kernel/trace/trace_events_filter.c

   1 /*
   2  * trace_events_filter - generic event filtering
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17  *
  18  * Copyright (C) 2009 Tom Zanussi <tzanussi@gmail.com>
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/ctype.h>
  23 #include <linux/mutex.h>
  24 #include <linux/perf_event.h>
  25 #include <linux/slab.h>
  26
  27 #include "trace.h"
  28 #include "trace_output.h"
  29
  30 #define DEFAULT_SYS_FILTER_MESSAGE                                      \
  31         "### global filter ###\n"                                       \
  32         "# Use this to set filters for multiple events.\n"              \
  33         "# Only events with the given fields will be affected.\n"       \
  34         "# If no events are modified, an error message will be displayed here"
  35
  36 enum filter_op_ids
  37 {
  38         OP_OR,
  39         OP_AND,
  40         OP_GLOB,
  41         OP_NE,
  42         OP_EQ,
  43         OP_LT,
  44         OP_LE,
  45         OP_GT,
  46         OP_GE,
  47         OP_BAND,
  48         OP_NOT,
  49         OP_NONE,
  50         OP_OPEN_PAREN,
  51 };
  52
  53 struct filter_op {
  54         int id;
  55         char *string;
  56         int precedence;
  57 };
  58
  59 /* Order must be the same as enum filter_op_ids above */
  60 static struct filter_op filter_ops[] = {
  61         { OP_OR,        "||",           1 },
  62         { OP_AND,       "&&",           2 },
  63         { OP_GLOB,      "~",            4 },
  64         { OP_NE,        "!=",           4 },
  65         { OP_EQ,        "==",           4 },
  66         { OP_LT,        "<",            5 },
  67         { OP_LE,        "<=",           5 },
  68         { OP_GT,        ">",            5 },
  69         { OP_GE,        ">=",           5 },
  70         { OP_BAND,      "&",            6 },
  71         { OP_NOT,       "!",            6 },
  72         { OP_NONE,      "OP_NONE",      0 },
  73         { OP_OPEN_PAREN, "(",           0 },
  74 };
  75
  76 enum {
  77         FILT_ERR_NONE,
  78         FILT_ERR_INVALID_OP,
  79         FILT_ERR_UNBALANCED_PAREN,
  80         FILT_ERR_TOO_MANY_OPERANDS,
  81         FILT_ERR_OPERAND_TOO_LONG,
  82         FILT_ERR_FIELD_NOT_FOUND,
  83         FILT_ERR_ILLEGAL_FIELD_OP,
  84         FILT_ERR_ILLEGAL_INTVAL,
  85         FILT_ERR_BAD_SUBSYS_FILTER,
  86         FILT_ERR_TOO_MANY_PREDS,
  87         FILT_ERR_MISSING_FIELD,
  88         FILT_ERR_INVALID_FILTER,
  89         FILT_ERR_IP_FIELD_ONLY,
  90         FILT_ERR_ILLEGAL_NOT_OP,
  91 };
  92
  93 static char *err_text[] = {
  94         "No error",
  95         "Invalid operator",
  96         "Unbalanced parens",
  97         "Too many operands",
  98         "Operand too long",
  99         "Field not found",
 100         "Illegal operation for field type",
 101         "Illegal integer value",
 102         "Couldn't find or set field in one of a subsystem's events",
 103         "Too many terms in predicate expression",
 104         "Missing field name and/or value",
 105         "Meaningless filter expression",
 106         "Only 'ip' field is supported for function trace",
 107         "Illegal use of '!'",
 108 };
 109
 110 struct opstack_op {
 111         int op;
 112         struct list_head list;
 113 };
 114
 115 struct postfix_elt {
 116         int op;
 117         char *operand;
 118         struct list_head list;
 119 };
 120
 121 struct filter_parse_state {
 122         struct filter_op *ops;
 123         struct list_head opstack;
 124         struct list_head postfix;
 125         int lasterr;
 126         int lasterr_pos;
 127
 128         struct {
 129                 char *string;
 130                 unsigned int cnt;
 131                 unsigned int tail;
 132         } infix;
 133
 134         struct {
 135                 char string[MAX_FILTER_STR_VAL];
 136                 int pos;
 137                 unsigned int tail;
 138         } operand;
 139 };
 140
 141 struct pred_stack {
 142         struct filter_pred      **preds;
 143         int                     index;
 144 };
 145
 146 /* If not of not match is equal to not of not, then it is a match */
 147 #define DEFINE_COMPARISON_PRED(type)                                    \
 148 static int filter_pred_##type(struct filter_pred *pred, void *event)    \
 149 {                                                                       \
 150         type *addr = (type *)(event + pred->offset);                    \
 151         type val = (type)pred->val;                                     \
 152         int match = 0;                                                  \
 153                                                                         \
 154         switch (pred->op) {                                             \
 155         case OP_LT:                                                     \
 156                 match = (*addr < val);                                  \
 157                 break;                                                  \
 158         case OP_LE:                                                     \
 159                 match = (*addr <= val);                                 \
 160                 break;                                                  \
 161         case OP_GT:                                                     \
 162                 match = (*addr > val);                                  \
 163                 break;                                                  \
 164         case OP_GE:                                                     \
 165                 match = (*addr >= val);                                 \
 166                 break;                                                  \
 167         case OP_BAND:                                                   \
 168                 match = (*addr & val);                                  \
 169                 break;                                                  \
 170         default:                                                        \
 171                 break;                                                  \
 172         }                                                               \
 173                                                                         \
 174         return !!match == !pred->not;                                   \
 175 }
 176
 177 #define DEFINE_EQUALITY_PRED(size)                                      \
 178 static int filter_pred_##size(struct filter_pred *pred, void *event)    \
 179 {                                                                       \
 180         u##size *addr = (u##size *)(event + pred->offset);              \
 181         u##size val = (u##size)pred->val;                               \
 182         int match;                                                      \
 183                                                                         \
 184         match = (val == *addr) ^ pred->not;                             \
 185                                                                         \
 186         return match;                                                   \
 187 }
 188
 189 DEFINE_COMPARISON_PRED(s64);
 190 DEFINE_COMPARISON_PRED(u64);
 191 DEFINE_COMPARISON_PRED(s32);
 192 DEFINE_COMPARISON_PRED(u32);
 193 DEFINE_COMPARISON_PRED(s16);
 194 DEFINE_COMPARISON_PRED(u16);
 195 DEFINE_COMPARISON_PRED(s8);
 196 DEFINE_COMPARISON_PRED(u8);
 197
 198 DEFINE_EQUALITY_PRED(64);
 199 DEFINE_EQUALITY_PRED(32);
 200 DEFINE_EQUALITY_PRED(16);
 201 DEFINE_EQUALITY_PRED(8);
 202
 203 /* Filter predicate for fixed sized arrays of characters */
 204 static int filter_pred_string(struct filter_pred *pred, void *event)
 205 {
 206         char *addr = (char *)(event + pred->offset);
 207         int cmp, match;
 208
 209         cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len);
 210
 211         match = cmp ^ pred->not;
 212
 213         return match;
 214 }
 215
 216 /* Filter predicate for char * pointers */
 217 static int filter_pred_pchar(struct filter_pred *pred, void *event)
 218 {
 219         char **addr = (char **)(event + pred->offset);
 220         int cmp, match;
 221         int len = strlen(*addr) + 1;    /* including tailing '\0' */
 222
 223         cmp = pred->regex.match(*addr, &pred->regex, len);
 224
 225         match = cmp ^ pred->not;
 226
 227         return match;
 228 }
 229
 230 /*
 231  * Filter predicate for dynamic sized arrays of characters.
 232  * These are implemented through a list of strings at the end
 233  * of the entry.
 234  * Also each of these strings have a field in the entry which
 235  * contains its offset from the beginning of the entry.
 236  * We have then first to get this field, dereference it
 237  * and add it to the address of the entry, and at last we have
 238  * the address of the string.
 239  */
 240 static int filter_pred_strloc(struct filter_pred *pred, void *event)
 241 {
 242         u32 str_item = *(u32 *)(event + pred->offset);
 243         int str_loc = str_item & 0xffff;
 244         int str_len = str_item >> 16;
 245         char *addr = (char *)(event + str_loc);
 246         int cmp, match;
 247
 248         cmp = pred->regex.match(addr, &pred->regex, str_len);
 249
 250         match = cmp ^ pred->not;
 251
 252         return match;
 253 }
 254
 255 static int filter_pred_none(struct filter_pred *pred, void *event)
 256 {
 257         return 0;
 258 }
 259
 260 /*
 261  * regex_match_foo - Basic regex callbacks
 262  *
 263  * @str: the string to be searched
 264  * @r:   the regex structure containing the pattern string
 265  * @len: the length of the string to be searched (including '\0')
 266  *
 267  * Note:
 268  * - @str might not be NULL-terminated if it's of type DYN_STRING
 269  *   or STATIC_STRING
 270  */
 271
 272 static int regex_match_full(char *str, struct regex *r, int len)
 273 {
 274         if (strncmp(str, r->pattern, len) == 0)
 275                 return 1;
 276         return 0;
 277 }
 278
 279 static int regex_match_front(char *str, struct regex *r, int len)
 280 {
 281         if (strncmp(str, r->pattern, r->len) == 0)
 282                 return 1;
 283         return 0;
 284 }
 285
 286 static int regex_match_middle(char *str, struct regex *r, int len)
 287 {
 288         if (strnstr(str, r->pattern, len))
 289                 return 1;
 290         return 0;
 291 }
 292
 293 static int regex_match_end(char *str, struct regex *r, int len)
 294 {
 295         int strlen = len - 1;
 296
 297         if (strlen >= r->len &&
 298             memcmp(str + strlen - r->len, r->pattern, r->len) == 0)
 299                 return 1;
 300         return 0;
 301 }
 302
 303 /**
 304  * filter_parse_regex - parse a basic regex
 305  * @buff:   the raw regex
 306  * @len:    length of the regex
 307  * @search: will point to the beginning of the string to compare
 308  * @not:    tell whether the match will have to be inverted
 309  *
 310  * This passes in a buffer containing a regex and this function will
 311  * set search to point to the search part of the buffer and
 312  * return the type of search it is (see enum above).
 313  * This does modify buff.
 314  *
 315  * Returns enum type.
 316  *  search returns the pointer to use for comparison.
 317  *  not returns 1 if buff started with a '!'
 318  *     0 otherwise.
 319  */
 320 enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not)
 321 {
 322         int type = MATCH_FULL;
 323         int i;
 324
 325         if (buff[0] == '!') {
 326                 *not = 1;
 327                 buff++;
 328                 len--;
 329         } else
 330                 *not = 0;
 331
 332         *search = buff;
 333
 334         for (i = 0; i < len; i++) {
 335                 if (buff[i] == '*') {
 336                         if (!i) {
 337                                 *search = buff + 1;
 338                                 type = MATCH_END_ONLY;
 339                         } else {
 340                                 if (type == MATCH_END_ONLY)
 341                                         type = MATCH_MIDDLE_ONLY;
 342                                 else
 343                                         type = MATCH_FRONT_ONLY;
 344                                 buff[i] = 0;
 345                                 break;
 346                         }
 347                 }
 348         }
 349
 350         return type;
 351 }
 352
 353 static void filter_build_regex(struct filter_pred *pred)
 354 {
 355         struct regex *r = &pred->regex;
 356         char *search;
 357         enum regex_type type = MATCH_FULL;
 358         int not = 0;
 359
 360         if (pred->op == OP_GLOB) {
 361                 type = filter_parse_regex(r->pattern, r->len, &search, &not);
 362                 r->len = strlen(search);
 363                 memmove(r->pattern, search, r->len+1);
 364         }
 365
 366         switch (type) {
 367         case MATCH_FULL:
 368                 r->match = regex_match_full;
 369                 break;
 370         case MATCH_FRONT_ONLY:
 371                 r->match = regex_match_front;
 372                 break;
 373         case MATCH_MIDDLE_ONLY:
 374                 r->match = regex_match_middle;
 375                 break;
 376         case MATCH_END_ONLY:
 377                 r->match = regex_match_end;
 378                 break;
 379         }
 380
 381         pred->not ^= not;
 382 }
 383
 384 enum move_type {
 385         MOVE_DOWN,
 386         MOVE_UP_FROM_LEFT,
 387         MOVE_UP_FROM_RIGHT
 388 };
 389
 390 static struct filter_pred *
 391 get_pred_parent(struct filter_pred *pred, struct filter_pred *preds,
 392                 int index, enum move_type *move)
 393 {
 394         if (pred->parent & FILTER_PRED_IS_RIGHT)
 395                 *move = MOVE_UP_FROM_RIGHT;
 396         else
 397                 *move = MOVE_UP_FROM_LEFT;
 398         pred = &preds[pred->parent & ~FILTER_PRED_IS_RIGHT];
 399
 400         return pred;
 401 }
 402
 403 enum walk_return {
 404         WALK_PRED_ABORT,
 405         WALK_PRED_PARENT,
 406         WALK_PRED_DEFAULT,
 407 };
 408
 409 typedef int (*filter_pred_walkcb_t) (enum move_type move,
 410                                      struct filter_pred *pred,
 411                                      int *err, void *data);
 412
 413 static int walk_pred_tree(struct filter_pred *preds,
 414                           struct filter_pred *root,
 415                           filter_pred_walkcb_t cb, void *data)
 416 {
 417         struct filter_pred *pred = root;
 418         enum move_type move = MOVE_DOWN;
 419         int done = 0;
 420
 421         if  (!preds)
 422                 return -EINVAL;
 423
 424         do {
 425                 int err = 0, ret;
 426
 427                 ret = cb(move, pred, &err, data);
 428                 if (ret == WALK_PRED_ABORT)
 429                         return err;
 430                 if (ret == WALK_PRED_PARENT)
 431                         goto get_parent;
 432
 433                 switch (move) {
 434                 case MOVE_DOWN:
 435                         if (pred->left != FILTER_PRED_INVALID) {
 436                                 pred = &preds[pred->left];
 437                                 continue;
 438                         }
 439                         goto get_parent;
 440                 case MOVE_UP_FROM_LEFT:
 441                         pred = &preds[pred->right];
 442                         move = MOVE_DOWN;
 443                         continue;
 444                 case MOVE_UP_FROM_RIGHT:
 445  get_parent:
 446                         if (pred == root)
 447                                 break;
 448                         pred = get_pred_parent(pred, preds,
 449                                                pred->parent,
 450                                                &move);
 451                         continue;
 452                 }
 453                 done = 1;
 454         } while (!done);
 455
 456         /* We are fine. */
 457         return 0;
 458 }
 459
 460 /*
 461  * A series of AND or ORs where found together. Instead of
 462  * climbing up and down the tree branches, an array of the
 463  * ops were made in order of checks. We can just move across
 464  * the array and short circuit if needed.
 465  */
 466 static int process_ops(struct filter_pred *preds,
 467                        struct filter_pred *op, void *rec)
 468 {
 469         struct filter_pred *pred;
 470         int match = 0;
 471         int type;
 472         int i;
 473
 474         /*
 475          * Micro-optimization: We set type to true if op
 476          * is an OR and false otherwise (AND). Then we
 477          * just need to test if the match is equal to
 478          * the type, and if it is, we can short circuit the
 479          * rest of the checks:
 480          *
 481          * if ((match && op->op == OP_OR) ||
 482          *     (!match && op->op == OP_AND))
 483          *        return match;
 484          */
 485         type = op->op == OP_OR;
 486
 487         for (i = 0; i < op->val; i++) {
 488                 pred = &preds[op->ops[i]];
 489                 if (!WARN_ON_ONCE(!pred->fn))
 490                         match = pred->fn(pred, rec);
 491                 if (!!match == type)
 492                         break;
 493         }
 494         /* If not of not match is equal to not of not, then it is a match */
 495         return !!match == !op->not;
 496 }
 497
 498 struct filter_match_preds_data {
 499         struct filter_pred *preds;
 500         int match;
 501         void *rec;
 502 };
 503
 504 static int filter_match_preds_cb(enum move_type move, struct filter_pred *pred,
 505                                  int *err, void *data)
 506 {
 507         struct filter_match_preds_data *d = data;
 508
 509         *err = 0;
 510         switch (move) {
 511         case MOVE_DOWN:
 512                 /* only AND and OR have children */
 513                 if (pred->left != FILTER_PRED_INVALID) {
 514                         /* If ops is set, then it was folded. */
 515                         if (!pred->ops)
 516                                 return WALK_PRED_DEFAULT;
 517                         /* We can treat folded ops as a leaf node */
 518                         d->match = process_ops(d->preds, pred, d->rec);
 519                 } else {
 520                         if (!WARN_ON_ONCE(!pred->fn))
 521                                 d->match = pred->fn(pred, d->rec);
 522                 }
 523
 524                 return WALK_PRED_PARENT;
 525         case MOVE_UP_FROM_LEFT:
 526                 /*
 527                  * Check for short circuits.
 528                  *
 529                  * Optimization: !!match == (pred->op == OP_OR)
 530                  *   is the same as:
 531                  * if ((match && pred->op == OP_OR) ||
 532                  *     (!match && pred->op == OP_AND))
 533                  */
 534                 if (!!d->match == (pred->op == OP_OR))
 535                         return WALK_PRED_PARENT;
 536                 break;
 537         case MOVE_UP_FROM_RIGHT:
 538                 break;
 539         }
 540
 541         return WALK_PRED_DEFAULT;
 542 }
 543
 544 /* return 1 if event matches, 0 otherwise (discard) */
 545 int filter_match_preds(struct event_filter *filter, void *rec)
 546 {
 547         struct filter_pred *preds;
 548         struct filter_pred *root;
 549         struct filter_match_preds_data data = {
 550                 /* match is currently meaningless */
 551                 .match = -1,
 552                 .rec   = rec,
 553         };
 554         int n_preds, ret;
 555
 556         /* no filter is considered a match */
 557         if (!filter)
 558                 return 1;
 559
 560         n_preds = filter->n_preds;
 561         if (!n_preds)
 562                 return 1;
 563
 564         /*
 565          * n_preds, root and filter->preds are protect with preemption disabled.
 566          */
 567         root = rcu_dereference_sched(filter->root);
 568         if (!root)
 569                 return 1;
 570
 571         data.preds = preds = rcu_dereference_sched(filter->preds);
 572         ret = walk_pred_tree(preds, root, filter_match_preds_cb, &data);
 573         WARN_ON(ret);
 574         return data.match;
 575 }
 576 EXPORT_SYMBOL_GPL(filter_match_preds);
 577
 578 static void parse_error(struct filter_parse_state *ps, int err, int pos)
 579 {
 580         ps->lasterr = err;
 581         ps->lasterr_pos = pos;
 582 }
 583
 584 static void remove_filter_string(struct event_filter *filter)
 585 {
 586         if (!filter)
 587                 return;
 588
 589         kfree(filter->filter_string);
 590         filter->filter_string = NULL;
 591 }
 592
 593 static int replace_filter_string(struct event_filter *filter,
 594                                  char *filter_string)
 595 {
 596         kfree(filter->filter_string);
 597         filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
 598         if (!filter->filter_string)
 599                 return -ENOMEM;
 600
 601         return 0;
 602 }
 603
 604 static int append_filter_string(struct event_filter *filter,
 605                                 char *string)
 606 {
 607         int newlen;
 608         char *new_filter_string;
 609
 610         BUG_ON(!filter->filter_string);
 611         newlen = strlen(filter->filter_string) + strlen(string) + 1;
 612         new_filter_string = kmalloc(newlen, GFP_KERNEL);
 613         if (!new_filter_string)
 614                 return -ENOMEM;
 615
 616         strcpy(new_filter_string, filter->filter_string);
 617         strcat(new_filter_string, string);
 618         kfree(filter->filter_string);
 619         filter->filter_string = new_filter_string;
 620
 621         return 0;
 622 }
 623
 624 static void append_filter_err(struct filter_parse_state *ps,
 625                               struct event_filter *filter)
 626 {
 627         int pos = ps->lasterr_pos;
 628         char *buf, *pbuf;
 629
 630         buf = (char *)__get_free_page(GFP_TEMPORARY);
 631         if (!buf)
 632                 return;
 633
 634         append_filter_string(filter, "\n");
 635         memset(buf, ' ', PAGE_SIZE);
 636         if (pos > PAGE_SIZE - 128)
 637                 pos = 0;
 638         buf[pos] = '^';
 639         pbuf = &buf[pos] + 1;
 640
 641         sprintf(pbuf, "\nparse_error: %s\n", err_text[ps->lasterr]);
 642         append_filter_string(filter, buf);
 643         free_page((unsigned long) buf);
 644 }
 645
 646 static inline struct event_filter *event_filter(struct ftrace_event_file *file)
 647 {
 648         if (file->event_call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
 649                 return file->event_call->filter;
 650         else
 651                 return file->filter;
 652 }
 653
 654 /* caller must hold event_mutex */
 655 void print_event_filter(struct ftrace_event_file *file, struct trace_seq *s)
 656 {
 657         struct event_filter *filter = event_filter(file);
 658
 659         if (filter && filter->filter_string)
 660                 trace_seq_printf(s, "%s\n", filter->filter_string);
 661         else
 662                 trace_seq_puts(s, "none\n");
 663 }
 664
 665 void print_subsystem_event_filter(struct event_subsystem *system,
 666                                   struct trace_seq *s)
 667 {
 668         struct event_filter *filter;
 669
 670         mutex_lock(&event_mutex);
 671         filter = system->filter;
 672         if (filter && filter->filter_string)
 673                 trace_seq_printf(s, "%s\n", filter->filter_string);
 674         else
 675                 trace_seq_puts(s, DEFAULT_SYS_FILTER_MESSAGE "\n");
 676         mutex_unlock(&event_mutex);
 677 }
 678
 679 static int __alloc_pred_stack(struct pred_stack *stack, int n_preds)
 680 {
 681         stack->preds = kcalloc(n_preds + 1, sizeof(*stack->preds), GFP_KERNEL);
 682         if (!stack->preds)
 683                 return -ENOMEM;
 684         stack->index = n_preds;
 685         return 0;
 686 }
 687
 688 static void __free_pred_stack(struct pred_stack *stack)
 689 {
 690         kfree(stack->preds);
 691         stack->index = 0;
 692 }
 693
 694 static int __push_pred_stack(struct pred_stack *stack,
 695                              struct filter_pred *pred)
 696 {
 697         int index = stack->index;
 698
 699         if (WARN_ON(index == 0))
 700                 return -ENOSPC;
 701
 702         stack->preds[--index] = pred;
 703         stack->index = index;
 704         return 0;
 705 }
 706
 707 static struct filter_pred *
 708 __pop_pred_stack(struct pred_stack *stack)
 709 {
 710         struct filter_pred *pred;
 711         int index = stack->index;
 712
 713         pred = stack->preds[index++];
 714         if (!pred)
 715                 return NULL;
 716
 717         stack->index = index;
 718         return pred;
 719 }
 720
 721 static int filter_set_pred(struct event_filter *filter,
 722                            int idx,
 723                            struct pred_stack *stack,
 724                            struct filter_pred *src)
 725 {
 726         struct filter_pred *dest = &filter->preds[idx];
 727         struct filter_pred *left;
 728         struct filter_pred *right;
 729
 730         *dest = *src;
 731         dest->index = idx;
 732
 733         if (dest->op == OP_OR || dest->op == OP_AND) {
 734                 right = __pop_pred_stack(stack);
 735                 left = __pop_pred_stack(stack);
 736                 if (!left || !right)
 737                         return -EINVAL;
 738                 /*
 739                  * If both children can be folded
 740                  * and they are the same op as this op or a leaf,
 741                  * then this op can be folded.
 742                  */
 743                 if (left->index & FILTER_PRED_FOLD &&
 744                     ((left->op == dest->op && !left->not) ||
 745                      left->left == FILTER_PRED_INVALID) &&
 746                     right->index & FILTER_PRED_FOLD &&
 747                     ((right->op == dest->op && !right->not) ||
 748                      right->left == FILTER_PRED_INVALID))
 749                         dest->index |= FILTER_PRED_FOLD;
 750
 751                 dest->left = left->index & ~FILTER_PRED_FOLD;
 752                 dest->right = right->index & ~FILTER_PRED_FOLD;
 753                 left->parent = dest->index & ~FILTER_PRED_FOLD;
 754                 right->parent = dest->index | FILTER_PRED_IS_RIGHT;
 755         } else {
 756                 /*
 757                  * Make dest->left invalid to be used as a quick
 758                  * way to know this is a leaf node.
 759                  */
 760                 dest->left = FILTER_PRED_INVALID;
 761
 762                 /* All leafs allow folding the parent ops. */
 763                 dest->index |= FILTER_PRED_FOLD;
 764         }
 765
 766         return __push_pred_stack(stack, dest);
 767 }
 768
 769 static void __free_preds(struct event_filter *filter)
 770 {
 771         int i;
 772
 773         if (filter->preds) {
 774                 for (i = 0; i < filter->n_preds; i++)
 775                         kfree(filter->preds[i].ops);
 776                 kfree(filter->preds);
 777                 filter->preds = NULL;
 778         }
 779         filter->a_preds = 0;
 780         filter->n_preds = 0;
 781 }
 782
 783 static void filter_disable(struct ftrace_event_file *file)
 784 {
 785         struct ftrace_event_call *call = file->event_call;
 786
 787         if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
 788                 call->flags &= ~TRACE_EVENT_FL_FILTERED;
 789         else
 790                 file->flags &= ~FTRACE_EVENT_FL_FILTERED;
 791 }
 792
 793 static void __free_filter(struct event_filter *filter)
 794 {
 795         if (!filter)
 796                 return;
 797
 798         __free_preds(filter);
 799         kfree(filter->filter_string);
 800         kfree(filter);
 801 }
 802
 803 void free_event_filter(struct event_filter *filter)
 804 {
 805         __free_filter(filter);
 806 }
 807
 808 static struct event_filter *__alloc_filter(void)
 809 {
 810         struct event_filter *filter;
 811
 812         filter = kzalloc(sizeof(*filter), GFP_KERNEL);
 813         return filter;
 814 }
 815
 816 static int __alloc_preds(struct event_filter *filter, int n_preds)
 817 {
 818         struct filter_pred *pred;
 819         int i;
 820
 821         if (filter->preds)
 822                 __free_preds(filter);
 823
 824         filter->preds = kcalloc(n_preds, sizeof(*filter->preds), GFP_KERNEL);
 825
 826         if (!filter->preds)
 827                 return -ENOMEM;
 828
 829         filter->a_preds = n_preds;
 830         filter->n_preds = 0;
 831
 832         for (i = 0; i < n_preds; i++) {
 833                 pred = &filter->preds[i];
 834                 pred->fn = filter_pred_none;
 835         }
 836
 837         return 0;
 838 }
 839
 840 static inline void __remove_filter(struct ftrace_event_file *file)
 841 {
 842         struct ftrace_event_call *call = file->event_call;
 843
 844         filter_disable(file);
 845         if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
 846                 remove_filter_string(call->filter);
 847         else
 848                 remove_filter_string(file->filter);
 849 }
 850
 851 static void filter_free_subsystem_preds(struct ftrace_subsystem_dir *dir,
 852                                         struct trace_array *tr)
 853 {
 854         struct ftrace_event_file *file;
 855
 856         list_for_each_entry(file, &tr->events, list) {
 857                 if (file->system != dir)
 858                         continue;
 859                 __remove_filter(file);
 860         }
 861 }
 862
 863 static inline void __free_subsystem_filter(struct ftrace_event_file *file)
 864 {
 865         struct ftrace_event_call *call = file->event_call;
 866
 867         if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) {
 868                 __free_filter(call->filter);
 869                 call->filter = NULL;
 870         } else {
 871                 __free_filter(file->filter);
 872                 file->filter = NULL;
 873         }
 874 }
 875
 876 static void filter_free_subsystem_filters(struct ftrace_subsystem_dir *dir,
 877                                           struct trace_array *tr)
 878 {
 879         struct ftrace_event_file *file;
 880
 881         list_for_each_entry(file, &tr->events, list) {
 882                 if (file->system != dir)
 883                         continue;
 884                 __free_subsystem_filter(file);
 885         }
 886 }
 887
 888 static int filter_add_pred(struct filter_parse_state *ps,
 889                            struct event_filter *filter,
 890                            struct filter_pred *pred,
 891                            struct pred_stack *stack)
 892 {
 893         int err;
 894
 895         if (WARN_ON(filter->n_preds == filter->a_preds)) {
 896                 parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
 897                 return -ENOSPC;
 898         }
 899
 900         err = filter_set_pred(filter, filter->n_preds, stack, pred);
 901         if (err)
 902                 return err;
 903
 904         filter->n_preds++;
 905
 906         return 0;
 907 }
 908
 909 int filter_assign_type(const char *type)
 910 {
 911         if (strstr(type, "__data_loc") && strstr(type, "char"))
 912                 return FILTER_DYN_STRING;
 913
 914         if (strchr(type, '[') && strstr(type, "char"))
 915                 return FILTER_STATIC_STRING;
 916
 917         return FILTER_OTHER;
 918 }
 919
 920 static bool is_function_field(struct ftrace_event_field *field)
 921 {
 922         return field->filter_type == FILTER_TRACE_FN;
 923 }
 924
 925 static bool is_string_field(struct ftrace_event_field *field)
 926 {
 927         return field->filter_type == FILTER_DYN_STRING ||
 928                field->filter_type == FILTER_STATIC_STRING ||
 929                field->filter_type == FILTER_PTR_STRING;
 930 }
 931
 932 static int is_legal_op(struct ftrace_event_field *field, int op)
 933 {
 934         if (is_string_field(field) &&
 935             (op != OP_EQ && op != OP_NE && op != OP_GLOB))
 936                 return 0;
 937         if (!is_string_field(field) && op == OP_GLOB)
 938                 return 0;
 939
 940         return 1;
 941 }
 942
 943 static filter_pred_fn_t select_comparison_fn(int op, int field_size,
 944                                              int field_is_signed)
 945 {
 946         filter_pred_fn_t fn = NULL;
 947
 948         switch (field_size) {
 949         case 8:
 950                 if (op == OP_EQ || op == OP_NE)
 951                         fn = filter_pred_64;
 952                 else if (field_is_signed)
 953                         fn = filter_pred_s64;
 954                 else
 955                         fn = filter_pred_u64;
 956                 break;
 957         case 4:
 958                 if (op == OP_EQ || op == OP_NE)
 959                         fn = filter_pred_32;
 960                 else if (field_is_signed)
 961                         fn = filter_pred_s32;
 962                 else
 963                         fn = filter_pred_u32;
 964                 break;
 965         case 2:
 966                 if (op == OP_EQ || op == OP_NE)
 967                         fn = filter_pred_16;
 968                 else if (field_is_signed)
 969                         fn = filter_pred_s16;
 970                 else
 971                         fn = filter_pred_u16;
 972                 break;
 973         case 1:
 974                 if (op == OP_EQ || op == OP_NE)
 975                         fn = filter_pred_8;
 976                 else if (field_is_signed)
 977                         fn = filter_pred_s8;
 978                 else
 979                         fn = filter_pred_u8;
 980                 break;
 981         }
 982
 983         return fn;
 984 }
 985
 986 static int init_pred(struct filter_parse_state *ps,
 987                      struct ftrace_event_field *field,
 988                      struct filter_pred *pred)
 989
 990 {
 991         filter_pred_fn_t fn = filter_pred_none;
 992         unsigned long long val;
 993         int ret;
 994
 995         pred->offset = field->offset;
 996
 997         if (!is_legal_op(field, pred->op)) {
 998                 parse_error(ps, FILT_ERR_ILLEGAL_FIELD_OP, 0);
 999                 return -EINVAL;
1000         }
1001
1002         if (is_string_field(field)) {
1003                 filter_build_regex(pred);
1004
1005                 if (field->filter_type == FILTER_STATIC_STRING) {
1006                         fn = filter_pred_string;
1007                         pred->regex.field_len = field->size;
1008                 } else if (field->filter_type == FILTER_DYN_STRING)
1009                         fn = filter_pred_strloc;
1010                 else
1011                         fn = filter_pred_pchar;
1012         } else if (is_function_field(field)) {
1013                 if (strcmp(field->name, "ip")) {
1014                         parse_error(ps, FILT_ERR_IP_FIELD_ONLY, 0);
1015                         return -EINVAL;
1016                 }
1017         } else {
1018                 if (field->is_signed)
1019                         ret = kstrtoll(pred->regex.pattern, 0, &val);
1020                 else
1021                         ret = kstrtoull(pred->regex.pattern, 0, &val);
1022                 if (ret) {
1023                         parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0);
1024                         return -EINVAL;
1025                 }
1026                 pred->val = val;
1027
1028                 fn = select_comparison_fn(pred->op, field->size,
1029                                           field->is_signed);
1030                 if (!fn) {
1031                         parse_error(ps, FILT_ERR_INVALID_OP, 0);
1032                         return -EINVAL;
1033                 }
1034         }
1035
1036         if (pred->op == OP_NE)
1037                 pred->not ^= 1;
1038
1039         pred->fn = fn;
1040         return 0;
1041 }
1042
1043 static void parse_init(struct filter_parse_state *ps,
1044                        struct filter_op *ops,
1045                        char *infix_string)
1046 {
1047         memset(ps, '\0', sizeof(*ps));
1048
1049         ps->infix.string = infix_string;
1050         ps->infix.cnt = strlen(infix_string);
1051         ps->ops = ops;
1052
1053         INIT_LIST_HEAD(&ps->opstack);
1054         INIT_LIST_HEAD(&ps->postfix);
1055 }
1056
1057 static char infix_next(struct filter_parse_state *ps)
1058 {
1059         ps->infix.cnt--;
1060
1061         return ps->infix.string[ps->infix.tail++];
1062 }
1063
1064 static char infix_peek(struct filter_parse_state *ps)
1065 {
1066         if (ps->infix.tail == strlen(ps->infix.string))
1067                 return 0;
1068
1069         return ps->infix.string[ps->infix.tail];
1070 }
1071
1072 static void infix_advance(struct filter_parse_state *ps)
1073 {
1074         ps->infix.cnt--;
1075         ps->infix.tail++;
1076 }
1077
1078 static inline int is_precedence_lower(struct filter_parse_state *ps,
1079                                       int a, int b)
1080 {
1081         return ps->ops[a].precedence < ps->ops[b].precedence;
1082 }
1083
1084 static inline int is_op_char(struct filter_parse_state *ps, char c)
1085 {
1086         int i;
1087
1088         for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
1089                 if (ps->ops[i].string[0] == c)
1090                         return 1;
1091         }
1092
1093         return 0;
1094 }
1095
1096 static int infix_get_op(struct filter_parse_state *ps, char firstc)
1097 {
1098         char nextc = infix_peek(ps);
1099         char opstr[3];
1100         int i;
1101
1102         opstr[0] = firstc;
1103         opstr[1] = nextc;
1104         opstr[2] = '\0';
1105
1106         for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
1107                 if (!strcmp(opstr, ps->ops[i].string)) {
1108                         infix_advance(ps);
1109                         return ps->ops[i].id;
1110                 }
1111         }
1112
1113         opstr[1] = '\0';
1114
1115         for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
1116                 if (!strcmp(opstr, ps->ops[i].string))
1117                         return ps->ops[i].id;
1118         }
1119
1120         return OP_NONE;
1121 }
1122
1123 static inline void clear_operand_string(struct filter_parse_state *ps)
1124 {
1125         memset(ps->operand.string, '\0', MAX_FILTER_STR_VAL);
1126         ps->operand.tail = 0;
1127 }
1128
1129 static inline int append_operand_char(struct filter_parse_state *ps, char c)
1130 {
1131         if (ps->operand.tail == MAX_FILTER_STR_VAL - 1)
1132                 return -EINVAL;
1133
1134         ps->operand.string[ps->operand.tail++] = c;
1135
1136         return 0;
1137 }
1138
1139 static int filter_opstack_push(struct filter_parse_state *ps, int op)
1140 {
1141         struct opstack_op *opstack_op;
1142
1143         opstack_op = kmalloc(sizeof(*opstack_op), GFP_KERNEL);
1144         if (!opstack_op)
1145                 return -ENOMEM;
1146
1147         opstack_op->op = op;
1148         list_add(&opstack_op->list, &ps->opstack);
1149
1150         return 0;
1151 }
1152
1153 static int filter_opstack_empty(struct filter_parse_state *ps)
1154 {
1155         return list_empty(&ps->opstack);
1156 }
1157
1158 static int filter_opstack_top(struct filter_parse_state *ps)
1159 {
1160         struct opstack_op *opstack_op;
1161
1162         if (filter_opstack_empty(ps))
1163                 return OP_NONE;
1164
1165         opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list);
1166
1167         return opstack_op->op;
1168 }
1169
1170 static int filter_opstack_pop(struct filter_parse_state *ps)
1171 {
1172         struct opstack_op *opstack_op;
1173         int op;
1174
1175         if (filter_opstack_empty(ps))
1176                 return OP_NONE;
1177
1178         opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list);
1179         op = opstack_op->op;
1180         list_del(&opstack_op->list);
1181
1182         kfree(opstack_op);
1183
1184         return op;
1185 }
1186
1187 static void filter_opstack_clear(struct filter_parse_state *ps)
1188 {
1189         while (!filter_opstack_empty(ps))
1190                 filter_opstack_pop(ps);
1191 }
1192
1193 static char *curr_operand(struct filter_parse_state *ps)
1194 {
1195         return ps->operand.string;
1196 }
1197
1198 static int postfix_append_operand(struct filter_parse_state *ps, char *operand)
1199 {
1200         struct postfix_elt *elt;
1201
1202         elt = kmalloc(sizeof(*elt), GFP_KERNEL);
1203         if (!elt)
1204                 return -ENOMEM;
1205
1206         elt->op = OP_NONE;
1207         elt->operand = kstrdup(operand, GFP_KERNEL);
1208         if (!elt->operand) {
1209                 kfree(elt);
1210                 return -ENOMEM;
1211         }
1212
1213         list_add_tail(&elt->list, &ps->postfix);
1214
1215         return 0;
1216 }
1217
1218 static int postfix_append_op(struct filter_parse_state *ps, int op)
1219 {
1220         struct postfix_elt *elt;
1221
1222         elt = kmalloc(sizeof(*elt), GFP_KERNEL);
1223         if (!elt)
1224                 return -ENOMEM;
1225
1226         elt->op = op;
1227         elt->operand = NULL;
1228
1229         list_add_tail(&elt->list, &ps->postfix);
1230
1231         return 0;
1232 }
1233
1234 static void postfix_clear(struct filter_parse_state *ps)
1235 {
1236         struct postfix_elt *elt;
1237
1238         while (!list_empty(&ps->postfix)) {
1239                 elt = list_first_entry(&ps->postfix, struct postfix_elt, list);
1240                 list_del(&elt->list);
1241                 kfree(elt->operand);
1242                 kfree(elt);
1243         }
1244 }
1245
1246 static int filter_parse(struct filter_parse_state *ps)
1247 {
1248         int in_string = 0;
1249         int op, top_op;
1250         char ch;
1251
1252         while ((ch = infix_next(ps))) {
1253                 if (ch == '"') {
1254                         in_string ^= 1;
1255                         continue;
1256                 }
1257
1258                 if (in_string)
1259                         goto parse_operand;
1260
1261                 if (isspace(ch))
1262                         continue;
1263
1264                 if (is_op_char(ps, ch)) {
1265                         op = infix_get_op(ps, ch);
1266                         if (op == OP_NONE) {
1267                                 parse_error(ps, FILT_ERR_INVALID_OP, 0);
1268                                 return -EINVAL;
1269                         }
1270
1271                         if (strlen(curr_operand(ps))) {
1272                                 postfix_append_operand(ps, curr_operand(ps));
1273                                 clear_operand_string(ps);
1274                         }
1275
1276                         while (!filter_opstack_empty(ps)) {
1277                                 top_op = filter_opstack_top(ps);
1278                                 if (!is_precedence_lower(ps, top_op, op)) {
1279                                         top_op = filter_opstack_pop(ps);
1280                                         postfix_append_op(ps, top_op);
1281                                         continue;
1282                                 }
1283                                 break;
1284                         }
1285
1286                         filter_opstack_push(ps, op);
1287                         continue;
1288                 }
1289
1290                 if (ch == '(') {
1291                         filter_opstack_push(ps, OP_OPEN_PAREN);
1292                         continue;
1293                 }
1294
1295                 if (ch == ')') {
1296                         if (strlen(curr_operand(ps))) {
1297                                 postfix_append_operand(ps, curr_operand(ps));
1298                                 clear_operand_string(ps);
1299                         }
1300
1301                         top_op = filter_opstack_pop(ps);
1302                         while (top_op != OP_NONE) {
1303                                 if (top_op == OP_OPEN_PAREN)
1304                                         break;
1305                                 postfix_append_op(ps, top_op);
1306                                 top_op = filter_opstack_pop(ps);
1307                         }
1308                         if (top_op == OP_NONE) {
1309                                 parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0);
1310                                 return -EINVAL;
1311                         }
1312                         continue;
1313                 }
1314 parse_operand:
1315                 if (append_operand_char(ps, ch)) {
1316                         parse_error(ps, FILT_ERR_OPERAND_TOO_LONG, 0);
1317                         return -EINVAL;
1318                 }
1319         }
1320
1321         if (strlen(curr_operand(ps)))
1322                 postfix_append_operand(ps, curr_operand(ps));
1323
1324         while (!filter_opstack_empty(ps)) {
1325                 top_op = filter_opstack_pop(ps);
1326                 if (top_op == OP_NONE)
1327                         break;
1328                 if (top_op == OP_OPEN_PAREN) {
1329                         parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0);
1330                         return -EINVAL;
1331                 }
1332                 postfix_append_op(ps, top_op);
1333         }
1334
1335         return 0;
1336 }
1337
1338 static struct filter_pred *create_pred(struct filter_parse_state *ps,
1339                                        struct ftrace_event_call *call,
1340                                        int op, char *operand1, char *operand2)
1341 {
1342         struct ftrace_event_field *field;
1343         static struct filter_pred pred;
1344
1345         memset(&pred, 0, sizeof(pred));
1346         pred.op = op;
1347
1348         if (op == OP_AND || op == OP_OR)
1349                 return &pred;
1350
1351         if (!operand1 || !operand2) {
1352                 parse_error(ps, FILT_ERR_MISSING_FIELD, 0);
1353                 return NULL;
1354         }
1355
1356         field = trace_find_event_field(call, operand1);
1357         if (!field) {
1358                 parse_error(ps, FILT_ERR_FIELD_NOT_FOUND, 0);
1359                 return NULL;
1360         }
1361
1362         strcpy(pred.regex.pattern, operand2);
1363         pred.regex.len = strlen(pred.regex.pattern);
1364         pred.field = field;
1365         return init_pred(ps, field, &pred) ? NULL : &pred;
1366 }
1367
1368 static int check_preds(struct filter_parse_state *ps)
1369 {
1370         int n_normal_preds = 0, n_logical_preds = 0;
1371         struct postfix_elt *elt;
1372         int cnt = 0;
1373
1374         list_for_each_entry(elt, &ps->postfix, list) {
1375                 if (elt->op == OP_NONE) {
1376                         cnt++;
1377                         continue;
1378                 }
1379
1380                 if (elt->op == OP_AND || elt->op == OP_OR) {
1381                         n_logical_preds++;
1382                         cnt--;
1383                         continue;
1384                 }
1385                 if (elt->op != OP_NOT)
1386                         cnt--;
1387                 n_normal_preds++;
1388                 /* all ops should have operands */
1389                 if (cnt < 0)
1390                         break;
1391         }
1392
1393         if (cnt != 1 || !n_normal_preds || n_logical_preds >= n_normal_preds) {
1394                 parse_error(ps, FILT_ERR_INVALID_FILTER, 0);
1395                 return -EINVAL;
1396         }
1397
1398         return 0;
1399 }
1400
1401 static int count_preds(struct filter_parse_state *ps)
1402 {
1403         struct postfix_elt *elt;
1404         int n_preds = 0;
1405
1406         list_for_each_entry(elt, &ps->postfix, list) {
1407                 if (elt->op == OP_NONE)
1408                         continue;
1409                 n_preds++;
1410         }
1411
1412         return n_preds;
1413 }
1414
1415 struct check_pred_data {
1416         int count;
1417         int max;
1418 };
1419
1420 static int check_pred_tree_cb(enum move_type move, struct filter_pred *pred,
1421                               int *err, void *data)
1422 {
1423         struct check_pred_data *d = data;
1424
1425         if (WARN_ON(d->count++ > d->max)) {
1426                 *err = -EINVAL;
1427                 return WALK_PRED_ABORT;
1428         }
1429         return WALK_PRED_DEFAULT;
1430 }
1431
1432 /*
1433  * The tree is walked at filtering of an event. If the tree is not correctly
1434  * built, it may cause an infinite loop. Check here that the tree does
1435  * indeed terminate.
1436  */
1437 static int check_pred_tree(struct event_filter *filter,
1438                            struct filter_pred *root)
1439 {
1440         struct check_pred_data data = {
1441                 /*
1442                  * The max that we can hit a node is three times.
1443                  * Once going down, once coming up from left, and
1444                  * once coming up from right. This is more than enough
1445                  * since leafs are only hit a single time.
1446                  */
1447                 .max   = 3 * filter->n_preds,
1448                 .count = 0,
1449         };
1450
1451         return walk_pred_tree(filter->preds, root,
1452                               check_pred_tree_cb, &data);
1453 }
1454
1455 static int count_leafs_cb(enum move_type move, struct filter_pred *pred,
1456                           int *err, void *data)
1457 {
1458         int *count = data;
1459
1460         if ((move == MOVE_DOWN) &&
1461             (pred->left == FILTER_PRED_INVALID))
1462                 (*count)++;
1463
1464         return WALK_PRED_DEFAULT;
1465 }
1466
1467 static int count_leafs(struct filter_pred *preds, struct filter_pred *root)
1468 {
1469         int count = 0, ret;
1470
1471         ret = walk_pred_tree(preds, root, count_leafs_cb, &count);
1472         WARN_ON(ret);
1473         return count;
1474 }
1475
1476 struct fold_pred_data {
1477         struct filter_pred *root;
1478         int count;
1479         int children;
1480 };
1481
1482 static int fold_pred_cb(enum move_type move, struct filter_pred *pred,
1483                         int *err, void *data)
1484 {
1485         struct fold_pred_data *d = data;
1486         struct filter_pred *root = d->root;
1487
1488         if (move != MOVE_DOWN)
1489                 return WALK_PRED_DEFAULT;
1490         if (pred->left != FILTER_PRED_INVALID)
1491                 return WALK_PRED_DEFAULT;
1492
1493         if (WARN_ON(d->count == d->children)) {
1494                 *err = -EINVAL;
1495                 return WALK_PRED_ABORT;
1496         }
1497
1498         pred->index &= ~FILTER_PRED_FOLD;
1499         root->ops[d->count++] = pred->index;
1500         return WALK_PRED_DEFAULT;
1501 }
1502
1503 static int fold_pred(struct filter_pred *preds, struct filter_pred *root)
1504 {
1505         struct fold_pred_data data = {
1506                 .root  = root,
1507                 .count = 0,
1508         };
1509         int children;
1510
1511         /* No need to keep the fold flag */
1512         root->index &= ~FILTER_PRED_FOLD;
1513
1514         /* If the root is a leaf then do nothing */
1515         if (root->left == FILTER_PRED_INVALID)
1516                 return 0;
1517
1518         /* count the children */
1519         children = count_leafs(preds, &preds[root->left]);
1520         children += count_leafs(preds, &preds[root->right]);
1521
1522         root->ops = kcalloc(children, sizeof(*root->ops), GFP_KERNEL);
1523         if (!root->ops)
1524                 return -ENOMEM;
1525
1526         root->val = children;
1527         data.children = children;
1528         return walk_pred_tree(preds, root, fold_pred_cb, &data);
1529 }
1530
1531 static int fold_pred_tree_cb(enum move_type move, struct filter_pred *pred,
1532                              int *err, void *data)
1533 {
1534         struct filter_pred *preds = data;
1535
1536         if (move != MOVE_DOWN)
1537                 return WALK_PRED_DEFAULT;
1538         if (!(pred->index & FILTER_PRED_FOLD))
1539                 return WALK_PRED_DEFAULT;
1540
1541         *err = fold_pred(preds, pred);
1542         if (*err)
1543                 return WALK_PRED_ABORT;
1544
1545         /* eveyrhing below is folded, continue with parent */
1546         return WALK_PRED_PARENT;
1547 }
1548
1549 /*
1550  * To optimize the processing of the ops, if we have several "ors" or
1551  * "ands" together, we can put them in an array and process them all
1552  * together speeding up the filter logic.
1553  */
1554 static int fold_pred_tree(struct event_filter *filter,
1555                            struct filter_pred *root)
1556 {
1557         return walk_pred_tree(filter->preds, root, fold_pred_tree_cb,
1558                               filter->preds);
1559 }
1560
1561 static int replace_preds(struct ftrace_event_call *call,
1562                          struct event_filter *filter,
1563                          struct filter_parse_state *ps,
1564                          bool dry_run)
1565 {
1566         char *operand1 = NULL, *operand2 = NULL;
1567         struct filter_pred *pred;
1568         struct filter_pred *root;
1569         struct postfix_elt *elt;
1570         struct pred_stack stack = { }; /* init to NULL */
1571         int err;
1572         int n_preds = 0;
1573
1574         n_preds = count_preds(ps);
1575         if (n_preds >= MAX_FILTER_PRED) {
1576                 parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
1577                 return -ENOSPC;
1578         }
1579
1580         err = check_preds(ps);
1581         if (err)
1582                 return err;
1583
1584         if (!dry_run) {
1585                 err = __alloc_pred_stack(&stack, n_preds);
1586                 if (err)
1587                         return err;
1588                 err = __alloc_preds(filter, n_preds);
1589                 if (err)
1590                         goto fail;
1591         }
1592
1593         n_preds = 0;
1594         list_for_each_entry(elt, &ps->postfix, list) {
1595                 if (elt->op == OP_NONE) {
1596                         if (!operand1)
1597                                 operand1 = elt->operand;
1598                         else if (!operand2)
1599                                 operand2 = elt->operand;
1600                         else {
1601                                 parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0);
1602                                 err = -EINVAL;
1603                                 goto fail;
1604                         }
1605                         continue;
1606                 }
1607
1608                 if (elt->op == OP_NOT) {
1609                         if (!n_preds || operand1 || operand2) {
1610                                 parse_error(ps, FILT_ERR_ILLEGAL_NOT_OP, 0);
1611                                 err = -EINVAL;
1612                                 goto fail;
1613                         }
1614                         if (!dry_run)
1615                                 filter->preds[n_preds - 1].not ^= 1;
1616                         continue;
1617                 }
1618
1619                 if (WARN_ON(n_preds++ == MAX_FILTER_PRED)) {
1620                         parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
1621                         err = -ENOSPC;
1622                         goto fail;
1623                 }
1624
1625                 pred = create_pred(ps, call, elt->op, operand1, operand2);
1626                 if (!pred) {
1627                         err = -EINVAL;
1628                         goto fail;
1629                 }
1630
1631                 if (!dry_run) {
1632                         err = filter_add_pred(ps, filter, pred, &stack);
1633                         if (err)
1634                                 goto fail;
1635                 }
1636
1637                 operand1 = operand2 = NULL;
1638         }
1639
1640         if (!dry_run) {
1641                 /* We should have one item left on the stack */
1642                 pred = __pop_pred_stack(&stack);
1643                 if (!pred)
1644                         return -EINVAL;
1645                 /* This item is where we start from in matching */
1646                 root = pred;
1647                 /* Make sure the stack is empty */
1648                 pred = __pop_pred_stack(&stack);
1649                 if (WARN_ON(pred)) {
1650                         err = -EINVAL;
1651                         filter->root = NULL;
1652                         goto fail;
1653                 }
1654                 err = check_pred_tree(filter, root);
1655                 if (err)
1656                         goto fail;
1657
1658                 /* Optimize the tree */
1659                 err = fold_pred_tree(filter, root);
1660                 if (err)
1661                         goto fail;
1662
1663                 /* We don't set root until we know it works */
1664                 barrier();
1665                 filter->root = root;
1666         }
1667
1668         err = 0;
1669 fail:
1670         __free_pred_stack(&stack);
1671         return err;
1672 }
1673
1674 static inline void event_set_filtered_flag(struct ftrace_event_file *file)
1675 {
1676         struct ftrace_event_call *call = file->event_call;
1677
1678         if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
1679                 call->flags |= TRACE_EVENT_FL_FILTERED;
1680         else
1681                 file->flags |= FTRACE_EVENT_FL_FILTERED;
1682 }
1683
1684 static inline void event_set_filter(struct ftrace_event_file *file,
1685                                     struct event_filter *filter)
1686 {
1687         struct ftrace_event_call *call = file->event_call;
1688
1689         if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
1690                 rcu_assign_pointer(call->filter, filter);
1691         else
1692                 rcu_assign_pointer(file->filter, filter);
1693 }
1694
1695 static inline void event_clear_filter(struct ftrace_event_file *file)
1696 {
1697         struct ftrace_event_call *call = file->event_call;
1698
1699         if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
1700                 RCU_INIT_POINTER(call->filter, NULL);
1701         else
1702                 RCU_INIT_POINTER(file->filter, NULL);
1703 }
1704
1705 static inline void
1706 event_set_no_set_filter_flag(struct ftrace_event_file *file)
1707 {
1708         struct ftrace_event_call *call = file->event_call;
1709
1710         if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
1711                 call->flags |= TRACE_EVENT_FL_NO_SET_FILTER;
1712         else
1713                 file->flags |= FTRACE_EVENT_FL_NO_SET_FILTER;
1714 }
1715
1716 static inline void
1717 event_clear_no_set_filter_flag(struct ftrace_event_file *file)
1718 {
1719         struct ftrace_event_call *call = file->event_call;
1720
1721         if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER)
1722                 call->flags &= ~TRACE_EVENT_FL_NO_SET_FILTER;
1723         else
1724                 file->flags &= ~FTRACE_EVENT_FL_NO_SET_FILTER;
1725 }
1726
1727 static inline bool
1728 event_no_set_filter_flag(struct ftrace_event_file *file)
1729 {
1730         struct ftrace_event_call *call = file->event_call;
1731
1732         if (file->flags & FTRACE_EVENT_FL_NO_SET_FILTER)
1733                 return true;
1734
1735         if ((call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) &&
1736             (call->flags & TRACE_EVENT_FL_NO_SET_FILTER))
1737                 return true;
1738
1739         return false;
1740 }
1741
1742 struct filter_list {
1743         struct list_head        list;
1744         struct event_filter     *filter;
1745 };
1746
1747 static int replace_system_preds(struct ftrace_subsystem_dir *dir,
1748                                 struct trace_array *tr,
1749                                 struct filter_parse_state *ps,
1750                                 char *filter_string)
1751 {
1752         struct ftrace_event_file *file;
1753         struct filter_list *filter_item;
1754         struct filter_list *tmp;
1755         LIST_HEAD(filter_list);
1756         bool fail = true;
1757         int err;
1758
1759         list_for_each_entry(file, &tr->events, list) {
1760                 if (file->system != dir)
1761                         continue;
1762
1763                 /*
1764                  * Try to see if the filter can be applied
1765                  *  (filter arg is ignored on dry_run)
1766                  */
1767                 err = replace_preds(file->event_call, NULL, ps, true);
1768                 if (err)
1769                         event_set_no_set_filter_flag(file);
1770                 else
1771                         event_clear_no_set_filter_flag(file);
1772         }
1773
1774         list_for_each_entry(file, &tr->events, list) {
1775                 struct event_filter *filter;
1776
1777                 if (file->system != dir)
1778                         continue;
1779
1780                 if (event_no_set_filter_flag(file))
1781                         continue;
1782
1783                 filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL);
1784                 if (!filter_item)
1785                         goto fail_mem;
1786
1787                 list_add_tail(&filter_item->list, &filter_list);
1788
1789                 filter_item->filter = __alloc_filter();
1790                 if (!filter_item->filter)
1791                         goto fail_mem;
1792                 filter = filter_item->filter;
1793
1794                 /* Can only fail on no memory */
1795                 err = replace_filter_string(filter, filter_string);
1796                 if (err)
1797                         goto fail_mem;
1798
1799                 err = replace_preds(file->event_call, filter, ps, false);
1800                 if (err) {
1801                         filter_disable(file);
1802                         parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
1803                         append_filter_err(ps, filter);
1804                 } else
1805                         event_set_filtered_flag(file);
1806                 /*
1807                  * Regardless of if this returned an error, we still
1808                  * replace the filter for the call.
1809                  */
1810                 filter = event_filter(file);
1811                 event_set_filter(file, filter_item->filter);
1812                 filter_item->filter = filter;
1813
1814                 fail = false;
1815         }
1816
1817         if (fail)
1818                 goto fail;
1819
1820         /*
1821          * The calls can still be using the old filters.
1822          * Do a synchronize_sched() to ensure all calls are
1823          * done with them before we free them.
1824          */
1825         synchronize_sched();
1826         list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
1827                 __free_filter(filter_item->filter);
1828                 list_del(&filter_item->list);
1829                 kfree(filter_item);
1830         }
1831         return 0;
1832  fail:
1833         /* No call succeeded */
1834         list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
1835                 list_del(&filter_item->list);
1836                 kfree(filter_item);
1837         }
1838         parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
1839         return -EINVAL;
1840  fail_mem:
1841         /* If any call succeeded, we still need to sync */
1842         if (!fail)
1843                 synchronize_sched();
1844         list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
1845                 __free_filter(filter_item->filter);
1846                 list_del(&filter_item->list);
1847                 kfree(filter_item);
1848         }
1849         return -ENOMEM;
1850 }
1851
1852 static int create_filter_start(char *filter_str, bool set_str,
1853                                struct filter_parse_state **psp,
1854                                struct event_filter **filterp)
1855 {
1856         struct event_filter *filter;
1857         struct filter_parse_state *ps = NULL;
1858         int err = 0;
1859
1860         WARN_ON_ONCE(*psp || *filterp);
1861
1862         /* allocate everything, and if any fails, free all and fail */
1863         filter = __alloc_filter();
1864         if (filter && set_str)
1865                 err = replace_filter_string(filter, filter_str);
1866
1867         ps = kzalloc(sizeof(*ps), GFP_KERNEL);
1868
1869         if (!filter || !ps || err) {
1870                 kfree(ps);
1871                 __free_filter(filter);
1872                 return -ENOMEM;
1873         }
1874
1875         /* we're committed to creating a new filter */
1876         *filterp = filter;
1877         *psp = ps;
1878
1879         parse_init(ps, filter_ops, filter_str);
1880         err = filter_parse(ps);
1881         if (err && set_str)
1882                 append_filter_err(ps, filter);
1883         return err;
1884 }
1885
1886 static void create_filter_finish(struct filter_parse_state *ps)
1887 {
1888         if (ps) {
1889                 filter_opstack_clear(ps);
1890                 postfix_clear(ps);
1891                 kfree(ps);
1892         }
1893 }
1894
1895 /**
1896  * create_filter - create a filter for a ftrace_event_call
1897  * @call: ftrace_event_call to create a filter for
1898  * @filter_str: filter string
1899  * @set_str: remember @filter_str and enable detailed error in filter
1900  * @filterp: out param for created filter (always updated on return)
1901  *
1902  * Creates a filter for @call with @filter_str.  If @set_str is %true,
1903  * @filter_str is copied and recorded in the new filter.
1904  *
1905  * On success, returns 0 and *@filterp points to the new filter.  On
1906  * failure, returns -errno and *@filterp may point to %NULL or to a new
1907  * filter.  In the latter case, the returned filter contains error
1908  * information if @set_str is %true and the caller is responsible for
1909  * freeing it.
1910  */
1911 static int create_filter(struct ftrace_event_call *call,
1912                          char *filter_str, bool set_str,
1913                          struct event_filter **filterp)
1914 {
1915         struct event_filter *filter = NULL;
1916         struct filter_parse_state *ps = NULL;
1917         int err;
1918
1919         err = create_filter_start(filter_str, set_str, &ps, &filter);
1920         if (!err) {
1921                 err = replace_preds(call, filter, ps, false);
1922                 if (err && set_str)
1923                         append_filter_err(ps, filter);
1924         }
1925         create_filter_finish(ps);
1926
1927         *filterp = filter;
1928         return err;
1929 }
1930
1931 int create_event_filter(struct ftrace_event_call *call,
1932                         char *filter_str, bool set_str,
1933                         struct event_filter **filterp)
1934 {
1935         return create_filter(call, filter_str, set_str, filterp);
1936 }
1937
1938 /**
1939  * create_system_filter - create a filter for an event_subsystem
1940  * @system: event_subsystem to create a filter for
1941  * @filter_str: filter string
1942  * @filterp: out param for created filter (always updated on return)
1943  *
1944  * Identical to create_filter() except that it creates a subsystem filter
1945  * and always remembers @filter_str.
1946  */
1947 static int create_system_filter(struct ftrace_subsystem_dir *dir,
1948                                 struct trace_array *tr,
1949                                 char *filter_str, struct event_filter **filterp)
1950 {
1951         struct event_filter *filter = NULL;
1952         struct filter_parse_state *ps = NULL;
1953         int err;
1954
1955         err = create_filter_start(filter_str, true, &ps, &filter);
1956         if (!err) {
1957                 err = replace_system_preds(dir, tr, ps, filter_str);
1958                 if (!err) {
1959                         /* System filters just show a default message */
1960                         kfree(filter->filter_string);
1961                         filter->filter_string = NULL;
1962                 } else {
1963                         append_filter_err(ps, filter);
1964                 }
1965         }
1966         create_filter_finish(ps);
1967
1968         *filterp = filter;
1969         return err;
1970 }
1971
1972 /* caller must hold event_mutex */
1973 int apply_event_filter(struct ftrace_event_file *file, char *filter_string)
1974 {
1975         struct ftrace_event_call *call = file->event_call;
1976         struct event_filter *filter;
1977         int err;
1978
1979         if (!strcmp(strstrip(filter_string), "0")) {
1980                 filter_disable(file);
1981                 filter = event_filter(file);
1982
1983                 if (!filter)
1984                         return 0;
1985
1986                 event_clear_filter(file);
1987
1988                 /* Make sure the filter is not being used */
1989                 synchronize_sched();
1990                 __free_filter(filter);
1991
1992                 return 0;
1993         }
1994
1995         err = create_filter(call, filter_string, true, &filter);
1996
1997         /*
1998          * Always swap the call filter with the new filter
1999          * even if there was an error. If there was an error
2000          * in the filter, we disable the filter and show the error
2001          * string
2002          */
2003         if (filter) {
2004                 struct event_filter *tmp;
2005
2006                 tmp = event_filter(file);
2007                 if (!err)
2008                         event_set_filtered_flag(file);
2009                 else
2010                         filter_disable(file);
2011
2012                 event_set_filter(file, filter);
2013
2014                 if (tmp) {
2015                         /* Make sure the call is done with the filter */
2016                         synchronize_sched();
2017                         __free_filter(tmp);
2018                 }
2019         }
2020
2021         return err;
2022 }
2023
2024 int apply_subsystem_event_filter(struct ftrace_subsystem_dir *dir,
2025                                  char *filter_string)
2026 {
2027         struct event_subsystem *system = dir->subsystem;
2028         struct trace_array *tr = dir->tr;
2029         struct event_filter *filter;
2030         int err = 0;
2031
2032         mutex_lock(&event_mutex);
2033
2034         /* Make sure the system still has events */
2035         if (!dir->nr_events) {
2036                 err = -ENODEV;
2037                 goto out_unlock;
2038         }
2039
2040         if (!strcmp(strstrip(filter_string), "0")) {
2041                 filter_free_subsystem_preds(dir, tr);
2042                 remove_filter_string(system->filter);
2043                 filter = system->filter;
2044                 system->filter = NULL;
2045                 /* Ensure all filters are no longer used */
2046                 synchronize_sched();
2047                 filter_free_subsystem_filters(dir, tr);
2048                 __free_filter(filter);
2049                 goto out_unlock;
2050         }
2051
2052         err = create_system_filter(dir, tr, filter_string, &filter);
2053         if (filter) {
2054                 /*
2055                  * No event actually uses the system filter
2056                  * we can free it without synchronize_sched().
2057                  */
2058                 __free_filter(system->filter);
2059                 system->filter = filter;
2060         }
2061 out_unlock:
2062         mutex_unlock(&event_mutex);
2063
2064         return err;
2065 }
2066
2067 #ifdef CONFIG_PERF_EVENTS
2068
2069 void ftrace_profile_free_filter(struct perf_event *event)
2070 {
2071         struct event_filter *filter = event->filter;
2072
2073         event->filter = NULL;
2074         __free_filter(filter);
2075 }
2076
2077 struct function_filter_data {
2078         struct ftrace_ops *ops;
2079         int first_filter;
2080         int first_notrace;
2081 };
2082
2083 #ifdef CONFIG_FUNCTION_TRACER
2084 static char **
2085 ftrace_function_filter_re(char *buf, int len, int *count)
2086 {
2087         char *str, *sep, **re;
2088
2089         str = kstrndup(buf, len, GFP_KERNEL);
2090         if (!str)
2091                 return NULL;
2092
2093         /*
2094          * The argv_split function takes white space
2095          * as a separator, so convert ',' into spaces.
2096          */
2097         while ((sep = strchr(str, ',')))
2098                 *sep = ' ';
2099
2100         re = argv_split(GFP_KERNEL, str, count);
2101         kfree(str);
2102         return re;
2103 }
2104
2105 static int ftrace_function_set_regexp(struct ftrace_ops *ops, int filter,
2106                                       int reset, char *re, int len)
2107 {
2108         int ret;
2109
2110         if (filter)
2111                 ret = ftrace_set_filter(ops, re, len, reset);
2112         else
2113                 ret = ftrace_set_notrace(ops, re, len, reset);
2114
2115         return ret;
2116 }
2117
2118 static int __ftrace_function_set_filter(int filter, char *buf, int len,
2119                                         struct function_filter_data *data)
2120 {
2121         int i, re_cnt, ret = -EINVAL;
2122         int *reset;
2123         char **re;
2124
2125         reset = filter ? &data->first_filter : &data->first_notrace;
2126
2127         /*
2128          * The 'ip' field could have multiple filters set, separated
2129          * either by space or comma. We first cut the filter and apply
2130          * all pieces separatelly.
2131          */
2132         re = ftrace_function_filter_re(buf, len, &re_cnt);
2133         if (!re)
2134                 return -EINVAL;
2135
2136         for (i = 0; i < re_cnt; i++) {
2137                 ret = ftrace_function_set_regexp(data->ops, filter, *reset,
2138                                                  re[i], strlen(re[i]));
2139                 if (ret)
2140                         break;
2141
2142                 if (*reset)
2143                         *reset = 0;
2144         }
2145
2146         argv_free(re);
2147         return ret;
2148 }
2149
2150 static int ftrace_function_check_pred(struct filter_pred *pred, int leaf)
2151 {
2152         struct ftrace_event_field *field = pred->field;
2153
2154         if (leaf) {
2155                 /*
2156                  * Check the leaf predicate for function trace, verify:
2157                  *  - only '==' and '!=' is used
2158                  *  - the 'ip' field is used
2159                  */
2160                 if ((pred->op != OP_EQ) && (pred->op != OP_NE))
2161                         return -EINVAL;
2162
2163                 if (strcmp(field->name, "ip"))
2164                         return -EINVAL;
2165         } else {
2166                 /*
2167                  * Check the non leaf predicate for function trace, verify:
2168                  *  - only '||' is used
2169                 */
2170                 if (pred->op != OP_OR)
2171                         return -EINVAL;
2172         }
2173
2174         return 0;
2175 }
2176
2177 static int ftrace_function_set_filter_cb(enum move_type move,
2178                                          struct filter_pred *pred,
2179                                          int *err, void *data)
2180 {
2181         /* Checking the node is valid for function trace. */
2182         if ((move != MOVE_DOWN) ||
2183             (pred->left != FILTER_PRED_INVALID)) {
2184                 *err = ftrace_function_check_pred(pred, 0);
2185         } else {
2186                 *err = ftrace_function_check_pred(pred, 1);
2187                 if (*err)
2188                         return WALK_PRED_ABORT;
2189
2190                 *err = __ftrace_function_set_filter(pred->op == OP_EQ,
2191                                                     pred->regex.pattern,
2192                                                     pred->regex.len,
2193                                                     data);
2194         }
2195
2196         return (*err) ? WALK_PRED_ABORT : WALK_PRED_DEFAULT;
2197 }
2198
2199 static int ftrace_function_set_filter(struct perf_event *event,
2200                                       struct event_filter *filter)
2201 {
2202         struct function_filter_data data = {
2203                 .first_filter  = 1,
2204                 .first_notrace = 1,
2205                 .ops           = &event->ftrace_ops,
2206         };
2207
2208         return walk_pred_tree(filter->preds, filter->root,
2209                               ftrace_function_set_filter_cb, &data);
2210 }
2211 #else
2212 static int ftrace_function_set_filter(struct perf_event *event,
2213                                       struct event_filter *filter)
2214 {
2215         return -ENODEV;
2216 }
2217 #endif /* CONFIG_FUNCTION_TRACER */
2218
2219 int ftrace_profile_set_filter(struct perf_event *event, int event_id,
2220                               char *filter_str)
2221 {
2222         int err;
2223         struct event_filter *filter;
2224         struct ftrace_event_call *call;
2225
2226         mutex_lock(&event_mutex);
2227
2228         call = event->tp_event;
2229
2230         err = -EINVAL;
2231         if (!call)
2232                 goto out_unlock;
2233
2234         err = -EEXIST;
2235         if (event->filter)
2236                 goto out_unlock;
2237
2238         err = create_filter(call, filter_str, false, &filter);
2239         if (err)
2240                 goto free_filter;
2241
2242         if (ftrace_event_is_function(call))
2243                 err = ftrace_function_set_filter(event, filter);
2244         else
2245                 event->filter = filter;
2246
2247 free_filter:
2248         if (err || ftrace_event_is_function(call))
2249                 __free_filter(filter);
2250
2251 out_unlock:
2252         mutex_unlock(&event_mutex);
2253
2254         return err;
2255 }
2256
2257 #endif /* CONFIG_PERF_EVENTS */
2258
2259 #ifdef CONFIG_FTRACE_STARTUP_TEST
2260
2261 #include <linux/types.h>
2262 #include <linux/tracepoint.h>
2263
2264 #define CREATE_TRACE_POINTS
2265 #include "trace_events_filter_test.h"
2266
2267 #define DATA_REC(m, va, vb, vc, vd, ve, vf, vg, vh, nvisit) \
2268 { \
2269         .filter = FILTER, \
2270         .rec    = { .a = va, .b = vb, .c = vc, .d = vd, \
2271                     .e = ve, .f = vf, .g = vg, .h = vh }, \
2272         .match  = m, \
2273         .not_visited = nvisit, \
2274 }
2275 #define YES 1
2276 #define NO  0
2277
2278 static struct test_filter_data_t {
2279         char *filter;
2280         struct ftrace_raw_ftrace_test_filter rec;
2281         int match;
2282         char *not_visited;
2283 } test_filter_data[] = {
2284 #define FILTER "a == 1 && b == 1 && c == 1 && d == 1 && " \
2285                "e == 1 && f == 1 && g == 1 && h == 1"
2286         DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, ""),
2287         DATA_REC(NO,  0, 1, 1, 1, 1, 1, 1, 1, "bcdefgh"),
2288         DATA_REC(NO,  1, 1, 1, 1, 1, 1, 1, 0, ""),
2289 #undef FILTER
2290 #define FILTER "a == 1 || b == 1 || c == 1 || d == 1 || " \
2291                "e == 1 || f == 1 || g == 1 || h == 1"
2292         DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 0, ""),
2293         DATA_REC(YES, 0, 0, 0, 0, 0, 0, 0, 1, ""),
2294         DATA_REC(YES, 1, 0, 0, 0, 0, 0, 0, 0, "bcdefgh"),
2295 #undef FILTER
2296 #define FILTER "(a == 1 || b == 1) && (c == 1 || d == 1) && " \
2297                "(e == 1 || f == 1) && (g == 1 || h == 1)"
2298         DATA_REC(NO,  0, 0, 1, 1, 1, 1, 1, 1, "dfh"),
2299         DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2300         DATA_REC(YES, 1, 0, 1, 0, 0, 1, 0, 1, "bd"),
2301         DATA_REC(NO,  1, 0, 1, 0, 0, 1, 0, 0, "bd"),
2302 #undef FILTER
2303 #define FILTER "(a == 1 && b == 1) || (c == 1 && d == 1) || " \
2304                "(e == 1 && f == 1) || (g == 1 && h == 1)"
2305         DATA_REC(YES, 1, 0, 1, 1, 1, 1, 1, 1, "efgh"),
2306         DATA_REC(YES, 0, 0, 0, 0, 0, 0, 1, 1, ""),
2307         DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 1, ""),
2308 #undef FILTER
2309 #define FILTER "(a == 1 && b == 1) && (c == 1 && d == 1) && " \
2310                "(e == 1 && f == 1) || (g == 1 && h == 1)"
2311         DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 0, "gh"),
2312         DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 1, ""),
2313         DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, ""),
2314 #undef FILTER
2315 #define FILTER "((a == 1 || b == 1) || (c == 1 || d == 1) || " \
2316                "(e == 1 || f == 1)) && (g == 1 || h == 1)"
2317         DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 1, "bcdef"),
2318         DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 0, ""),
2319         DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, "h"),
2320 #undef FILTER
2321 #define FILTER "((((((((a == 1) && (b == 1)) || (c == 1)) && (d == 1)) || " \
2322                "(e == 1)) && (f == 1)) || (g == 1)) && (h == 1))"
2323         DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "ceg"),
2324         DATA_REC(NO,  0, 1, 0, 1, 0, 1, 0, 1, ""),
2325         DATA_REC(NO,  1, 0, 1, 0, 1, 0, 1, 0, ""),
2326 #undef FILTER
2327 #define FILTER "((((((((a == 1) || (b == 1)) && (c == 1)) || (d == 1)) && " \
2328                "(e == 1)) || (f == 1)) && (g == 1)) || (h == 1))"
2329         DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "bdfh"),
2330         DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2331         DATA_REC(YES, 1, 0, 1, 0, 1, 0, 1, 0, "bdfh"),
2332 };
2333
2334 #undef DATA_REC
2335 #undef FILTER
2336 #undef YES
2337 #undef NO
2338
2339 #define DATA_CNT (sizeof(test_filter_data)/sizeof(struct test_filter_data_t))
2340
2341 static int test_pred_visited;
2342
2343 static int test_pred_visited_fn(struct filter_pred *pred, void *event)
2344 {
2345         struct ftrace_event_field *field = pred->field;
2346
2347         test_pred_visited = 1;
2348         printk(KERN_INFO "\npred visited %s\n", field->name);
2349         return 1;
2350 }
2351
2352 static int test_walk_pred_cb(enum move_type move, struct filter_pred *pred,
2353                              int *err, void *data)
2354 {
2355         char *fields = data;
2356
2357         if ((move == MOVE_DOWN) &&
2358             (pred->left == FILTER_PRED_INVALID)) {
2359                 struct ftrace_event_field *field = pred->field;
2360
2361                 if (!field) {
2362                         WARN(1, "all leafs should have field defined");
2363                         return WALK_PRED_DEFAULT;
2364                 }
2365                 if (!strchr(fields, *field->name))
2366                         return WALK_PRED_DEFAULT;
2367
2368                 WARN_ON(!pred->fn);
2369                 pred->fn = test_pred_visited_fn;
2370         }
2371         return WALK_PRED_DEFAULT;
2372 }
2373
2374 static __init int ftrace_test_event_filter(void)
2375 {
2376         int i;
2377
2378         printk(KERN_INFO "Testing ftrace filter: ");
2379
2380         for (i = 0; i < DATA_CNT; i++) {
2381                 struct event_filter *filter = NULL;
2382                 struct test_filter_data_t *d = &test_filter_data[i];
2383                 int err;
2384
2385                 err = create_filter(&event_ftrace_test_filter, d->filter,
2386                                     false, &filter);
2387                 if (err) {
2388                         printk(KERN_INFO
2389                                "Failed to get filter for '%s', err %d\n",
2390                                d->filter, err);
2391                         __free_filter(filter);
2392                         break;
2393                 }
2394
2395                 /*
2396                  * The preemption disabling is not really needed for self
2397                  * tests, but the rcu dereference will complain without it.
2398                  */
2399                 preempt_disable();
2400                 if (*d->not_visited)
2401                         walk_pred_tree(filter->preds, filter->root,
2402                                        test_walk_pred_cb,
2403                                        d->not_visited);
2404
2405                 test_pred_visited = 0;
2406                 err = filter_match_preds(filter, &d->rec);
2407                 preempt_enable();
2408
2409                 __free_filter(filter);
2410
2411                 if (test_pred_visited) {
2412                         printk(KERN_INFO
2413                                "Failed, unwanted pred visited for filter %s\n",
2414                                d->filter);
2415                         break;
2416                 }
2417
2418                 if (err != d->match) {
2419                         printk(KERN_INFO
2420                                "Failed to match filter '%s', expected %d\n",
2421                                d->filter, d->match);
2422                         break;
2423                 }
2424         }
2425
2426         if (i == DATA_CNT)
2427                 printk(KERN_CONT "OK\n");
2428
2429         return 0;
2430 }
2431
2432 late_initcall(ftrace_test_event_filter);
2433
2434 #endif /* CONFIG_FTRACE_STARTUP_TEST */