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