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