linux/kernel/trace/trace_events_filter.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * trace_events_filter - generic event filtering
   4 *
   5 * Copyright (C) 2009 Tom Zanussi <tzanussi@gmail.com>
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/ctype.h>
  10#include <linux/mutex.h>
  11#include <linux/perf_event.h>
  12#include <linux/slab.h>
  13
  14#include "trace.h"
  15#include "trace_output.h"
  16
  17#define DEFAULT_SYS_FILTER_MESSAGE                                      \
  18        "### global filter ###\n"                                       \
  19        "# Use this to set filters for multiple events.\n"              \
  20        "# Only events with the given fields will be affected.\n"       \
  21        "# If no events are modified, an error message will be displayed here"
  22
  23/* Due to token parsing '<=' must be before '<' and '>=' must be before '>' */
  24#define OPS                                     \
  25        C( OP_GLOB,     "~"  ),                 \
  26        C( OP_NE,       "!=" ),                 \
  27        C( OP_EQ,       "==" ),                 \
  28        C( OP_LE,       "<=" ),                 \
  29        C( OP_LT,       "<"  ),                 \
  30        C( OP_GE,       ">=" ),                 \
  31        C( OP_GT,       ">"  ),                 \
  32        C( OP_BAND,     "&"  ),                 \
  33        C( OP_MAX,      NULL )
  34
  35#undef C
  36#define C(a, b) a
  37
  38enum filter_op_ids { OPS };
  39
  40#undef C
  41#define C(a, b) b
  42
  43static const char * ops[] = { OPS };
  44
  45/*
  46 * pred functions are OP_LE, OP_LT, OP_GE, OP_GT, and OP_BAND
  47 * pred_funcs_##type below must match the order of them above.
  48 */
  49#define PRED_FUNC_START                 OP_LE
  50#define PRED_FUNC_MAX                   (OP_BAND - PRED_FUNC_START)
  51
  52#define ERRORS                                                          \
  53        C(NONE,                 "No error"),                            \
  54        C(INVALID_OP,           "Invalid operator"),                    \
  55        C(TOO_MANY_OPEN,        "Too many '('"),                        \
  56        C(TOO_MANY_CLOSE,       "Too few '('"),                         \
  57        C(MISSING_QUOTE,        "Missing matching quote"),              \
  58        C(OPERAND_TOO_LONG,     "Operand too long"),                    \
  59        C(EXPECT_STRING,        "Expecting string field"),              \
  60        C(EXPECT_DIGIT,         "Expecting numeric field"),             \
  61        C(ILLEGAL_FIELD_OP,     "Illegal operation for field type"),    \
  62        C(FIELD_NOT_FOUND,      "Field not found"),                     \
  63        C(ILLEGAL_INTVAL,       "Illegal integer value"),               \
  64        C(BAD_SUBSYS_FILTER,    "Couldn't find or set field in one of a subsystem's events"), \
  65        C(TOO_MANY_PREDS,       "Too many terms in predicate expression"), \
  66        C(INVALID_FILTER,       "Meaningless filter expression"),       \
  67        C(IP_FIELD_ONLY,        "Only 'ip' field is supported for function trace"), \
  68        C(INVALID_VALUE,        "Invalid value (did you forget quotes)?"), \
  69        C(ERRNO,                "Error"),                               \
  70        C(NO_FILTER,            "No filter found")
  71
  72#undef C
  73#define C(a, b)         FILT_ERR_##a
  74
  75enum { ERRORS };
  76
  77#undef C
  78#define C(a, b)         b
  79
  80static const char *err_text[] = { ERRORS };
  81
  82/* Called after a '!' character but "!=" and "!~" are not "not"s */
  83static bool is_not(const char *str)
  84{
  85        switch (str[1]) {
  86        case '=':
  87        case '~':
  88                return false;
  89        }
  90        return true;
  91}
  92
  93/**
  94 * prog_entry - a singe entry in the filter program
  95 * @target:          Index to jump to on a branch (actually one minus the index)
  96 * @when_to_branch:  The value of the result of the predicate to do a branch
  97 * @pred:            The predicate to execute.
  98 */
  99struct prog_entry {
 100        int                     target;
 101        int                     when_to_branch;
 102        struct filter_pred      *pred;
 103};
 104
 105/**
 106 * update_preds- assign a program entry a label target
 107 * @prog: The program array
 108 * @N: The index of the current entry in @prog
 109 * @when_to_branch: What to assign a program entry for its branch condition
 110 *
 111 * The program entry at @N has a target that points to the index of a program
 112 * entry that can have its target and when_to_branch fields updated.
 113 * Update the current program entry denoted by index @N target field to be
 114 * that of the updated entry. This will denote the entry to update if
 115 * we are processing an "||" after an "&&"
 116 */
 117static void update_preds(struct prog_entry *prog, int N, int invert)
 118{
 119        int t, s;
 120
 121        t = prog[N].target;
 122        s = prog[t].target;
 123        prog[t].when_to_branch = invert;
 124        prog[t].target = N;
 125        prog[N].target = s;
 126}
 127
 128struct filter_parse_error {
 129        int lasterr;
 130        int lasterr_pos;
 131};
 132
 133static void parse_error(struct filter_parse_error *pe, int err, int pos)
 134{
 135        pe->lasterr = err;
 136        pe->lasterr_pos = pos;
 137}
 138
 139typedef int (*parse_pred_fn)(const char *str, void *data, int pos,
 140                             struct filter_parse_error *pe,
 141                             struct filter_pred **pred);
 142
 143enum {
 144        INVERT          = 1,
 145        PROCESS_AND     = 2,
 146        PROCESS_OR      = 4,
 147};
 148
 149/*
 150 * Without going into a formal proof, this explains the method that is used in
 151 * parsing the logical expressions.
 152 *
 153 * For example, if we have: "a && !(!b || (c && g)) || d || e && !f"
 154 * The first pass will convert it into the following program:
 155 *
 156 * n1: r=a;       l1: if (!r) goto l4;
 157 * n2: r=b;       l2: if (!r) goto l4;
 158 * n3: r=c; r=!r; l3: if (r) goto l4;
 159 * n4: r=g; r=!r; l4: if (r) goto l5;
 160 * n5: r=d;       l5: if (r) goto T
 161 * n6: r=e;       l6: if (!r) goto l7;
 162 * n7: r=f; r=!r; l7: if (!r) goto F
 163 * T: return TRUE
 164 * F: return FALSE
 165 *
 166 * To do this, we use a data structure to represent each of the above
 167 * predicate and conditions that has:
 168 *
 169 *  predicate, when_to_branch, invert, target
 170 *
 171 * The "predicate" will hold the function to determine the result "r".
 172 * The "when_to_branch" denotes what "r" should be if a branch is to be taken
 173 * "&&" would contain "!r" or (0) and "||" would contain "r" or (1).
 174 * The "invert" holds whether the value should be reversed before testing.
 175 * The "target" contains the label "l#" to jump to.
 176 *
 177 * A stack is created to hold values when parentheses are used.
 178 *
 179 * To simplify the logic, the labels will start at 0 and not 1.
 180 *
 181 * The possible invert values are 1 and 0. The number of "!"s that are in scope
 182 * before the predicate determines the invert value, if the number is odd then
 183 * the invert value is 1 and 0 otherwise. This means the invert value only
 184 * needs to be toggled when a new "!" is introduced compared to what is stored
 185 * on the stack, where parentheses were used.
 186 *
 187 * The top of the stack and "invert" are initialized to zero.
 188 *
 189 * ** FIRST PASS **
 190 *
 191 * #1 A loop through all the tokens is done:
 192 *
 193 * #2 If the token is an "(", the stack is push, and the current stack value
 194 *    gets the current invert value, and the loop continues to the next token.
 195 *    The top of the stack saves the "invert" value to keep track of what
 196 *    the current inversion is. As "!(a && !b || c)" would require all
 197 *    predicates being affected separately by the "!" before the parentheses.
 198 *    And that would end up being equivalent to "(!a || b) && !c"
 199 *
 200 * #3 If the token is an "!", the current "invert" value gets inverted, and
 201 *    the loop continues. Note, if the next token is a predicate, then
 202 *    this "invert" value is only valid for the current program entry,
 203 *    and does not affect other predicates later on.
 204 *
 205 * The only other acceptable token is the predicate string.
 206 *
 207 * #4 A new entry into the program is added saving: the predicate and the
 208 *    current value of "invert". The target is currently assigned to the
 209 *    previous program index (this will not be its final value).
 210 *
 211 * #5 We now enter another loop and look at the next token. The only valid
 212 *    tokens are ")", "&&", "||" or end of the input string "\0".
 213 *
 214 * #6 The invert variable is reset to the current value saved on the top of
 215 *    the stack.
 216 *
 217 * #7 The top of the stack holds not only the current invert value, but also
 218 *    if a "&&" or "||" needs to be processed. Note, the "&&" takes higher
 219 *    precedence than "||". That is "a && b || c && d" is equivalent to
 220 *    "(a && b) || (c && d)". Thus the first thing to do is to see if "&&" needs
 221 *    to be processed. This is the case if an "&&" was the last token. If it was
 222 *    then we call update_preds(). This takes the program, the current index in
 223 *    the program, and the current value of "invert".  More will be described
 224 *    below about this function.
 225 *
 226 * #8 If the next token is "&&" then we set a flag in the top of the stack
 227 *    that denotes that "&&" needs to be processed, break out of this loop
 228 *    and continue with the outer loop.
 229 *
 230 * #9 Otherwise, if a "||" needs to be processed then update_preds() is called.
 231 *    This is called with the program, the current index in the program, but
 232 *    this time with an inverted value of "invert" (that is !invert). This is
 233 *    because the value taken will become the "when_to_branch" value of the
 234 *    program.
 235 *    Note, this is called when the next token is not an "&&". As stated before,
 236 *    "&&" takes higher precedence, and "||" should not be processed yet if the
 237 *    next logical operation is "&&".
 238 *
 239 * #10 If the next token is "||" then we set a flag in the top of the stack
 240 *     that denotes that "||" needs to be processed, break out of this loop
 241 *     and continue with the outer loop.
 242 *
 243 * #11 If this is the end of the input string "\0" then we break out of both
 244 *     loops.
 245 *
 246 * #12 Otherwise, the next token is ")", where we pop the stack and continue
 247 *     this inner loop.
 248 *
 249 * Now to discuss the update_pred() function, as that is key to the setting up
 250 * of the program. Remember the "target" of the program is initialized to the
 251 * previous index and not the "l" label. The target holds the index into the
 252 * program that gets affected by the operand. Thus if we have something like
 253 *  "a || b && c", when we process "a" the target will be "-1" (undefined).
 254 * When we process "b", its target is "0", which is the index of "a", as that's
 255 * the predicate that is affected by "||". But because the next token after "b"
 256 * is "&&" we don't call update_preds(). Instead continue to "c". As the
 257 * next token after "c" is not "&&" but the end of input, we first process the
 258 * "&&" by calling update_preds() for the "&&" then we process the "||" by
 259 * callin updates_preds() with the values for processing "||".
 260 *
 261 * What does that mean? What update_preds() does is to first save the "target"
 262 * of the program entry indexed by the current program entry's "target"
 263 * (remember the "target" is initialized to previous program entry), and then
 264 * sets that "target" to the current index which represents the label "l#".
 265 * That entry's "when_to_branch" is set to the value passed in (the "invert"
 266 * or "!invert"). Then it sets the current program entry's target to the saved
 267 * "target" value (the old value of the program that had its "target" updated
 268 * to the label).
 269 *
 270 * Looking back at "a || b && c", we have the following steps:
 271 *  "a"  - prog[0] = { "a", X, -1 } // pred, when_to_branch, target
 272 *  "||" - flag that we need to process "||"; continue outer loop
 273 *  "b"  - prog[1] = { "b", X, 0 }
 274 *  "&&" - flag that we need to process "&&"; continue outer loop
 275 * (Notice we did not process "||")
 276 *  "c"  - prog[2] = { "c", X, 1 }
 277 *  update_preds(prog, 2, 0); // invert = 0 as we are processing "&&"
 278 *    t = prog[2].target; // t = 1
 279 *    s = prog[t].target; // s = 0
 280 *    prog[t].target = 2; // Set target to "l2"
 281 *    prog[t].when_to_branch = 0;
 282 *    prog[2].target = s;
 283 * update_preds(prog, 2, 1); // invert = 1 as we are now processing "||"
 284 *    t = prog[2].target; // t = 0
 285 *    s = prog[t].target; // s = -1
 286 *    prog[t].target = 2; // Set target to "l2"
 287 *    prog[t].when_to_branch = 1;
 288 *    prog[2].target = s;
 289 *
 290 * #13 Which brings us to the final step of the first pass, which is to set
 291 *     the last program entry's when_to_branch and target, which will be
 292 *     when_to_branch = 0; target = N; ( the label after the program entry after
 293 *     the last program entry processed above).
 294 *
 295 * If we denote "TRUE" to be the entry after the last program entry processed,
 296 * and "FALSE" the program entry after that, we are now done with the first
 297 * pass.
 298 *
 299 * Making the above "a || b && c" have a progam of:
 300 *  prog[0] = { "a", 1, 2 }
 301 *  prog[1] = { "b", 0, 2 }
 302 *  prog[2] = { "c", 0, 3 }
 303 *
 304 * Which translates into:
 305 * n0: r = a; l0: if (r) goto l2;
 306 * n1: r = b; l1: if (!r) goto l2;
 307 * n2: r = c; l2: if (!r) goto l3;  // Which is the same as "goto F;"
 308 * T: return TRUE; l3:
 309 * F: return FALSE
 310 *
 311 * Although, after the first pass, the program is correct, it is
 312 * inefficient. The simple sample of "a || b && c" could be easily been
 313 * converted into:
 314 * n0: r = a; if (r) goto T
 315 * n1: r = b; if (!r) goto F
 316 * n2: r = c; if (!r) goto F
 317 * T: return TRUE;
 318 * F: return FALSE;
 319 *
 320 * The First Pass is over the input string. The next too passes are over
 321 * the program itself.
 322 *
 323 * ** SECOND PASS **
 324 *
 325 * Which brings us to the second pass. If a jump to a label has the
 326 * same condition as that label, it can instead jump to its target.
 327 * The original example of "a && !(!b || (c && g)) || d || e && !f"
 328 * where the first pass gives us:
 329 *
 330 * n1: r=a;       l1: if (!r) goto l4;
 331 * n2: r=b;       l2: if (!r) goto l4;
 332 * n3: r=c; r=!r; l3: if (r) goto l4;
 333 * n4: r=g; r=!r; l4: if (r) goto l5;
 334 * n5: r=d;       l5: if (r) goto T
 335 * n6: r=e;       l6: if (!r) goto l7;
 336 * n7: r=f; r=!r; l7: if (!r) goto F:
 337 * T: return TRUE;
 338 * F: return FALSE
 339 *
 340 * We can see that "l3: if (r) goto l4;" and at l4, we have "if (r) goto l5;".
 341 * And "l5: if (r) goto T", we could optimize this by converting l3 and l4
 342 * to go directly to T. To accomplish this, we start from the last
 343 * entry in the program and work our way back. If the target of the entry
 344 * has the same "when_to_branch" then we could use that entry's target.
 345 * Doing this, the above would end up as:
 346 *
 347 * n1: r=a;       l1: if (!r) goto l4;
 348 * n2: r=b;       l2: if (!r) goto l4;
 349 * n3: r=c; r=!r; l3: if (r) goto T;
 350 * n4: r=g; r=!r; l4: if (r) goto T;
 351 * n5: r=d;       l5: if (r) goto T;
 352 * n6: r=e;       l6: if (!r) goto F;
 353 * n7: r=f; r=!r; l7: if (!r) goto F;
 354 * T: return TRUE
 355 * F: return FALSE
 356 *
 357 * In that same pass, if the "when_to_branch" doesn't match, we can simply
 358 * go to the program entry after the label. That is, "l2: if (!r) goto l4;"
 359 * where "l4: if (r) goto T;", then we can convert l2 to be:
 360 * "l2: if (!r) goto n5;".
 361 *
 362 * This will have the second pass give us:
 363 * n1: r=a;       l1: if (!r) goto n5;
 364 * n2: r=b;       l2: if (!r) goto n5;
 365 * n3: r=c; r=!r; l3: if (r) goto T;
 366 * n4: r=g; r=!r; l4: if (r) goto T;
 367 * n5: r=d;       l5: if (r) goto T
 368 * n6: r=e;       l6: if (!r) goto F;
 369 * n7: r=f; r=!r; l7: if (!r) goto F
 370 * T: return TRUE
 371 * F: return FALSE
 372 *
 373 * Notice, all the "l#" labels are no longer used, and they can now
 374 * be discarded.
 375 *
 376 * ** THIRD PASS **
 377 *
 378 * For the third pass we deal with the inverts. As they simply just
 379 * make the "when_to_branch" get inverted, a simple loop over the
 380 * program to that does: "when_to_branch ^= invert;" will do the
 381 * job, leaving us with:
 382 * n1: r=a; if (!r) goto n5;
 383 * n2: r=b; if (!r) goto n5;
 384 * n3: r=c: if (!r) goto T;
 385 * n4: r=g; if (!r) goto T;
 386 * n5: r=d; if (r) goto T
 387 * n6: r=e; if (!r) goto F;
 388 * n7: r=f; if (r) goto F
 389 * T: return TRUE
 390 * F: return FALSE
 391 *
 392 * As "r = a; if (!r) goto n5;" is obviously the same as
 393 * "if (!a) goto n5;" without doing anything we can interperate the
 394 * program as:
 395 * n1: if (!a) goto n5;
 396 * n2: if (!b) goto n5;
 397 * n3: if (!c) goto T;
 398 * n4: if (!g) goto T;
 399 * n5: if (d) goto T
 400 * n6: if (!e) goto F;
 401 * n7: if (f) goto F
 402 * T: return TRUE
 403 * F: return FALSE
 404 *
 405 * Since the inverts are discarded at the end, there's no reason to store
 406 * them in the program array (and waste memory). A separate array to hold
 407 * the inverts is used and freed at the end.
 408 */
 409static struct prog_entry *
 410predicate_parse(const char *str, int nr_parens, int nr_preds,
 411                parse_pred_fn parse_pred, void *data,
 412                struct filter_parse_error *pe)
 413{
 414        struct prog_entry *prog_stack;
 415        struct prog_entry *prog;
 416        const char *ptr = str;
 417        char *inverts = NULL;
 418        int *op_stack;
 419        int *top;
 420        int invert = 0;
 421        int ret = -ENOMEM;
 422        int len;
 423        int N = 0;
 424        int i;
 425
 426        nr_preds += 2; /* For TRUE and FALSE */
 427
 428        op_stack = kmalloc_array(nr_parens, sizeof(*op_stack), GFP_KERNEL);
 429        if (!op_stack)
 430                return ERR_PTR(-ENOMEM);
 431        prog_stack = kcalloc(nr_preds, sizeof(*prog_stack), GFP_KERNEL);
 432        if (!prog_stack) {
 433                parse_error(pe, -ENOMEM, 0);
 434                goto out_free;
 435        }
 436        inverts = kmalloc_array(nr_preds, sizeof(*inverts), GFP_KERNEL);
 437        if (!inverts) {
 438                parse_error(pe, -ENOMEM, 0);
 439                goto out_free;
 440        }
 441
 442        top = op_stack;
 443        prog = prog_stack;
 444        *top = 0;
 445
 446        /* First pass */
 447        while (*ptr) {                                          /* #1 */
 448                const char *next = ptr++;
 449
 450                if (isspace(*next))
 451                        continue;
 452
 453                switch (*next) {
 454                case '(':                                       /* #2 */
 455                        if (top - op_stack > nr_parens) {
 456                                ret = -EINVAL;
 457                                goto out_free;
 458                        }
 459                        *(++top) = invert;
 460                        continue;
 461                case '!':                                       /* #3 */
 462                        if (!is_not(next))
 463                                break;
 464                        invert = !invert;
 465                        continue;
 466                }
 467
 468                if (N >= nr_preds) {
 469                        parse_error(pe, FILT_ERR_TOO_MANY_PREDS, next - str);
 470                        goto out_free;
 471                }
 472
 473                inverts[N] = invert;                            /* #4 */
 474                prog[N].target = N-1;
 475
 476                len = parse_pred(next, data, ptr - str, pe, &prog[N].pred);
 477                if (len < 0) {
 478                        ret = len;
 479                        goto out_free;
 480                }
 481                ptr = next + len;
 482
 483                N++;
 484
 485                ret = -1;
 486                while (1) {                                     /* #5 */
 487                        next = ptr++;
 488                        if (isspace(*next))
 489                                continue;
 490
 491                        switch (*next) {
 492                        case ')':
 493                        case '\0':
 494                                break;
 495                        case '&':
 496                        case '|':
 497                                /* accepting only "&&" or "||" */
 498                                if (next[1] == next[0]) {
 499                                        ptr++;
 500                                        break;
 501                                }
 502                                /* fall through */
 503                        default:
 504                                parse_error(pe, FILT_ERR_TOO_MANY_PREDS,
 505                                            next - str);
 506                                goto out_free;
 507                        }
 508
 509                        invert = *top & INVERT;
 510
 511                        if (*top & PROCESS_AND) {               /* #7 */
 512                                update_preds(prog, N - 1, invert);
 513                                *top &= ~PROCESS_AND;
 514                        }
 515                        if (*next == '&') {                     /* #8 */
 516                                *top |= PROCESS_AND;
 517                                break;
 518                        }
 519                        if (*top & PROCESS_OR) {                /* #9 */
 520                                update_preds(prog, N - 1, !invert);
 521                                *top &= ~PROCESS_OR;
 522                        }
 523                        if (*next == '|') {                     /* #10 */
 524                                *top |= PROCESS_OR;
 525                                break;
 526                        }
 527                        if (!*next)                             /* #11 */
 528                                goto out;
 529
 530                        if (top == op_stack) {
 531                                ret = -1;
 532                                /* Too few '(' */
 533                                parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, ptr - str);
 534                                goto out_free;
 535                        }
 536                        top--;                                  /* #12 */
 537                }
 538        }
 539 out:
 540        if (top != op_stack) {
 541                /* Too many '(' */
 542                parse_error(pe, FILT_ERR_TOO_MANY_OPEN, ptr - str);
 543                goto out_free;
 544        }
 545
 546        if (!N) {
 547                /* No program? */
 548                ret = -EINVAL;
 549                parse_error(pe, FILT_ERR_NO_FILTER, ptr - str);
 550                goto out_free;
 551        }
 552
 553        prog[N].pred = NULL;                                    /* #13 */
 554        prog[N].target = 1;             /* TRUE */
 555        prog[N+1].pred = NULL;
 556        prog[N+1].target = 0;           /* FALSE */
 557        prog[N-1].target = N;
 558        prog[N-1].when_to_branch = false;
 559
 560        /* Second Pass */
 561        for (i = N-1 ; i--; ) {
 562                int target = prog[i].target;
 563                if (prog[i].when_to_branch == prog[target].when_to_branch)
 564                        prog[i].target = prog[target].target;
 565        }
 566
 567        /* Third Pass */
 568        for (i = 0; i < N; i++) {
 569                invert = inverts[i] ^ prog[i].when_to_branch;
 570                prog[i].when_to_branch = invert;
 571                /* Make sure the program always moves forward */
 572                if (WARN_ON(prog[i].target <= i)) {
 573                        ret = -EINVAL;
 574                        goto out_free;
 575                }
 576        }
 577
 578        kfree(op_stack);
 579        kfree(inverts);
 580        return prog;
 581out_free:
 582        kfree(op_stack);
 583        kfree(inverts);
 584        if (prog_stack) {
 585                for (i = 0; prog_stack[i].pred; i++)
 586                        kfree(prog_stack[i].pred);
 587                kfree(prog_stack);
 588        }
 589        return ERR_PTR(ret);
 590}
 591
 592#define DEFINE_COMPARISON_PRED(type)                                    \
 593static int filter_pred_LT_##type(struct filter_pred *pred, void *event) \
 594{                                                                       \
 595        type *addr = (type *)(event + pred->offset);                    \
 596        type val = (type)pred->val;                                     \
 597        return *addr < val;                                             \
 598}                                                                       \
 599static int filter_pred_LE_##type(struct filter_pred *pred, void *event) \
 600{                                                                       \
 601        type *addr = (type *)(event + pred->offset);                    \
 602        type val = (type)pred->val;                                     \
 603        return *addr <= val;                                            \
 604}                                                                       \
 605static int filter_pred_GT_##type(struct filter_pred *pred, void *event) \
 606{                                                                       \
 607        type *addr = (type *)(event + pred->offset);                    \
 608        type val = (type)pred->val;                                     \
 609        return *addr > val;                                     \
 610}                                                                       \
 611static int filter_pred_GE_##type(struct filter_pred *pred, void *event) \
 612{                                                                       \
 613        type *addr = (type *)(event + pred->offset);                    \
 614        type val = (type)pred->val;                                     \
 615        return *addr >= val;                                            \
 616}                                                                       \
 617static int filter_pred_BAND_##type(struct filter_pred *pred, void *event) \
 618{                                                                       \
 619        type *addr = (type *)(event + pred->offset);                    \
 620        type val = (type)pred->val;                                     \
 621        return !!(*addr & val);                                         \
 622}                                                                       \
 623static const filter_pred_fn_t pred_funcs_##type[] = {                   \
 624        filter_pred_LE_##type,                                          \
 625        filter_pred_LT_##type,                                          \
 626        filter_pred_GE_##type,                                          \
 627        filter_pred_GT_##type,                                          \
 628        filter_pred_BAND_##type,                                        \
 629};
 630
 631#define DEFINE_EQUALITY_PRED(size)                                      \
 632static int filter_pred_##size(struct filter_pred *pred, void *event)    \
 633{                                                                       \
 634        u##size *addr = (u##size *)(event + pred->offset);              \
 635        u##size val = (u##size)pred->val;                               \
 636        int match;                                                      \
 637                                                                        \
 638        match = (val == *addr) ^ pred->not;                             \
 639                                                                        \
 640        return match;                                                   \
 641}
 642
 643DEFINE_COMPARISON_PRED(s64);
 644DEFINE_COMPARISON_PRED(u64);
 645DEFINE_COMPARISON_PRED(s32);
 646DEFINE_COMPARISON_PRED(u32);
 647DEFINE_COMPARISON_PRED(s16);
 648DEFINE_COMPARISON_PRED(u16);
 649DEFINE_COMPARISON_PRED(s8);
 650DEFINE_COMPARISON_PRED(u8);
 651
 652DEFINE_EQUALITY_PRED(64);
 653DEFINE_EQUALITY_PRED(32);
 654DEFINE_EQUALITY_PRED(16);
 655DEFINE_EQUALITY_PRED(8);
 656
 657/* Filter predicate for fixed sized arrays of characters */
 658static int filter_pred_string(struct filter_pred *pred, void *event)
 659{
 660        char *addr = (char *)(event + pred->offset);
 661        int cmp, match;
 662
 663        cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len);
 664
 665        match = cmp ^ pred->not;
 666
 667        return match;
 668}
 669
 670/* Filter predicate for char * pointers */
 671static int filter_pred_pchar(struct filter_pred *pred, void *event)
 672{
 673        char **addr = (char **)(event + pred->offset);
 674        int cmp, match;
 675        int len = strlen(*addr) + 1;    /* including tailing '\0' */
 676
 677        cmp = pred->regex.match(*addr, &pred->regex, len);
 678
 679        match = cmp ^ pred->not;
 680
 681        return match;
 682}
 683
 684/*
 685 * Filter predicate for dynamic sized arrays of characters.
 686 * These are implemented through a list of strings at the end
 687 * of the entry.
 688 * Also each of these strings have a field in the entry which
 689 * contains its offset from the beginning of the entry.
 690 * We have then first to get this field, dereference it
 691 * and add it to the address of the entry, and at last we have
 692 * the address of the string.
 693 */
 694static int filter_pred_strloc(struct filter_pred *pred, void *event)
 695{
 696        u32 str_item = *(u32 *)(event + pred->offset);
 697        int str_loc = str_item & 0xffff;
 698        int str_len = str_item >> 16;
 699        char *addr = (char *)(event + str_loc);
 700        int cmp, match;
 701
 702        cmp = pred->regex.match(addr, &pred->regex, str_len);
 703
 704        match = cmp ^ pred->not;
 705
 706        return match;
 707}
 708
 709/* Filter predicate for CPUs. */
 710static int filter_pred_cpu(struct filter_pred *pred, void *event)
 711{
 712        int cpu, cmp;
 713
 714        cpu = raw_smp_processor_id();
 715        cmp = pred->val;
 716
 717        switch (pred->op) {
 718        case OP_EQ:
 719                return cpu == cmp;
 720        case OP_NE:
 721                return cpu != cmp;
 722        case OP_LT:
 723                return cpu < cmp;
 724        case OP_LE:
 725                return cpu <= cmp;
 726        case OP_GT:
 727                return cpu > cmp;
 728        case OP_GE:
 729                return cpu >= cmp;
 730        default:
 731                return 0;
 732        }
 733}
 734
 735/* Filter predicate for COMM. */
 736static int filter_pred_comm(struct filter_pred *pred, void *event)
 737{
 738        int cmp;
 739
 740        cmp = pred->regex.match(current->comm, &pred->regex,
 741                                TASK_COMM_LEN);
 742        return cmp ^ pred->not;
 743}
 744
 745static int filter_pred_none(struct filter_pred *pred, void *event)
 746{
 747        return 0;
 748}
 749
 750/*
 751 * regex_match_foo - Basic regex callbacks
 752 *
 753 * @str: the string to be searched
 754 * @r:   the regex structure containing the pattern string
 755 * @len: the length of the string to be searched (including '\0')
 756 *
 757 * Note:
 758 * - @str might not be NULL-terminated if it's of type DYN_STRING
 759 *   or STATIC_STRING, unless @len is zero.
 760 */
 761
 762static int regex_match_full(char *str, struct regex *r, int len)
 763{
 764        /* len of zero means str is dynamic and ends with '\0' */
 765        if (!len)
 766                return strcmp(str, r->pattern) == 0;
 767
 768        return strncmp(str, r->pattern, len) == 0;
 769}
 770
 771static int regex_match_front(char *str, struct regex *r, int len)
 772{
 773        if (len && len < r->len)
 774                return 0;
 775
 776        return strncmp(str, r->pattern, r->len) == 0;
 777}
 778
 779static int regex_match_middle(char *str, struct regex *r, int len)
 780{
 781        if (!len)
 782                return strstr(str, r->pattern) != NULL;
 783
 784        return strnstr(str, r->pattern, len) != NULL;
 785}
 786
 787static int regex_match_end(char *str, struct regex *r, int len)
 788{
 789        int strlen = len - 1;
 790
 791        if (strlen >= r->len &&
 792            memcmp(str + strlen - r->len, r->pattern, r->len) == 0)
 793                return 1;
 794        return 0;
 795}
 796
 797static int regex_match_glob(char *str, struct regex *r, int len __maybe_unused)
 798{
 799        if (glob_match(r->pattern, str))
 800                return 1;
 801        return 0;
 802}
 803
 804/**
 805 * filter_parse_regex - parse a basic regex
 806 * @buff:   the raw regex
 807 * @len:    length of the regex
 808 * @search: will point to the beginning of the string to compare
 809 * @not:    tell whether the match will have to be inverted
 810 *
 811 * This passes in a buffer containing a regex and this function will
 812 * set search to point to the search part of the buffer and
 813 * return the type of search it is (see enum above).
 814 * This does modify buff.
 815 *
 816 * Returns enum type.
 817 *  search returns the pointer to use for comparison.
 818 *  not returns 1 if buff started with a '!'
 819 *     0 otherwise.
 820 */
 821enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not)
 822{
 823        int type = MATCH_FULL;
 824        int i;
 825
 826        if (buff[0] == '!') {
 827                *not = 1;
 828                buff++;
 829                len--;
 830        } else
 831                *not = 0;
 832
 833        *search = buff;
 834
 835        if (isdigit(buff[0]))
 836                return MATCH_INDEX;
 837
 838        for (i = 0; i < len; i++) {
 839                if (buff[i] == '*') {
 840                        if (!i) {
 841                                type = MATCH_END_ONLY;
 842                        } else if (i == len - 1) {
 843                                if (type == MATCH_END_ONLY)
 844                                        type = MATCH_MIDDLE_ONLY;
 845                                else
 846                                        type = MATCH_FRONT_ONLY;
 847                                buff[i] = 0;
 848                                break;
 849                        } else {        /* pattern continues, use full glob */
 850                                return MATCH_GLOB;
 851                        }
 852                } else if (strchr("[?\\", buff[i])) {
 853                        return MATCH_GLOB;
 854                }
 855        }
 856        if (buff[0] == '*')
 857                *search = buff + 1;
 858
 859        return type;
 860}
 861
 862static void filter_build_regex(struct filter_pred *pred)
 863{
 864        struct regex *r = &pred->regex;
 865        char *search;
 866        enum regex_type type = MATCH_FULL;
 867
 868        if (pred->op == OP_GLOB) {
 869                type = filter_parse_regex(r->pattern, r->len, &search, &pred->not);
 870                r->len = strlen(search);
 871                memmove(r->pattern, search, r->len+1);
 872        }
 873
 874        switch (type) {
 875        /* MATCH_INDEX should not happen, but if it does, match full */
 876        case MATCH_INDEX:
 877        case MATCH_FULL:
 878                r->match = regex_match_full;
 879                break;
 880        case MATCH_FRONT_ONLY:
 881                r->match = regex_match_front;
 882                break;
 883        case MATCH_MIDDLE_ONLY:
 884                r->match = regex_match_middle;
 885                break;
 886        case MATCH_END_ONLY:
 887                r->match = regex_match_end;
 888                break;
 889        case MATCH_GLOB:
 890                r->match = regex_match_glob;
 891                break;
 892        }
 893}
 894
 895/* return 1 if event matches, 0 otherwise (discard) */
 896int filter_match_preds(struct event_filter *filter, void *rec)
 897{
 898        struct prog_entry *prog;
 899        int i;
 900
 901        /* no filter is considered a match */
 902        if (!filter)
 903                return 1;
 904
 905        /* Protected by either SRCU(tracepoint_srcu) or preempt_disable */
 906        prog = rcu_dereference_raw(filter->prog);
 907        if (!prog)
 908                return 1;
 909
 910        for (i = 0; prog[i].pred; i++) {
 911                struct filter_pred *pred = prog[i].pred;
 912                int match = pred->fn(pred, rec);
 913                if (match == prog[i].when_to_branch)
 914                        i = prog[i].target;
 915        }
 916        return prog[i].target;
 917}
 918EXPORT_SYMBOL_GPL(filter_match_preds);
 919
 920static void remove_filter_string(struct event_filter *filter)
 921{
 922        if (!filter)
 923                return;
 924
 925        kfree(filter->filter_string);
 926        filter->filter_string = NULL;
 927}
 928
 929static void append_filter_err(struct trace_array *tr,
 930                              struct filter_parse_error *pe,
 931                              struct event_filter *filter)
 932{
 933        struct trace_seq *s;
 934        int pos = pe->lasterr_pos;
 935        char *buf;
 936        int len;
 937
 938        if (WARN_ON(!filter->filter_string))
 939                return;
 940
 941        s = kmalloc(sizeof(*s), GFP_KERNEL);
 942        if (!s)
 943                return;
 944        trace_seq_init(s);
 945
 946        len = strlen(filter->filter_string);
 947        if (pos > len)
 948                pos = len;
 949
 950        /* indexing is off by one */
 951        if (pos)
 952                pos++;
 953
 954        trace_seq_puts(s, filter->filter_string);
 955        if (pe->lasterr > 0) {
 956                trace_seq_printf(s, "\n%*s", pos, "^");
 957                trace_seq_printf(s, "\nparse_error: %s\n", err_text[pe->lasterr]);
 958                tracing_log_err(tr, "event filter parse error",
 959                                filter->filter_string, err_text,
 960                                pe->lasterr, pe->lasterr_pos);
 961        } else {
 962                trace_seq_printf(s, "\nError: (%d)\n", pe->lasterr);
 963                tracing_log_err(tr, "event filter parse error",
 964                                filter->filter_string, err_text,
 965                                FILT_ERR_ERRNO, 0);
 966        }
 967        trace_seq_putc(s, 0);
 968        buf = kmemdup_nul(s->buffer, s->seq.len, GFP_KERNEL);
 969        if (buf) {
 970                kfree(filter->filter_string);
 971                filter->filter_string = buf;
 972        }
 973        kfree(s);
 974}
 975
 976static inline struct event_filter *event_filter(struct trace_event_file *file)
 977{
 978        return file->filter;
 979}
 980
 981/* caller must hold event_mutex */
 982void print_event_filter(struct trace_event_file *file, struct trace_seq *s)
 983{
 984        struct event_filter *filter = event_filter(file);
 985
 986        if (filter && filter->filter_string)
 987                trace_seq_printf(s, "%s\n", filter->filter_string);
 988        else
 989                trace_seq_puts(s, "none\n");
 990}
 991
 992void print_subsystem_event_filter(struct event_subsystem *system,
 993                                  struct trace_seq *s)
 994{
 995        struct event_filter *filter;
 996
 997        mutex_lock(&event_mutex);
 998        filter = system->filter;
 999        if (filter && filter->filter_string)
1000                trace_seq_printf(s, "%s\n", filter->filter_string);
1001        else
1002                trace_seq_puts(s, DEFAULT_SYS_FILTER_MESSAGE "\n");
1003        mutex_unlock(&event_mutex);
1004}
1005
1006static void free_prog(struct event_filter *filter)
1007{
1008        struct prog_entry *prog;
1009        int i;
1010
1011        prog = rcu_access_pointer(filter->prog);
1012        if (!prog)
1013                return;
1014
1015        for (i = 0; prog[i].pred; i++)
1016                kfree(prog[i].pred);
1017        kfree(prog);
1018}
1019
1020static void filter_disable(struct trace_event_file *file)
1021{
1022        unsigned long old_flags = file->flags;
1023
1024        file->flags &= ~EVENT_FILE_FL_FILTERED;
1025
1026        if (old_flags != file->flags)
1027                trace_buffered_event_disable();
1028}
1029
1030static void __free_filter(struct event_filter *filter)
1031{
1032        if (!filter)
1033                return;
1034
1035        free_prog(filter);
1036        kfree(filter->filter_string);
1037        kfree(filter);
1038}
1039
1040void free_event_filter(struct event_filter *filter)
1041{
1042        __free_filter(filter);
1043}
1044
1045static inline void __remove_filter(struct trace_event_file *file)
1046{
1047        filter_disable(file);
1048        remove_filter_string(file->filter);
1049}
1050
1051static void filter_free_subsystem_preds(struct trace_subsystem_dir *dir,
1052                                        struct trace_array *tr)
1053{
1054        struct trace_event_file *file;
1055
1056        list_for_each_entry(file, &tr->events, list) {
1057                if (file->system != dir)
1058                        continue;
1059                __remove_filter(file);
1060        }
1061}
1062
1063static inline void __free_subsystem_filter(struct trace_event_file *file)
1064{
1065        __free_filter(file->filter);
1066        file->filter = NULL;
1067}
1068
1069static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir,
1070                                          struct trace_array *tr)
1071{
1072        struct trace_event_file *file;
1073
1074        list_for_each_entry(file, &tr->events, list) {
1075                if (file->system != dir)
1076                        continue;
1077                __free_subsystem_filter(file);
1078        }
1079}
1080
1081int filter_assign_type(const char *type)
1082{
1083        if (strstr(type, "__data_loc") && strstr(type, "char"))
1084                return FILTER_DYN_STRING;
1085
1086        if (strchr(type, '[') && strstr(type, "char"))
1087                return FILTER_STATIC_STRING;
1088
1089        if (strcmp(type, "char *") == 0 || strcmp(type, "const char *") == 0)
1090                return FILTER_PTR_STRING;
1091
1092        return FILTER_OTHER;
1093}
1094
1095static filter_pred_fn_t select_comparison_fn(enum filter_op_ids op,
1096                                            int field_size, int field_is_signed)
1097{
1098        filter_pred_fn_t fn = NULL;
1099        int pred_func_index = -1;
1100
1101        switch (op) {
1102        case OP_EQ:
1103        case OP_NE:
1104                break;
1105        default:
1106                if (WARN_ON_ONCE(op < PRED_FUNC_START))
1107                        return NULL;
1108                pred_func_index = op - PRED_FUNC_START;
1109                if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX))
1110                        return NULL;
1111        }
1112
1113        switch (field_size) {
1114        case 8:
1115                if (pred_func_index < 0)
1116                        fn = filter_pred_64;
1117                else if (field_is_signed)
1118                        fn = pred_funcs_s64[pred_func_index];
1119                else
1120                        fn = pred_funcs_u64[pred_func_index];
1121                break;
1122        case 4:
1123                if (pred_func_index < 0)
1124                        fn = filter_pred_32;
1125                else if (field_is_signed)
1126                        fn = pred_funcs_s32[pred_func_index];
1127                else
1128                        fn = pred_funcs_u32[pred_func_index];
1129                break;
1130        case 2:
1131                if (pred_func_index < 0)
1132                        fn = filter_pred_16;
1133                else if (field_is_signed)
1134                        fn = pred_funcs_s16[pred_func_index];
1135                else
1136                        fn = pred_funcs_u16[pred_func_index];
1137                break;
1138        case 1:
1139                if (pred_func_index < 0)
1140                        fn = filter_pred_8;
1141                else if (field_is_signed)
1142                        fn = pred_funcs_s8[pred_func_index];
1143                else
1144                        fn = pred_funcs_u8[pred_func_index];
1145                break;
1146        }
1147
1148        return fn;
1149}
1150
1151/* Called when a predicate is encountered by predicate_parse() */
1152static int parse_pred(const char *str, void *data,
1153                      int pos, struct filter_parse_error *pe,
1154                      struct filter_pred **pred_ptr)
1155{
1156        struct trace_event_call *call = data;
1157        struct ftrace_event_field *field;
1158        struct filter_pred *pred = NULL;
1159        char num_buf[24];       /* Big enough to hold an address */
1160        char *field_name;
1161        char q;
1162        u64 val;
1163        int len;
1164        int ret;
1165        int op;
1166        int s;
1167        int i = 0;
1168
1169        /* First find the field to associate to */
1170        while (isspace(str[i]))
1171                i++;
1172        s = i;
1173
1174        while (isalnum(str[i]) || str[i] == '_')
1175                i++;
1176
1177        len = i - s;
1178
1179        if (!len)
1180                return -1;
1181
1182        field_name = kmemdup_nul(str + s, len, GFP_KERNEL);
1183        if (!field_name)
1184                return -ENOMEM;
1185
1186        /* Make sure that the field exists */
1187
1188        field = trace_find_event_field(call, field_name);
1189        kfree(field_name);
1190        if (!field) {
1191                parse_error(pe, FILT_ERR_FIELD_NOT_FOUND, pos + i);
1192                return -EINVAL;
1193        }
1194
1195        while (isspace(str[i]))
1196                i++;
1197
1198        /* Make sure this op is supported */
1199        for (op = 0; ops[op]; op++) {
1200                /* This is why '<=' must come before '<' in ops[] */
1201                if (strncmp(str + i, ops[op], strlen(ops[op])) == 0)
1202                        break;
1203        }
1204
1205        if (!ops[op]) {
1206                parse_error(pe, FILT_ERR_INVALID_OP, pos + i);
1207                goto err_free;
1208        }
1209
1210        i += strlen(ops[op]);
1211
1212        while (isspace(str[i]))
1213                i++;
1214
1215        s = i;
1216
1217        pred = kzalloc(sizeof(*pred), GFP_KERNEL);
1218        if (!pred)
1219                return -ENOMEM;
1220
1221        pred->field = field;
1222        pred->offset = field->offset;
1223        pred->op = op;
1224
1225        if (ftrace_event_is_function(call)) {
1226                /*
1227                 * Perf does things different with function events.
1228                 * It only allows an "ip" field, and expects a string.
1229                 * But the string does not need to be surrounded by quotes.
1230                 * If it is a string, the assigned function as a nop,
1231                 * (perf doesn't use it) and grab everything.
1232                 */
1233                if (strcmp(field->name, "ip") != 0) {
1234                        parse_error(pe, FILT_ERR_IP_FIELD_ONLY, pos + i);
1235                        goto err_free;
1236                }
1237                pred->fn = filter_pred_none;
1238
1239                /*
1240                 * Quotes are not required, but if they exist then we need
1241                 * to read them till we hit a matching one.
1242                 */
1243                if (str[i] == '\'' || str[i] == '"')
1244                        q = str[i];
1245                else
1246                        q = 0;
1247
1248                for (i++; str[i]; i++) {
1249                        if (q && str[i] == q)
1250                                break;
1251                        if (!q && (str[i] == ')' || str[i] == '&' ||
1252                                   str[i] == '|'))
1253                                break;
1254                }
1255                /* Skip quotes */
1256                if (q)
1257                        s++;
1258                len = i - s;
1259                if (len >= MAX_FILTER_STR_VAL) {
1260                        parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
1261                        goto err_free;
1262                }
1263
1264                pred->regex.len = len;
1265                strncpy(pred->regex.pattern, str + s, len);
1266                pred->regex.pattern[len] = 0;
1267
1268        /* This is either a string, or an integer */
1269        } else if (str[i] == '\'' || str[i] == '"') {
1270                char q = str[i];
1271
1272                /* Make sure the op is OK for strings */
1273                switch (op) {
1274                case OP_NE:
1275                        pred->not = 1;
1276                        /* Fall through */
1277                case OP_GLOB:
1278                case OP_EQ:
1279                        break;
1280                default:
1281                        parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
1282                        goto err_free;
1283                }
1284
1285                /* Make sure the field is OK for strings */
1286                if (!is_string_field(field)) {
1287                        parse_error(pe, FILT_ERR_EXPECT_DIGIT, pos + i);
1288                        goto err_free;
1289                }
1290
1291                for (i++; str[i]; i++) {
1292                        if (str[i] == q)
1293                                break;
1294                }
1295                if (!str[i]) {
1296                        parse_error(pe, FILT_ERR_MISSING_QUOTE, pos + i);
1297                        goto err_free;
1298                }
1299
1300                /* Skip quotes */
1301                s++;
1302                len = i - s;
1303                if (len >= MAX_FILTER_STR_VAL) {
1304                        parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
1305                        goto err_free;
1306                }
1307
1308                pred->regex.len = len;
1309                strncpy(pred->regex.pattern, str + s, len);
1310                pred->regex.pattern[len] = 0;
1311
1312                filter_build_regex(pred);
1313
1314                if (field->filter_type == FILTER_COMM) {
1315                        pred->fn = filter_pred_comm;
1316
1317                } else if (field->filter_type == FILTER_STATIC_STRING) {
1318                        pred->fn = filter_pred_string;
1319                        pred->regex.field_len = field->size;
1320
1321                } else if (field->filter_type == FILTER_DYN_STRING)
1322                        pred->fn = filter_pred_strloc;
1323                else
1324                        pred->fn = filter_pred_pchar;
1325                /* go past the last quote */
1326                i++;
1327
1328        } else if (isdigit(str[i]) || str[i] == '-') {
1329
1330                /* Make sure the field is not a string */
1331                if (is_string_field(field)) {
1332                        parse_error(pe, FILT_ERR_EXPECT_STRING, pos + i);
1333                        goto err_free;
1334                }
1335
1336                if (op == OP_GLOB) {
1337                        parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
1338                        goto err_free;
1339                }
1340
1341                if (str[i] == '-')
1342                        i++;
1343
1344                /* We allow 0xDEADBEEF */
1345                while (isalnum(str[i]))
1346                        i++;
1347
1348                len = i - s;
1349                /* 0xfeedfacedeadbeef is 18 chars max */
1350                if (len >= sizeof(num_buf)) {
1351                        parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
1352                        goto err_free;
1353                }
1354
1355                strncpy(num_buf, str + s, len);
1356                num_buf[len] = 0;
1357
1358                /* Make sure it is a value */
1359                if (field->is_signed)
1360                        ret = kstrtoll(num_buf, 0, &val);
1361                else
1362                        ret = kstrtoull(num_buf, 0, &val);
1363                if (ret) {
1364                        parse_error(pe, FILT_ERR_ILLEGAL_INTVAL, pos + s);
1365                        goto err_free;
1366                }
1367
1368                pred->val = val;
1369
1370                if (field->filter_type == FILTER_CPU)
1371                        pred->fn = filter_pred_cpu;
1372                else {
1373                        pred->fn = select_comparison_fn(pred->op, field->size,
1374                                                        field->is_signed);
1375                        if (pred->op == OP_NE)
1376                                pred->not = 1;
1377                }
1378
1379        } else {
1380                parse_error(pe, FILT_ERR_INVALID_VALUE, pos + i);
1381                goto err_free;
1382        }
1383
1384        *pred_ptr = pred;
1385        return i;
1386
1387err_free:
1388        kfree(pred);
1389        return -EINVAL;
1390}
1391
1392enum {
1393        TOO_MANY_CLOSE          = -1,
1394        TOO_MANY_OPEN           = -2,
1395        MISSING_QUOTE           = -3,
1396};
1397
1398/*
1399 * Read the filter string once to calculate the number of predicates
1400 * as well as how deep the parentheses go.
1401 *
1402 * Returns:
1403 *   0 - everything is fine (err is undefined)
1404 *  -1 - too many ')'
1405 *  -2 - too many '('
1406 *  -3 - No matching quote
1407 */
1408static int calc_stack(const char *str, int *parens, int *preds, int *err)
1409{
1410        bool is_pred = false;
1411        int nr_preds = 0;
1412        int open = 1; /* Count the expression as "(E)" */
1413        int last_quote = 0;
1414        int max_open = 1;
1415        int quote = 0;
1416        int i;
1417
1418        *err = 0;
1419
1420        for (i = 0; str[i]; i++) {
1421                if (isspace(str[i]))
1422                        continue;
1423                if (quote) {
1424                        if (str[i] == quote)
1425                               quote = 0;
1426                        continue;
1427                }
1428
1429                switch (str[i]) {
1430                case '\'':
1431                case '"':
1432                        quote = str[i];
1433                        last_quote = i;
1434                        break;
1435                case '|':
1436                case '&':
1437                        if (str[i+1] != str[i])
1438                                break;
1439                        is_pred = false;
1440                        continue;
1441                case '(':
1442                        is_pred = false;
1443                        open++;
1444                        if (open > max_open)
1445                                max_open = open;
1446                        continue;
1447                case ')':
1448                        is_pred = false;
1449                        if (open == 1) {
1450                                *err = i;
1451                                return TOO_MANY_CLOSE;
1452                        }
1453                        open--;
1454                        continue;
1455                }
1456                if (!is_pred) {
1457                        nr_preds++;
1458                        is_pred = true;
1459                }
1460        }
1461
1462        if (quote) {
1463                *err = last_quote;
1464                return MISSING_QUOTE;
1465        }
1466
1467        if (open != 1) {
1468                int level = open;
1469
1470                /* find the bad open */
1471                for (i--; i; i--) {
1472                        if (quote) {
1473                                if (str[i] == quote)
1474                                        quote = 0;
1475                                continue;
1476                        }
1477                        switch (str[i]) {
1478                        case '(':
1479                                if (level == open) {
1480                                        *err = i;
1481                                        return TOO_MANY_OPEN;
1482                                }
1483                                level--;
1484                                break;
1485                        case ')':
1486                                level++;
1487                                break;
1488                        case '\'':
1489                        case '"':
1490                                quote = str[i];
1491                                break;
1492                        }
1493                }
1494                /* First character is the '(' with missing ')' */
1495                *err = 0;
1496                return TOO_MANY_OPEN;
1497        }
1498
1499        /* Set the size of the required stacks */
1500        *parens = max_open;
1501        *preds = nr_preds;
1502        return 0;
1503}
1504
1505static int process_preds(struct trace_event_call *call,
1506                         const char *filter_string,
1507                         struct event_filter *filter,
1508                         struct filter_parse_error *pe)
1509{
1510        struct prog_entry *prog;
1511        int nr_parens;
1512        int nr_preds;
1513        int index;
1514        int ret;
1515
1516        ret = calc_stack(filter_string, &nr_parens, &nr_preds, &index);
1517        if (ret < 0) {
1518                switch (ret) {
1519                case MISSING_QUOTE:
1520                        parse_error(pe, FILT_ERR_MISSING_QUOTE, index);
1521                        break;
1522                case TOO_MANY_OPEN:
1523                        parse_error(pe, FILT_ERR_TOO_MANY_OPEN, index);
1524                        break;
1525                default:
1526                        parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, index);
1527                }
1528                return ret;
1529        }
1530
1531        if (!nr_preds)
1532                return -EINVAL;
1533
1534        prog = predicate_parse(filter_string, nr_parens, nr_preds,
1535                               parse_pred, call, pe);
1536        if (IS_ERR(prog))
1537                return PTR_ERR(prog);
1538
1539        rcu_assign_pointer(filter->prog, prog);
1540        return 0;
1541}
1542
1543static inline void event_set_filtered_flag(struct trace_event_file *file)
1544{
1545        unsigned long old_flags = file->flags;
1546
1547        file->flags |= EVENT_FILE_FL_FILTERED;
1548
1549        if (old_flags != file->flags)
1550                trace_buffered_event_enable();
1551}
1552
1553static inline void event_set_filter(struct trace_event_file *file,
1554                                    struct event_filter *filter)
1555{
1556        rcu_assign_pointer(file->filter, filter);
1557}
1558
1559static inline void event_clear_filter(struct trace_event_file *file)
1560{
1561        RCU_INIT_POINTER(file->filter, NULL);
1562}
1563
1564static inline void
1565event_set_no_set_filter_flag(struct trace_event_file *file)
1566{
1567        file->flags |= EVENT_FILE_FL_NO_SET_FILTER;
1568}
1569
1570static inline void
1571event_clear_no_set_filter_flag(struct trace_event_file *file)
1572{
1573        file->flags &= ~EVENT_FILE_FL_NO_SET_FILTER;
1574}
1575
1576static inline bool
1577event_no_set_filter_flag(struct trace_event_file *file)
1578{
1579        if (file->flags & EVENT_FILE_FL_NO_SET_FILTER)
1580                return true;
1581
1582        return false;
1583}
1584
1585struct filter_list {
1586        struct list_head        list;
1587        struct event_filter     *filter;
1588};
1589
1590static int process_system_preds(struct trace_subsystem_dir *dir,
1591                                struct trace_array *tr,
1592                                struct filter_parse_error *pe,
1593                                char *filter_string)
1594{
1595        struct trace_event_file *file;
1596        struct filter_list *filter_item;
1597        struct event_filter *filter = NULL;
1598        struct filter_list *tmp;
1599        LIST_HEAD(filter_list);
1600        bool fail = true;
1601        int err;
1602
1603        list_for_each_entry(file, &tr->events, list) {
1604
1605                if (file->system != dir)
1606                        continue;
1607
1608                filter = kzalloc(sizeof(*filter), GFP_KERNEL);
1609                if (!filter)
1610                        goto fail_mem;
1611
1612                filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
1613                if (!filter->filter_string)
1614                        goto fail_mem;
1615
1616                err = process_preds(file->event_call, filter_string, filter, pe);
1617                if (err) {
1618                        filter_disable(file);
1619                        parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0);
1620                        append_filter_err(tr, pe, filter);
1621                } else
1622                        event_set_filtered_flag(file);
1623
1624
1625                filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL);
1626                if (!filter_item)
1627                        goto fail_mem;
1628
1629                list_add_tail(&filter_item->list, &filter_list);
1630                /*
1631                 * Regardless of if this returned an error, we still
1632                 * replace the filter for the call.
1633                 */
1634                filter_item->filter = event_filter(file);
1635                event_set_filter(file, filter);
1636                filter = NULL;
1637
1638                fail = false;
1639        }
1640
1641        if (fail)
1642                goto fail;
1643
1644        /*
1645         * The calls can still be using the old filters.
1646         * Do a synchronize_rcu() and to ensure all calls are
1647         * done with them before we free them.
1648         */
1649        tracepoint_synchronize_unregister();
1650        list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
1651                __free_filter(filter_item->filter);
1652                list_del(&filter_item->list);
1653                kfree(filter_item);
1654        }
1655        return 0;
1656 fail:
1657        /* No call succeeded */
1658        list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
1659                list_del(&filter_item->list);
1660                kfree(filter_item);
1661        }
1662        parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0);
1663        return -EINVAL;
1664 fail_mem:
1665        kfree(filter);
1666        /* If any call succeeded, we still need to sync */
1667        if (!fail)
1668                tracepoint_synchronize_unregister();
1669        list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
1670                __free_filter(filter_item->filter);
1671                list_del(&filter_item->list);
1672                kfree(filter_item);
1673        }
1674        return -ENOMEM;
1675}
1676
1677static int create_filter_start(char *filter_string, bool set_str,
1678                               struct filter_parse_error **pse,
1679                               struct event_filter **filterp)
1680{
1681        struct event_filter *filter;
1682        struct filter_parse_error *pe = NULL;
1683        int err = 0;
1684
1685        if (WARN_ON_ONCE(*pse || *filterp))
1686                return -EINVAL;
1687
1688        filter = kzalloc(sizeof(*filter), GFP_KERNEL);
1689        if (filter && set_str) {
1690                filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
1691                if (!filter->filter_string)
1692                        err = -ENOMEM;
1693        }
1694
1695        pe = kzalloc(sizeof(*pe), GFP_KERNEL);
1696
1697        if (!filter || !pe || err) {
1698                kfree(pe);
1699                __free_filter(filter);
1700                return -ENOMEM;
1701        }
1702
1703        /* we're committed to creating a new filter */
1704        *filterp = filter;
1705        *pse = pe;
1706
1707        return 0;
1708}
1709
1710static void create_filter_finish(struct filter_parse_error *pe)
1711{
1712        kfree(pe);
1713}
1714
1715/**
1716 * create_filter - create a filter for a trace_event_call
1717 * @call: trace_event_call to create a filter for
1718 * @filter_str: filter string
1719 * @set_str: remember @filter_str and enable detailed error in filter
1720 * @filterp: out param for created filter (always updated on return)
1721 *           Must be a pointer that references a NULL pointer.
1722 *
1723 * Creates a filter for @call with @filter_str.  If @set_str is %true,
1724 * @filter_str is copied and recorded in the new filter.
1725 *
1726 * On success, returns 0 and *@filterp points to the new filter.  On
1727 * failure, returns -errno and *@filterp may point to %NULL or to a new
1728 * filter.  In the latter case, the returned filter contains error
1729 * information if @set_str is %true and the caller is responsible for
1730 * freeing it.
1731 */
1732static int create_filter(struct trace_array *tr,
1733                         struct trace_event_call *call,
1734                         char *filter_string, bool set_str,
1735                         struct event_filter **filterp)
1736{
1737        struct filter_parse_error *pe = NULL;
1738        int err;
1739
1740        /* filterp must point to NULL */
1741        if (WARN_ON(*filterp))
1742                *filterp = NULL;
1743
1744        err = create_filter_start(filter_string, set_str, &pe, filterp);
1745        if (err)
1746                return err;
1747
1748        err = process_preds(call, filter_string, *filterp, pe);
1749        if (err && set_str)
1750                append_filter_err(tr, pe, *filterp);
1751        create_filter_finish(pe);
1752
1753        return err;
1754}
1755
1756int create_event_filter(struct trace_array *tr,
1757                        struct trace_event_call *call,
1758                        char *filter_str, bool set_str,
1759                        struct event_filter **filterp)
1760{
1761        return create_filter(tr, call, filter_str, set_str, filterp);
1762}
1763
1764/**
1765 * create_system_filter - create a filter for an event_subsystem
1766 * @system: event_subsystem to create a filter for
1767 * @filter_str: filter string
1768 * @filterp: out param for created filter (always updated on return)
1769 *
1770 * Identical to create_filter() except that it creates a subsystem filter
1771 * and always remembers @filter_str.
1772 */
1773static int create_system_filter(struct trace_subsystem_dir *dir,
1774                                struct trace_array *tr,
1775                                char *filter_str, struct event_filter **filterp)
1776{
1777        struct filter_parse_error *pe = NULL;
1778        int err;
1779
1780        err = create_filter_start(filter_str, true, &pe, filterp);
1781        if (!err) {
1782                err = process_system_preds(dir, tr, pe, filter_str);
1783                if (!err) {
1784                        /* System filters just show a default message */
1785                        kfree((*filterp)->filter_string);
1786                        (*filterp)->filter_string = NULL;
1787                } else {
1788                        append_filter_err(tr, pe, *filterp);
1789                }
1790        }
1791        create_filter_finish(pe);
1792
1793        return err;
1794}
1795
1796/* caller must hold event_mutex */
1797int apply_event_filter(struct trace_event_file *file, char *filter_string)
1798{
1799        struct trace_event_call *call = file->event_call;
1800        struct event_filter *filter = NULL;
1801        int err;
1802
1803        if (!strcmp(strstrip(filter_string), "0")) {
1804                filter_disable(file);
1805                filter = event_filter(file);
1806
1807                if (!filter)
1808                        return 0;
1809
1810                event_clear_filter(file);
1811
1812                /* Make sure the filter is not being used */
1813                tracepoint_synchronize_unregister();
1814                __free_filter(filter);
1815
1816                return 0;
1817        }
1818
1819        err = create_filter(file->tr, call, filter_string, true, &filter);
1820
1821        /*
1822         * Always swap the call filter with the new filter
1823         * even if there was an error. If there was an error
1824         * in the filter, we disable the filter and show the error
1825         * string
1826         */
1827        if (filter) {
1828                struct event_filter *tmp;
1829
1830                tmp = event_filter(file);
1831                if (!err)
1832                        event_set_filtered_flag(file);
1833                else
1834                        filter_disable(file);
1835
1836                event_set_filter(file, filter);
1837
1838                if (tmp) {
1839                        /* Make sure the call is done with the filter */
1840                        tracepoint_synchronize_unregister();
1841                        __free_filter(tmp);
1842                }
1843        }
1844
1845        return err;
1846}
1847
1848int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1849                                 char *filter_string)
1850{
1851        struct event_subsystem *system = dir->subsystem;
1852        struct trace_array *tr = dir->tr;
1853        struct event_filter *filter = NULL;
1854        int err = 0;
1855
1856        mutex_lock(&event_mutex);
1857
1858        /* Make sure the system still has events */
1859        if (!dir->nr_events) {
1860                err = -ENODEV;
1861                goto out_unlock;
1862        }
1863
1864        if (!strcmp(strstrip(filter_string), "0")) {
1865                filter_free_subsystem_preds(dir, tr);
1866                remove_filter_string(system->filter);
1867                filter = system->filter;
1868                system->filter = NULL;
1869                /* Ensure all filters are no longer used */
1870                tracepoint_synchronize_unregister();
1871                filter_free_subsystem_filters(dir, tr);
1872                __free_filter(filter);
1873                goto out_unlock;
1874        }
1875
1876        err = create_system_filter(dir, tr, filter_string, &filter);
1877        if (filter) {
1878                /*
1879                 * No event actually uses the system filter
1880                 * we can free it without synchronize_rcu().
1881                 */
1882                __free_filter(system->filter);
1883                system->filter = filter;
1884        }
1885out_unlock:
1886        mutex_unlock(&event_mutex);
1887
1888        return err;
1889}
1890
1891#ifdef CONFIG_PERF_EVENTS
1892
1893void ftrace_profile_free_filter(struct perf_event *event)
1894{
1895        struct event_filter *filter = event->filter;
1896
1897        event->filter = NULL;
1898        __free_filter(filter);
1899}
1900
1901struct function_filter_data {
1902        struct ftrace_ops *ops;
1903        int first_filter;
1904        int first_notrace;
1905};
1906
1907#ifdef CONFIG_FUNCTION_TRACER
1908static char **
1909ftrace_function_filter_re(char *buf, int len, int *count)
1910{
1911        char *str, **re;
1912
1913        str = kstrndup(buf, len, GFP_KERNEL);
1914        if (!str)
1915                return NULL;
1916
1917        /*
1918         * The argv_split function takes white space
1919         * as a separator, so convert ',' into spaces.
1920         */
1921        strreplace(str, ',', ' ');
1922
1923        re = argv_split(GFP_KERNEL, str, count);
1924        kfree(str);
1925        return re;
1926}
1927
1928static int ftrace_function_set_regexp(struct ftrace_ops *ops, int filter,
1929                                      int reset, char *re, int len)
1930{
1931        int ret;
1932
1933        if (filter)
1934                ret = ftrace_set_filter(ops, re, len, reset);
1935        else
1936                ret = ftrace_set_notrace(ops, re, len, reset);
1937
1938        return ret;
1939}
1940
1941static int __ftrace_function_set_filter(int filter, char *buf, int len,
1942                                        struct function_filter_data *data)
1943{
1944        int i, re_cnt, ret = -EINVAL;
1945        int *reset;
1946        char **re;
1947
1948        reset = filter ? &data->first_filter : &data->first_notrace;
1949
1950        /*
1951         * The 'ip' field could have multiple filters set, separated
1952         * either by space or comma. We first cut the filter and apply
1953         * all pieces separatelly.
1954         */
1955        re = ftrace_function_filter_re(buf, len, &re_cnt);
1956        if (!re)
1957                return -EINVAL;
1958
1959        for (i = 0; i < re_cnt; i++) {
1960                ret = ftrace_function_set_regexp(data->ops, filter, *reset,
1961                                                 re[i], strlen(re[i]));
1962                if (ret)
1963                        break;
1964
1965                if (*reset)
1966                        *reset = 0;
1967        }
1968
1969        argv_free(re);
1970        return ret;
1971}
1972
1973static int ftrace_function_check_pred(struct filter_pred *pred)
1974{
1975        struct ftrace_event_field *field = pred->field;
1976
1977        /*
1978         * Check the predicate for function trace, verify:
1979         *  - only '==' and '!=' is used
1980         *  - the 'ip' field is used
1981         */
1982        if ((pred->op != OP_EQ) && (pred->op != OP_NE))
1983                return -EINVAL;
1984
1985        if (strcmp(field->name, "ip"))
1986                return -EINVAL;
1987
1988        return 0;
1989}
1990
1991static int ftrace_function_set_filter_pred(struct filter_pred *pred,
1992                                           struct function_filter_data *data)
1993{
1994        int ret;
1995
1996        /* Checking the node is valid for function trace. */
1997        ret = ftrace_function_check_pred(pred);
1998        if (ret)
1999                return ret;
2000
2001        return __ftrace_function_set_filter(pred->op == OP_EQ,
2002                                            pred->regex.pattern,
2003                                            pred->regex.len,
2004                                            data);
2005}
2006
2007static bool is_or(struct prog_entry *prog, int i)
2008{
2009        int target;
2010
2011        /*
2012         * Only "||" is allowed for function events, thus,
2013         * all true branches should jump to true, and any
2014         * false branch should jump to false.
2015         */
2016        target = prog[i].target + 1;
2017        /* True and false have NULL preds (all prog entries should jump to one */
2018        if (prog[target].pred)
2019                return false;
2020
2021        /* prog[target].target is 1 for TRUE, 0 for FALSE */
2022        return prog[i].when_to_branch == prog[target].target;
2023}
2024
2025static int ftrace_function_set_filter(struct perf_event *event,
2026                                      struct event_filter *filter)
2027{
2028        struct prog_entry *prog = rcu_dereference_protected(filter->prog,
2029                                                lockdep_is_held(&event_mutex));
2030        struct function_filter_data data = {
2031                .first_filter  = 1,
2032                .first_notrace = 1,
2033                .ops           = &event->ftrace_ops,
2034        };
2035        int i;
2036
2037        for (i = 0; prog[i].pred; i++) {
2038                struct filter_pred *pred = prog[i].pred;
2039
2040                if (!is_or(prog, i))
2041                        return -EINVAL;
2042
2043                if (ftrace_function_set_filter_pred(pred, &data) < 0)
2044                        return -EINVAL;
2045        }
2046        return 0;
2047}
2048#else
2049static int ftrace_function_set_filter(struct perf_event *event,
2050                                      struct event_filter *filter)
2051{
2052        return -ENODEV;
2053}
2054#endif /* CONFIG_FUNCTION_TRACER */
2055
2056int ftrace_profile_set_filter(struct perf_event *event, int event_id,
2057                              char *filter_str)
2058{
2059        int err;
2060        struct event_filter *filter = NULL;
2061        struct trace_event_call *call;
2062
2063        mutex_lock(&event_mutex);
2064
2065        call = event->tp_event;
2066
2067        err = -EINVAL;
2068        if (!call)
2069                goto out_unlock;
2070
2071        err = -EEXIST;
2072        if (event->filter)
2073                goto out_unlock;
2074
2075        err = create_filter(NULL, call, filter_str, false, &filter);
2076        if (err)
2077                goto free_filter;
2078
2079        if (ftrace_event_is_function(call))
2080                err = ftrace_function_set_filter(event, filter);
2081        else
2082                event->filter = filter;
2083
2084free_filter:
2085        if (err || ftrace_event_is_function(call))
2086                __free_filter(filter);
2087
2088out_unlock:
2089        mutex_unlock(&event_mutex);
2090
2091        return err;
2092}
2093
2094#endif /* CONFIG_PERF_EVENTS */
2095
2096#ifdef CONFIG_FTRACE_STARTUP_TEST
2097
2098#include <linux/types.h>
2099#include <linux/tracepoint.h>
2100
2101#define CREATE_TRACE_POINTS
2102#include "trace_events_filter_test.h"
2103
2104#define DATA_REC(m, va, vb, vc, vd, ve, vf, vg, vh, nvisit) \
2105{ \
2106        .filter = FILTER, \
2107        .rec    = { .a = va, .b = vb, .c = vc, .d = vd, \
2108                    .e = ve, .f = vf, .g = vg, .h = vh }, \
2109        .match  = m, \
2110        .not_visited = nvisit, \
2111}
2112#define YES 1
2113#define NO  0
2114
2115static struct test_filter_data_t {
2116        char *filter;
2117        struct trace_event_raw_ftrace_test_filter rec;
2118        int match;
2119        char *not_visited;
2120} test_filter_data[] = {
2121#define FILTER "a == 1 && b == 1 && c == 1 && d == 1 && " \
2122               "e == 1 && f == 1 && g == 1 && h == 1"
2123        DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, ""),
2124        DATA_REC(NO,  0, 1, 1, 1, 1, 1, 1, 1, "bcdefgh"),
2125        DATA_REC(NO,  1, 1, 1, 1, 1, 1, 1, 0, ""),
2126#undef FILTER
2127#define FILTER "a == 1 || b == 1 || c == 1 || d == 1 || " \
2128               "e == 1 || f == 1 || g == 1 || h == 1"
2129        DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 0, ""),
2130        DATA_REC(YES, 0, 0, 0, 0, 0, 0, 0, 1, ""),
2131        DATA_REC(YES, 1, 0, 0, 0, 0, 0, 0, 0, "bcdefgh"),
2132#undef FILTER
2133#define FILTER "(a == 1 || b == 1) && (c == 1 || d == 1) && " \
2134               "(e == 1 || f == 1) && (g == 1 || h == 1)"
2135        DATA_REC(NO,  0, 0, 1, 1, 1, 1, 1, 1, "dfh"),
2136        DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2137        DATA_REC(YES, 1, 0, 1, 0, 0, 1, 0, 1, "bd"),
2138        DATA_REC(NO,  1, 0, 1, 0, 0, 1, 0, 0, "bd"),
2139#undef FILTER
2140#define FILTER "(a == 1 && b == 1) || (c == 1 && d == 1) || " \
2141               "(e == 1 && f == 1) || (g == 1 && h == 1)"
2142        DATA_REC(YES, 1, 0, 1, 1, 1, 1, 1, 1, "efgh"),
2143        DATA_REC(YES, 0, 0, 0, 0, 0, 0, 1, 1, ""),
2144        DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 1, ""),
2145#undef FILTER
2146#define FILTER "(a == 1 && b == 1) && (c == 1 && d == 1) && " \
2147               "(e == 1 && f == 1) || (g == 1 && h == 1)"
2148        DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 0, "gh"),
2149        DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 1, ""),
2150        DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, ""),
2151#undef FILTER
2152#define FILTER "((a == 1 || b == 1) || (c == 1 || d == 1) || " \
2153               "(e == 1 || f == 1)) && (g == 1 || h == 1)"
2154        DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 1, "bcdef"),
2155        DATA_REC(NO,  0, 0, 0, 0, 0, 0, 0, 0, ""),
2156        DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, "h"),
2157#undef FILTER
2158#define FILTER "((((((((a == 1) && (b == 1)) || (c == 1)) && (d == 1)) || " \
2159               "(e == 1)) && (f == 1)) || (g == 1)) && (h == 1))"
2160        DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "ceg"),
2161        DATA_REC(NO,  0, 1, 0, 1, 0, 1, 0, 1, ""),
2162        DATA_REC(NO,  1, 0, 1, 0, 1, 0, 1, 0, ""),
2163#undef FILTER
2164#define FILTER "((((((((a == 1) || (b == 1)) && (c == 1)) || (d == 1)) && " \
2165               "(e == 1)) || (f == 1)) && (g == 1)) || (h == 1))"
2166        DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "bdfh"),
2167        DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2168        DATA_REC(YES, 1, 0, 1, 0, 1, 0, 1, 0, "bdfh"),
2169};
2170
2171#undef DATA_REC
2172#undef FILTER
2173#undef YES
2174#undef NO
2175
2176#define DATA_CNT ARRAY_SIZE(test_filter_data)
2177
2178static int test_pred_visited;
2179
2180static int test_pred_visited_fn(struct filter_pred *pred, void *event)
2181{
2182        struct ftrace_event_field *field = pred->field;
2183
2184        test_pred_visited = 1;
2185        printk(KERN_INFO "\npred visited %s\n", field->name);
2186        return 1;
2187}
2188
2189static void update_pred_fn(struct event_filter *filter, char *fields)
2190{
2191        struct prog_entry *prog = rcu_dereference_protected(filter->prog,
2192                                                lockdep_is_held(&event_mutex));
2193        int i;
2194
2195        for (i = 0; prog[i].pred; i++) {
2196                struct filter_pred *pred = prog[i].pred;
2197                struct ftrace_event_field *field = pred->field;
2198
2199                WARN_ON_ONCE(!pred->fn);
2200
2201                if (!field) {
2202                        WARN_ONCE(1, "all leafs should have field defined %d", i);
2203                        continue;
2204                }
2205
2206                if (!strchr(fields, *field->name))
2207                        continue;
2208
2209                pred->fn = test_pred_visited_fn;
2210        }
2211}
2212
2213static __init int ftrace_test_event_filter(void)
2214{
2215        int i;
2216
2217        printk(KERN_INFO "Testing ftrace filter: ");
2218
2219        for (i = 0; i < DATA_CNT; i++) {
2220                struct event_filter *filter = NULL;
2221                struct test_filter_data_t *d = &test_filter_data[i];
2222                int err;
2223
2224                err = create_filter(NULL, &event_ftrace_test_filter,
2225                                    d->filter, false, &filter);
2226                if (err) {
2227                        printk(KERN_INFO
2228                               "Failed to get filter for '%s', err %d\n",
2229                               d->filter, err);
2230                        __free_filter(filter);
2231                        break;
2232                }
2233
2234                /* Needed to dereference filter->prog */
2235                mutex_lock(&event_mutex);
2236                /*
2237                 * The preemption disabling is not really needed for self
2238                 * tests, but the rcu dereference will complain without it.
2239                 */
2240                preempt_disable();
2241                if (*d->not_visited)
2242                        update_pred_fn(filter, d->not_visited);
2243
2244                test_pred_visited = 0;
2245                err = filter_match_preds(filter, &d->rec);
2246                preempt_enable();
2247
2248                mutex_unlock(&event_mutex);
2249
2250                __free_filter(filter);
2251
2252                if (test_pred_visited) {
2253                        printk(KERN_INFO
2254                               "Failed, unwanted pred visited for filter %s\n",
2255                               d->filter);
2256                        break;
2257                }
2258
2259                if (err != d->match) {
2260                        printk(KERN_INFO
2261                               "Failed to match filter '%s', expected %d\n",
2262                               d->filter, d->match);
2263                        break;
2264                }
2265        }
2266
2267        if (i == DATA_CNT)
2268                printk(KERN_CONT "OK\n");
2269
2270        return 0;
2271}
2272
2273late_initcall(ftrace_test_event_filter);
2274
2275#endif /* CONFIG_FTRACE_STARTUP_TEST */
2276