root/kernel/trace/trace_events_filter.c

DEFINITIONS

1. is_not
2. update_preds
3. parse_error
4. predicate_parse
5. filter_pred_string
6. filter_pred_pchar
7. filter_pred_strloc
8. filter_pred_cpu
9. filter_pred_comm
10. filter_pred_none
11. regex_match_full
12. regex_match_front
13. regex_match_middle
14. regex_match_end
15. regex_match_glob
16. filter_parse_regex
17. filter_build_regex
18. filter_match_preds
19. remove_filter_string
20. append_filter_err
21. print_event_filter
22. print_subsystem_event_filter
23. free_prog
24. filter_disable
25. __free_filter
26. free_event_filter
27. __remove_filter
28. filter_free_subsystem_preds
29. __free_subsystem_filter
30. filter_free_subsystem_filters
31. filter_assign_type
32. select_comparison_fn
33. parse_pred
34. calc_stack
35. process_preds
36. event_set_filtered_flag
37. event_set_filter
38. event_clear_filter
39. event_set_no_set_filter_flag
40. event_clear_no_set_filter_flag
41. event_no_set_filter_flag
42. process_system_preds
43. create_filter_start
44. create_filter_finish
45. create_filter
46. create_event_filter
47. create_system_filter
48. apply_event_filter
49. apply_subsystem_event_filter
50. ftrace_profile_free_filter
51. ftrace_function_filter_re
52. ftrace_function_set_regexp
53. __ftrace_function_set_filter
54. ftrace_function_check_pred
55. ftrace_function_set_filter_pred
56. is_or
57. ftrace_function_set_filter
58. ftrace_function_set_filter
59. ftrace_profile_set_filter
60. test_pred_visited_fn
61. update_pred_fn
62. ftrace_test_event_filter

   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 
  38 enum filter_op_ids { OPS };
  39 
  40 #undef C
  41 #define C(a, b) b
  42 
  43 static 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 
  75 enum { ERRORS };
  76 
  77 #undef C
  78 #define C(a, b)         b
  79 
  80 static const char *err_text[] = { ERRORS };
  81 
  82 /* Called after a '!' character but "!=" and "!~" are not "not"s */
  83 static 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  */
  99 struct 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  */
 117 static 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 
 128 struct filter_parse_error {
 129         int lasterr;
 130         int lasterr_pos;
 131 };
 132 
 133 static void parse_error(struct filter_parse_error *pe, int err, int pos)
 134 {
 135         pe->lasterr = err;
 136         pe->lasterr_pos = pos;
 137 }
 138 
 139 typedef int (*parse_pred_fn)(const char *str, void *data, int pos,
 140                              struct filter_parse_error *pe,
 141                              struct filter_pred **pred);
 142 
 143 enum {
 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  */
 409 static struct prog_entry *
 410 predicate_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;
 581 out_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)                                    \
 593 static 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 }                                                                       \
 599 static 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 }                                                                       \
 605 static 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 }                                                                       \
 611 static 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 }                                                                       \
 617 static 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 }                                                                       \
 623 static 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)                                      \
 632 static 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 
 643 DEFINE_COMPARISON_PRED(s64);
 644 DEFINE_COMPARISON_PRED(u64);
 645 DEFINE_COMPARISON_PRED(s32);
 646 DEFINE_COMPARISON_PRED(u32);
 647 DEFINE_COMPARISON_PRED(s16);
 648 DEFINE_COMPARISON_PRED(u16);
 649 DEFINE_COMPARISON_PRED(s8);
 650 DEFINE_COMPARISON_PRED(u8);
 651 
 652 DEFINE_EQUALITY_PRED(64);
 653 DEFINE_EQUALITY_PRED(32);
 654 DEFINE_EQUALITY_PRED(16);
 655 DEFINE_EQUALITY_PRED(8);
 656 
 657 /* Filter predicate for fixed sized arrays of characters */
 658 static 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 */
 671 static 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  */
 694 static 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. */
 710 static 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. */
 736 static 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 
 745 static 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 
 762 static 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 
 771 static 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 
 779 static 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 
 787 static 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 
 797 static 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  */
 821 enum 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 
 862 static 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) */
 896 int 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 }
 918 EXPORT_SYMBOL_GPL(filter_match_preds);
 919 
 920 static 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 
 929 static 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 
 976 static inline struct event_filter *event_filter(struct trace_event_file *file)
 977 {
 978         return file->filter;
 979 }
 980 
 981 /* caller must hold event_mutex */
 982 void 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 
 992 void 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 
1006 static 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 
1020 static 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 
1030 static 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 
1040 void free_event_filter(struct event_filter *filter)
1041 {
1042         __free_filter(filter);
1043 }
1044 
1045 static inline void __remove_filter(struct trace_event_file *file)
1046 {
1047         filter_disable(file);
1048         remove_filter_string(file->filter);
1049 }
1050 
1051 static 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 
1063 static inline void __free_subsystem_filter(struct trace_event_file *file)
1064 {
1065         __free_filter(file->filter);
1066         file->filter = NULL;
1067 }
1068 
1069 static 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 
1081 int 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 
1095 static 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() */
1152 static 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 
1387 err_free:
1388         kfree(pred);
1389         return -EINVAL;
1390 }
1391 
1392 enum {
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  */
1408 static 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 
1505 static 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 
1543 static 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 
1553 static 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 
1559 static inline void event_clear_filter(struct trace_event_file *file)
1560 {
1561         RCU_INIT_POINTER(file->filter, NULL);
1562 }
1563 
1564 static inline void
1565 event_set_no_set_filter_flag(struct trace_event_file *file)
1566 {
1567         file->flags |= EVENT_FILE_FL_NO_SET_FILTER;
1568 }
1569 
1570 static inline void
1571 event_clear_no_set_filter_flag(struct trace_event_file *file)
1572 {
1573         file->flags &= ~EVENT_FILE_FL_NO_SET_FILTER;
1574 }
1575 
1576 static inline bool
1577 event_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 
1585 struct filter_list {
1586         struct list_head        list;
1587         struct event_filter     *filter;
1588 };
1589 
1590 static 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         __free_filter(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 
1677 static 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 
1710 static 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  */
1732 static 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 
1756 int 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  */
1773 static 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 */
1797 int 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 
1848 int 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         }
1885 out_unlock:
1886         mutex_unlock(&event_mutex);
1887 
1888         return err;
1889 }
1890 
1891 #ifdef CONFIG_PERF_EVENTS
1892 
1893 void 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 
1901 struct function_filter_data {
1902         struct ftrace_ops *ops;
1903         int first_filter;
1904         int first_notrace;
1905 };
1906 
1907 #ifdef CONFIG_FUNCTION_TRACER
1908 static char **
1909 ftrace_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 
1928 static 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 
1941 static 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 
1973 static 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 
1991 static 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 
2007 static 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 
2025 static 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
2049 static 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 
2056 int 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 
2084 free_filter:
2085         if (err || ftrace_event_is_function(call))
2086                 __free_filter(filter);
2087 
2088 out_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 
2115 static 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 
2178 static int test_pred_visited;
2179 
2180 static 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 
2189 static 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 
2213 static __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 
2273 late_initcall(ftrace_test_event_filter);
2274 
2275 #endif /* CONFIG_FTRACE_STARTUP_TEST */