prefix(str, "values="))) {
1484 attrs->vals_str = kstrdup(str + len, GFP_KERNEL);
1485 if (!attrs->vals_str) {
1486 ret = -ENOMEM;
1487 goto out;
1488 }
1489 } else if ((len = str_has_prefix(str, "sort="))) {
1490 attrs->sort_key_str = kstrdup(str + len, GFP_KERNEL);
1491 if (!attrs->sort_key_str) {
1492 ret = -ENOMEM;
1493 goto out;
1494 }
1495 } else if (str_has_prefix(str, "name=")) {
1496 attrs->name = kstrdup(str, GFP_KERNEL);
1497 if (!attrs->name) {
1498 ret = -ENOMEM;
1499 goto out;
1500 }
1501 } else if ((len = str_has_prefix(str, "clock="))) {
1502 str += len;
1503
1504 str = strstrip(str);
1505 attrs->clock = kstrdup(str, GFP_KERNEL);
1506 if (!attrs->clock) {
1507 ret = -ENOMEM;
1508 goto out;
1509 }
1510 } else if ((len = str_has_prefix(str, "size="))) {
1511 int map_bits = parse_map_size(str + len);
1512
1513 if (map_bits < 0) {
1514 ret = map_bits;
1515 goto out;
1516 }
1517 attrs->map_bits = map_bits;
1518 } else {
1519 char *assignment;
1520
1521 if (attrs->n_assignments == TRACING_MAP_VARS_MAX) {
1522 hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(str));
1523 ret = -EINVAL;
1524 goto out;
1525 }
1526
1527 assignment = kstrdup(str, GFP_KERNEL);
1528 if (!assignment) {
1529 ret = -ENOMEM;
1530 goto out;
1531 }
1532
1533 attrs->assignment_str[attrs->n_assignments++] = assignment;
1534 }
1535 out:
1536 return ret;
1537 }
1538
1539 static struct hist_trigger_attrs *
1540 parse_hist_trigger_attrs(struct trace_array *tr, char *trigger_str)
1541 {
1542 struct hist_trigger_attrs *attrs;
1543 int ret = 0;
1544
1545 attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
1546 if (!attrs)
1547 return ERR_PTR(-ENOMEM);
1548
1549 while (trigger_str) {
1550 char *str = strsep(&trigger_str, ":");
1551 char *rhs;
1552
1553 rhs = strchr(str, '=');
1554 if (rhs) {
1555 if (!strlen(++rhs)) {
1556 ret = -EINVAL;
1557 hist_err(tr, HIST_ERR_EMPTY_ASSIGNMENT, errpos(str));
1558 goto free;
1559 }
1560 ret = parse_assignment(tr, str, attrs);
1561 if (ret)
1562 goto free;
1563 } else if (strcmp(str, "nohitcount") == 0 ||
1564 strcmp(str, "NOHC") == 0)
1565 attrs->no_hitcount = true;
1566 else if (strcmp(str, "pause") == 0)
1567 attrs->pause = true;
1568 else if ((strcmp(str, "cont") == 0) ||
1569 (strcmp(str, "continue") == 0))
1570 attrs->cont = true;
1571 else if (strcmp(str, "clear") == 0)
1572 attrs->clear = true;
1573 else {
1574 ret = parse_action(str, attrs);
1575 if (ret)
1576 goto free;
1577 }
1578 }
1579
1580 if (!attrs->keys_str) {
1581 ret = -EINVAL;
1582 goto free;
1583 }
1584
1585 if (!attrs->clock) {
1586 attrs->clock = kstrdup("global", GFP_KERNEL);
1587 if (!attrs->clock) {
1588 ret = -ENOMEM;
1589 goto free;
1590 }
1591 }
1592
1593 return attrs;
1594 free:
1595 destroy_hist_trigger_attrs(attrs);
1596
1597 return ERR_PTR(ret);
1598 }
1599
1600 static inline void save_comm(char *comm, struct task_struct *task)
1601 {
1602 if (!task->pid) {
1603 strcpy(comm, "<idle>");
1604 return;
1605 }
1606
1607 if (WARN_ON_ONCE(task->pid < 0)) {
1608 strcpy(comm, "<XXX>");
1609 return;
1610 }
1611
1612 strscpy(comm, task->comm, TASK_COMM_LEN);
1613 }
1614
1615 static void hist_elt_data_free(struct hist_elt_data *elt_data)
1616 {
1617 unsigned int i;
1618
1619 for (i = 0; i < elt_data->n_field_var_str; i++)
1620 kfree(elt_data->field_var_str[i]);
1621
1622 kfree(elt_data->field_var_str);
1623
1624 kfree(elt_data->comm);
1625 kfree(elt_data);
1626 }
1627
1628 static void hist_trigger_elt_data_free(struct tracing_map_elt *elt)
1629 {
1630 struct hist_elt_data *elt_data = elt->private_data;
1631
1632 hist_elt_data_free(elt_data);
1633 }
1634
1635 static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
1636 {
1637 struct hist_trigger_data *hist_data = elt->map->private_data;
1638 unsigned int size = TASK_COMM_LEN;
1639 struct hist_elt_data *elt_data;
1640 struct hist_field *hist_field;
1641 unsigned int i, n_str;
1642
1643 elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
1644 if (!elt_data)
1645 return -ENOMEM;
1646
1647 for_each_hist_field(i, hist_data) {
1648 hist_field = hist_data->fields[i];
1649
1650 if (hist_field->flags & HIST_FIELD_FL_EXECNAME) {
1651 elt_data->comm = kzalloc(size, GFP_KERNEL);
1652 if (!elt_data->comm) {
1653 kfree(elt_data);
1654 return -ENOMEM;
1655 }
1656 break;
1657 }
1658 }
1659
1660 n_str = hist_data->n_field_var_str + hist_data->n_save_var_str +
1661 hist_data->n_var_str;
1662 if (n_str > SYNTH_FIELDS_MAX) {
1663 hist_elt_data_free(elt_data);
1664 return -EINVAL;
1665 }
1666
1667 BUILD_BUG_ON(STR_VAR_LEN_MAX & (sizeof(u64) - 1));
1668
1669 size = STR_VAR_LEN_MAX;
1670
1671 elt_data->field_var_str = kcalloc(n_str, sizeof(char *), GFP_KERNEL);
1672 if (!elt_data->field_var_str) {
1673 hist_elt_data_free(elt_data);
1674 return -EINVAL;
1675 }
1676 elt_data->n_field_var_str = n_str;
1677
1678 for (i = 0; i < n_str; i++) {
1679 elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL);
1680 if (!elt_data->field_var_str[i]) {
1681 hist_elt_data_free(elt_data);
1682 return -ENOMEM;
1683 }
1684 }
1685
1686 elt->private_data = elt_data;
1687
1688 return 0;
1689 }
1690
1691 static void hist_trigger_elt_data_init(struct tracing_map_elt *elt)
1692 {
1693 struct hist_elt_data *elt_data = elt->private_data;
1694
1695 if (elt_data->comm)
1696 save_comm(elt_data->comm, current);
1697 }
1698
1699 static const struct tracing_map_ops hist_trigger_elt_data_ops = {
1700 .elt_alloc = hist_trigger_elt_data_alloc,
1701 .elt_free = hist_trigger_elt_data_free,
1702 .elt_init = hist_trigger_elt_data_init,
1703 };
1704
1705 static const char *get_hist_field_flags(struct hist_field *hist_field)
1706 {
1707 const char *flags_str = NULL;
1708
1709 if (hist_field->flags & HIST_FIELD_FL_HEX)
1710 flags_str = "hex";
1711 else if (hist_field->flags & HIST_FIELD_FL_SYM)
1712 flags_str = "sym";
1713 else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
1714 flags_str = "sym-offset";
1715 else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
1716 flags_str = "execname";
1717 else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
1718 flags_str = "syscall";
1719 else if (hist_field->flags & HIST_FIELD_FL_LOG2)
1720 flags_str = "log2";
1721 else if (hist_field->flags & HIST_FIELD_FL_BUCKET)
1722 flags_str = "buckets";
1723 else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS)
1724 flags_str = "usecs";
1725 else if (hist_field->flags & HIST_FIELD_FL_PERCENT)
1726 flags_str = "percent";
1727 else if (hist_field->flags & HIST_FIELD_FL_GRAPH)
1728 flags_str = "graph";
1729 else if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
1730 flags_str = "stacktrace";
1731
1732 return flags_str;
1733 }
1734
1735 static void expr_field_str(struct hist_field *field, char *expr)
1736 {
1737 if (field->flags & HIST_FIELD_FL_VAR_REF)
1738 strcat(expr, "$");
1739 else if (field->flags & HIST_FIELD_FL_CONST) {
1740 char str[HIST_CONST_DIGITS_MAX];
1741
1742 snprintf(str, HIST_CONST_DIGITS_MAX, "%llu", field->constant);
1743 strcat(expr, str);
1744 }
1745
1746 strcat(expr, hist_field_name(field, 0));
1747
1748 if (field->flags && !(field->flags & HIST_FIELD_FL_VAR_REF)) {
1749 const char *flags_str = get_hist_field_flags(field);
1750
1751 if (flags_str) {
1752 strcat(expr, ".");
1753 strcat(expr, flags_str);
1754 }
1755 }
1756 }
1757
1758 static char *expr_str(struct hist_field *field, unsigned int level)
1759 {
1760 char *expr;
1761
1762 if (level > 1)
1763 return NULL;
1764
1765 expr = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
1766 if (!expr)
1767 return NULL;
1768
1769 if (!field->operands[0]) {
1770 expr_field_str(field, expr);
1771 return expr;
1772 }
1773
1774 if (field->operator == FIELD_OP_UNARY_MINUS) {
1775 char *subexpr;
1776
1777 strcat(expr, "-(");
1778 subexpr = expr_str(field->operands[0], ++level);
1779 if (!subexpr) {
1780 kfree(expr);
1781 return NULL;
1782 }
1783 strcat(expr, subexpr);
1784 strcat(expr, ")");
1785
1786 kfree(subexpr);
1787
1788 return expr;
1789 }
1790
1791 expr_field_str(field->operands[0], expr);
1792
1793 switch (field->operator) {
1794 case FIELD_OP_MINUS:
1795 strcat(expr, "-");
1796 break;
1797 case FIELD_OP_PLUS:
1798 strcat(expr, "+");
1799 break;
1800 case FIELD_OP_DIV:
1801 strcat(expr, "/");
1802 break;
1803 case FIELD_OP_MULT:
1804 strcat(expr, "*");
1805 break;
1806 default:
1807 kfree(expr);
1808 return NULL;
1809 }
1810
1811 expr_field_str(field->operands[1], expr);
1812
1813 return expr;
1814 }
1815
1816 /*
1817 * If field_op != FIELD_OP_NONE, *sep points to the root operator
1818 * of the expression tree to be evaluated.
1819 */
1820 static int contains_operator(char *str, char **sep)
1821 {
1822 enum field_op_id field_op = FIELD_OP_NONE;
1823 char *minus_op, *plus_op, *div_op, *mult_op;
1824
1825
1826 /*
1827 * Report the last occurrence of the operators first, so that the
1828 * expression is evaluated left to right. This is important since
1829 * subtraction and division are not associative.
1830 *
1831 * e.g
1832 * 64/8/4/2 is 1, i.e 64/8/4/2 = ((64/8)/4)/2
1833 * 14-7-5-2 is 0, i.e 14-7-5-2 = ((14-7)-5)-2
1834 */
1835
1836 /*
1837 * First, find lower precedence addition and subtraction
1838 * since the expression will be evaluated recursively.
1839 */
1840 minus_op = strrchr(str, '-');
1841 if (minus_op) {
1842 /*
1843 * Unary minus is not supported in sub-expressions. If
1844 * present, it is always the next root operator.
1845 */
1846 if (minus_op == str) {
1847 field_op = FIELD_OP_UNARY_MINUS;
1848 goto out;
1849 }
1850
1851 field_op = FIELD_OP_MINUS;
1852 }
1853
1854 plus_op = strrchr(str, '+');
1855 if (plus_op || minus_op) {
1856 /*
1857 * For operators of the same precedence use to rightmost as the
1858 * root, so that the expression is evaluated left to right.
1859 */
1860 if (plus_op > minus_op)
1861 field_op = FIELD_OP_PLUS;
1862 goto out;
1863 }
1864
1865 /*
1866 * Multiplication and division have higher precedence than addition and
1867 * subtraction.
1868 */
1869 div_op = strrchr(str, '/');
1870 if (div_op)
1871 field_op = FIELD_OP_DIV;
1872
1873 mult_op = strrchr(str, '*');
1874 /*
1875 * For operators of the same precedence use to rightmost as the
1876 * root, so that the expression is evaluated left to right.
1877 */
1878 if (mult_op > div_op)
1879 field_op = FIELD_OP_MULT;
1880
1881 out:
1882 if (sep) {
1883 switch (field_op) {
1884 case FIELD_OP_UNARY_MINUS:
1885 case FIELD_OP_MINUS:
1886 *sep = minus_op;
1887 break;
1888 case FIELD_OP_PLUS:
1889 *sep = plus_op;
1890 break;
1891 case FIELD_OP_DIV:
1892 *sep = div_op;
1893 break;
1894 case FIELD_OP_MULT:
1895 *sep = mult_op;
1896 break;
1897 case FIELD_OP_NONE:
1898 default:
1899 *sep = NULL;
1900 break;
1901 }
1902 }
1903
1904 return field_op;
1905 }
1906
1907 static void get_hist_field(struct hist_field *hist_field)
1908 {
1909 hist_field->ref++;
1910 }
1911
1912 static void __destroy_hist_field(struct hist_field *hist_field)
1913 {
1914 if (--hist_field->ref > 1)
1915 return;
1916
1917 kfree(hist_field->var.name);
1918 kfree(hist_field->name);
1919
1920 /* Can likely be a const */
1921 kfree_const(hist_field->type);
1922
1923 kfree(hist_field->system);
1924 kfree(hist_field->event_name);
1925
1926 kfree(hist_field);
1927 }
1928
1929 static void destroy_hist_field(struct hist_field *hist_field,
1930 unsigned int level)
1931 {
1932 unsigned int i;
1933
1934 if (level > 3)
1935 return;
1936
1937 if (!hist_field)
1938 return;
1939
1940 if (hist_field->flags & HIST_FIELD_FL_VAR_REF)
1941 return; /* var refs will be destroyed separately */
1942
1943 for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
1944 destroy_hist_field(hist_field->operands[i], level + 1);
1945
1946 __destroy_hist_field(hist_field);
1947 }
1948
1949 static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
1950 struct ftrace_event_field *field,
1951 unsigned long flags,
1952 char *var_name)
1953 {
1954 struct hist_field *hist_field;
1955
1956 if (field && is_function_field(field))
1957 return NULL;
1958
1959 hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
1960 if (!hist_field)
1961 return NULL;
1962
1963 hist_field->ref = 1;
1964
1965 hist_field->hist_data = hist_data;
1966
1967 if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS)
1968 goto out; /* caller will populate */
1969
1970 if (flags & HIST_FIELD_FL_VAR_REF) {
1971 hist_field->fn_num = HIST_FIELD_FN_VAR_REF;
1972 goto out;
1973 }
1974
1975 if (flags & HIST_FIELD_FL_HITCOUNT) {
1976 hist_field->fn_num = HIST_FIELD_FN_COUNTER;
1977 hist_field->size = sizeof(u64);
1978 hist_field->type = "u64";
1979 goto out;
1980 }
1981
1982 if (flags & HIST_FIELD_FL_CONST) {
1983 hist_field->fn_num = HIST_FIELD_FN_CONST;
1984 hist_field->size = sizeof(u64);
1985 hist_field->type = kstrdup("u64", GFP_KERNEL);
1986 if (!hist_field->type)
1987 goto free;
1988 goto out;
1989 }
1990
1991 if (flags & HIST_FIELD_FL_STACKTRACE) {
1992 if (field)
1993 hist_field->fn_num = HIST_FIELD_FN_STACK;
1994 else
1995 hist_field->fn_num = HIST_FIELD_FN_NOP;
1996 hist_field->size = HIST_STACKTRACE_SIZE;
1997 hist_field->type = kstrdup_const("unsigned long[]", GFP_KERNEL);
1998 if (!hist_field->type)
1999 goto free;
2000 goto out;
2001 }
2002
2003 if (flags & (HIST_FIELD_FL_LOG2 | HIST_FIELD_FL_BUCKET)) {
2004 unsigned long fl = flags & ~(HIST_FIELD_FL_LOG2 | HIST_FIELD_FL_BUCKET);
2005 hist_field->fn_num = flags & HIST_FIELD_FL_LOG2 ? HIST_FIELD_FN_LOG2 :
2006 HIST_FIELD_FN_BUCKET;
2007 hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
2008 if (!hist_field->operands[0])
2009 goto free;
2010 hist_field->size = hist_field->operands[0]->size;
2011 hist_field->type = kstrdup_const(hist_field->operands[0]->type, GFP_KERNEL);
2012 if (!hist_field->type)
2013 goto free;
2014 goto out;
2015 }
2016
2017 if (flags & HIST_FIELD_FL_TIMESTAMP) {
2018 hist_field->fn_num = HIST_FIELD_FN_TIMESTAMP;
2019 hist_field->size = sizeof(u64);
2020 hist_field->type = "u64";
2021 goto out;
2022 }
2023
2024 if (flags & HIST_FIELD_FL_CPU) {
2025 hist_field->fn_num = HIST_FIELD_FN_CPU;
2026 hist_field->size = sizeof(int);
2027 hist_field->type = "unsigned int";
2028 goto out;
2029 }
2030
2031 if (flags & HIST_FIELD_FL_COMM) {
2032 hist_field->fn_num = HIST_FIELD_FN_COMM;
2033 hist_field->size = MAX_FILTER_STR_VAL;
2034 hist_field->type = "char[]";
2035 goto out;
2036 }
2037
2038 if (WARN_ON_ONCE(!field))
2039 goto out;
2040
2041 /* Pointers to strings are just pointers and dangerous to dereference */
2042 if (is_string_field(field) &&
2043 (field->filter_type != FILTER_PTR_STRING)) {
2044 flags |= HIST_FIELD_FL_STRING;
2045
2046 hist_field->size = MAX_FILTER_STR_VAL;
2047 hist_field->type = kstrdup_const(field->type, GFP_KERNEL);
2048 if (!hist_field->type)
2049 goto free;
2050
2051 if (field->filter_type == FILTER_STATIC_STRING) {
2052 hist_field->fn_num = HIST_FIELD_FN_STRING;
2053 hist_field->size = field->size;
2054 } else if (field->filter_type == FILTER_DYN_STRING) {
2055 hist_field->fn_num = HIST_FIELD_FN_DYNSTRING;
2056 } else if (field->filter_type == FILTER_RDYN_STRING)
2057 hist_field->fn_num = HIST_FIELD_FN_RELDYNSTRING;
2058 else
2059 hist_field->fn_num = HIST_FIELD_FN_PSTRING;
2060 } else {
2061 hist_field->size = field->size;
2062 hist_field->is_signed = field->is_signed;
2063 hist_field->type = kstrdup_const(field->type, GFP_KERNEL);
2064 if (!hist_field->type)
2065 goto free;
2066
2067 hist_field->fn_num = select_value_fn(field->size,
2068 field->is_signed);
2069 if (hist_field->fn_num == HIST_FIELD_FN_NOP) {
2070 destroy_hist_field(hist_field, 0);
2071 return NULL;
2072 }
2073 }
2074 out:
2075 hist_field->field = field;
2076 hist_field->flags = flags;
2077
2078 if (var_name) {
2079 hist_field->var.name = kstrdup(var_name, GFP_KERNEL);
2080 if (!hist_field->var.name)
2081 goto free;
2082 }
2083
2084 return hist_field;
2085 free:
2086 destroy_hist_field(hist_field, 0);
2087 return NULL;
2088 }
2089
2090 static void destroy_hist_fields(struct hist_trigger_data *hist_data)
2091 {
2092 unsigned int i;
2093
2094 for (i = 0; i < HIST_FIELDS_MAX; i++) {
2095 if (hist_data->fields[i]) {
2096 destroy_hist_field(hist_data->fields[i], 0);
2097 hist_data->fields[i] = NULL;
2098 }
2099 }
2100
2101 for (i = 0; i < hist_data->n_var_refs; i++) {
2102 WARN_ON(!(hist_data->var_refs[i]->flags & HIST_FIELD_FL_VAR_REF));
2103 __destroy_hist_field(hist_data->var_refs[i]);
2104 hist_data->var_refs[i] = NULL;
2105 }
2106 }
2107
2108 static int init_var_ref(struct hist_field *ref_field,
2109 struct hist_field *var_field,
2110 char *system, char *event_name)
2111 {
2112 int err = 0;
2113
2114 ref_field->var.idx = var_field->var.idx;
2115 ref_field->var.hist_data = var_field->hist_data;
2116 ref_field->size = var_field->size;
2117 ref_field->is_signed = var_field->is_signed;
2118 ref_field->flags |= var_field->flags &
2119 (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
2120
2121 if (system) {
2122 ref_field->system = kstrdup(system, GFP_KERNEL);
2123 if (!ref_field->system)
2124 return -ENOMEM;
2125 }
2126
2127 if (event_name) {
2128 ref_field->event_name = kstrdup(event_name, GFP_KERNEL);
2129 if (!ref_field->event_name) {
2130 err = -ENOMEM;
2131 goto free;
2132 }
2133 }
2134
2135 if (var_field->var.name) {
2136 ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL);
2137 if (!ref_field->name) {
2138 err = -ENOMEM;
2139 goto free;
2140 }
2141 } else if (var_field->name) {
2142 ref_field->name = kstrdup(var_field->name, GFP_KERNEL);
2143 if (!ref_field->name) {
2144 err = -ENOMEM;
2145 goto free;
2146 }
2147 }
2148
2149 ref_field->type = kstrdup_const(var_field->type, GFP_KERNEL);
2150 if (!ref_field->type) {
2151 err = -ENOMEM;
2152 goto free;
2153 }
2154 out:
2155 return err;
2156 free:
2157 kfree(ref_field->system);
2158 ref_field->system = NULL;
2159 kfree(ref_field->event_name);
2160 ref_field->event_name = NULL;
2161 kfree(ref_field->name);
2162 ref_field->name = NULL;
2163
2164 goto out;
2165 }
2166
2167 static int find_var_ref_idx(struct hist_trigger_data *hist_data,
2168 struct hist_field *var_field)
2169 {
2170 struct hist_field *ref_field;
2171 int i;
2172
2173 for (i = 0; i < hist_data->n_var_refs; i++) {
2174 ref_field = hist_data->var_refs[i];
2175 if (ref_field->var.idx == var_field->var.idx &&
2176 ref_field->var.hist_data == var_field->hist_data)
2177 return i;
2178 }
2179
2180 return -ENOENT;
2181 }
2182
2183 /**
2184 * create_var_ref - Create a variable reference and attach it to trigger
2185 * @hist_data: The trigger that will be referencing the variable
2186 * @var_field: The VAR field to create a reference to
2187 * @system: The optional system string
2188 * @event_name: The optional event_name string
2189 *
2190 * Given a variable hist_field, create a VAR_REF hist_field that
2191 * represents a reference to it.
2192 *
2193 * This function also adds the reference to the trigger that
2194 * now references the variable.
2195 *
2196 * Return: The VAR_REF field if successful, NULL if not
2197 */
2198 static struct hist_field *create_var_ref(struct hist_trigger_data *hist_data,
2199 struct hist_field *var_field,
2200 char *system, char *event_name)
2201 {
2202 unsigned long flags = HIST_FIELD_FL_VAR_REF;
2203 struct hist_field *ref_field;
2204 int i;
2205
2206 /* Check if the variable already exists */
2207 for (i = 0; i < hist_data->n_var_refs; i++) {
2208 ref_field = hist_data->var_refs[i];
2209 if (ref_field->var.idx == var_field->var.idx &&
2210 ref_field->var.hist_data == var_field->hist_data) {
2211 get_hist_field(ref_field);
2212 return ref_field;
2213 }
2214 }
2215 /* Sanity check to avoid out-of-bound write on 'hist_data->var_refs' */
2216 if (hist_data->n_var_refs >= TRACING_MAP_VARS_MAX)
2217 return NULL;
2218 ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL);
2219 if (ref_field) {
2220 if (init_var_ref(ref_field, var_field, system, event_name)) {
2221 destroy_hist_field(ref_field, 0);
2222 return NULL;
2223 }
2224
2225 hist_data->var_refs[hist_data->n_var_refs] = ref_field;
2226 ref_field->var_ref_idx = hist_data->n_var_refs++;
2227 }
2228
2229 return ref_field;
2230 }
2231
2232 static bool is_var_ref(char *var_name)
2233 {
2234 if (!var_name || strlen(var_name) < 2 || var_name[0] != '$')
2235 return false;
2236
2237 return true;
2238 }
2239
2240 static char *field_name_from_var(struct hist_trigger_data *hist_data,
2241 char *var_name)
2242 {
2243 char *name, *field;
2244 unsigned int i;
2245
2246 for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
2247 name = hist_data->attrs->var_defs.name[i];
2248
2249 if (strcmp(var_name, name) == 0) {
2250 field = hist_data->attrs->var_defs.expr[i];
2251 if (contains_operator(field, NULL) || is_var_ref(field))
2252 continue;
2253 return field;
2254 }
2255 }
2256
2257 return NULL;
2258 }
2259
2260 static char *local_field_var_ref(struct hist_trigger_data *hist_data,
2261 char *system, char *event_name,
2262 char *var_name)
2263 {
2264 struct trace_event_call *call;
2265
2266 if (system && event_name) {
2267 call = hist_data->event_file->event_call;
2268
2269 if (strcmp(system, call->class->system) != 0)
2270 return NULL;
2271
2272 if (strcmp(event_name, trace_event_name(call)) != 0)
2273 return NULL;
2274 }
2275
2276 if (!!system != !!event_name)
2277 return NULL;
2278
2279 if (!is_var_ref(var_name))
2280 return NULL;
2281
2282 var_name++;
2283
2284 return field_name_from_var(hist_data, var_name);
2285 }
2286
2287 static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data,
2288 char *system, char *event_name,
2289 char *var_name)
2290 {
2291 struct hist_field *var_field = NULL, *ref_field = NULL;
2292 struct trace_array *tr = hist_data->event_file->tr;
2293
2294 if (!is_var_ref(var_name))
2295 return NULL;
2296
2297 var_name++;
2298
2299 var_field = find_event_var(hist_data, system, event_name, var_name);
2300 if (var_field)
2301 ref_field = create_var_ref(hist_data, var_field,
2302 system, event_name);
2303
2304 if (!ref_field)
2305 hist_err(tr, HIST_ERR_VAR_NOT_FOUND, errpos(var_name));
2306
2307 return ref_field;
2308 }
2309
2310 static struct ftrace_event_field *
2311 parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
2312 char *field_str, unsigned long *flags, unsigned long *buckets)
2313 {
2314 struct ftrace_event_field *field = NULL;
2315 char *field_name, *modifier, *str;
2316 struct trace_array *tr = file->tr;
2317
2318 modifier = str = kstrdup(field_str, GFP_KERNEL);
2319 if (!modifier)
2320 return ERR_PTR(-ENOMEM);
2321
2322 field_name = strsep(&modifier, ".");
2323 if (modifier) {
2324 if (strcmp(modifier, "hex") == 0)
2325 *flags |= HIST_FIELD_FL_HEX;
2326 else if (strcmp(modifier, "sym") == 0)
2327 *flags |= HIST_FIELD_FL_SYM;
2328 /*
2329 * 'sym-offset' occurrences in the trigger string are modified
2330 * to 'symXoffset' to simplify arithmetic expression parsing.
2331 */
2332 else if (strcmp(modifier, "symXoffset") == 0)
2333 *flags |= HIST_FIELD_FL_SYM_OFFSET;
2334 else if ((strcmp(modifier, "execname") == 0) &&
2335 (strcmp(field_name, "common_pid") == 0))
2336 *flags |= HIST_FIELD_FL_EXECNAME;
2337 else if (strcmp(modifier, "syscall") == 0)
2338 *flags |= HIST_FIELD_FL_SYSCALL;
2339 else if (strcmp(modifier, "stacktrace") == 0)
2340 *flags |= HIST_FIELD_FL_STACKTRACE;
2341 else if (strcmp(modifier, "log2") == 0)
2342 *flags |= HIST_FIELD_FL_LOG2;
2343 else if (strcmp(modifier, "usecs") == 0)
2344 *flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
2345 else if (strncmp(modifier, "bucket", 6) == 0) {
2346 int ret;
2347
2348 modifier += 6;
2349
2350 if (*modifier == 's')
2351 modifier++;
2352 if (*modifier != '=')
2353 goto error;
2354 modifier++;
2355 ret = kstrtoul(modifier, 0, buckets);
2356 if (ret || !(*buckets))
2357 goto error;
2358 *flags |= HIST_FIELD_FL_BUCKET;
2359 } else if (strncmp(modifier, "percent", 7) == 0) {
2360 if (*flags & (HIST_FIELD_FL_VAR | HIST_FIELD_FL_KEY))
2361 goto error;
2362 *flags |= HIST_FIELD_FL_PERCENT;
2363 } else if (strncmp(modifier, "graph", 5) == 0) {
2364 if (*flags & (HIST_FIELD_FL_VAR | HIST_FIELD_FL_KEY))
2365 goto error;
2366 *flags |= HIST_FIELD_FL_GRAPH;
2367 } else {
2368 error:
2369 hist_err(tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(modifier));
2370 field = ERR_PTR(-EINVAL);
2371 goto out;
2372 }
2373 }
2374
2375 if (strcmp(field_name, "common_timestamp") == 0) {
2376 *flags |= HIST_FIELD_FL_TIMESTAMP;
2377 hist_data->enable_timestamps = true;
2378 if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS)
2379 hist_data->attrs->ts_in_usecs = true;
2380 } else if (strcmp(field_name, "common_stacktrace") == 0) {
2381 *flags |= HIST_FIELD_FL_STACKTRACE;
2382 } else if (strcmp(field_name, "common_cpu") == 0) {
2383 *flags |= HIST_FIELD_FL_CPU;
2384 } else if (strcmp(field_name, "common_comm") == 0) {
2385 *flags |= HIST_FIELD_FL_COMM | HIST_FIELD_FL_STRING;
2386 } else if (strcmp(field_name, "hitcount") == 0)
2387 *flags |= HIST_FIELD_FL_HITCOUNT;
2388 else {
2389 field = trace_find_event_field(file->event_call, field_name);
2390 if (!field || !field->size) {
2391 /*
2392 * For backward compatibility, if field_name
2393 * was "cpu" or "stacktrace", then we treat this
2394 * the same as common_cpu and common_stacktrace
2395 * respectively. This also works for "CPU", and
2396 * "STACKTRACE".
2397 */
2398 if (field && field->filter_type == FILTER_CPU) {
2399 *flags |= HIST_FIELD_FL_CPU;
2400 } else if (field && field->filter_type == FILTER_STACKTRACE) {
2401 *flags |= HIST_FIELD_FL_STACKTRACE;
2402 } else if (field && field->filter_type == FILTER_COMM) {
2403 *flags |= HIST_FIELD_FL_COMM | HIST_FIELD_FL_STRING;
2404 } else {
2405 hist_err(tr, HIST_ERR_FIELD_NOT_FOUND,
2406 errpos(field_name));
2407 field = ERR_PTR(-EINVAL);
2408 goto out;
2409 }
2410 }
2411 }
2412 out:
2413 kfree(str);
2414
2415 return field;
2416 }
2417
2418 static struct hist_field *create_alias(struct hist_trigger_data *hist_data,
2419 struct hist_field *var_ref,
2420 char *var_name)
2421 {
2422 struct hist_field *alias = NULL;
2423 unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR;
2424
2425 alias = create_hist_field(hist_data, NULL, flags, var_name);
2426 if (!alias)
2427 return NULL;
2428
2429 alias->fn_num = var_ref->fn_num;
2430 alias->operands[0] = var_ref;
2431
2432 if (init_var_ref(alias, var_ref, var_ref->system, var_ref->event_name)) {
2433 destroy_hist_field(alias, 0);
2434 return NULL;
2435 }
2436
2437 alias->var_ref_idx = var_ref->var_ref_idx;
2438
2439 return alias;
2440 }
2441
2442 static struct hist_field *parse_const(struct hist_trigger_data *hist_data,
2443 char *str, char *var_name,
2444 unsigned long *flags)
2445 {
2446 struct trace_array *tr = hist_data->event_file->tr;
2447 struct hist_field *field = NULL;
2448 u64 constant;
2449
2450 if (kstrtoull(str, 0, &constant)) {
2451 hist_err(tr, HIST_ERR_EXPECT_NUMBER, errpos(str));
2452 return NULL;
2453 }
2454
2455 *flags |= HIST_FIELD_FL_CONST;
2456 field = create_hist_field(hist_data, NULL, *flags, var_name);
2457 if (!field)
2458 return NULL;
2459
2460 field->constant = constant;
2461
2462 return field;
2463 }
2464
2465 static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
2466 struct trace_event_file *file, char *str,
2467 unsigned long *flags, char *var_name)
2468 {
2469 char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str;
2470 struct ftrace_event_field *field = NULL;
2471 struct hist_field *hist_field = NULL;
2472 unsigned long buckets = 0;
2473 int ret = 0;
2474
2475 if (isdigit(str[0])) {
2476 hist_field = parse_const(hist_data, str, var_name, flags);
2477 if (!hist_field) {
2478 ret = -EINVAL;
2479 goto out;
2480 }
2481 return hist_field;
2482 }
2483
2484 s = strchr(str, '.');
2485 if (s) {
2486 s = strchr(++s, '.');
2487 if (s) {
2488 ref_system = strsep(&str, ".");
2489 if (!str) {
2490 ret = -EINVAL;
2491 goto out;
2492 }
2493 ref_event = strsep(&str, ".");
2494 if (!str) {
2495 ret = -EINVAL;
2496 goto out;
2497 }
2498 ref_var = str;
2499 }
2500 }
2501
2502 s = local_field_var_ref(hist_data, ref_system, ref_event, ref_var);
2503 if (!s) {
2504 hist_field = parse_var_ref(hist_data, ref_system,
2505 ref_event, ref_var);
2506 if (hist_field) {
2507 if (var_name) {
2508 hist_field = create_alias(hist_data, hist_field, var_name);
2509 if (!hist_field) {
2510 ret = -ENOMEM;
2511 goto out;
2512 }
2513 }
2514 return hist_field;
2515 }
2516 } else
2517 str = s;
2518
2519 field = parse_field(hist_data, file, str, flags, &buckets);
2520 if (IS_ERR(field)) {
2521 ret = PTR_ERR(field);
2522 goto out;
2523 }
2524
2525 hist_field = create_hist_field(hist_data, field, *flags, var_name);
2526 if (!hist_field) {
2527 ret = -ENOMEM;
2528 goto out;
2529 }
2530 hist_field->buckets = buckets;
2531
2532 return hist_field;
2533 out:
2534 return ERR_PTR(ret);
2535 }
2536
2537 static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
2538 struct trace_event_file *file,
2539 char *str, unsigned long flags,
2540 char *var_name, unsigned int *n_subexprs);
2541
2542 static struct hist_field *parse_unary(struct hist_trigger_data *hist_data,
2543 struct trace_event_file *file,
2544 char *str, unsigned long flags,
2545 char *var_name, unsigned int *n_subexprs)
2546 {
2547 struct hist_field *operand1, *expr = NULL;
2548 unsigned long operand_flags;
2549 int ret = 0;
2550 char *s;
2551
2552 /* Unary minus operator, increment n_subexprs */
2553 ++*n_subexprs;
2554
2555 /* we support only -(xxx) i.e. explicit parens required */
2556
2557 if (*n_subexprs > 3) {
2558 hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str));
2559 ret = -EINVAL;
2560 goto free;
2561 }
2562
2563 str++; /* skip leading '-' */
2564
2565 s = strchr(str, '(');
2566 if (s)
2567 str++;
2568 else {
2569 ret = -EINVAL;
2570 goto free;
2571 }
2572
2573 s = strrchr(str, ')');
2574 if (s) {
2575 /* unary minus not supported in sub-expressions */
2576 if (*(s+1) != '\0') {
2577 hist_err(file->tr, HIST_ERR_UNARY_MINUS_SUBEXPR,
2578 errpos(str));
2579 ret = -EINVAL;
2580 goto free;
2581 }
2582 *s = '\0';
2583 }
2584 else {
2585 ret = -EINVAL; /* no closing ')' */
2586 goto free;
2587 }
2588
2589 flags |= HIST_FIELD_FL_EXPR;
2590 expr = create_hist_field(hist_data, NULL, flags, var_name);
2591 if (!expr) {
2592 ret = -ENOMEM;
2593 goto free;
2594 }
2595
2596 operand_flags = 0;
2597 operand1 = parse_expr(hist_data, file, str, operand_flags, NULL, n_subexprs);
2598 if (IS_ERR(operand1)) {
2599 ret = PTR_ERR(operand1);
2600 goto free;
2601 }
2602 if (operand1->flags & HIST_FIELD_FL_STRING) {
2603 /* String type can not be the operand of unary operator. */
2604 hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str));
2605 destroy_hist_field(operand1, 0);
2606 ret = -EINVAL;
2607 goto free;
2608 }
2609
2610 expr->flags |= operand1->flags &
2611 (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
2612 expr->fn_num = HIST_FIELD_FN_UMINUS;
2613 expr->operands[0] = operand1;
2614 expr->size = operand1->size;
2615 expr->is_signed = operand1->is_signed;
2616 expr->operator = FIELD_OP_UNARY_MINUS;
2617 expr->name = expr_str(expr, 0);
2618 expr->type = kstrdup_const(operand1->type, GFP_KERNEL);
2619 if (!expr->type) {
2620 ret = -ENOMEM;
2621 goto free;
2622 }
2623
2624 return expr;
2625 free:
2626 destroy_hist_field(expr, 0);
2627 return ERR_PTR(ret);
2628 }
2629
2630 /*
2631 * If the operands are var refs, return pointers the
2632 * variable(s) referenced in var1 and var2, else NULL.
2633 */
2634 static int check_expr_operands(struct trace_array *tr,
2635 struct hist_field *operand1,
2636 struct hist_field *operand2,
2637 struct hist_field **var1,
2638 struct hist_field **var2)
2639 {
2640 unsigned long operand1_flags = operand1->flags;
2641 unsigned long operand2_flags = operand2->flags;
2642
2643 if ((operand1_flags & HIST_FIELD_FL_VAR_REF) ||
2644 (operand1_flags & HIST_FIELD_FL_ALIAS)) {
2645 struct hist_field *var;
2646
2647 var = find_var_field(operand1->var.hist_data, operand1->name);
2648 if (!var)
2649 return -EINVAL;
2650 operand1_flags = var->flags;
2651 *var1 = var;
2652 }
2653
2654 if ((operand2_flags & HIST_FIELD_FL_VAR_REF) ||
2655 (operand2_flags & HIST_FIELD_FL_ALIAS)) {
2656 struct hist_field *var;
2657
2658 var = find_var_field(operand2->var.hist_data, operand2->name);
2659 if (!var)
2660 return -EINVAL;
2661 operand2_flags = var->flags;
2662 *var2 = var;
2663 }
2664
2665 if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) !=
2666 (operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS)) {
2667 hist_err(tr, HIST_ERR_TIMESTAMP_MISMATCH, 0);
2668 return -EINVAL;
2669 }
2670
2671 return 0;
2672 }
2673
2674 static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
2675 struct trace_event_file *file,
2676 char *str, unsigned long flags,
2677 char *var_name, unsigned int *n_subexprs)
2678 {
2679 struct hist_field *operand1 = NULL, *operand2 = NULL, *expr = NULL;
2680 struct hist_field *var1 = NULL, *var2 = NULL;
2681 unsigned long operand_flags, operand2_flags;
2682 int field_op, ret = -EINVAL;
2683 char *sep, *operand1_str;
2684 enum hist_field_fn op_fn;
2685 bool combine_consts;
2686
2687 if (*n_subexprs > 3) {
2688 hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str));
2689 return ERR_PTR(-EINVAL);
2690 }
2691
2692 field_op = contains_operator(str, &sep);
2693
2694 if (field_op == FIELD_OP_NONE)
2695 return parse_atom(hist_data, file, str, &flags, var_name);
2696
2697 if (field_op == FIELD_OP_UNARY_MINUS)
2698 return parse_unary(hist_data, file, str, flags, var_name, n_subexprs);
2699
2700 /* Binary operator found, increment n_subexprs */
2701 ++*n_subexprs;
2702
2703 /* Split the expression string at the root operator */
2704 if (!sep)
2705 return ERR_PTR(-EINVAL);
2706
2707 *sep = '\0';
2708 operand1_str = str;
2709 str = sep+1;
2710
2711 /* Binary operator requires both operands */
2712 if (*operand1_str == '\0' || *str == '\0')
2713 return ERR_PTR(-EINVAL);
2714
2715 operand_flags = 0;
2716
2717 /* LHS of string is an expression e.g. a+b in a+b+c */
2718 operand1 = parse_expr(hist_data, file, operand1_str, operand_flags, NULL, n_subexprs);
2719 if (IS_ERR(operand1))
2720 return ERR_CAST(operand1);
2721
2722 if (operand1->flags & HIST_FIELD_FL_STRING) {
2723 hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(operand1_str));
2724 ret = -EINVAL;
2725 goto free_op1;
2726 }
2727
2728 /* RHS of string is another expression e.g. c in a+b+c */
2729 operand_flags = 0;
2730 operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, n_subexprs);
2731 if (IS_ERR(operand2)) {
2732 ret = PTR_ERR(operand2);
2733 goto free_op1;
2734 }
2735 if (operand2->flags & HIST_FIELD_FL_STRING) {
2736 hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str));
2737 ret = -EINVAL;
2738 goto free_operands;
2739 }
2740
2741 switch (field_op) {
2742 case FIELD_OP_MINUS:
2743 op_fn = HIST_FIELD_FN_MINUS;
2744 break;
2745 case FIELD_OP_PLUS:
2746 op_fn = HIST_FIELD_FN_PLUS;
2747 break;
2748 case FIELD_OP_DIV:
2749 op_fn = HIST_FIELD_FN_DIV;
2750 break;
2751 case FIELD_OP_MULT:
2752 op_fn = HIST_FIELD_FN_MULT;
2753 break;
2754 default:
2755 ret = -EINVAL;
2756 goto free_operands;
2757 }
2758
2759 ret = check_expr_operands(file->tr, operand1, operand2, &var1, &var2);
2760 if (ret)
2761 goto free_operands;
2762
2763 operand_flags = var1 ? var1->flags : operand1->flags;
2764 operand2_flags = var2 ? var2->flags : operand2->flags;
2765
2766 /*
2767 * If both operands are constant, the expression can be
2768 * collapsed to a single constant.
2769 */
2770 combine_consts = operand_flags & operand2_flags & HIST_FIELD_FL_CONST;
2771
2772 flags |= combine_consts ? HIST_FIELD_FL_CONST : HIST_FIELD_FL_EXPR;
2773
2774 flags |= operand1->flags &
2775 (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
2776
2777 expr = create_hist_field(hist_data, NULL, flags, var_name);
2778 if (!expr) {
2779 ret = -ENOMEM;
2780 goto free_operands;
2781 }
2782
2783 operand1->read_once = true;
2784 operand2->read_once = true;
2785
2786 /* The operands are now owned and free'd by 'expr' */
2787 expr->operands[0] = operand1;
2788 expr->operands[1] = operand2;
2789
2790 if (field_op == FIELD_OP_DIV &&
2791 operand2_flags & HIST_FIELD_FL_CONST) {
2792 u64 divisor = var2 ? var2->constant : operand2->constant;
2793
2794 if (!divisor) {
2795 hist_err(file->tr, HIST_ERR_DIVISION_BY_ZERO, errpos(str));
2796 ret = -EDOM;
2797 goto free_expr;
2798 }
2799
2800 /*
2801 * Copy the divisor here so we don't have to look it up
2802 * later if this is a var ref
2803 */
2804 operand2->constant = divisor;
2805 op_fn = hist_field_get_div_fn(operand2);
2806 }
2807
2808 expr->fn_num = op_fn;
2809
2810 if (combine_consts) {
2811 if (var1)
2812 expr->operands[0] = var1;
2813 if (var2)
2814 expr->operands[1] = var2;
2815
2816 expr->constant = hist_fn_call(expr, NULL, NULL, NULL, NULL);
2817 expr->fn_num = HIST_FIELD_FN_CONST;
2818
2819 expr->operands[0] = NULL;
2820 expr->operands[1] = NULL;
2821
2822 /*
2823 * var refs won't be destroyed immediately
2824 * See: destroy_hist_field()
2825 */
2826 destroy_hist_field(operand2, 0);
2827 destroy_hist_field(operand1, 0);
2828
2829 expr->name = expr_str(expr, 0);
2830 } else {
2831 /* The operand sizes should be the same, so just pick one */
2832 expr->size = operand1->size;
2833 expr->is_signed = operand1->is_signed;
2834
2835 expr->operator = field_op;
2836 expr->type = kstrdup_const(operand1->type, GFP_KERNEL);
2837 if (!expr->type) {
2838 ret = -ENOMEM;
2839 goto free_expr;
2840 }
2841
2842 expr->name = expr_str(expr, 0);
2843 }
2844
2845 return expr;
2846
2847 free_operands:
2848 destroy_hist_field(operand2, 0);
2849 free_op1:
2850 destroy_hist_field(operand1, 0);
2851 return ERR_PTR(ret);
2852
2853 free_expr:
2854 destroy_hist_field(expr, 0);
2855 return ERR_PTR(ret);
2856 }
2857
2858 static char *find_trigger_filter(struct hist_trigger_data *hist_data,
2859 struct trace_event_file *file)
2860 {
2861 struct event_trigger_data *test;
2862
2863 lockdep_assert_held(&event_mutex);
2864
2865 list_for_each_entry(test, &file->triggers, list) {
2866 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
2867 if (test->private_data == hist_data)
2868 return test->filter_str;
2869 }
2870 }
2871
2872 return NULL;
2873 }
2874
2875 static struct event_command trigger_hist_cmd;
2876 static int event_hist_trigger_parse(struct event_command *cmd_ops,
2877 struct trace_event_file *file,
2878 char *glob, char *cmd,
2879 char *param_and_filter);
2880
2881 static bool compatible_keys(struct hist_trigger_data *target_hist_data,
2882 struct hist_trigger_data *hist_data,
2883 unsigned int n_keys)
2884 {
2885 struct hist_field *target_hist_field, *hist_field;
2886 unsigned int n, i, j;
2887
2888 if (hist_data->n_fields - hist_data->n_vals != n_keys)
2889 return false;
2890
2891 i = hist_data->n_vals;
2892 j = target_hist_data->n_vals;
2893
2894 for (n = 0; n < n_keys; n++) {
2895 hist_field = hist_data->fields[i + n];
2896 target_hist_field = target_hist_data->fields[j + n];
2897
2898 if (strcmp(hist_field->type, target_hist_field->type) != 0)
2899 return false;
2900 if (hist_field->size != target_hist_field->size)
2901 return false;
2902 if (hist_field->is_signed != target_hist_field->is_signed)
2903 return false;
2904 }
2905
2906 return true;
2907 }
2908
2909 static struct hist_trigger_data *
2910 find_compatible_hist(struct hist_trigger_data *target_hist_data,
2911 struct trace_event_file *file)
2912 {
2913 struct hist_trigger_data *hist_data;
2914 struct event_trigger_data *test;
2915 unsigned int n_keys;
2916
2917 lockdep_assert_held(&event_mutex);
2918
2919 n_keys = target_hist_data->n_fields - target_hist_data->n_vals;
2920
2921 list_for_each_entry(test, &file->triggers, list) {
2922 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
2923 hist_data = test->private_data;
2924
2925 if (compatible_keys(target_hist_data, hist_data, n_keys))
2926 return hist_data;
2927 }
2928 }
2929
2930 return NULL;
2931 }
2932
2933 static struct trace_event_file *event_file(struct trace_array *tr,
2934 char *system, char *event_name)
2935 {
2936 struct trace_event_file *file;
2937
2938 file = __find_event_file(tr, system, event_name);
2939 if (!file)
2940 return ERR_PTR(-EINVAL);
2941
2942 return file;
2943 }
2944
2945 static struct hist_field *
2946 find_synthetic_field_var(struct hist_trigger_data *target_hist_data,
2947 char *system, char *event_name, char *field_name)
2948 {
2949 struct hist_field *event_var;
2950 char *synthetic_name;
2951
2952 synthetic_name = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
2953 if (!synthetic_name)
2954 return ERR_PTR(-ENOMEM);
2955
2956 strcpy(synthetic_name, "synthetic_");
2957 strcat(synthetic_name, field_name);
2958
2959 event_var = find_event_var(target_hist_data, system, event_name, synthetic_name);
2960
2961 kfree(synthetic_name);
2962
2963 return event_var;
2964 }
2965
2966 /**
2967 * create_field_var_hist - Automatically create a histogram and var for a field
2968 * @target_hist_data: The target hist trigger
2969 * @subsys_name: Optional subsystem name
2970 * @event_name: Optional event name
2971 * @field_name: The name of the field (and the resulting variable)
2972 *
2973 * Hist trigger actions fetch data from variables, not directly from
2974 * events. However, for convenience, users are allowed to directly
2975 * specify an event field in an action, which will be automatically
2976 * converted into a variable on their behalf.
2977 *
2978 * If a user specifies a field on an event that isn't the event the
2979 * histogram currently being defined (the target event histogram), the
2980 * only way that can be accomplished is if a new hist trigger is
2981 * created and the field variable defined on that.
2982 *
2983 * This function creates a new histogram compatible with the target
2984 * event (meaning a histogram with the same key as the target
2985 * histogram), and creates a variable for the specified field, but
2986 * with 'synthetic_' prepended to the variable name in order to avoid
2987 * collision with normal field variables.
2988 *
2989 * Return: The variable created for the field.
2990 */
2991 static struct hist_field *
2992 create_field_var_hist(struct hist_trigger_data *target_hist_data,
2993 char *subsys_name, char *event_name, char *field_name)
2994 {
2995 struct trace_array *tr = target_hist_data->event_file->tr;
2996 struct hist_trigger_data *hist_data;
2997 unsigned int i, n, first = true;
2998 struct field_var_hist *var_hist;
2999 struct trace_event_file *file;
3000 struct hist_field *key_field;
3001 struct hist_field *event_var;
3002 char *saved_filter;
3003 char *cmd;
3004 int ret;
3005
3006 if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) {
3007 hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name));
3008 return ERR_PTR(-EINVAL);
3009 }
3010
3011 file = event_file(tr, subsys_name, event_name);
3012
3013 if (IS_ERR(file)) {
3014 hist_err(tr, HIST_ERR_EVENT_FILE_NOT_FOUND, errpos(field_name));
3015 ret = PTR_ERR(file);
3016 return ERR_PTR(ret);
3017 }
3018
3019 /*
3020 * Look for a histogram compatible with target. We'll use the
3021 * found histogram specification to create a new matching
3022 * histogram with our variable on it. target_hist_data is not
3023 * yet a registered histogram so we can't use that.
3024 */
3025 hist_data = find_compatible_hist(target_hist_data, file);
3026 if (!hist_data) {
3027 hist_err(tr, HIST_ERR_HIST_NOT_FOUND, errpos(field_name));
3028 return ERR_PTR(-EINVAL);
3029 }
3030
3031 /* See if a synthetic field variable has already been created */
3032 event_var = find_synthetic_field_var(target_hist_data, subsys_name,
3033 event_name, field_name);
3034 if (!IS_ERR_OR_NULL(event_var))
3035 return event_var;
3036
3037 var_hist = kzalloc(sizeof(*var_hist), GFP_KERNEL);
3038 if (!var_hist)
3039 return ERR_PTR(-ENOMEM);
3040
3041 cmd = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
3042 if (!cmd) {
3043 kfree(var_hist);
3044 return ERR_PTR(-ENOMEM);
3045 }
3046
3047 /* Use the same keys as the compatible histogram */
3048 strcat(cmd, "keys=");
3049
3050 for_each_hist_key_field(i, hist_data) {
3051 key_field = hist_data->fields[i];
3052 if (!first)
3053 strcat(cmd, ",");
3054 strcat(cmd, key_field->field->name);
3055 first = false;
3056 }
3057
3058 /* Create the synthetic field variable specification */
3059 strcat(cmd, ":synthetic_");
3060 strcat(cmd, field_name);
3061 strcat(cmd, "=");
3062 strcat(cmd, field_name);
3063
3064 /* Use the same filter as the compatible histogram */
3065 saved_filter = find_trigger_filter(hist_data, file);
3066 if (saved_filter) {
3067 strcat(cmd, " if ");
3068 strcat(cmd, saved_filter);
3069 }
3070
3071 var_hist->cmd = kstrdup(cmd, GFP_KERNEL);
3072 if (!var_hist->cmd) {
3073 kfree(cmd);
3074 kfree(var_hist);
3075 return ERR_PTR(-ENOMEM);
3076 }
3077
3078 /* Save the compatible histogram information */
3079 var_hist->hist_data = hist_data;
3080
3081 /* Create the new histogram with our variable */
3082 ret = event_hist_trigger_parse(&trigger_hist_cmd, file,
3083 "", "hist", cmd);
3084 if (ret) {
3085 kfree(cmd);
3086 kfree(var_hist->cmd);
3087 kfree(var_hist);
3088 hist_err(tr, HIST_ERR_HIST_CREATE_FAIL, errpos(field_name));
3089 return ERR_PTR(ret);
3090 }
3091
3092 kfree(cmd);
3093
3094 /* If we can't find the variable, something went wrong */
3095 event_var = find_synthetic_field_var(target_hist_data, subsys_name,
3096 event_name, field_name);
3097 if (IS_ERR_OR_NULL(event_var)) {
3098 kfree(var_hist->cmd);
3099 kfree(var_hist);
3100 hist_err(tr, HIST_ERR_SYNTH_VAR_NOT_FOUND, errpos(field_name));
3101 return ERR_PTR(-EINVAL);
3102 }
3103
3104 n = target_hist_data->n_field_var_hists;
3105 target_hist_data->field_var_hists[n] = var_hist;
3106 target_hist_data->n_field_var_hists++;
3107
3108 return event_var;
3109 }
3110
3111 static struct hist_field *
3112 find_target_event_var(struct hist_trigger_data *hist_data,
3113 char *subsys_name, char *event_name, char *var_name)
3114 {
3115 struct trace_event_file *file = hist_data->event_file;
3116 struct hist_field *hist_field = NULL;
3117
3118 if (subsys_name) {
3119 struct trace_event_call *call;
3120
3121 if (!event_name)
3122 return NULL;
3123
3124 call = file->event_call;
3125
3126 if (strcmp(subsys_name, call->class->system) != 0)
3127 return NULL;
3128
3129 if (strcmp(event_name, trace_event_name(call)) != 0)
3130 return NULL;
3131 }
3132
3133 hist_field = find_var_field(hist_data, var_name);
3134
3135 return hist_field;
3136 }
3137
3138 static inline void __update_field_vars(struct tracing_map_elt *elt,
3139 struct trace_buffer *buffer,
3140 struct ring_buffer_event *rbe,
3141 void *rec,
3142 struct field_var **field_vars,
3143 unsigned int n_field_vars,
3144 unsigned int field_var_str_start)
3145 {
3146 struct hist_elt_data *elt_data = elt->private_data;
3147 unsigned int i, j, var_idx;
3148 u64 var_val;
3149
3150 /* Make sure stacktrace can fit in the string variable length */
3151 BUILD_BUG_ON((HIST_STACKTRACE_DEPTH + 1) * sizeof(long) >= STR_VAR_LEN_MAX);
3152
3153 for (i = 0, j = field_var_str_start; i < n_field_vars; i++) {
3154 struct field_var *field_var = field_vars[i];
3155 struct hist_field *var = field_var->var;
3156 struct hist_field *val = field_var->val;
3157
3158 var_val = hist_fn_call(val, elt, buffer, rbe, rec);
3159 var_idx = var->var.idx;
3160
3161 if (val->flags & (HIST_FIELD_FL_STRING |
3162 HIST_FIELD_FL_STACKTRACE)) {
3163 char *str = elt_data->field_var_str[j++];
3164 char *val_str = (char *)(uintptr_t)var_val;
3165 unsigned int size;
3166
3167 if (val->flags & HIST_FIELD_FL_STRING) {
3168 size = min(val->size, STR_VAR_LEN_MAX);
3169 strscpy(str, val_str, size);
3170 } else {
3171 char *stack_start = str + sizeof(unsigned long);
3172 int e;
3173
3174 e = stack_trace_save((void *)stack_start,
3175 HIST_STACKTRACE_DEPTH,
3176 HIST_STACKTRACE_SKIP);
3177 if (e < HIST_STACKTRACE_DEPTH - 1)
3178 ((unsigned long *)stack_start)[e] = 0;
3179 *((unsigned long *)str) = e;
3180 }
3181 var_val = (u64)(uintptr_t)str;
3182 }
3183 tracing_map_set_var(elt, var_idx, var_val);
3184 }
3185 }
3186
3187 static void update_field_vars(struct hist_trigger_data *hist_data,
3188 struct tracing_map_elt *elt,
3189 struct trace_buffer *buffer,
3190 struct ring_buffer_event *rbe,
3191 void *rec)
3192 {
3193 __update_field_vars(elt, buffer, rbe, rec, hist_data->field_vars,
3194 hist_data->n_field_vars, 0);
3195 }
3196
3197 static void save_track_data_vars(struct hist_trigger_data *hist_data,
3198 struct tracing_map_elt *elt,
3199 struct trace_buffer *buffer, void *rec,
3200 struct ring_buffer_event *rbe, void *key,
3201 struct action_data *data, u64 *var_ref_vals)
3202 {
3203 __update_field_vars(elt, buffer, rbe, rec, hist_data->save_vars,
3204 hist_data->n_save_vars, hist_data->n_field_var_str);
3205 }
3206
3207 static struct hist_field *create_var(struct hist_trigger_data *hist_data,
3208 struct trace_event_file *file,
3209 char *name, int size, const char *type)
3210 {
3211 struct hist_field *var;
3212 int idx;
3213
3214 if (find_var(hist_data, file, name) && !hist_data->remove) {
3215 var = ERR_PTR(-EINVAL);
3216 goto out;
3217 }
3218
3219 var = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
3220 if (!var) {
3221 var = ERR_PTR(-ENOMEM);
3222 goto out;
3223 }
3224
3225 idx = tracing_map_add_var(hist_data->map);
3226 if (idx < 0) {
3227 kfree(var);
3228 var = ERR_PTR(-EINVAL);
3229 goto out;
3230 }
3231
3232 var->ref = 1;
3233 var->flags = HIST_FIELD_FL_VAR;
3234 var->var.idx = idx;
3235 var->var.hist_data = var->hist_data = hist_data;
3236 var->size = size;
3237 var->var.name = kstrdup(name, GFP_KERNEL);
3238 var->type = kstrdup_const(type, GFP_KERNEL);
3239 if (!var->var.name || !var->type) {
3240 kfree_const(var->type);
3241 kfree(var->var.name);
3242 kfree(var);
3243 var = ERR_PTR(-ENOMEM);
3244 }
3245 out:
3246 return var;
3247 }
3248
3249 static struct field_var *create_field_var(struct hist_trigger_data *hist_data,
3250 struct trace_event_file *file,
3251 char *field_name)
3252 {
3253 struct hist_field *val = NULL, *var = NULL;
3254 unsigned long flags = HIST_FIELD_FL_VAR;
3255 struct trace_array *tr = file->tr;
3256 struct field_var *field_var;
3257 int ret = 0;
3258
3259 if (hist_data->n_field_vars >= SYNTH_FIELDS_MAX) {
3260 hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name));
3261 ret = -EINVAL;
3262 goto err;
3263 }
3264
3265 val = parse_atom(hist_data, file, field_name, &flags, NULL);
3266 if (IS_ERR(val)) {
3267 hist_err(tr, HIST_ERR_FIELD_VAR_PARSE_FAIL, errpos(field_name));
3268 ret = PTR_ERR(val);
3269 goto err;
3270 }
3271
3272 var = create_var(hist_data, file, field_name, val->size, val->type);
3273 if (IS_ERR(var)) {
3274 hist_err(tr, HIST_ERR_VAR_CREATE_FIND_FAIL, errpos(field_name));
3275 kfree(val);
3276 ret = PTR_ERR(var);
3277 goto err;
3278 }
3279
3280 field_var = kzalloc(sizeof(struct field_var), GFP_KERNEL);
3281 if (!field_var) {
3282 kfree(val);
3283 kfree(var);
3284 ret = -ENOMEM;
3285 goto err;
3286 }
3287
3288 field_var->var = var;
3289 field_var->val = val;
3290 out:
3291 return field_var;
3292 err:
3293 field_var = ERR_PTR(ret);
3294 goto out;
3295 }
3296
3297 /**
3298 * create_target_field_var - Automatically create a variable for a field
3299 * @target_hist_data: The target hist trigger
3300 * @subsys_name: Optional subsystem name
3301 * @event_name: Optional event name
3302 * @var_name: The name of the field (and the resulting variable)
3303 *
3304 * Hist trigger actions fetch data from variables, not directly from
3305 * events. However, for convenience, users are allowed to directly
3306 * specify an event field in an action, which will be automatically
3307 * converted into a variable on their behalf.
3308 *
3309 * This function creates a field variable with the name var_name on
3310 * the hist trigger currently being defined on the target event. If
3311 * subsys_name and event_name are specified, this function simply
3312 * verifies that they do in fact match the target event subsystem and
3313 * event name.
3314 *
3315 * Return: The variable created for the field.
3316 */
3317 static struct field_var *
3318 create_target_field_var(struct hist_trigger_data *target_hist_data,
3319 char *subsys_name, char *event_name, char *var_name)
3320 {
3321 struct trace_event_file *file = target_hist_data->event_file;
3322
3323 if (subsys_name) {
3324 struct trace_event_call *call;
3325
3326 if (!event_name)
3327 return NULL;
3328
3329 call = file->event_call;
3330
3331 if (strcmp(subsys_name, call->class->system) != 0)
3332 return NULL;
3333
3334 if (strcmp(event_name, trace_event_name(call)) != 0)
3335 return NULL;
3336 }
3337
3338 return create_field_var(target_hist_data, file, var_name);
3339 }
3340
3341 static bool check_track_val_max(u64 track_val, u64 var_val)
3342 {
3343 if (var_val <= track_val)
3344 return false;
3345
3346 return true;
3347 }
3348
3349 static bool check_track_val_changed(u64 track_val, u64 var_val)
3350 {
3351 if (var_val == track_val)
3352 return false;
3353
3354 return true;
3355 }
3356
3357 static u64 get_track_val(struct hist_trigger_data *hist_data,
3358 struct tracing_map_elt *elt,
3359 struct action_data *data)
3360 {
3361 unsigned int track_var_idx = data->track_data.track_var->var.idx;
3362 u64 track_val;
3363
3364 track_val = tracing_map_read_var(elt, track_var_idx);
3365
3366 return track_val;
3367 }
3368
3369 static void save_track_val(struct hist_trigger_data *hist_data,
3370 struct tracing_map_elt *elt,
3371 struct action_data *data, u64 var_val)
3372 {
3373 unsigned int track_var_idx = data->track_data.track_var->var.idx;
3374
3375 tracing_map_set_var(elt, track_var_idx, var_val);
3376 }
3377
3378 static void save_track_data(struct hist_trigger_data *hist_data,
3379 struct tracing_map_elt *elt,
3380 struct trace_buffer *buffer, void *rec,
3381 struct ring_buffer_event *rbe, void *key,
3382 struct action_data *data, u64 *var_ref_vals)
3383 {
3384 if (data->track_data.save_data)
3385 data->track_data.save_data(hist_data, elt, buffer, rec, rbe,
3386 key, data, var_ref_vals);
3387 }
3388
3389 static bool check_track_val(struct tracing_map_elt *elt,
3390 struct action_data *data,
3391 u64 var_val)
3392 {
3393 struct hist_trigger_data *hist_data;
3394 u64 track_val;
3395
3396 hist_data = data->track_data.track_var->hist_data;
3397 track_val = get_track_val(hist_data, elt, data);
3398
3399 return data->track_data.check_val(track_val, var_val);
3400 }
3401
3402 #ifdef CONFIG_TRACER_SNAPSHOT
3403 static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
3404 {
3405 /* called with tr->max_lock held */
3406 struct track_data *track_data = tr->cond_snapshot->cond_data;
3407 struct hist_elt_data *elt_data, *track_elt_data;
3408 struct snapshot_context *context = cond_data;
3409 struct action_data *action;
3410 u64 track_val;
3411
3412 if (!track_data)
3413 return false;
3414
3415 action = track_data->action_data;
3416
3417 track_val = get_track_val(track_data->hist_data, context->elt,
3418 track_data->action_data);
3419
3420 if (!action->track_data.check_val(track_data->track_val, track_val))
3421 return false;
3422
3423 track_data->track_val = track_val;
3424 memcpy(track_data->key, context->key, track_data->key_len);
3425
3426 elt_data = context->elt->private_data;
3427 track_elt_data = track_data->elt.private_data;
3428 if (elt_data->comm)
3429 strscpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN);
3430
3431 track_data->updated = true;
3432
3433 return true;
3434 }
3435
3436 static void save_track_data_snapshot(struct hist_trigger_data *hist_data,
3437 struct tracing_map_elt *elt,
3438 struct trace_buffer *buffer, void *rec,
3439 struct ring_buffer_event *rbe, void *key,
3440 struct action_data *data,
3441 u64 *var_ref_vals)
3442 {
3443 struct trace_event_file *file = hist_data->event_file;
3444 struct snapshot_context context;
3445
3446 context.elt = elt;
3447 context.key = key;
3448
3449 tracing_snapshot_cond(file->tr, &context);
3450 }
3451
3452 static void hist_trigger_print_key(struct seq_file *m,
3453 struct hist_trigger_data *hist_data,
3454 void *key,
3455 struct tracing_map_elt *elt);
3456
3457 static struct action_data *snapshot_action(struct hist_trigger_data *hist_data)
3458 {
3459 unsigned int i;
3460
3461 if (!hist_data->n_actions)
3462 return NULL;
3463
3464 for (i = 0; i < hist_data->n_actions; i++) {
3465 struct action_data *data = hist_data->actions[i];
3466
3467 if (data->action == ACTION_SNAPSHOT)
3468 return data;
3469 }
3470
3471 return NULL;
3472 }
3473
3474 static void track_data_snapshot_print(struct seq_file *m,
3475 struct hist_trigger_data *hist_data)
3476 {
3477 struct trace_event_file *file = hist_data->event_file;
3478 struct track_data *track_data;
3479 struct action_data *action;
3480
3481 track_data = tracing_cond_snapshot_data(file->tr);
3482 if (!track_data)
3483 return;
3484
3485 if (!track_data->updated)
3486 return;
3487
3488 action = snapshot_action(hist_data);
3489 if (!action)
3490 return;
3491
3492 seq_puts(m, "\nSnapshot taken (see tracing/snapshot). Details:\n");
3493 seq_printf(m, "\ttriggering value { %s(%s) }: %10llu",
3494 action->handler == HANDLER_ONMAX ? "onmax" : "onchange",
3495 action->track_data.var_str, track_data->track_val);
3496
3497 seq_puts(m, "\ttriggered by event with key: ");
3498 hist_trigger_print_key(m, hist_data, track_data->key, &track_data->elt);
3499 seq_putc(m, '\n');
3500 }
3501 #else
3502 static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
3503 {
3504 return false;
3505 }
3506 static void save_track_data_snapshot(struct hist_trigger_data *hist_data,
3507 struct tracing_map_elt *elt,
3508 struct trace_buffer *buffer, void *rec,
3509 struct ring_buffer_event *rbe, void *key,
3510 struct action_data *data,
3511 u64 *var_ref_vals) {}
3512 static void track_data_snapshot_print(struct seq_file *m,
3513 struct hist_trigger_data *hist_data) {}
3514 #endif /* CONFIG_TRACER_SNAPSHOT */
3515
3516 static void track_data_print(struct seq_file *m,
3517 struct hist_trigger_data *hist_data,
3518 struct tracing_map_elt *elt,
3519 struct action_data *data)
3520 {
3521 u64 track_val = get_track_val(hist_data, elt, data);
3522 unsigned int i, save_var_idx;
3523
3524 if (data->handler == HANDLER_ONMAX)
3525 seq_printf(m, "\n\tmax: %10llu", track_val);
3526 else if (data->handler == HANDLER_ONCHANGE)
3527 seq_printf(m, "\n\tchanged: %10llu", track_val);
3528
3529 if (data->action == ACTION_SNAPSHOT)
3530 return;
3531
3532 for (i = 0; i < hist_data->n_save_vars; i++) {
3533 struct hist_field *save_val = hist_data->save_vars[i]->val;
3534 struct hist_field *save_var = hist_data->save_vars[i]->var;
3535 u64 val;
3536
3537 save_var_idx = save_var->var.idx;
3538
3539 val = tracing_map_read_var(elt, save_var_idx);
3540
3541 if (save_val->flags & HIST_FIELD_FL_STRING) {
3542 seq_printf(m, " %s: %-32s", save_var->var.name,
3543 (char *)(uintptr_t)(val));
3544 } else
3545 seq_printf(m, " %s: %10llu", save_var->var.name, val);
3546 }
3547 }
3548
3549 static void ontrack_action(struct hist_trigger_data *hist_data,
3550 struct tracing_map_elt *elt,
3551 struct trace_buffer *buffer, void *rec,
3552 struct ring_buffer_event *rbe, void *key,
3553 struct action_data *data, u64 *var_ref_vals)
3554 {
3555 u64 var_val = var_ref_vals[data->track_data.var_ref->var_ref_idx];
3556
3557 if (check_track_val(elt, data, var_val)) {
3558 save_track_val(hist_data, elt, data, var_val);
3559 save_track_data(hist_data, elt, buffer, rec, rbe,
3560 key, data, var_ref_vals);
3561 }
3562 }
3563
3564 static void action_data_destroy(struct action_data *data)
3565 {
3566 unsigned int i;
3567
3568 lockdep_assert_held(&event_mutex);
3569
3570 kfree(data->action_name);
3571
3572 for (i = 0; i < data->n_params; i++)
3573 kfree(data->params[i]);
3574
3575 if (data->synth_event)
3576 data->synth_event->ref--;
3577
3578 kfree(data->synth_event_name);
3579
3580 kfree(data);
3581 }
3582
3583 static void track_data_destroy(struct hist_trigger_data *hist_data,
3584 struct action_data *data)
3585 {
3586 struct trace_event_file *file = hist_data->event_file;
3587
3588 destroy_hist_field(data->track_data.track_var, 0);
3589
3590 if (data->action == ACTION_SNAPSHOT) {
3591 struct track_data *track_data;
3592
3593 track_data = tracing_cond_snapshot_data(file->tr);
3594 if (track_data && track_data->hist_data == hist_data) {
3595 tracing_snapshot_cond_disable(file->tr);
3596 track_data_free(track_data);
3597 }
3598 }
3599
3600 kfree(data->track_data.var_str);
3601
3602 action_data_destroy(data);
3603 }
3604
3605 static int action_create(struct hist_trigger_data *hist_data,
3606 struct action_data *data);
3607
3608 static int track_data_create(struct hist_trigger_data *hist_data,
3609 struct action_data *data)
3610 {
3611 struct hist_field *var_field, *ref_field, *track_var = NULL;
3612 struct trace_event_file *file = hist_data->event_file;
3613 struct trace_array *tr = file->tr;
3614 char *track_data_var_str;
3615 int ret = 0;
3616
3617 track_data_var_str = data->track_data.var_str;
3618 if (track_data_var_str[0] != '$') {
3619 hist_err(tr, HIST_ERR_ONX_NOT_VAR, errpos(track_data_var_str));
3620 return -EINVAL;
3621 }
3622 track_data_var_str++;
3623
3624 var_field = find_target_event_var(hist_data, NULL, NULL, track_data_var_str);
3625 if (!var_field) {
3626 hist_err(tr, HIST_ERR_ONX_VAR_NOT_FOUND, errpos(track_data_var_str));
3627 return -EINVAL;
3628 }
3629
3630 ref_field = create_var_ref(hist_data, var_field, NULL, NULL);
3631 if (!ref_field)
3632 return -ENOMEM;
3633
3634 data->track_data.var_ref = ref_field;
3635
3636 if (data->handler == HANDLER_ONMAX)
3637 track_var = create_var(hist_data, file, "__max", sizeof(u64), "u64");
3638 if (IS_ERR(track_var)) {
3639 hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0);
3640 ret = PTR_ERR(track_var);
3641 goto out;
3642 }
3643
3644 if (data->handler == HANDLER_ONCHANGE)
3645 track_var = create_var(hist_data, file, "__change", sizeof(u64), "u64");
3646 if (IS_ERR(track_var)) {
3647 hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0);
3648 ret = PTR_ERR(track_var);
3649 goto out;
3650 }
3651 data->track_data.track_var = track_var;
3652
3653 ret = action_create(hist_data, data);
3654 out:
3655 return ret;
3656 }
3657
3658 static int parse_action_params(struct trace_array *tr, char *params,
3659 struct action_data *data)
3660 {
3661 char *param, *saved_param;
3662 bool first_param = true;
3663 int ret = 0;
3664
3665 while (params) {
3666 if (data->n_params >= SYNTH_FIELDS_MAX) {
3667 hist_err(tr, HIST_ERR_TOO_MANY_PARAMS, 0);
3668 ret = -EINVAL;
3669 goto out;
3670 }
3671
3672 param = strsep(&params, ",");
3673 if (!param) {
3674 hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, 0);
3675 ret = -EINVAL;
3676 goto out;
3677 }
3678
3679 param = strstrip(param);
3680 if (strlen(param) < 2) {
3681 hist_err(tr, HIST_ERR_INVALID_PARAM, errpos(param));
3682 ret = -EINVAL;
3683 goto out;
3684 }
3685
3686 saved_param = kstrdup(param, GFP_KERNEL);
3687 if (!saved_param) {
3688 ret = -ENOMEM;
3689 goto out;
3690 }
3691
3692 if (first_param && data->use_trace_keyword) {
3693 data->synth_event_name = saved_param;
3694 first_param = false;
3695 continue;
3696 }
3697 first_param = false;
3698
3699 data->params[data->n_params++] = saved_param;
3700 }
3701 out:
3702 return ret;
3703 }
3704
3705 static int action_parse(struct trace_array *tr, char *str, struct action_data *data,
3706 enum handler_id handler)
3707 {
3708 char *action_name;
3709 int ret = 0;
3710
3711 strsep(&str, ".");
3712 if (!str) {
3713 hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0);
3714 ret = -EINVAL;
3715 goto out;
3716 }
3717
3718 action_name = strsep(&str, "(");
3719 if (!action_name || !str) {
3720 hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0);
3721 ret = -EINVAL;
3722 goto out;
3723 }
3724
3725 if (str_has_prefix(action_name, "save")) {
3726 char *params = strsep(&str, ")");
3727
3728 if (!params) {
3729 hist_err(tr, HIST_ERR_NO_SAVE_PARAMS, 0);
3730 ret = -EINVAL;
3731 goto out;
3732 }
3733
3734 ret = parse_action_params(tr, params, data);
3735 if (ret)
3736 goto out;
3737
3738 if (handler == HANDLER_ONMAX)
3739 data->track_data.check_val = check_track_val_max;
3740 else if (handler == HANDLER_ONCHANGE)
3741 data->track_data.check_val = check_track_val_changed;
3742 else {
3743 hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name));
3744 ret = -EINVAL;
3745 goto out;
3746 }
3747
3748 data->track_data.save_data = save_track_data_vars;
3749 data->fn = ontrack_action;
3750 data->action = ACTION_SAVE;
3751 } else if (str_has_prefix(action_name, "snapshot")) {
3752 char *params = strsep(&str, ")");
3753
3754 if (!str) {
3755 hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(params));
3756 ret = -EINVAL;
3757 goto out;
3758 }
3759
3760 if (handler == HANDLER_ONMAX)
3761 data->track_data.check_val = check_track_val_max;
3762 else if (handler == HANDLER_ONCHANGE)
3763 data->track_data.check_val = check_track_val_changed;
3764 else {
3765 hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name));
3766 ret = -EINVAL;
3767 goto out;
3768 }
3769
3770 data->track_data.save_data = save_track_data_snapshot;
3771 data->fn = ontrack_action;
3772 data->action = ACTION_SNAPSHOT;
3773 } else {
3774 char *params = strsep(&str, ")");
3775
3776 if (str_has_prefix(action_name, "trace"))
3777 data->use_trace_keyword = true;
3778
3779 if (params) {
3780 ret = parse_action_params(tr, params, data);
3781 if (ret)
3782 goto out;
3783 }
3784
3785 if (handler == HANDLER_ONMAX)
3786 data->track_data.check_val = check_track_val_max;
3787 else if (handler == HANDLER_ONCHANGE)
3788 data->track_data.check_val = check_track_val_changed;
3789
3790 if (handler != HANDLER_ONMATCH) {
3791 data->track_data.save_data = action_trace;
3792 data->fn = ontrack_action;
3793 } else
3794 data->fn = action_trace;
3795
3796 data->action = ACTION_TRACE;
3797 }
3798
3799 data->action_name = kstrdup(action_name, GFP_KERNEL);
3800 if (!data->action_name) {
3801 ret = -ENOMEM;
3802 goto out;
3803 }
3804
3805 data->handler = handler;
3806 out:
3807 return ret;
3808 }
3809
3810 static struct action_data *track_data_parse(struct hist_trigger_data *hist_data,
3811 char *str, enum handler_id handler)
3812 {
3813 struct action_data *data;
3814 int ret = -EINVAL;
3815 char *var_str;
3816
3817 data = kzalloc(sizeof(*data), GFP_KERNEL);
3818 if (!data)
3819 return ERR_PTR(-ENOMEM);
3820
3821 var_str = strsep(&str, ")");
3822 if (!var_str || !str) {
3823 ret = -EINVAL;
3824 goto free;
3825 }
3826
3827 data->track_data.var_str = kstrdup(var_str, GFP_KERNEL);
3828 if (!data->track_data.var_str) {
3829 ret = -ENOMEM;
3830 goto free;
3831 }
3832
3833 ret = action_parse(hist_data->event_file->tr, str, data, handler);
3834 if (ret)
3835 goto free;
3836 out:
3837 return data;
3838 free:
3839 track_data_destroy(hist_data, data);
3840 data = ERR_PTR(ret);
3841 goto out;
3842 }
3843
3844 static void onmatch_destroy(struct action_data *data)
3845 {
3846 kfree(data->match_data.event);
3847 kfree(data->match_data.event_system);
3848
3849 action_data_destroy(data);
3850 }
3851
3852 static void destroy_field_var(struct field_var *field_var)
3853 {
3854 if (!field_var)
3855 return;
3856
3857 destroy_hist_field(field_var->var, 0);
3858 destroy_hist_field(field_var->val, 0);
3859
3860 kfree(field_var);
3861 }
3862
3863 static void destroy_field_vars(struct hist_trigger_data *hist_data)
3864 {
3865 unsigned int i;
3866
3867 for (i = 0; i < hist_data->n_field_vars; i++)
3868 destroy_field_var(hist_data->field_vars[i]);
3869
3870 for (i = 0; i < hist_data->n_save_vars; i++)
3871 destroy_field_var(hist_data->save_vars[i]);
3872 }
3873
3874 static void save_field_var(struct hist_trigger_data *hist_data,
3875 struct field_var *field_var)
3876 {
3877 hist_data->field_vars[hist_data->n_field_vars++] = field_var;
3878
3879 /* Stack traces are saved in the string storage too */
3880 if (field_var->val->flags & (HIST_FIELD_FL_STRING | HIST_FIELD_FL_STACKTRACE))
3881 hist_data->n_field_var_str++;
3882 }
3883
3884
3885 static int check_synth_field(struct synth_event *event,
3886 struct hist_field *hist_field,
3887 unsigned int field_pos)
3888 {
3889 struct synth_field *field;
3890
3891 if (field_pos >= event->n_fields)
3892 return -EINVAL;
3893
3894 field = event->fields[field_pos];
3895
3896 /*
3897 * A dynamic string synth field can accept static or
3898 * dynamic. A static string synth field can only accept a
3899 * same-sized static string, which is checked for later.
3900 */
3901 if (strstr(hist_field->type, "char[") && field->is_string
3902 && field->is_dynamic)
3903 return 0;
3904
3905 if (strstr(hist_field->type, "long[") && field->is_stack)
3906 return 0;
3907
3908 if (strcmp(field->type, hist_field->type) != 0) {
3909 if (field->size != hist_field->size ||
3910 (!field->is_string && field->is_signed != hist_field->is_signed))
3911 return -EINVAL;
3912 }
3913
3914 return 0;
3915 }
3916
3917 static struct hist_field *
3918 trace_action_find_var(struct hist_trigger_data *hist_data,
3919 struct action_data *data,
3920 char *system, char *event, char *var)
3921 {
3922 struct trace_array *tr = hist_data->event_file->tr;
3923 struct hist_field *hist_field;
3924
3925 var++; /* skip '$' */
3926
3927 hist_field = find_target_event_var(hist_data, system, event, var);
3928 if (!hist_field) {
3929 if (!system && data->handler == HANDLER_ONMATCH) {
3930 system = data->match_data.event_system;
3931 event = data->match_data.event;
3932 }
3933
3934 hist_field = find_event_var(hist_data, system, event, var);
3935 }
3936
3937 if (!hist_field)
3938 hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, errpos(var));
3939
3940 return hist_field;
3941 }
3942
3943 static struct hist_field *
3944 trace_action_create_field_var(struct hist_trigger_data *hist_data,
3945 struct action_data *data, char *system,
3946 char *event, char *var)
3947 {
3948 struct hist_field *hist_field = NULL;
3949 struct field_var *field_var;
3950
3951 /*
3952 * First try to create a field var on the target event (the
3953 * currently being defined). This will create a variable for
3954 * unqualified fields on the target event, or if qualified,
3955 * target fields that have qualified names matching the target.
3956 */
3957 field_var = create_target_field_var(hist_data, system, event, var);
3958
3959 if (field_var && !IS_ERR(field_var)) {
3960 save_field_var(hist_data, field_var);
3961 hist_field = field_var->var;
3962 } else {
3963 field_var = NULL;
3964 /*
3965 * If no explicit system.event is specified, default to
3966 * looking for fields on the onmatch(system.event.xxx)
3967 * event.
3968 */
3969 if (!system && data->handler == HANDLER_ONMATCH) {
3970 system = data->match_data.event_system;
3971 event = data->match_data.event;
3972 }
3973
3974 if (!event)
3975 goto free;
3976 /*
3977 * At this point, we're looking at a field on another
3978 * event. Because we can't modify a hist trigger on
3979 * another event to add a variable for a field, we need
3980 * to create a new trigger on that event and create the
3981 * variable at the same time.
3982 */
3983 hist_field = create_field_var_hist(hist_data, system, event, var);
3984 if (IS_ERR(hist_field))
3985 goto free;
3986 }
3987 out:
3988 return hist_field;
3989 free:
3990 destroy_field_var(field_var);
3991 hist_field = NULL;
3992 goto out;
3993 }
3994
3995 static int trace_action_create(struct hist_trigger_data *hist_data,
3996 struct action_data *data)
3997 {
3998 struct trace_array *tr = hist_data->event_file->tr;
3999 char *event_name, *param, *system = NULL;
4000 struct hist_field *hist_field, *var_ref;
4001 unsigned int i;
4002 unsigned int field_pos = 0;
4003 struct synth_event *event;
4004 char *synth_event_name;
4005 int var_ref_idx, ret = 0;
4006
4007 lockdep_assert_held(&event_mutex);
4008
4009 /* Sanity check to avoid out-of-bound write on 'data->var_ref_idx' */
4010 if (data->n_params > SYNTH_FIELDS_MAX)
4011 return -EINVAL;
4012
4013 if (data->use_trace_keyword)
4014 synth_event_name = data->synth_event_name;
4015 else
4016 synth_event_name = data->action_name;
4017
4018 event = find_synth_event(synth_event_name);
4019 if (!event) {
4020 hist_err(tr, HIST_ERR_SYNTH_EVENT_NOT_FOUND, errpos(synth_event_name));
4021 return -EINVAL;
4022 }
4023
4024 event->ref++;
4025
4026 for (i = 0; i < data->n_params; i++) {
4027 char *p;
4028
4029 p = param = kstrdup(data->params[i], GFP_KERNEL);
4030 if (!param) {
4031 ret = -ENOMEM;
4032 goto err;
4033 }
4034
4035 system = strsep(&param, ".");
4036 if (!param) {
4037 param = (char *)system;
4038 system = event_name = NULL;
4039 } else {
4040 event_name = strsep(&param, ".");
4041 if (!param) {
4042 kfree(p);
4043 ret = -EINVAL;
4044 goto err;
4045 }
4046 }
4047
4048 if (param[0] == '$')
4049 hist_field = trace_action_find_var(hist_data, data,
4050 system, event_name,
4051 param);
4052 else
4053 hist_field = trace_action_create_field_var(hist_data,
4054 data,
4055 system,
4056 event_name,
4057 param);
4058
4059 if (!hist_field) {
4060 kfree(p);
4061 ret = -EINVAL;
4062 goto err;
4063 }
4064
4065 if (check_synth_field(event, hist_field, field_pos) == 0) {
4066 var_ref = create_var_ref(hist_data, hist_field,
4067 system, event_name);
4068 if (!var_ref) {
4069 kfree(p);
4070 ret = -ENOMEM;
4071 goto err;
4072 }
4073
4074 var_ref_idx = find_var_ref_idx(hist_data, var_ref);
4075 if (WARN_ON(var_ref_idx < 0)) {
4076 kfree(p);
4077 ret = var_ref_idx;
4078 goto err;
4079 }
4080
4081 data->var_ref_idx[i] = var_ref_idx;
4082
4083 field_pos++;
4084 kfree(p);
4085 continue;
4086 }
4087
4088 hist_err(tr, HIST_ERR_SYNTH_TYPE_MISMATCH, errpos(param));
4089 kfree(p);
4090 ret = -EINVAL;
4091 goto err;
4092 }
4093
4094 if (field_pos != event->n_fields) {
4095 hist_err(tr, HIST_ERR_SYNTH_COUNT_MISMATCH, errpos(event->name));
4096 ret = -EINVAL;
4097 goto err;
4098 }
4099
4100 data->synth_event = event;
4101 out:
4102 return ret;
4103 err:
4104 event->ref--;
4105
4106 goto out;
4107 }
4108
4109 static int action_create(struct hist_trigger_data *hist_data,
4110 struct action_data *data)
4111 {
4112 struct trace_event_file *file = hist_data->event_file;
4113 struct trace_array *tr = file->tr;
4114 struct track_data *track_data;
4115 struct field_var *field_var;
4116 unsigned int i;
4117 char *param;
4118 int ret = 0;
4119
4120 if (data->action == ACTION_TRACE)
4121 return trace_action_create(hist_data, data);
4122
4123 if (data->action == ACTION_SNAPSHOT) {
4124 track_data = track_data_alloc(hist_data->key_size, data, hist_data);
4125 if (IS_ERR(track_data)) {
4126 ret = PTR_ERR(track_data);
4127 goto out;
4128 }
4129
4130 ret = tracing_snapshot_cond_enable(file->tr, track_data,
4131 cond_snapshot_update);
4132 if (ret)
4133 track_data_free(track_data);
4134
4135 goto out;
4136 }
4137
4138 if (data->action == ACTION_SAVE) {
4139 if (hist_data->n_save_vars) {
4140 ret = -EEXIST;
4141 hist_err(tr, HIST_ERR_TOO_MANY_SAVE_ACTIONS, 0);
4142 goto out;
4143 }
4144
4145 for (i = 0; i < data->n_params; i++) {
4146 param = kstrdup(data->params[i], GFP_KERNEL);
4147 if (!param) {
4148 ret = -ENOMEM;
4149 goto out;
4150 }
4151
4152 field_var = create_target_field_var(hist_data, NULL, NULL, param);
4153 if (IS_ERR(field_var)) {
4154 hist_err(tr, HIST_ERR_FIELD_VAR_CREATE_FAIL,
4155 errpos(param));
4156 ret = PTR_ERR(field_var);
4157 kfree(param);
4158 goto out;
4159 }
4160
4161 hist_data->save_vars[hist_data->n_save_vars++] = field_var;
4162 if (field_var->val->flags &
4163 (HIST_FIELD_FL_STRING | HIST_FIELD_FL_STACKTRACE))
4164 hist_data->n_save_var_str++;
4165 kfree(param);
4166 }
4167 }
4168 out:
4169 return ret;
4170 }
4171
4172 static int onmatch_create(struct hist_trigger_data *hist_data,
4173 struct action_data *data)
4174 {
4175 return action_create(hist_data, data);
4176 }
4177
4178 static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
4179 {
4180 char *match_event, *match_event_system;
4181 struct action_data *data;
4182 int ret = -EINVAL;
4183
4184 data = kzalloc(sizeof(*data), GFP_KERNEL);
4185 if (!data)
4186 return ERR_PTR(-ENOMEM);
4187
4188 match_event = strsep(&str, ")");
4189 if (!match_event || !str) {
4190 hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(match_event));
4191 goto free;
4192 }
4193
4194 match_event_system = strsep(&match_event, ".");
4195 if (!match_event) {
4196 hist_err(tr, HIST_ERR_SUBSYS_NOT_FOUND, errpos(match_event_system));
4197 goto free;
4198 }
4199
4200 if (IS_ERR(event_file(tr, match_event_system, match_event))) {
4201 hist_err(tr, HIST_ERR_INVALID_SUBSYS_EVENT, errpos(match_event));
4202 goto free;
4203 }
4204
4205 data->match_data.event = kstrdup(match_event, GFP_KERNEL);
4206 if (!data->match_data.event) {
4207 ret = -ENOMEM;
4208 goto free;
4209 }
4210
4211 data->match_data.event_system = kstrdup(match_event_system, GFP_KERNEL);
4212 if (!data->match_data.event_system) {
4213 ret = -ENOMEM;
4214 goto free;
4215 }
4216
4217 ret = action_parse(tr, str, data, HANDLER_ONMATCH);
4218 if (ret)
4219 goto free;
4220 out:
4221 return data;
4222 free:
4223 onmatch_destroy(data);
4224 data = ERR_PTR(ret);
4225 goto out;
4226 }
4227
4228 static int create_hitcount_val(struct hist_trigger_data *hist_data)
4229 {
4230 hist_data->fields[HITCOUNT_IDX] =
4231 create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL);
4232 if (!hist_data->fields[HITCOUNT_IDX])
4233 return -ENOMEM;
4234
4235 hist_data->n_vals++;
4236 hist_data->n_fields++;
4237
4238 if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
4239 return -EINVAL;
4240
4241 return 0;
4242 }
4243
4244 static int __create_val_field(struct hist_trigger_data *hist_data,
4245 unsigned int val_idx,
4246 struct trace_event_file *file,
4247 char *var_name, char *field_str,
4248 unsigned long flags)
4249 {
4250 struct hist_field *hist_field;
4251 int ret = 0, n_subexprs = 0;
4252
4253 hist_field = parse_expr(hist_data, file, field_str, flags, var_name, &n_subexprs);
4254 if (IS_ERR(hist_field)) {
4255 ret = PTR_ERR(hist_field);
4256 goto out;
4257 }
4258
4259 /* values and variables should not have some modifiers */
4260 if (hist_field->flags & HIST_FIELD_FL_VAR) {
4261 /* Variable */
4262 if (hist_field->flags & (HIST_FIELD_FL_GRAPH | HIST_FIELD_FL_PERCENT |
4263 HIST_FIELD_FL_BUCKET | HIST_FIELD_FL_LOG2))
4264 goto err;
4265 } else {
4266 /* Value */
4267 if (hist_field->flags & (HIST_FIELD_FL_GRAPH | HIST_FIELD_FL_PERCENT |
4268 HIST_FIELD_FL_BUCKET | HIST_FIELD_FL_LOG2 |
4269 HIST_FIELD_FL_SYM | HIST_FIELD_FL_SYM_OFFSET |
4270 HIST_FIELD_FL_SYSCALL | HIST_FIELD_FL_STACKTRACE))
4271 goto err;
4272 }
4273
4274 hist_data->fields[val_idx] = hist_field;
4275
4276 ++hist_data->n_vals;
4277 ++hist_data->n_fields;
4278
4279 if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
4280 ret = -EINVAL;
4281 out:
4282 return ret;
4283 err:
4284 hist_err(file->tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(field_str));
4285 return -EINVAL;
4286 }
4287
4288 static int create_val_field(struct hist_trigger_data *hist_data,
4289 unsigned int val_idx,
4290 struct trace_event_file *file,
4291 char *field_str)
4292 {
4293 if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
4294 return -EINVAL;
4295
4296 return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0);
4297 }
4298
4299 static const char no_comm[] = "(no comm)";
4300
4301 static u64 hist_field_execname(struct hist_field *hist_field,
4302 struct tracing_map_elt *elt,
4303 struct trace_buffer *buffer,
4304 struct ring_buffer_event *rbe,
4305 void *event)
4306 {
4307 struct hist_elt_data *elt_data;
4308
4309 if (WARN_ON_ONCE(!elt))
4310 return (u64)(unsigned long)no_comm;
4311
4312 elt_data = elt->private_data;
4313
4314 if (WARN_ON_ONCE(!elt_data->comm))
4315 return (u64)(unsigned long)no_comm;
4316
4317 return (u64)(unsigned long)(elt_data->comm);
4318 }
4319
4320 static u64 hist_field_stack(struct hist_field *hist_field,
4321 struct tracing_map_elt *elt,
4322 struct trace_buffer *buffer,
4323 struct ring_buffer_event *rbe,
4324 void *event)
4325 {
4326 u32 str_item = *(u32 *)(event + hist_field->field->offset);
4327 int str_loc = str_item & 0xffff;
4328 char *addr = (char *)(event + str_loc);
4329
4330 return (u64)(unsigned long)addr;
4331 }
4332
4333 static u64 hist_fn_call(struct hist_field *hist_field,
4334 struct tracing_map_elt *elt,
4335 struct trace_buffer *buffer,
4336 struct ring_buffer_event *rbe,
4337 void *event)
4338 {
4339 switch (hist_field->fn_num) {
4340 case HIST_FIELD_FN_VAR_REF:
4341 return hist_field_var_ref(hist_field, elt, buffer, rbe, event);
4342 case HIST_FIELD_FN_COUNTER:
4343 return hist_field_counter(hist_field, elt, buffer, rbe, event);
4344 case HIST_FIELD_FN_CONST:
4345 return hist_field_const(hist_field, elt, buffer, rbe, event);
4346 case HIST_FIELD_FN_LOG2:
4347 return hist_field_log2(hist_field, elt, buffer, rbe, event);
4348 case HIST_FIELD_FN_BUCKET:
4349 return hist_field_bucket(hist_field, elt, buffer, rbe, event);
4350 case HIST_FIELD_FN_TIMESTAMP:
4351 return hist_field_timestamp(hist_field, elt, buffer, rbe, event);
4352 case HIST_FIELD_FN_CPU:
4353 return hist_field_cpu(hist_field, elt, buffer, rbe, event);
4354 case HIST_FIELD_FN_COMM:
4355 return hist_field_comm(hist_field, elt, buffer, rbe, event);
4356 case HIST_FIELD_FN_STRING:
4357 return hist_field_string(hist_field, elt, buffer, rbe, event);
4358 case HIST_FIELD_FN_DYNSTRING:
4359 return hist_field_dynstring(hist_field, elt, buffer, rbe, event);
4360 case HIST_FIELD_FN_RELDYNSTRING:
4361 return hist_field_reldynstring(hist_field, elt, buffer, rbe, event);
4362 case HIST_FIELD_FN_PSTRING:
4363 return hist_field_pstring(hist_field, elt, buffer, rbe, event);
4364 case HIST_FIELD_FN_S64:
4365 return hist_field_s64(hist_field, elt, buffer, rbe, event);
4366 case HIST_FIELD_FN_U64:
4367 return hist_field_u64(hist_field, elt, buffer, rbe, event);
4368 case HIST_FIELD_FN_S32:
4369 return hist_field_s32(hist_field, elt, buffer, rbe, event);
4370 case HIST_FIELD_FN_U32:
4371 return hist_field_u32(hist_field, elt, buffer, rbe, event);
4372 case HIST_FIELD_FN_S16:
4373 return hist_field_s16(hist_field, elt, buffer, rbe, event);
4374 case HIST_FIELD_FN_U16:
4375 return hist_field_u16(hist_field, elt, buffer, rbe, event);
4376 case HIST_FIELD_FN_S8:
4377 return hist_field_s8(hist_field, elt, buffer, rbe, event);
4378 case HIST_FIELD_FN_U8:
4379 return hist_field_u8(hist_field, elt, buffer, rbe, event);
4380 case HIST_FIELD_FN_UMINUS:
4381 return hist_field_unary_minus(hist_field, elt, buffer, rbe, event);
4382 case HIST_FIELD_FN_MINUS:
4383 return hist_field_minus(hist_field, elt, buffer, rbe, event);
4384 case HIST_FIELD_FN_PLUS:
4385 return hist_field_plus(hist_field, elt, buffer, rbe, event);
4386 case HIST_FIELD_FN_DIV:
4387 return hist_field_div(hist_field, elt, buffer, rbe, event);
4388 case HIST_FIELD_FN_MULT:
4389 return hist_field_mult(hist_field, elt, buffer, rbe, event);
4390 case HIST_FIELD_FN_DIV_POWER2:
4391 return div_by_power_of_two(hist_field, elt, buffer, rbe, event);
4392 case HIST_FIELD_FN_DIV_NOT_POWER2:
4393 return div_by_not_power_of_two(hist_field, elt, buffer, rbe, event);
4394 case HIST_FIELD_FN_DIV_MULT_SHIFT:
4395 return div_by_mult_and_shift(hist_field, elt, buffer, rbe, event);
4396 case HIST_FIELD_FN_EXECNAME:
4397 return hist_field_execname(hist_field, elt, buffer, rbe, event);
4398 case HIST_FIELD_FN_STACK:
4399 return hist_field_stack(hist_field, elt, buffer, rbe, event);
4400 default:
4401 return 0;
4402 }
4403 }
4404
4405 /* Convert a var that points to common_pid.execname to a string */
4406 static void update_var_execname(struct hist_field *hist_field)
4407 {
4408 hist_field->flags = HIST_FIELD_FL_STRING | HIST_FIELD_FL_VAR |
4409 HIST_FIELD_FL_EXECNAME;
4410 hist_field->size = MAX_FILTER_STR_VAL;
4411 hist_field->is_signed = 0;
4412
4413 kfree_const(hist_field->type);
4414 hist_field->type = "char[]";
4415
4416 hist_field->fn_num = HIST_FIELD_FN_EXECNAME;
4417 }
4418
4419 static int create_var_field(struct hist_trigger_data *hist_data,
4420 unsigned int val_idx,
4421 struct trace_event_file *file,
4422 char *var_name, char *expr_str)
4423 {
4424 struct trace_array *tr = hist_data->event_file->tr;
4425 unsigned long flags = 0;
4426 int ret;
4427
4428 if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
4429 return -EINVAL;
4430
4431 if (find_var(hist_data, file, var_name) && !hist_data->remove) {
4432 hist_err(tr, HIST_ERR_DUPLICATE_VAR, errpos(var_name));
4433 return -EINVAL;
4434 }
4435
4436 flags |= HIST_FIELD_FL_VAR;
4437 hist_data->n_vars++;
4438 if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX))
4439 return -EINVAL;
4440
4441 ret = __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);
4442
4443 if (!ret && hist_data->fields[val_idx]->flags & HIST_FIELD_FL_EXECNAME)
4444 update_var_execname(hist_data->fields[val_idx]);
4445
4446 if (!ret && hist_data->fields[val_idx]->flags &
4447 (HIST_FIELD_FL_STRING | HIST_FIELD_FL_STACKTRACE))
4448 hist_data->fields[val_idx]->var_str_idx = hist_data->n_var_str++;
4449
4450 return ret;
4451 }
4452
4453 static int create_val_fields(struct hist_trigger_data *hist_data,
4454 struct trace_event_file *file)
4455 {
4456 unsigned int i, j = 1, n_hitcount = 0;
4457 char *fields_str, *field_str;
4458 int ret;
4459
4460 ret = create_hitcount_val(hist_data);
4461 if (ret)
4462 goto out;
4463
4464 fields_str = hist_data->attrs->vals_str;
4465 if (!fields_str)
4466 goto out;
4467
4468 for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
4469 j < TRACING_MAP_VALS_MAX; i++) {
4470 field_str = strsep(&fields_str, ",");
4471 if (!field_str)
4472 break;
4473
4474 if (strcmp(field_str, "hitcount") == 0) {
4475 if (!n_hitcount++)
4476 continue;
4477 }
4478
4479 ret = create_val_field(hist_data, j++, file, field_str);
4480 if (ret)
4481 goto out;
4482 }
4483
4484 if (fields_str && (strcmp(fields_str, "hitcount") != 0))
4485 ret = -EINVAL;
4486 out:
4487 /* There is only raw hitcount but nohitcount suppresses it. */
4488 if (j == 1 && hist_data->attrs->no_hitcount) {
4489 hist_err(hist_data->event_file->tr, HIST_ERR_NEED_NOHC_VAL, 0);
4490 ret = -ENOENT;
4491 }
4492
4493 return ret;
4494 }
4495
4496 static int create_key_field(struct hist_trigger_data *hist_data,
4497 unsigned int key_idx,
4498 unsigned int key_offset,
4499 struct trace_event_file *file,
4500 char *field_str)
4501 {
4502 struct trace_array *tr = hist_data->event_file->tr;
4503 struct hist_field *hist_field = NULL;
4504 unsigned long flags = 0;
4505 unsigned int key_size;
4506 int ret = 0, n_subexprs = 0;
4507
4508 if (WARN_ON(key_idx >= HIST_FIELDS_MAX))
4509 return -EINVAL;
4510
4511 flags |= HIST_FIELD_FL_KEY;
4512
4513 if (strcmp(field_str, "stacktrace") == 0) {
4514 flags |= HIST_FIELD_FL_STACKTRACE;
4515 key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
4516 hist_field = create_hist_field(hist_data, NULL, flags, NULL);
4517 } else {
4518 hist_field = parse_expr(hist_data, file, field_str, flags,
4519 NULL, &n_subexprs);
4520 if (IS_ERR(hist_field)) {
4521 ret = PTR_ERR(hist_field);
4522 goto out;
4523 }
4524
4525 if (field_has_hist_vars(hist_field, 0)) {
4526 hist_err(tr, HIST_ERR_INVALID_REF_KEY, errpos(field_str));
4527 destroy_hist_field(hist_field, 0);
4528 ret = -EINVAL;
4529 goto out;
4530 }
4531
4532 key_size = hist_field->size;
4533 }
4534
4535 hist_data->fields[key_idx] = hist_field;
4536
4537 key_size = ALIGN(key_size, sizeof(u64));
4538 hist_data->fields[key_idx]->size = key_size;
4539 hist_data->fields[key_idx]->offset = key_offset;
4540
4541 hist_data->key_size += key_size;
4542
4543 if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
4544 ret = -EINVAL;
4545 goto out;
4546 }
4547
4548 hist_data->n_keys++;
4549 hist_data->n_fields++;
4550
4551 if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
4552 return -EINVAL;
4553
4554 ret = key_size;
4555 out:
4556 return ret;
4557 }
4558
4559 static int create_key_fields(struct hist_trigger_data *hist_data,
4560 struct trace_event_file *file)
4561 {
4562 unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
4563 char *fields_str, *field_str;
4564 int ret = -EINVAL;
4565
4566 fields_str = hist_data->attrs->keys_str;
4567 if (!fields_str)
4568 goto out;
4569
4570 for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
4571 field_str = strsep(&fields_str, ",");
4572 if (!field_str)
4573 break;
4574 ret = create_key_field(hist_data, i, key_offset,
4575 file, field_str);
4576 if (ret < 0)
4577 goto out;
4578 key_offset += ret;
4579 }
4580 if (fields_str) {
4581 ret = -EINVAL;
4582 goto out;
4583 }
4584 ret = 0;
4585 out:
4586 return ret;
4587 }
4588
4589 static int create_var_fields(struct hist_trigger_data *hist_data,
4590 struct trace_event_file *file)
4591 {
4592 unsigned int i, j = hist_data->n_vals;
4593 int ret = 0;
4594
4595 unsigned int n_vars = hist_data->attrs->var_defs.n_vars;
4596
4597 for (i = 0; i < n_vars; i++) {
4598 char *var_name = hist_data->attrs->var_defs.name[i];
4599 char *expr = hist_data->attrs->var_defs.expr[i];
4600
4601 ret = create_var_field(hist_data, j++, file, var_name, expr);
4602 if (ret)
4603 goto out;
4604 }
4605 out:
4606 return ret;
4607 }
4608
4609 static void free_var_defs(struct hist_trigger_data *hist_data)
4610 {
4611 unsigned int i;
4612
4613 for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
4614 kfree(hist_data->attrs->var_defs.name[i]);
4615 kfree(hist_data->attrs->var_defs.expr[i]);
4616 }
4617
4618 hist_data->attrs->var_defs.n_vars = 0;
4619 }
4620
4621 static int parse_var_defs(struct hist_trigger_data *hist_data)
4622 {
4623 struct trace_array *tr = hist_data->event_file->tr;
4624 char *s, *str, *var_name, *field_str;
4625 unsigned int i, j, n_vars = 0;
4626 int ret = 0;
4627
4628 for (i = 0; i < hist_data->attrs->n_assignments; i++) {
4629 str = hist_data->attrs->assignment_str[i];
4630 for (j = 0; j < TRACING_MAP_VARS_MAX; j++) {
4631 field_str = strsep(&str, ",");
4632 if (!field_str)
4633 break;
4634
4635 var_name = strsep(&field_str, "=");
4636 if (!var_name || !field_str) {
4637 hist_err(tr, HIST_ERR_MALFORMED_ASSIGNMENT,
4638 errpos(var_name));
4639 ret = -EINVAL;
4640 goto free;
4641 }
4642
4643 if (n_vars == TRACING_MAP_VARS_MAX) {
4644 hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(var_name));
4645 ret = -EINVAL;
4646 goto free;
4647 }
4648
4649 s = kstrdup(var_name, GFP_KERNEL);
4650 if (!s) {
4651 ret = -ENOMEM;
4652 goto free;
4653 }
4654 hist_data->attrs->var_defs.name[n_vars] = s;
4655
4656 s = kstrdup(field_str, GFP_KERNEL);
4657 if (!s) {
4658 kfree(hist_data->attrs->var_defs.name[n_vars]);
4659 hist_data->attrs->var_defs.name[n_vars] = NULL;
4660 ret = -ENOMEM;
4661 goto free;
4662 }
4663 hist_data->attrs->var_defs.expr[n_vars++] = s;
4664
4665 hist_data->attrs->var_defs.n_vars = n_vars;
4666 }
4667 }
4668
4669 return ret;
4670 free:
4671 free_var_defs(hist_data);
4672
4673 return ret;
4674 }
4675
4676 static int create_hist_fields(struct hist_trigger_data *hist_data,
4677 struct trace_event_file *file)
4678 {
4679 int ret;
4680
4681 ret = parse_var_defs(hist_data);
4682 if (ret)
4683 return ret;
4684
4685 ret = create_val_fields(hist_data, file);
4686 if (ret)
4687 goto out;
4688
4689 ret = create_var_fields(hist_data, file);
4690 if (ret)
4691 goto out;
4692
4693 ret = create_key_fields(hist_data, file);
4694
4695 out:
4696 free_var_defs(hist_data);
4697
4698 return ret;
4699 }
4700
4701 static int is_descending(struct trace_array *tr, const char *str)
4702 {
4703 if (!str)
4704 return 0;
4705
4706 if (strcmp(str, "descending") == 0)
4707 return 1;
4708
4709 if (strcmp(str, "ascending") == 0)
4710 return 0;
4711
4712 hist_err(tr, HIST_ERR_INVALID_SORT_MODIFIER, errpos((char *)str));
4713
4714 return -EINVAL;
4715 }
4716
4717 static int create_sort_keys(struct hist_trigger_data *hist_data)
4718 {
4719 struct trace_array *tr = hist_data->event_file->tr;
4720 char *fields_str = hist_data->attrs->sort_key_str;
4721 struct tracing_map_sort_key *sort_key;
4722 int descending, ret = 0;
4723 unsigned int i, j, k;
4724
4725 hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
4726
4727 if (!fields_str)
4728 goto out;
4729
4730 for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
4731 struct hist_field *hist_field;
4732 char *field_str, *field_name;
4733 const char *test_name;
4734
4735 sort_key = &hist_data->sort_keys[i];
4736
4737 field_str = strsep(&fields_str, ",");
4738 if (!field_str)
4739 break;
4740
4741 if (!*field_str) {
4742 ret = -EINVAL;
4743 hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
4744 break;
4745 }
4746
4747 if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
4748 hist_err(tr, HIST_ERR_TOO_MANY_SORT_FIELDS, errpos("sort="));
4749 ret = -EINVAL;
4750 break;
4751 }
4752
4753 field_name = strsep(&field_str, ".");
4754 if (!field_name || !*field_name) {
4755 ret = -EINVAL;
4756 hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
4757 break;
4758 }
4759
4760 if (strcmp(field_name, "hitcount") == 0) {
4761 descending = is_descending(tr, field_str);
4762 if (descending < 0) {
4763 ret = descending;
4764 break;
4765 }
4766 sort_key->descending = descending;
4767 continue;
4768 }
4769
4770 for (j = 1, k = 1; j < hist_data->n_fields; j++) {
4771 unsigned int idx;
4772
4773 hist_field = hist_data->fields[j];
4774 if (hist_field->flags & HIST_FIELD_FL_VAR)
4775 continue;
4776
4777 idx = k++;
4778
4779 test_name = hist_field_name(hist_field, 0);
4780
4781 if (strcmp(field_name, test_name) == 0) {
4782 sort_key->field_idx = idx;
4783 descending = is_descending(tr, field_str);
4784 if (descending < 0) {
4785 ret = descending;
4786 goto out;
4787 }
4788 sort_key->descending = descending;
4789 break;
4790 }
4791 }
4792 if (j == hist_data->n_fields) {
4793 ret = -EINVAL;
4794 hist_err(tr, HIST_ERR_INVALID_SORT_FIELD, errpos(field_name));
4795 break;
4796 }
4797 }
4798
4799 hist_data->n_sort_keys = i;
4800 out:
4801 return ret;
4802 }
4803
4804 static void destroy_actions(struct hist_trigger_data *hist_data)
4805 {
4806 unsigned int i;
4807
4808 for (i = 0; i < hist_data->n_actions; i++) {
4809 struct action_data *data = hist_data->actions[i];
4810
4811 if (data->handler == HANDLER_ONMATCH)
4812 onmatch_destroy(data);
4813 else if (data->handler == HANDLER_ONMAX ||
4814 data->handler == HANDLER_ONCHANGE)
4815 track_data_destroy(hist_data, data);
4816 else
4817 kfree(data);
4818 }
4819 }
4820
4821 static int parse_actions(struct hist_trigger_data *hist_data)
4822 {
4823 struct trace_array *tr = hist_data->event_file->tr;
4824 struct action_data *data;
4825 unsigned int i;
4826 int ret = 0;
4827 char *str;
4828 int len;
4829
4830 for (i = 0; i < hist_data->attrs->n_actions; i++) {
4831 enum handler_id hid = 0;
4832 char *action_str;
4833
4834 str = hist_data->attrs->action_str[i];
4835
4836 if ((len = str_has_prefix(str, "onmatch(")))
4837 hid = HANDLER_ONMATCH;
4838 else if ((len = str_has_prefix(str, "onmax(")))
4839 hid = HANDLER_ONMAX;
4840 else if ((len = str_has_prefix(str, "onchange(")))
4841 hid = HANDLER_ONCHANGE;
4842
4843 action_str = str + len;
4844
4845 switch (hid) {
4846 case HANDLER_ONMATCH:
4847 data = onmatch_parse(tr, action_str);
4848 break;
4849 case HANDLER_ONMAX:
4850 case HANDLER_ONCHANGE:
4851 data = track_data_parse(hist_data, action_str, hid);
4852 break;
4853 default:
4854 data = ERR_PTR(-EINVAL);
4855 break;
4856 }
4857
4858 if (IS_ERR(data)) {
4859 ret = PTR_ERR(data);
4860 break;
4861 }
4862
4863 hist_data->actions[hist_data->n_actions++] = data;
4864 }
4865
4866 return ret;
4867 }
4868
4869 static int create_actions(struct hist_trigger_data *hist_data)
4870 {
4871 struct action_data *data;
4872 unsigned int i;
4873 int ret = 0;
4874
4875 for (i = 0; i < hist_data->attrs->n_actions; i++) {
4876 data = hist_data->actions[i];
4877
4878 if (data->handler == HANDLER_ONMATCH) {
4879 ret = onmatch_create(hist_data, data);
4880 if (ret)
4881 break;
4882 } else if (data->handler == HANDLER_ONMAX ||
4883 data->handler == HANDLER_ONCHANGE) {
4884 ret = track_data_create(hist_data, data);
4885 if (ret)
4886 break;
4887 } else {
4888 ret = -EINVAL;
4889 break;
4890 }
4891 }
4892
4893 return ret;
4894 }
4895
4896 static void print_actions(struct seq_file *m,
4897 struct hist_trigger_data *hist_data,
4898 struct tracing_map_elt *elt)
4899 {
4900 unsigned int i;
4901
4902 for (i = 0; i < hist_data->n_actions; i++) {
4903 struct action_data *data = hist_data->actions[i];
4904
4905 if (data->action == ACTION_SNAPSHOT)
4906 continue;
4907
4908 if (data->handler == HANDLER_ONMAX ||
4909 data->handler == HANDLER_ONCHANGE)
4910 track_data_print(m, hist_data, elt, data);
4911 }
4912 }
4913
4914 static void print_action_spec(struct seq_file *m,
4915 struct hist_trigger_data *hist_data,
4916 struct action_data *data)
4917 {
4918 unsigned int i;
4919
4920 if (data->action == ACTION_SAVE) {
4921 for (i = 0; i < hist_data->n_save_vars; i++) {
4922 seq_printf(m, "%s", hist_data->save_vars[i]->var->var.name);
4923 if (i < hist_data->n_save_vars - 1)
4924 seq_puts(m, ",");
4925 }
4926 } else if (data->action == ACTION_TRACE) {
4927 if (data->use_trace_keyword)
4928 seq_printf(m, "%s", data->synth_event_name);
4929 for (i = 0; i < data->n_params; i++) {
4930 if (i || data->use_trace_keyword)
4931 seq_puts(m, ",");
4932 seq_printf(m, "%s", data->params[i]);
4933 }
4934 }
4935 }
4936
4937 static void print_track_data_spec(struct seq_file *m,
4938 struct hist_trigger_data *hist_data,
4939 struct action_data *data)
4940 {
4941 if (data->handler == HANDLER_ONMAX)
4942 seq_puts(m, ":onmax(");
4943 else if (data->handler == HANDLER_ONCHANGE)
4944 seq_puts(m, ":onchange(");
4945 seq_printf(m, "%s", data->track_data.var_str);
4946 seq_printf(m, ").%s(", data->action_name);
4947
4948 print_action_spec(m, hist_data, data);
4949
4950 seq_puts(m, ")");
4951 }
4952
4953 static void print_onmatch_spec(struct seq_file *m,
4954 struct hist_trigger_data *hist_data,
4955 struct action_data *data)
4956 {
4957 seq_printf(m, ":onmatch(%s.%s).", data->match_data.event_system,
4958 data->match_data.event);
4959
4960 seq_printf(m, "%s(", data->action_name);
4961
4962 print_action_spec(m, hist_data, data);
4963
4964 seq_puts(m, ")");
4965 }
4966
4967 static bool actions_match(struct hist_trigger_data *hist_data,
4968 struct hist_trigger_data *hist_data_test)
4969 {
4970 unsigned int i, j;
4971
4972 if (hist_data->n_actions != hist_data_test->n_actions)
4973 return false;
4974
4975 for (i = 0; i < hist_data->n_actions; i++) {
4976 struct action_data *data = hist_data->actions[i];
4977 struct action_data *data_test = hist_data_test->actions[i];
4978 char *action_name, *action_name_test;
4979
4980 if (data->handler != data_test->handler)
4981 return false;
4982 if (data->action != data_test->action)
4983 return false;
4984
4985 if (data->n_params != data_test->n_params)
4986 return false;
4987
4988 for (j = 0; j < data->n_params; j++) {
4989 if (strcmp(data->params[j], data_test->params[j]) != 0)
4990 return false;
4991 }
4992
4993 if (data->use_trace_keyword)
4994 action_name = data->synth_event_name;
4995 else
4996 action_name = data->action_name;
4997
4998 if (data_test->use_trace_keyword)
4999 action_name_test = data_test->synth_event_name;
5000 else
5001 action_name_test = data_test->action_name;
5002
5003 if (strcmp(action_name, action_name_test) != 0)
5004 return false;
5005
5006 if (data->handler == HANDLER_ONMATCH) {
5007 if (strcmp(data->match_data.event_system,
5008 data_test->match_data.event_system) != 0)
5009 return false;
5010 if (strcmp(data->match_data.event,
5011 data_test->match_data.event) != 0)
5012 return false;
5013 } else if (data->handler == HANDLER_ONMAX ||
5014 data->handler == HANDLER_ONCHANGE) {
5015 if (strcmp(data->track_data.var_str,
5016 data_test->track_data.var_str) != 0)
5017 return false;
5018 }
5019 }
5020
5021 return true;
5022 }
5023
5024
5025 static void print_actions_spec(struct seq_file *m,
5026 struct hist_trigger_data *hist_data)
5027 {
5028 unsigned int i;
5029
5030 for (i = 0; i < hist_data->n_actions; i++) {
5031 struct action_data *data = hist_data->actions[i];
5032
5033 if (data->handler == HANDLER_ONMATCH)
5034 print_onmatch_spec(m, hist_data, data);
5035 else if (data->handler == HANDLER_ONMAX ||
5036 data->handler == HANDLER_ONCHANGE)
5037 print_track_data_spec(m, hist_data, data);
5038 }
5039 }
5040
5041 static void destroy_field_var_hists(struct hist_trigger_data *hist_data)
5042 {
5043 unsigned int i;
5044
5045 for (i = 0; i < hist_data->n_field_var_hists; i++) {
5046 kfree(hist_data->field_var_hists[i]->cmd);
5047 kfree(hist_data->field_var_hists[i]);
5048 }
5049 }
5050
5051 static void destroy_hist_data(struct hist_trigger_data *hist_data)
5052 {
5053 if (!hist_data)
5054 return;
5055
5056 destroy_hist_trigger_attrs(hist_data->attrs);
5057 destroy_hist_fields(hist_data);
5058 tracing_map_destroy(hist_data->map);
5059
5060 destroy_actions(hist_data);
5061 destroy_field_vars(hist_data);
5062 destroy_field_var_hists(hist_data);
5063
5064 kfree(hist_data);
5065 }
5066
5067 static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
5068 {
5069 struct tracing_map *map = hist_data->map;
5070 struct ftrace_event_field *field;
5071 struct hist_field *hist_field;
5072 int i, idx = 0;
5073
5074 for_each_hist_field(i, hist_data) {
5075 hist_field = hist_data->fields[i];
5076 if (hist_field->flags & HIST_FIELD_FL_KEY) {
5077 tracing_map_cmp_fn_t cmp_fn;
5078
5079 field = hist_field->field;
5080
5081 if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
5082 cmp_fn = tracing_map_cmp_none;
5083 else if (!field || hist_field->flags & HIST_FIELD_FL_CPU)
5084 cmp_fn = tracing_map_cmp_num(hist_field->size,
5085 hist_field->is_signed);
5086 else if (is_string_field(field))
5087 cmp_fn = tracing_map_cmp_string;
5088 else
5089 cmp_fn = tracing_map_cmp_num(field->size,
5090 field->is_signed);
5091 idx = tracing_map_add_key_field(map,
5092 hist_field->offset,
5093 cmp_fn);
5094 } else if (!(hist_field->flags & HIST_FIELD_FL_VAR))
5095 idx = tracing_map_add_sum_field(map);
5096
5097 if (idx < 0)
5098 return idx;
5099
5100 if (hist_field->flags & HIST_FIELD_FL_VAR) {
5101 idx = tracing_map_add_var(map);
5102 if (idx < 0)
5103 return idx;
5104 hist_field->var.idx = idx;
5105 hist_field->var.hist_data = hist_data;
5106 }
5107 }
5108
5109 return 0;
5110 }
5111
5112 static struct hist_trigger_data *
5113 create_hist_data(unsigned int map_bits,
5114 struct hist_trigger_attrs *attrs,
5115 struct trace_event_file *file,
5116 bool remove)
5117 {
5118 const struct tracing_map_ops *map_ops = NULL;
5119 struct hist_trigger_data *hist_data;
5120 int ret = 0;
5121
5122 hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL);
5123 if (!hist_data)
5124 return ERR_PTR(-ENOMEM);
5125
5126 hist_data->attrs = attrs;
5127 hist_data->remove = remove;
5128 hist_data->event_file = file;
5129
5130 ret = parse_actions(hist_data);
5131 if (ret)
5132 goto free;
5133
5134 ret = create_hist_fields(hist_data, file);
5135 if (ret)
5136 goto free;
5137
5138 ret = create_sort_keys(hist_data);
5139 if (ret)
5140 goto free;
5141
5142 map_ops = &hist_trigger_elt_data_ops;
5143
5144 hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
5145 map_ops, hist_data);
5146 if (IS_ERR(hist_data->map)) {
5147 ret = PTR_ERR(hist_data->map);
5148 hist_data->map = NULL;
5149 goto free;
5150 }
5151
5152 ret = create_tracing_map_fields(hist_data);
5153 if (ret)
5154 goto free;
5155 out:
5156 return hist_data;
5157 free:
5158 hist_data->attrs = NULL;
5159
5160 destroy_hist_data(hist_data);
5161
5162 hist_data = ERR_PTR(ret);
5163
5164 goto out;
5165 }
5166
5167 static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
5168 struct tracing_map_elt *elt,
5169 struct trace_buffer *buffer, void *rec,
5170 struct ring_buffer_event *rbe,
5171 u64 *var_ref_vals)
5172 {
5173 struct hist_elt_data *elt_data;
5174 struct hist_field *hist_field;
5175 unsigned int i, var_idx;
5176 u64 hist_val;
5177
5178 elt_data = elt->private_data;
5179 elt_data->var_ref_vals = var_ref_vals;
5180
5181 for_each_hist_val_field(i, hist_data) {
5182 hist_field = hist_data->fields[i];
5183 hist_val = hist_fn_call(hist_field, elt, buffer, rbe, rec);
5184 if (hist_field->flags & HIST_FIELD_FL_VAR) {
5185 var_idx = hist_field->var.idx;
5186
5187 if (hist_field->flags &
5188 (HIST_FIELD_FL_STRING | HIST_FIELD_FL_STACKTRACE)) {
5189 unsigned int str_start, var_str_idx, idx;
5190 char *str, *val_str;
5191 unsigned int size;
5192
5193 str_start = hist_data->n_field_var_str +
5194 hist_data->n_save_var_str;
5195 var_str_idx = hist_field->var_str_idx;
5196 idx = str_start + var_str_idx;
5197
5198 str = elt_data->field_var_str[idx];
5199 val_str = (char *)(uintptr_t)hist_val;
5200
5201 if (hist_field->flags & HIST_FIELD_FL_STRING) {
5202 size = min(hist_field->size, STR_VAR_LEN_MAX);
5203 strscpy(str, val_str, size);
5204 } else {
5205 char *stack_start = str + sizeof(unsigned long);
5206 int e;
5207
5208 e = stack_trace_save((void *)stack_start,
5209 HIST_STACKTRACE_DEPTH,
5210 HIST_STACKTRACE_SKIP);
5211 if (e < HIST_STACKTRACE_DEPTH - 1)
5212 ((unsigned long *)stack_start)[e] = 0;
5213 *((unsigned long *)str) = e;
5214 }
5215 hist_val = (u64)(uintptr_t)str;
5216 }
5217 tracing_map_set_var(elt, var_idx, hist_val);
5218 continue;
5219 }
5220 tracing_map_update_sum(elt, i, hist_val);
5221 }
5222
5223 for_each_hist_key_field(i, hist_data) {
5224 hist_field = hist_data->fields[i];
5225 if (hist_field->flags & HIST_FIELD_FL_VAR) {
5226 hist_val = hist_fn_call(hist_field, elt, buffer, rbe, rec);
5227 var_idx = hist_field->var.idx;
5228 tracing_map_set_var(elt, var_idx, hist_val);
5229 }
5230 }
5231
5232 update_field_vars(hist_data, elt, buffer, rbe, rec);
5233 }
5234
5235 static inline void add_to_key(char *compound_key, void *key,
5236 struct hist_field *key_field, void *rec)
5237 {
5238 size_t size = key_field->size;
5239
5240 if (key_field->flags & HIST_FIELD_FL_STRING) {
5241
5242 if (key_field->flags & HIST_FIELD_FL_COMM) {
5243 size = strlen((char *)key);
5244 } else {
5245 struct ftrace_event_field *field;
5246
5247 field = key_field->field;
5248 if (field->filter_type == FILTER_DYN_STRING ||
5249 field->filter_type == FILTER_RDYN_STRING)
5250 size = *(u32 *)(rec + field->offset) >> 16;
5251 else if (field->filter_type == FILTER_STATIC_STRING)
5252 size = field->size;
5253 }
5254
5255 /* ensure NULL-termination */
5256 if (size > key_field->size - 1)
5257 size = key_field->size - 1;
5258 }
5259 memcpy(compound_key + key_field->offset, key, size);
5260 }
5261
5262 static void
5263 hist_trigger_actions(struct hist_trigger_data *hist_data,
5264 struct tracing_map_elt *elt,
5265 struct trace_buffer *buffer, void *rec,
5266 struct ring_buffer_event *rbe, void *key,
5267 u64 *var_ref_vals)
5268 {
5269 struct action_data *data;
5270 unsigned int i;
5271
5272 for (i = 0; i < hist_data->n_actions; i++) {
5273 data = hist_data->actions[i];
5274 data->fn(hist_data, elt, buffer, rec, rbe, key, data, var_ref_vals);
5275 }
5276 }
5277
5278 /*
5279 * The hist_pad structure is used to save information to create
5280 * a histogram from the histogram trigger. It's too big to store
5281 * on the stack, so when the histogram trigger is initialized
5282 * a percpu array of 4 hist_pad structures is allocated.
5283 * This will cover every context from normal, softirq, irq and NMI
5284 * in the very unlikely event that a tigger happens at each of
5285 * these contexts and interrupts a currently active trigger.
5286 */
5287 struct hist_pad {
5288 unsigned long entries[HIST_STACKTRACE_DEPTH];
5289 u64 var_ref_vals[TRACING_MAP_VARS_MAX];
5290 char compound_key[HIST_KEY_SIZE_MAX];
5291 };
5292
5293 static struct hist_pad __percpu *hist_pads;
5294 static DEFINE_PER_CPU(int, hist_pad_cnt);
5295 static refcount_t hist_pad_ref;
5296
5297 /* One hist_pad for every context (normal, softirq, irq, NMI) */
5298 #define MAX_HIST_CNT 4
5299
5300 static int alloc_hist_pad(void)
5301 {
5302 lockdep_assert_held(&event_mutex);
5303
5304 if (refcount_read(&hist_pad_ref)) {
5305 refcount_inc(&hist_pad_ref);
5306 return 0;
5307 }
5308
5309 hist_pads = __alloc_percpu(sizeof(struct hist_pad) * MAX_HIST_CNT,
5310 __alignof__(struct hist_pad));
5311 if (!hist_pads)
5312 return -ENOMEM;
5313
5314 refcount_set(&hist_pad_ref, 1);
5315 return 0;
5316 }
5317
5318 static void free_hist_pad(void)
5319 {
5320 lockdep_assert_held(&event_mutex);
5321
5322 if (!refcount_dec_and_test(&hist_pad_ref))
5323 return;
5324
5325 free_percpu(hist_pads);
5326 hist_pads = NULL;
5327 }
5328
5329 static struct hist_pad *get_hist_pad(void)
5330 {
5331 struct hist_pad *hist_pad;
5332 int cnt;
5333
5334 if (WARN_ON_ONCE(!hist_pads))
5335 return NULL;
5336
5337 preempt_disable();
5338
5339 hist_pad = per_cpu_ptr(hist_pads, smp_processor_id());
5340
5341 if (this_cpu_read(hist_pad_cnt) == MAX_HIST_CNT) {
5342 preempt_enable();
5343 return NULL;
5344 }
5345
5346 cnt = this_cpu_inc_return(hist_pad_cnt) - 1;
5347
5348 return &hist_pad[cnt];
5349 }
5350
5351 static void put_hist_pad(void)
5352 {
5353 this_cpu_dec(hist_pad_cnt);
5354 preempt_enable();
5355 }
5356
5357 static void event_hist_trigger(struct event_trigger_data *data,
5358 struct trace_buffer *buffer, void *rec,
5359 struct ring_buffer_event *rbe)
5360 {
5361 struct hist_trigger_data *hist_data = data->private_data;
5362 bool use_compound_key = (hist_data->n_keys > 1);
5363 struct tracing_map_elt *elt = NULL;
5364 struct hist_field *key_field;
5365 struct hist_pad *hist_pad;
5366 u64 field_contents;
5367 void *key = NULL;
5368 unsigned int i;
5369
5370 if (unlikely(!rbe))
5371 return;
5372
5373 hist_pad = get_hist_pad();
5374 if (!hist_pad)
5375 return;
5376
5377 memset(hist_pad->compound_key, 0, hist_data->key_size);
5378
5379 for_each_hist_key_field(i, hist_data) {
5380 key_field = hist_data->fields[i];
5381
5382 if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
5383 unsigned long *entries = hist_pad->entries;
5384
5385 memset(entries, 0, HIST_STACKTRACE_SIZE);
5386 if (key_field->field) {
5387 unsigned long *stack, n_entries;
5388
5389 field_contents = hist_fn_call(key_field, elt, buffer, rbe, rec);
5390 stack = (unsigned long *)(long)field_contents;
5391 n_entries = *stack;
5392 memcpy(entries, ++stack, n_entries * sizeof(unsigned long));
5393 } else {
5394 stack_trace_save(entries, HIST_STACKTRACE_DEPTH,
5395 HIST_STACKTRACE_SKIP);
5396 }
5397 key = entries;
5398 } else {
5399 field_contents = hist_fn_call(key_field, elt, buffer, rbe, rec);
5400 if (key_field->flags & HIST_FIELD_FL_STRING) {
5401 key = (void *)(unsigned long)field_contents;
5402 use_compound_key = true;
5403 } else
5404 key = (void *)&field_contents;
5405 }
5406
5407 if (use_compound_key)
5408 add_to_key(hist_pad->compound_key, key, key_field, rec);
5409 }
5410
5411 if (use_compound_key)
5412 key = hist_pad->compound_key;
5413
5414 if (hist_data->n_var_refs &&
5415 !resolve_var_refs(hist_data, key, hist_pad->var_ref_vals, false))
5416 goto out;
5417
5418 elt = tracing_map_insert(hist_data->map, key);
5419 if (!elt)
5420 goto out;
5421
5422 hist_trigger_elt_update(hist_data, elt, buffer, rec, rbe, hist_pad->var_ref_vals);
5423
5424 if (resolve_var_refs(hist_data, key, hist_pad->var_ref_vals, true)) {
5425 hist_trigger_actions(hist_data, elt, buffer, rec, rbe,
5426 key, hist_pad->var_ref_vals);
5427 }
5428
5429 hist_poll_wakeup();
5430
5431 out:
5432 put_hist_pad();
5433 }
5434
5435 static void hist_trigger_stacktrace_print(struct seq_file *m,
5436 unsigned long *stacktrace_entries,
5437 unsigned int max_entries)
5438 {
5439 unsigned int spaces = 8;
5440 unsigned int i;
5441
5442 for (i = 0; i < max_entries; i++) {
5443 if (!stacktrace_entries[i])
5444 return;
5445
5446 seq_printf(m, "%*c", 1 + spaces, ' ');
5447 seq_printf(m, "%pS\n", (void*)stacktrace_entries[i]);
5448 }
5449 }
5450
5451 static void hist_trigger_print_key(struct seq_file *m,
5452 struct hist_trigger_data *hist_data,
5453 void *key,
5454 struct tracing_map_elt *elt)
5455 {
5456 struct hist_field *key_field;
5457 bool multiline = false;
5458 const char *field_name;
5459 unsigned int i;
5460 u64 uval;
5461
5462 seq_puts(m, "{ ");
5463
5464 for_each_hist_key_field(i, hist_data) {
5465 key_field = hist_data->fields[i];
5466
5467 if (i > hist_data->n_vals)
5468 seq_puts(m, ", ");
5469
5470 field_name = hist_field_name(key_field, 0);
5471
5472 if (key_field->flags & HIST_FIELD_FL_HEX) {
5473 uval = *(u64 *)(key + key_field->offset);
5474 seq_printf(m, "%s: %llx", field_name, uval);
5475 } else if (key_field->flags & HIST_FIELD_FL_SYM) {
5476 uval = *(u64 *)(key + key_field->offset);
5477 seq_printf(m, "%s: [%llx] %-45ps", field_name,
5478 uval, (void *)(uintptr_t)uval);
5479 } else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
5480 uval = *(u64 *)(key + key_field->offset);
5481 seq_printf(m, "%s: [%llx] %-55pS", field_name,
5482 uval, (void *)(uintptr_t)uval);
5483 } else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
5484 struct hist_elt_data *elt_data = elt->private_data;
5485 char *comm;
5486
5487 if (WARN_ON_ONCE(!elt_data))
5488 return;
5489
5490 comm = elt_data->comm;
5491
5492 uval = *(u64 *)(key + key_field->offset);
5493 seq_printf(m, "%s: %-16s[%10llu]", field_name,
5494 comm, uval);
5495 } else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
5496 const char *syscall_name;
5497
5498 uval = *(u64 *)(key + key_field->offset);
5499 syscall_name = get_syscall_name(uval);
5500 if (!syscall_name)
5501 syscall_name = "unknown_syscall";
5502
5503 seq_printf(m, "%s: %-30s[%3llu]", field_name,
5504 syscall_name, uval);
5505 } else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
5506 if (key_field->field)
5507 seq_printf(m, "%s.stacktrace", key_field->field->name);
5508 else
5509 seq_puts(m, "common_stacktrace:\n");
5510 hist_trigger_stacktrace_print(m,
5511 key + key_field->offset,
5512 HIST_STACKTRACE_DEPTH);
5513 multiline = true;
5514 } else if (key_field->flags & HIST_FIELD_FL_LOG2) {
5515 seq_printf(m, "%s: ~ 2^%-2llu", field_name,
5516 *(u64 *)(key + key_field->offset));
5517 } else if (key_field->flags & HIST_FIELD_FL_BUCKET) {
5518 unsigned long buckets = key_field->buckets;
5519 uval = *(u64 *)(key + key_field->offset);
5520 seq_printf(m, "%s: ~ %llu-%llu", field_name,
5521 uval, uval + buckets -1);
5522 } else if (key_field->flags & HIST_FIELD_FL_STRING) {
5523 seq_printf(m, "%s: %-50s", field_name,
5524 (char *)(key + key_field->offset));
5525 } else {
5526 uval = *(u64 *)(key + key_field->offset);
5527 seq_printf(m, "%s: %10llu", field_name, uval);
5528 }
5529 }
5530
5531 if (!multiline)
5532 seq_puts(m, " ");
5533
5534 seq_puts(m, "}");
5535 }
5536
5537 /* Get the 100 times of the percentage of @val in @total */
5538 static inline unsigned int __get_percentage(u64 val, u64 total)
5539 {
5540 if (!total)
5541 goto div0;
5542
5543 if (val < (U64_MAX / 10000))
5544 return (unsigned int)div64_ul(val * 10000, total);
5545
5546 total = div64_u64(total, 10000);
5547 if (!total)
5548 goto div0;
5549
5550 return (unsigned int)div64_ul(val, total);
5551 div0:
5552 return val ? UINT_MAX : 0;
5553 }
5554
5555 #define BAR_CHAR '#'
5556
5557 static inline const char *__fill_bar_str(char *buf, int size, u64 val, u64 max)
5558 {
5559 unsigned int len = __get_percentage(val, max);
5560 int i;
5561
5562 if (len == UINT_MAX) {
5563 snprintf(buf, size, "[ERROR]");
5564 return buf;
5565 }
5566
5567 len = len * size / 10000;
5568 for (i = 0; i < len && i < size; i++)
5569 buf[i] = BAR_CHAR;
5570 while (i < size)
5571 buf[i++] = ' ';
5572 buf[size] = '\0';
5573
5574 return buf;
5575 }
5576
5577 struct hist_val_stat {
5578 u64 max;
5579 u64 total;
5580 };
5581
5582 static void hist_trigger_print_val(struct seq_file *m, unsigned int idx,
5583 const char *field_name, unsigned long flags,
5584 struct hist_val_stat *stats,
5585 struct tracing_map_elt *elt)
5586 {
5587 u64 val = tracing_map_read_sum(elt, idx);
5588 unsigned int pc;
5589 char bar[21];
5590
5591 if (flags & HIST_FIELD_FL_PERCENT) {
5592 pc = __get_percentage(val, stats[idx].total);
5593 if (pc == UINT_MAX)
5594 seq_printf(m, " %s (%%):[ERROR]", field_name);
5595 else
5596 seq_printf(m, " %s (%%): %3u.%02u", field_name,
5597 pc / 100, pc % 100);
5598 } else if (flags & HIST_FIELD_FL_GRAPH) {
5599 seq_printf(m, " %s: %20s", field_name,
5600 __fill_bar_str(bar, 20, val, stats[idx].max));
5601 } else if (flags & HIST_FIELD_FL_HEX) {
5602 seq_printf(m, " %s: %10llx", field_name, val);
5603 } else {
5604 seq_printf(m, " %s: %10llu", field_name, val);
5605 }
5606 }
5607
5608 static void hist_trigger_entry_print(struct seq_file *m,
5609 struct hist_trigger_data *hist_data,
5610 struct hist_val_stat *stats,
5611 void *key,
5612 struct tracing_map_elt *elt)
5613 {
5614 const char *field_name;
5615 unsigned int i = HITCOUNT_IDX;
5616 unsigned long flags;
5617
5618 hist_trigger_print_key(m, hist_data, key, elt);
5619
5620 /* At first, show the raw hitcount if !nohitcount */
5621 if (!hist_data->attrs->no_hitcount)
5622 hist_trigger_print_val(m, i, "hitcount", 0, stats, elt);
5623
5624 for (i = 1; i < hist_data->n_vals; i++) {
5625 field_name = hist_field_name(hist_data->fields[i], 0);
5626 flags = hist_data->fields[i]->flags;
5627 if (flags & HIST_FIELD_FL_VAR || flags & HIST_FIELD_FL_EXPR)
5628 continue;
5629
5630 seq_puts(m, " ");
5631 hist_trigger_print_val(m, i, field_name, flags, stats, elt);
5632 }
5633
5634 print_actions(m, hist_data, elt);
5635
5636 seq_puts(m, "\n");
5637 }
5638
5639 static int print_entries(struct seq_file *m,
5640 struct hist_trigger_data *hist_data)
5641 {
5642 struct tracing_map_sort_entry **sort_entries = NULL;
5643 struct tracing_map *map = hist_data->map;
5644 int i, j, n_entries;
5645 struct hist_val_stat *stats = NULL;
5646 u64 val;
5647
5648 n_entries = tracing_map_sort_entries(map, hist_data->sort_keys,
5649 hist_data->n_sort_keys,
5650 &sort_entries);
5651 if (n_entries < 0)
5652 return n_entries;
5653
5654 /* Calculate the max and the total for each field if needed. */
5655 for (j = 0; j < hist_data->n_vals; j++) {
5656 if (!(hist_data->fields[j]->flags &
5657 (HIST_FIELD_FL_PERCENT | HIST_FIELD_FL_GRAPH)))
5658 continue;
5659 if (!stats) {
5660 stats = kcalloc(hist_data->n_vals, sizeof(*stats),
5661 GFP_KERNEL);
5662 if (!stats) {
5663 n_entries = -ENOMEM;
5664 goto out;
5665 }
5666 }
5667 for (i = 0; i < n_entries; i++) {
5668 val = tracing_map_read_sum(sort_entries[i]->elt, j);
5669 stats[j].total += val;
5670 if (stats[j].max < val)
5671 stats[j].max = val;
5672 }
5673 }
5674
5675 for (i = 0; i < n_entries; i++)
5676 hist_trigger_entry_print(m, hist_data, stats,
5677 sort_entries[i]->key,
5678 sort_entries[i]->elt);
5679
5680 kfree(stats);
5681 out:
5682 tracing_map_destroy_sort_entries(sort_entries, n_entries);
5683
5684 return n_entries;
5685 }
5686
5687 static void hist_trigger_show(struct seq_file *m,
5688 struct event_trigger_data *data, int n)
5689 {
5690 struct hist_trigger_data *hist_data;
5691 int n_entries;
5692
5693 if (n > 0)
5694 seq_puts(m, "\n\n");
5695
5696 seq_puts(m, "# event histogram\n#\n# trigger info: ");
5697 data->ops->print(m, data);
5698 seq_puts(m, "#\n\n");
5699
5700 hist_data = data->private_data;
5701 n_entries = print_entries(m, hist_data);
5702 if (n_entries < 0)
5703 n_entries = 0;
5704
5705 track_data_snapshot_print(m, hist_data);
5706
5707 seq_printf(m, "\nTotals:\n Hits: %llu\n Entries: %u\n Dropped: %llu\n",
5708 (u64)atomic64_read(&hist_data->map->hits),
5709 n_entries, (u64)atomic64_read(&hist_data->map->drops));
5710 }
5711
5712 struct hist_file_data {
5713 struct file *file;
5714 u64 last_read;
5715 u64 last_act;
5716 };
5717
5718 static u64 get_hist_hit_count(struct trace_event_file *event_file)
5719 {
5720 struct hist_trigger_data *hist_data;
5721 struct event_trigger_data *data;
5722 u64 ret = 0;
5723
5724 list_for_each_entry(data, &event_file->triggers, list) {
5725 if (data->cmd_ops->trigger_type == ETT_EVENT_HIST) {
5726 hist_data = data->private_data;
5727 ret += atomic64_read(&hist_data->map->hits);
5728 }
5729 }
5730 return ret;
5731 }
5732
5733 static int hist_show(struct seq_file *m, void *v)
5734 {
5735 struct hist_file_data *hist_file = m->private;
5736 struct event_trigger_data *data;
5737 struct trace_event_file *event_file;
5738 int n = 0;
5739
5740 guard(mutex)(&event_mutex);
5741
5742 event_file = event_file_file(hist_file->file);
5743 if (unlikely(!event_file))
5744 return -ENODEV;
5745
5746 list_for_each_entry(data, &event_file->triggers, list) {
5747 if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
5748 hist_trigger_show(m, data, n++);
5749 }
5750 hist_file->last_read = get_hist_hit_count(event_file);
5751 /*
5752 * Update last_act too so that poll()/POLLPRI can wait for the next
5753 * event after any syscall on hist file.
5754 */
5755 hist_file->last_act = hist_file->last_read;
5756
5757 return 0;
5758 }
5759
5760 static __poll_t event_hist_poll(struct file *file, struct poll_table_struct *wait)
5761 {
5762 struct trace_event_file *event_file;
5763 struct seq_file *m = file->private_data;
5764 struct hist_file_data *hist_file = m->private;
5765 __poll_t ret = 0;
5766 u64 cnt;
5767
5768 guard(mutex)(&event_mutex);
5769
5770 event_file = event_file_data(file);
5771 if (!event_file)
5772 return EPOLLERR;
5773
5774 hist_poll_wait(file, wait);
5775
5776 cnt = get_hist_hit_count(event_file);
5777 if (hist_file->last_read != cnt)
5778 ret |= EPOLLIN | EPOLLRDNORM;
5779 if (hist_file->last_act != cnt) {
5780 hist_file->last_act = cnt;
5781 ret |= EPOLLPRI;
5782 }
5783
5784 return ret;
5785 }
5786
5787 static int event_hist_release(struct inode *inode, struct file *file)
5788 {
5789 struct seq_file *m = file->private_data;
5790 struct hist_file_data *hist_file = m->private;
5791
5792 kfree(hist_file);
5793 return tracing_single_release_file_tr(inode, file);
5794 }
5795
5796 static int event_hist_open(struct inode *inode, struct file *file)
5797 {
5798 struct trace_event_file *event_file;
5799 struct hist_file_data *hist_file;
5800 int ret;
5801
5802 ret = tracing_open_file_tr(inode, file);
5803 if (ret)
5804 return ret;
5805
5806 guard(mutex)(&event_mutex);
5807
5808 event_file = event_file_data(file);
5809 if (!event_file) {
5810 ret = -ENODEV;
5811 goto err;
5812 }
5813
5814 hist_file = kzalloc(sizeof(*hist_file), GFP_KERNEL);
5815 if (!hist_file) {
5816 ret = -ENOMEM;
5817 goto err;
5818 }
5819
5820 hist_file->file = file;
5821 hist_file->last_act = get_hist_hit_count(event_file);
5822
5823 /* Clear private_data to avoid warning in single_open() */
5824 file->private_data = NULL;
5825 ret = single_open(file, hist_show, hist_file);
5826 if (ret) {
5827 kfree(hist_file);
5828 goto err;
5829 }
5830
5831 return 0;
5832 err:
5833 tracing_release_file_tr(inode, file);
5834 return ret;
5835 }
5836
5837 const struct file_operations event_hist_fops = {
5838 .open = event_hist_open,
5839 .read = seq_read,
5840 .llseek = seq_lseek,
5841 .release = event_hist_release,
5842 .poll = event_hist_poll,
5843 };
5844
5845 #ifdef CONFIG_HIST_TRIGGERS_DEBUG
5846 static void hist_field_debug_show_flags(struct seq_file *m,
5847 unsigned long flags)
5848 {
5849 seq_puts(m, " flags:\n");
5850
5851 if (flags & HIST_FIELD_FL_KEY)
5852 seq_puts(m, " HIST_FIELD_FL_KEY\n");
5853 else if (flags & HIST_FIELD_FL_HITCOUNT)
5854 seq_puts(m, " VAL: HIST_FIELD_FL_HITCOUNT\n");
5855 else if (flags & HIST_FIELD_FL_VAR)
5856 seq_puts(m, " HIST_FIELD_FL_VAR\n");
5857 else if (flags & HIST_FIELD_FL_VAR_REF)
5858 seq_puts(m, " HIST_FIELD_FL_VAR_REF\n");
5859 else
5860 seq_puts(m, " VAL: normal u64 value\n");
5861
5862 if (flags & HIST_FIELD_FL_ALIAS)
5863 seq_puts(m, " HIST_FIELD_FL_ALIAS\n");
5864 else if (flags & HIST_FIELD_FL_CONST)
5865 seq_puts(m, " HIST_FIELD_FL_CONST\n");
5866 }
5867
5868 static int hist_field_debug_show(struct seq_file *m,
5869 struct hist_field *field, unsigned long flags)
5870 {
5871 if ((field->flags & flags) != flags) {
5872 seq_printf(m, "ERROR: bad flags - %lx\n", flags);
5873 return -EINVAL;
5874 }
5875
5876 hist_field_debug_show_flags(m, field->flags);
5877 if (field->field)
5878 seq_printf(m, " ftrace_event_field name: %s\n",
5879 field->field->name);
5880
5881 if (field->flags & HIST_FIELD_FL_VAR) {
5882 seq_printf(m, " var.name: %s\n", field->var.name);
5883 seq_printf(m, " var.idx (into tracing_map_elt.vars[]): %u\n",
5884 field->var.idx);
5885 }
5886
5887 if (field->flags & HIST_FIELD_FL_CONST)
5888 seq_printf(m, " constant: %llu\n", field->constant);
5889
5890 if (field->flags & HIST_FIELD_FL_ALIAS)
5891 seq_printf(m, " var_ref_idx (into hist_data->var_refs[]): %u\n",
5892 field->var_ref_idx);
5893
5894 if (field->flags & HIST_FIELD_FL_VAR_REF) {
5895 seq_printf(m, " name: %s\n", field->name);
5896 seq_printf(m, " var.idx (into tracing_map_elt.vars[]): %u\n",
5897 field->var.idx);
5898 seq_printf(m, " var.hist_data: %p\n", field->var.hist_data);
5899 seq_printf(m, " var_ref_idx (into hist_data->var_refs[]): %u\n",
5900 field->var_ref_idx);
5901 if (field->system)
5902 seq_printf(m, " system: %s\n", field->system);
5903 if (field->event_name)
5904 seq_printf(m, " event_name: %s\n", field->event_name);
5905 }
5906
5907 seq_printf(m, " type: %s\n", field->type);
5908 seq_printf(m, " size: %u\n", field->size);
5909 seq_printf(m, " is_signed: %u\n", field->is_signed);
5910
5911 return 0;
5912 }
5913
5914 static int field_var_debug_show(struct seq_file *m,
5915 struct field_var *field_var, unsigned int i,
5916 bool save_vars)
5917 {
5918 const char *vars_name = save_vars ? "save_vars" : "field_vars";
5919 struct hist_field *field;
5920 int ret = 0;
5921
5922 seq_printf(m, "\n hist_data->%s[%d]:\n", vars_name, i);
5923
5924 field = field_var->var;
5925
5926 seq_printf(m, "\n %s[%d].var:\n", vars_name, i);
5927
5928 hist_field_debug_show_flags(m, field->flags);
5929 seq_printf(m, " var.name: %s\n", field->var.name);
5930 seq_printf(m, " var.idx (into tracing_map_elt.vars[]): %u\n",
5931 field->var.idx);
5932
5933 field = field_var->val;
5934
5935 seq_printf(m, "\n %s[%d].val:\n", vars_name, i);
5936 if (field->field)
5937 seq_printf(m, " ftrace_event_field name: %s\n",
5938 field->field->name);
5939 else {
5940 ret = -EINVAL;
5941 goto out;
5942 }
5943
5944 seq_printf(m, " type: %s\n", field->type);
5945 seq_printf(m, " size: %u\n", field->size);
5946 seq_printf(m, " is_signed: %u\n", field->is_signed);
5947 out:
5948 return ret;
5949 }
5950
5951 static int hist_action_debug_show(struct seq_file *m,
5952 struct action_data *data, int i)
5953 {
5954 int ret = 0;
5955
5956 if (data->handler == HANDLER_ONMAX ||
5957 data->handler == HANDLER_ONCHANGE) {
5958 seq_printf(m, "\n hist_data->actions[%d].track_data.var_ref:\n", i);
5959 ret = hist_field_debug_show(m, data->track_data.var_ref,
5960 HIST_FIELD_FL_VAR_REF);
5961 if (ret)
5962 goto out;
5963
5964 seq_printf(m, "\n hist_data->actions[%d].track_data.track_var:\n", i);
5965 ret = hist_field_debug_show(m, data->track_data.track_var,
5966 HIST_FIELD_FL_VAR);
5967 if (ret)
5968 goto out;
5969 }
5970
5971 if (data->handler == HANDLER_ONMATCH) {
5972 seq_printf(m, "\n hist_data->actions[%d].match_data.event_system: %s\n",
5973 i, data->match_data.event_system);
5974 seq_printf(m, " hist_data->actions[%d].match_data.event: %s\n",
5975 i, data->match_data.event);
5976 }
5977 out:
5978 return ret;
5979 }
5980
5981 static int hist_actions_debug_show(struct seq_file *m,
5982 struct hist_trigger_data *hist_data)
5983 {
5984 int i, ret = 0;
5985
5986 if (hist_data->n_actions)
5987 seq_puts(m, "\n action tracking variables (for onmax()/onchange()/onmatch()):\n");
5988
5989 for (i = 0; i < hist_data->n_actions; i++) {
5990 struct action_data *action = hist_data->actions[i];
5991
5992 ret = hist_action_debug_show(m, action, i);
5993 if (ret)
5994 goto out;
5995 }
5996
5997 if (hist_data->n_save_vars)
5998 seq_puts(m, "\n save action variables (save() params):\n");
5999
6000 for (i = 0; i < hist_data->n_save_vars; i++) {
6001 ret = field_var_debug_show(m, hist_data->save_vars[i], i, true);
6002 if (ret)
6003 goto out;
6004 }
6005 out:
6006 return ret;
6007 }
6008
6009 static void hist_trigger_debug_show(struct seq_file *m,
6010 struct event_trigger_data *data, int n)
6011 {
6012 struct hist_trigger_data *hist_data;
6013 int i, ret;
6014
6015 if (n > 0)
6016 seq_puts(m, "\n\n");
6017
6018 seq_puts(m, "# event histogram\n#\n# trigger info: ");
6019 data->ops->print(m, data);
6020 seq_puts(m, "#\n\n");
6021
6022 hist_data = data->private_data;
6023
6024 seq_printf(m, "hist_data: %p\n\n", hist_data);
6025 seq_printf(m, " n_vals: %u\n", hist_data->n_vals);
6026 seq_printf(m, " n_keys: %u\n", hist_data->n_keys);
6027 seq_printf(m, " n_fields: %u\n", hist_data->n_fields);
6028
6029 seq_puts(m, "\n val fields:\n\n");
6030
6031 seq_puts(m, " hist_data->fields[0]:\n");
6032 ret = hist_field_debug_show(m, hist_data->fields[0],
6033 HIST_FIELD_FL_HITCOUNT);
6034 if (ret)
6035 return;
6036
6037 for (i = 1; i < hist_data->n_vals; i++) {
6038 seq_printf(m, "\n hist_data->fields[%d]:\n", i);
6039 ret = hist_field_debug_show(m, hist_data->fields[i], 0);
6040 if (ret)
6041 return;
6042 }
6043
6044 seq_puts(m, "\n key fields:\n");
6045
6046 for (i = hist_data->n_vals; i < hist_data->n_fields; i++) {
6047 seq_printf(m, "\n hist_data->fields[%d]:\n", i);
6048 ret = hist_field_debug_show(m, hist_data->fields[i],
6049 HIST_FIELD_FL_KEY);
6050 if (ret)
6051 return;
6052 }
6053
6054 if (hist_data->n_var_refs)
6055 seq_puts(m, "\n variable reference fields:\n");
6056
6057 for (i = 0; i < hist_data->n_var_refs; i++) {
6058 seq_printf(m, "\n hist_data->var_refs[%d]:\n", i);
6059 ret = hist_field_debug_show(m, hist_data->var_refs[i],
6060 HIST_FIELD_FL_VAR_REF);
6061 if (ret)
6062 return;
6063 }
6064
6065 if (hist_data->n_field_vars)
6066 seq_puts(m, "\n field variables:\n");
6067
6068 for (i = 0; i < hist_data->n_field_vars; i++) {
6069 ret = field_var_debug_show(m, hist_data->field_vars[i], i, false);
6070 if (ret)
6071 return;
6072 }
6073
6074 ret = hist_actions_debug_show(m, hist_data);
6075 if (ret)
6076 return;
6077 }
6078
6079 static int hist_debug_show(struct seq_file *m, void *v)
6080 {
6081 struct event_trigger_data *data;
6082 struct trace_event_file *event_file;
6083 int n = 0;
6084
6085 guard(mutex)(&event_mutex);
6086
6087 event_file = event_file_file(m->private);
6088 if (unlikely(!event_file))
6089 return -ENODEV;
6090
6091 list_for_each_entry(data, &event_file->triggers, list) {
6092 if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
6093 hist_trigger_debug_show(m, data, n++);
6094 }
6095 return 0;
6096 }
6097
6098 static int event_hist_debug_open(struct inode *inode, struct file *file)
6099 {
6100 int ret;
6101
6102 ret = tracing_open_file_tr(inode, file);
6103 if (ret)
6104 return ret;
6105
6106 /* Clear private_data to avoid warning in single_open() */
6107 file->private_data = NULL;
6108 ret = single_open(file, hist_debug_show, file);
6109 if (ret)
6110 tracing_release_file_tr(inode, file);
6111 return ret;
6112 }
6113
6114 const struct file_operations event_hist_debug_fops = {
6115 .open = event_hist_debug_open,
6116 .read = seq_read,
6117 .llseek = seq_lseek,
6118 .release = tracing_single_release_file_tr,
6119 };
6120 #endif
6121
6122 static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
6123 {
6124 const char *field_name = hist_field_name(hist_field, 0);
6125
6126 if (hist_field->var.name)
6127 seq_printf(m, "%s=", hist_field->var.name);
6128
6129 if (hist_field->flags & HIST_FIELD_FL_CPU)
6130 seq_puts(m, "common_cpu");
6131 if (hist_field->flags & HIST_FIELD_FL_COMM)
6132 seq_puts(m, "common_comm");
6133 else if (hist_field->flags & HIST_FIELD_FL_CONST)
6134 seq_printf(m, "%llu", hist_field->constant);
6135 else if (field_name) {
6136 if (hist_field->flags & HIST_FIELD_FL_VAR_REF ||
6137 hist_field->flags & HIST_FIELD_FL_ALIAS)
6138 seq_putc(m, '$');
6139 seq_printf(m, "%s", field_name);
6140 } else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP)
6141 seq_puts(m, "common_timestamp");
6142
6143 if (hist_field->flags) {
6144 if (!(hist_field->flags & HIST_FIELD_FL_VAR_REF) &&
6145 !(hist_field->flags & HIST_FIELD_FL_EXPR) &&
6146 !(hist_field->flags & HIST_FIELD_FL_STACKTRACE)) {
6147 const char *flags = get_hist_field_flags(hist_field);
6148
6149 if (flags)
6150 seq_printf(m, ".%s", flags);
6151 }
6152 }
6153 if (hist_field->buckets)
6154 seq_printf(m, "=%ld", hist_field->buckets);
6155 }
6156
6157 static int event_hist_trigger_print(struct seq_file *m,
6158 struct event_trigger_data *data)
6159 {
6160 struct hist_trigger_data *hist_data = data->private_data;
6161 struct hist_field *field;
6162 bool have_var = false;
6163 bool show_val = false;
6164 unsigned int i;
6165
6166 seq_puts(m, HIST_PREFIX);
6167
6168 if (data->name)
6169 seq_printf(m, "%s:", data->name);
6170
6171 seq_puts(m, "keys=");
6172
6173 for_each_hist_key_field(i, hist_data) {
6174 field = hist_data->fields[i];
6175
6176 if (i > hist_data->n_vals)
6177 seq_puts(m, ",");
6178
6179 if (field->flags & HIST_FIELD_FL_STACKTRACE) {
6180 if (field->field)
6181 seq_printf(m, "%s.stacktrace", field->field->name);
6182 else
6183 seq_puts(m, "common_stacktrace");
6184 } else
6185 hist_field_print(m, field);
6186 }
6187
6188 seq_puts(m, ":vals=");
6189
6190 for_each_hist_val_field(i, hist_data) {
6191 field = hist_data->fields[i];
6192 if (field->flags & HIST_FIELD_FL_VAR) {
6193 have_var = true;
6194 continue;
6195 }
6196
6197 if (i == HITCOUNT_IDX) {
6198 if (hist_data->attrs->no_hitcount)
6199 continue;
6200 seq_puts(m, "hitcount");
6201 } else {
6202 if (show_val)
6203 seq_puts(m, ",");
6204 hist_field_print(m, field);
6205 }
6206 show_val = true;
6207 }
6208
6209 if (have_var) {
6210 unsigned int n = 0;
6211
6212 seq_puts(m, ":");
6213
6214 for_each_hist_val_field(i, hist_data) {
6215 field = hist_data->fields[i];
6216
6217 if (field->flags & HIST_FIELD_FL_VAR) {
6218 if (n++)
6219 seq_puts(m, ",");
6220 hist_field_print(m, field);
6221 }
6222 }
6223 }
6224
6225 seq_puts(m, ":sort=");
6226
6227 for (i = 0; i < hist_data->n_sort_keys; i++) {
6228 struct tracing_map_sort_key *sort_key;
6229 unsigned int idx, first_key_idx;
6230
6231 /* skip VAR vals */
6232 first_key_idx = hist_data->n_vals - hist_data->n_vars;
6233
6234 sort_key = &hist_data->sort_keys[i];
6235 idx = sort_key->field_idx;
6236
6237 if (WARN_ON(idx >= HIST_FIELDS_MAX))
6238 return -EINVAL;
6239
6240 if (i > 0)
6241 seq_puts(m, ",");
6242
6243 if (idx == HITCOUNT_IDX)
6244 seq_puts(m, "hitcount");
6245 else {
6246 if (idx >= first_key_idx)
6247 idx += hist_data->n_vars;
6248 hist_field_print(m, hist_data->fields[idx]);
6249 }
6250
6251 if (sort_key->descending)
6252 seq_puts(m, ".descending");
6253 }
6254 seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
6255 if (hist_data->enable_timestamps)
6256 seq_printf(m, ":clock=%s", hist_data->attrs->clock);
6257 if (hist_data->attrs->no_hitcount)
6258 seq_puts(m, ":nohitcount");
6259
6260 print_actions_spec(m, hist_data);
6261
6262 if (data->filter_str)
6263 seq_printf(m, " if %s", data->filter_str);
6264
6265 if (data->paused)
6266 seq_puts(m, " [paused]");
6267 else
6268 seq_puts(m, " [active]");
6269
6270 seq_putc(m, '\n');
6271
6272 return 0;
6273 }
6274
6275 static int event_hist_trigger_init(struct event_trigger_data *data)
6276 {
6277 struct hist_trigger_data *hist_data = data->private_data;
6278
6279 if (alloc_hist_pad() < 0)
6280 return -ENOMEM;
6281
6282 if (!data->ref && hist_data->attrs->name)
6283 save_named_trigger(hist_data->attrs->name, data);
6284
6285 data->ref++;
6286
6287 return 0;
6288 }
6289
6290 static void unregister_field_var_hists(struct hist_trigger_data *hist_data)
6291 {
6292 struct trace_event_file *file;
6293 unsigned int i;
6294 char *cmd;
6295 int ret;
6296
6297 for (i = 0; i < hist_data->n_field_var_hists; i++) {
6298 file = hist_data->field_var_hists[i]->hist_data->event_file;
6299 cmd = hist_data->field_var_hists[i]->cmd;
6300 ret = event_hist_trigger_parse(&trigger_hist_cmd, file,
6301 "!hist", "hist", cmd);
6302 WARN_ON_ONCE(ret < 0);
6303 }
6304 }
6305
6306 static void event_hist_trigger_free(struct event_trigger_data *data)
6307 {
6308 struct hist_trigger_data *hist_data = data->private_data;
6309
6310 if (WARN_ON_ONCE(data->ref <= 0))
6311 return;
6312
6313 data->ref--;
6314 if (!data->ref) {
6315 if (data->name)
6316 del_named_trigger(data);
6317
6318 trigger_data_free(data);
6319
6320 remove_hist_vars(hist_data);
6321
6322 unregister_field_var_hists(hist_data);
6323
6324 destroy_hist_data(hist_data);
6325 }
6326 free_hist_pad();
6327 }
6328
6329 static const struct event_trigger_ops event_hist_trigger_ops = {
6330 .trigger = event_hist_trigger,
6331 .print = event_hist_trigger_print,
6332 .init = event_hist_trigger_init,
6333 .free = event_hist_trigger_free,
6334 };
6335
6336 static int event_hist_trigger_named_init(struct event_trigger_data *data)
6337 {
6338 data->ref++;
6339
6340 save_named_trigger(data->named_data->name, data);
6341
6342 return event_hist_trigger_init(data->named_data);
6343 }
6344
6345 static void event_hist_trigger_named_free(struct event_trigger_data *data)
6346 {
6347 if (WARN_ON_ONCE(data->ref <= 0))
6348 return;
6349
6350 event_hist_trigger_free(data->named_data);
6351
6352 data->ref--;
6353 if (!data->ref) {
6354 del_named_trigger(data);
6355 trigger_data_free(data);
6356 }
6357 }
6358
6359 static const struct event_trigger_ops event_hist_trigger_named_ops = {
6360 .trigger = event_hist_trigger,
6361 .print = event_hist_trigger_print,
6362 .init = event_hist_trigger_named_init,
6363 .free = event_hist_trigger_named_free,
6364 };
6365
6366 static const struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
6367 char *param)
6368 {
6369 return &event_hist_trigger_ops;
6370 }
6371
6372 static void hist_clear(struct event_trigger_data *data)
6373 {
6374 struct hist_trigger_data *hist_data = data->private_data;
6375
6376 if (data->name)
6377 pause_named_trigger(data);
6378
6379 tracepoint_synchronize_unregister();
6380
6381 tracing_map_clear(hist_data->map);
6382
6383 if (data->name)
6384 unpause_named_trigger(data);
6385 }
6386
6387 static bool compatible_field(struct ftrace_event_field *field,
6388 struct ftrace_event_field *test_field)
6389 {
6390 if (field == test_field)
6391 return true;
6392 if (field == NULL || test_field == NULL)
6393 return false;
6394 if (strcmp(field->name, test_field->name) != 0)
6395 return false;
6396 if (strcmp(field->type, test_field->type) != 0)
6397 return false;
6398 if (field->size != test_field->size)
6399 return false;
6400 if (field->is_signed != test_field->is_signed)
6401 return false;
6402
6403 return true;
6404 }
6405
6406 static bool hist_trigger_match(struct event_trigger_data *data,
6407 struct event_trigger_data *data_test,
6408 struct event_trigger_data *named_data,
6409 bool ignore_filter)
6410 {
6411 struct tracing_map_sort_key *sort_key, *sort_key_test;
6412 struct hist_trigger_data *hist_data, *hist_data_test;
6413 struct hist_field *key_field, *key_field_test;
6414 unsigned int i;
6415
6416 if (named_data && (named_data != data_test) &&
6417 (named_data != data_test->named_data))
6418 return false;
6419
6420 if (!named_data && is_named_trigger(data_test))
6421 return false;
6422
6423 hist_data = data->private_data;
6424 hist_data_test = data_test->private_data;
6425
6426 if (hist_data->n_vals != hist_data_test->n_vals ||
6427 hist_data->n_fields != hist_data_test->n_fields ||
6428 hist_data->n_sort_keys != hist_data_test->n_sort_keys)
6429 return false;
6430
6431 if (!ignore_filter) {
6432 if ((data->filter_str && !data_test->filter_str) ||
6433 (!data->filter_str && data_test->filter_str))
6434 return false;
6435 }
6436
6437 for_each_hist_field(i, hist_data) {
6438 key_field = hist_data->fields[i];
6439 key_field_test = hist_data_test->fields[i];
6440
6441 if (key_field->flags != key_field_test->flags)
6442 return false;
6443 if (!compatible_field(key_field->field, key_field_test->field))
6444 return false;
6445 if (key_field->offset != key_field_test->offset)
6446 return false;
6447 if (key_field->size != key_field_test->size)
6448 return false;
6449 if (key_field->is_signed != key_field_test->is_signed)
6450 return false;
6451 if (!!key_field->var.name != !!key_field_test->var.name)
6452 return false;
6453 if (key_field->var.name &&
6454 strcmp(key_field->var.name, key_field_test->var.name) != 0)
6455 return false;
6456 }
6457
6458 for (i = 0; i < hist_data->n_sort_keys; i++) {
6459 sort_key = &hist_data->sort_keys[i];
6460 sort_key_test = &hist_data_test->sort_keys[i];
6461
6462 if (sort_key->field_idx != sort_key_test->field_idx ||
6463 sort_key->descending != sort_key_test->descending)
6464 return false;
6465 }
6466
6467 if (!ignore_filter && data->filter_str &&
6468 (strcmp(data->filter_str, data_test->filter_str) != 0))
6469 return false;
6470
6471 if (!actions_match(hist_data, hist_data_test))
6472 return false;
6473
6474 return true;
6475 }
6476
6477 static bool existing_hist_update_only(char *glob,
6478 struct event_trigger_data *data,
6479 struct trace_event_file *file)
6480 {
6481 struct hist_trigger_data *hist_data = data->private_data;
6482 struct event_trigger_data *test, *named_data = NULL;
6483 bool updated = false;
6484
6485 if (!hist_data->attrs->pause && !hist_data->attrs->cont &&
6486 !hist_data->attrs->clear)
6487 goto out;
6488
6489 if (hist_data->attrs->name) {
6490 named_data = find_named_trigger(hist_data->attrs->name);
6491 if (named_data) {
6492 if (!hist_trigger_match(data, named_data, named_data,
6493 true))
6494 goto out;
6495 }
6496 }
6497
6498 if (hist_data->attrs->name && !named_data)
6499 goto out;
6500
6501 list_for_each_entry(test, &file->triggers, list) {
6502 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
6503 if (!hist_trigger_match(data, test, named_data, false))
6504 continue;
6505 if (hist_data->attrs->pause)
6506 test->paused = true;
6507 else if (hist_data->attrs->cont)
6508 test->paused = false;
6509 else if (hist_data->attrs->clear)
6510 hist_clear(test);
6511 updated = true;
6512 goto out;
6513 }
6514 }
6515 out:
6516 return updated;
6517 }
6518
6519 static int hist_register_trigger(char *glob,
6520 struct event_trigger_data *data,
6521 struct trace_event_file *file)
6522 {
6523 struct hist_trigger_data *hist_data = data->private_data;
6524 struct event_trigger_data *test, *named_data = NULL;
6525 struct trace_array *tr = file->tr;
6526 int ret = 0;
6527
6528 if (hist_data->attrs->name) {
6529 named_data = find_named_trigger(hist_data->attrs->name);
6530 if (named_data) {
6531 if (!hist_trigger_match(data, named_data, named_data,
6532 true)) {
6533 hist_err(tr, HIST_ERR_NAMED_MISMATCH, errpos(hist_data->attrs->name));
6534 ret = -EINVAL;
6535 goto out;
6536 }
6537 }
6538 }
6539
6540 if (hist_data->attrs->name && !named_data)
6541 goto new;
6542
6543 lockdep_assert_held(&event_mutex);
6544
6545 list_for_each_entry(test, &file->triggers, list) {
6546 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
6547 if (hist_trigger_match(data, test, named_data, false)) {
6548 hist_err(tr, HIST_ERR_TRIGGER_EEXIST, 0);
6549 ret = -EEXIST;
6550 goto out;
6551 }
6552 }
6553 }
6554 new:
6555 if (hist_data->attrs->cont || hist_data->attrs->clear) {
6556 hist_err(tr, HIST_ERR_TRIGGER_ENOENT_CLEAR, 0);
6557 ret = -ENOENT;
6558 goto out;
6559 }
6560
6561 if (hist_data->attrs->pause)
6562 data->paused = true;
6563
6564 if (named_data) {
6565 data->private_data = named_data->private_data;
6566 set_named_trigger_data(data, named_data);
6567 data->ops = &event_hist_trigger_named_ops;
6568 }
6569
6570 if (data->ops->init) {
6571 ret = data->ops->init(data);
6572 if (ret < 0)
6573 goto out;
6574 }
6575
6576 if (hist_data->enable_timestamps) {
6577 char *clock = hist_data->attrs->clock;
6578
6579 ret = tracing_set_clock(file->tr, hist_data->attrs->clock);
6580 if (ret) {
6581 hist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock));
6582 goto out;
6583 }
6584
6585 tracing_set_filter_buffering(file->tr, true);
6586 }
6587
6588 if (named_data)
6589 destroy_hist_data(hist_data);
6590 out:
6591 return ret;
6592 }
6593
6594 static int hist_trigger_enable(struct event_trigger_data *data,
6595 struct trace_event_file *file)
6596 {
6597 int ret = 0;
6598
6599 list_add_tail_rcu(&data->list, &file->triggers);
6600
6601 update_cond_flag(file);
6602
6603 if (trace_event_trigger_enable_disable(file, 1) < 0) {
6604 list_del_rcu(&data->list);
6605 update_cond_flag(file);
6606 ret--;
6607 }
6608
6609 return ret;
6610 }
6611
6612 static bool have_hist_trigger_match(struct event_trigger_data *data,
6613 struct trace_event_file *file)
6614 {
6615 struct hist_trigger_data *hist_data = data->private_data;
6616 struct event_trigger_data *test, *named_data = NULL;
6617 bool match = false;
6618
6619 lockdep_assert_held(&event_mutex);
6620
6621 if (hist_data->attrs->name)
6622 named_data = find_named_trigger(hist_data->attrs->name);
6623
6624 list_for_each_entry(test, &file->triggers, list) {
6625 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
6626 if (hist_trigger_match(data, test, named_data, false)) {
6627 match = true;
6628 break;
6629 }
6630 }
6631 }
6632
6633 return match;
6634 }
6635
6636 static bool hist_trigger_check_refs(struct event_trigger_data *data,
6637 struct trace_event_file *file)
6638 {
6639 struct hist_trigger_data *hist_data = data->private_data;
6640 struct event_trigger_data *test, *named_data = NULL;
6641
6642 lockdep_assert_held(&event_mutex);
6643
6644 if (hist_data->attrs->name)
6645 named_data = find_named_trigger(hist_data->attrs->name);
6646
6647 list_for_each_entry(test, &file->triggers, list) {
6648 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
6649 if (!hist_trigger_match(data, test, named_data, false))
6650 continue;
6651 hist_data = test->private_data;
6652 if (check_var_refs(hist_data))
6653 return true;
6654 break;
6655 }
6656 }
6657
6658 return false;
6659 }
6660
6661 static void hist_unregister_trigger(char *glob,
6662 struct event_trigger_data *data,
6663 struct trace_event_file *file)
6664 {
6665 struct event_trigger_data *test = NULL, *iter, *named_data = NULL;
6666 struct hist_trigger_data *hist_data = data->private_data;
6667
6668 lockdep_assert_held(&event_mutex);
6669
6670 if (hist_data->attrs->name)
6671 named_data = find_named_trigger(hist_data->attrs->name);
6672
6673 list_for_each_entry(iter, &file->triggers, list) {
6674 if (iter->cmd_ops->trigger_type == ETT_EVENT_HIST) {
6675 if (!hist_trigger_match(data, iter, named_data, false))
6676 continue;
6677 test = iter;
6678 list_del_rcu(&test->list);
6679 trace_event_trigger_enable_disable(file, 0);
6680 update_cond_flag(file);
6681 break;
6682 }
6683 }
6684
6685 if (test && test->ops->free)
6686 test->ops->free(test);
6687
6688 if (hist_data->enable_timestamps) {
6689 if (!hist_data->remove || test)
6690 tracing_set_filter_buffering(file->tr, false);
6691 }
6692 }
6693
6694 static bool hist_file_check_refs(struct trace_event_file *file)
6695 {
6696 struct hist_trigger_data *hist_data;
6697 struct event_trigger_data *test;
6698
6699 lockdep_assert_held(&event_mutex);
6700
6701 list_for_each_entry(test, &file->triggers, list) {
6702 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
6703 hist_data = test->private_data;
6704 if (check_var_refs(hist_data))
6705 return true;
6706 }
6707 }
6708
6709 return false;
6710 }
6711
6712 static void hist_unreg_all(struct trace_event_file *file)
6713 {
6714 struct event_trigger_data *test, *n;
6715 struct hist_trigger_data *hist_data;
6716 struct synth_event *se;
6717 const char *se_name;
6718
6719 lockdep_assert_held(&event_mutex);
6720
6721 if (hist_file_check_refs(file))
6722 return;
6723
6724 list_for_each_entry_safe(test, n, &file->triggers, list) {
6725 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
6726 hist_data = test->private_data;
6727 list_del_rcu(&test->list);
6728 trace_event_trigger_enable_disable(file, 0);
6729
6730 se_name = trace_event_name(file->event_call);
6731 se = find_synth_event(se_name);
6732 if (se)
6733 se->ref--;
6734
6735 update_cond_flag(file);
6736 if (hist_data->enable_timestamps)
6737 tracing_set_filter_buffering(file->tr, false);
6738 if (test->ops->free)
6739 test->ops->free(test);
6740 }
6741 }
6742 }
6743
6744 static int event_hist_trigger_parse(struct event_command *cmd_ops,
6745 struct trace_event_file *file,
6746 char *glob, char *cmd,
6747 char *param_and_filter)
6748 {
6749 unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
6750 struct event_trigger_data *trigger_data;
6751 struct hist_trigger_attrs *attrs;
6752 struct hist_trigger_data *hist_data;
6753 char *param, *filter, *p, *start;
6754 struct synth_event *se;
6755 const char *se_name;
6756 bool remove;
6757 int ret = 0;
6758
6759 lockdep_assert_held(&event_mutex);
6760
6761 if (WARN_ON(!glob))
6762 return -EINVAL;
6763
6764 if (glob[0]) {
6765 hist_err_clear();
6766 last_cmd_set(file, param_and_filter);
6767 }
6768
6769 remove = event_trigger_check_remove(glob);
6770
6771 if (event_trigger_empty_param(param_and_filter))
6772 return -EINVAL;
6773
6774 /*
6775 * separate the trigger from the filter (k:v [if filter])
6776 * allowing for whitespace in the trigger
6777 */
6778 p = param = param_and_filter;
6779 do {
6780 p = strstr(p, "if");
6781 if (!p)
6782 break;
6783 if (p == param_and_filter)
6784 return -EINVAL;
6785 if (*(p - 1) != ' ' && *(p - 1) != '\t') {
6786 p++;
6787 continue;
6788 }
6789 if (p >= param_and_filter + strlen(param_and_filter) - (sizeof("if") - 1) - 1)
6790 return -EINVAL;
6791 if (*(p + sizeof("if") - 1) != ' ' && *(p + sizeof("if") - 1) != '\t') {
6792 p++;
6793 continue;
6794 }
6795 break;
6796 } while (1);
6797
6798 if (!p)
6799 filter = NULL;
6800 else {
6801 *(p - 1) = '\0';
6802 filter = strstrip(p);
6803 param = strstrip(param);
6804 }
6805
6806 /*
6807 * To simplify arithmetic expression parsing, replace occurrences of
6808 * '.sym-offset' modifier with '.symXoffset'
6809 */
6810 start = strstr(param, ".sym-offset");
6811 while (start) {
6812 *(start + 4) = 'X';
6813 start = strstr(start + 11, ".sym-offset");
6814 }
6815
6816 attrs = parse_hist_trigger_attrs(file->tr, param);
6817 if (IS_ERR(attrs))
6818 return PTR_ERR(attrs);
6819
6820 if (attrs->map_bits)
6821 hist_trigger_bits = attrs->map_bits;
6822
6823 hist_data = create_hist_data(hist_trigger_bits, attrs, file, remove);
6824 if (IS_ERR(hist_data)) {
6825 destroy_hist_trigger_attrs(attrs);
6826 return PTR_ERR(hist_data);
6827 }
6828
6829 trigger_data = trigger_data_alloc(cmd_ops, cmd, param, hist_data);
6830 if (!trigger_data) {
6831 ret = -ENOMEM;
6832 goto out_free;
6833 }
6834
6835 ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data);
6836 if (ret < 0)
6837 goto out_free;
6838
6839 if (remove) {
6840 if (!have_hist_trigger_match(trigger_data, file))
6841 goto out_free;
6842
6843 if (hist_trigger_check_refs(trigger_data, file)) {
6844 ret = -EBUSY;
6845 goto out_free;
6846 }
6847
6848 event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
6849 se_name = trace_event_name(file->event_call);
6850 se = find_synth_event(se_name);
6851 if (se)
6852 se->ref--;
6853 ret = 0;
6854 goto out_free;
6855 }
6856
6857 if (existing_hist_update_only(glob, trigger_data, file))
6858 goto out_free;
6859
6860 if (!get_named_trigger_data(trigger_data)) {
6861
6862 ret = create_actions(hist_data);
6863 if (ret)
6864 goto out_free;
6865
6866 if (has_hist_vars(hist_data) || hist_data->n_var_refs) {
6867 ret = save_hist_vars(hist_data);
6868 if (ret)
6869 goto out_free;
6870 }
6871
6872 ret = tracing_map_init(hist_data->map);
6873 if (ret)
6874 goto out_free;
6875 }
6876
6877 ret = event_trigger_register(cmd_ops, file, glob, trigger_data);
6878 if (ret < 0)
6879 goto out_free;
6880
6881 ret = hist_trigger_enable(trigger_data, file);
6882 if (ret)
6883 goto out_unreg;
6884
6885 se_name = trace_event_name(file->event_call);
6886 se = find_synth_event(se_name);
6887 if (se)
6888 se->ref++;
6889 out:
6890 if (ret == 0 && glob[0])
6891 hist_err_clear();
6892
6893 return ret;
6894 out_unreg:
6895 event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
6896 out_free:
6897 event_trigger_reset_filter(cmd_ops, trigger_data);
6898
6899 remove_hist_vars(hist_data);
6900
6901 kfree(trigger_data);
6902
6903 destroy_hist_data(hist_data);
6904 goto out;
6905 }
6906
6907 static struct event_command trigger_hist_cmd = {
6908 .name = "hist",
6909 .trigger_type = ETT_EVENT_HIST,
6910 .flags = EVENT_CMD_FL_NEEDS_REC,
6911 .parse = event_hist_trigger_parse,
6912 .reg = hist_register_trigger,
6913 .unreg = hist_unregister_trigger,
6914 .unreg_all = hist_unreg_all,
6915 .get_trigger_ops = event_hist_get_trigger_ops,
6916 .set_filter = set_trigger_filter,
6917 };
6918
6919 __init int register_trigger_hist_cmd(void)
6920 {
6921 int ret;
6922
6923 ret = register_event_command(&trigger_hist_cmd);
6924 WARN_ON(ret < 0);
6925
6926 return ret;
6927 }
6928
6929 static void
6930 hist_enable_trigger(struct event_trigger_data *data,
6931 struct trace_buffer *buffer, void *rec,
6932 struct ring_buffer_event *event)
6933 {
6934 struct enable_trigger_data *enable_data = data->private_data;
6935 struct event_trigger_data *test;
6936
6937 list_for_each_entry_rcu(test, &enable_data->file->triggers, list,
6938 lockdep_is_held(&event_mutex)) {
6939 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
6940 if (enable_data->enable)
6941 test->paused = false;
6942 else
6943 test->paused = true;
6944 }
6945 }
6946 }
6947
6948 static void
6949 hist_enable_count_trigger(struct event_trigger_data *data,
6950 struct trace_buffer *buffer, void *rec,
6951 struct ring_buffer_event *event)
6952 {
6953 if (!data->count)
6954 return;
6955
6956 if (data->count != -1)
6957 (data->count)--;
6958
6959 hist_enable_trigger(data, buffer, rec, event);
6960 }
6961
6962 static const struct event_trigger_ops hist_enable_trigger_ops = {
6963 .trigger = hist_enable_trigger,
6964 .print = event_enable_trigger_print,
6965 .init = event_trigger_init,
6966 .free = event_enable_trigger_free,
6967 };
6968
6969 static const struct event_trigger_ops hist_enable_count_trigger_ops = {
6970 .trigger = hist_enable_count_trigger,
6971 .print = event_enable_trigger_print,
6972 .init = event_trigger_init,
6973 .free = event_enable_trigger_free,
6974 };
6975
6976 static const struct event_trigger_ops hist_disable_trigger_ops = {
6977 .trigger = hist_enable_trigger,
6978 .print = event_enable_trigger_print,
6979 .init = event_trigger_init,
6980 .free = event_enable_trigger_free,
6981 };
6982
6983 static const struct event_trigger_ops hist_disable_count_trigger_ops = {
6984 .trigger = hist_enable_count_trigger,
6985 .print = event_enable_trigger_print,
6986 .init = event_trigger_init,
6987 .free = event_enable_trigger_free,
6988 };
6989
6990 static const struct event_trigger_ops *
6991 hist_enable_get_trigger_ops(char *cmd, char *param)
6992 {
6993 const struct event_trigger_ops *ops;
6994 bool enable;
6995
6996 enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
6997
6998 if (enable)
6999 ops = param ? &hist_enable_count_trigger_ops :
7000 &hist_enable_trigger_ops;
7001 else
7002 ops = param ? &hist_disable_count_trigger_ops :
7003 &hist_disable_trigger_ops;
7004
7005 return ops;
7006 }
7007
7008 static void hist_enable_unreg_all(struct trace_event_file *file)
7009 {
7010 struct event_trigger_data *test, *n;
7011
7012 list_for_each_entry_safe(test, n, &file->triggers, list) {
7013 if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) {
7014 list_del_rcu(&test->list);
7015 update_cond_flag(file);
7016 trace_event_trigger_enable_disable(file, 0);
7017 if (test->ops->free)
7018 test->ops->free(test);
7019 }
7020 }
7021 }
7022
7023 static struct event_command trigger_hist_enable_cmd = {
7024 .name = ENABLE_HIST_STR,
7025 .trigger_type = ETT_HIST_ENABLE,
7026 .parse = event_enable_trigger_parse,
7027 .reg = event_enable_register_trigger,
7028 .unreg = event_enable_unregister_trigger,
7029 .unreg_all = hist_enable_unreg_all,
7030 .get_trigger_ops = hist_enable_get_trigger_ops,
7031 .set_filter = set_trigger_filter,
7032 };
7033
7034 static struct event_command trigger_hist_disable_cmd = {
7035 .name = DISABLE_HIST_STR,
7036 .trigger_type = ETT_HIST_ENABLE,
7037 .parse = event_enable_trigger_parse,
7038 .reg = event_enable_register_trigger,
7039 .unreg = event_enable_unregister_trigger,
7040 .unreg_all = hist_enable_unreg_all,
7041 .get_trigger_ops = hist_enable_get_trigger_ops,
7042 .set_filter = set_trigger_filter,
7043 };
7044
7045 static __init void unregister_trigger_hist_enable_disable_cmds(void)
7046 {
7047 unregister_event_command(&trigger_hist_enable_cmd);
7048 unregister_event_command(&trigger_hist_disable_cmd);
7049 }
7050
7051 __init int register_trigger_hist_enable_disable_cmds(void)
7052 {
7053 int ret;
7054
7055 ret = register_event_command(&trigger_hist_enable_cmd);
7056 if (WARN_ON(ret < 0))
7057 return ret;
7058 ret = register_event_command(&trigger_hist_disable_cmd);
7059 if (WARN_ON(ret < 0))
7060 unregister_trigger_hist_enable_disable_cmds();
7061
7062 return ret;
7063 }
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