Line data Source code
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 0 : static bool is_not(const char *str)
84 : {
85 0 : switch (str[1]) {
86 : case '=':
87 : case '~':
88 : return false;
89 : }
90 0 : 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 0 : static void update_preds(struct prog_entry *prog, int N, int invert)
118 : {
119 0 : int t, s;
120 :
121 0 : t = prog[N].target;
122 0 : s = prog[t].target;
123 0 : prog[t].when_to_branch = invert;
124 0 : prog[t].target = N;
125 0 : prog[N].target = s;
126 : }
127 :
128 : struct filter_parse_error {
129 : int lasterr;
130 : int lasterr_pos;
131 : };
132 :
133 0 : static void parse_error(struct filter_parse_error *pe, int err, int pos)
134 : {
135 0 : pe->lasterr = err;
136 0 : pe->lasterr_pos = pos;
137 0 : }
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 0 : 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 0 : struct prog_entry *prog_stack;
415 0 : struct prog_entry *prog;
416 0 : const char *ptr = str;
417 0 : char *inverts = NULL;
418 0 : int *op_stack;
419 0 : int *top;
420 0 : int invert = 0;
421 0 : int ret = -ENOMEM;
422 0 : int len;
423 0 : int N = 0;
424 0 : int i;
425 :
426 0 : nr_preds += 2; /* For TRUE and FALSE */
427 :
428 0 : op_stack = kmalloc_array(nr_parens, sizeof(*op_stack), GFP_KERNEL);
429 0 : if (!op_stack)
430 0 : return ERR_PTR(-ENOMEM);
431 0 : prog_stack = kcalloc(nr_preds, sizeof(*prog_stack), GFP_KERNEL);
432 0 : if (!prog_stack) {
433 0 : parse_error(pe, -ENOMEM, 0);
434 0 : goto out_free;
435 : }
436 0 : inverts = kmalloc_array(nr_preds, sizeof(*inverts), GFP_KERNEL);
437 0 : if (!inverts) {
438 0 : parse_error(pe, -ENOMEM, 0);
439 0 : goto out_free;
440 : }
441 :
442 0 : top = op_stack;
443 0 : prog = prog_stack;
444 0 : *top = 0;
445 :
446 : /* First pass */
447 0 : while (*ptr) { /* #1 */
448 0 : const char *next = ptr++;
449 :
450 0 : if (isspace(*next))
451 0 : continue;
452 :
453 0 : switch (*next) {
454 0 : case '(': /* #2 */
455 0 : if (top - op_stack > nr_parens) {
456 0 : ret = -EINVAL;
457 0 : goto out_free;
458 : }
459 0 : *(++top) = invert;
460 0 : continue;
461 : case '!': /* #3 */
462 0 : if (!is_not(next))
463 : break;
464 0 : invert = !invert;
465 0 : continue;
466 : }
467 :
468 0 : if (N >= nr_preds) {
469 0 : parse_error(pe, FILT_ERR_TOO_MANY_PREDS, next - str);
470 0 : goto out_free;
471 : }
472 :
473 0 : inverts[N] = invert; /* #4 */
474 0 : prog[N].target = N-1;
475 :
476 0 : len = parse_pred(next, data, ptr - str, pe, &prog[N].pred);
477 0 : if (len < 0) {
478 0 : ret = len;
479 0 : goto out_free;
480 : }
481 0 : ptr = next + len;
482 :
483 0 : N++;
484 :
485 0 : ret = -1;
486 0 : while (1) { /* #5 */
487 0 : next = ptr++;
488 0 : if (isspace(*next))
489 0 : continue;
490 :
491 0 : switch (*next) {
492 : case ')':
493 : case '\0':
494 : break;
495 0 : case '&':
496 : case '|':
497 : /* accepting only "&&" or "||" */
498 0 : if (next[1] == next[0]) {
499 0 : ptr++;
500 0 : break;
501 : }
502 0 : fallthrough;
503 : default:
504 0 : parse_error(pe, FILT_ERR_TOO_MANY_PREDS,
505 0 : next - str);
506 0 : goto out_free;
507 : }
508 :
509 0 : invert = *top & INVERT;
510 :
511 0 : if (*top & PROCESS_AND) { /* #7 */
512 0 : update_preds(prog, N - 1, invert);
513 0 : *top &= ~PROCESS_AND;
514 : }
515 0 : if (*next == '&') { /* #8 */
516 0 : *top |= PROCESS_AND;
517 0 : break;
518 : }
519 0 : if (*top & PROCESS_OR) { /* #9 */
520 0 : update_preds(prog, N - 1, !invert);
521 0 : *top &= ~PROCESS_OR;
522 : }
523 0 : if (*next == '|') { /* #10 */
524 0 : *top |= PROCESS_OR;
525 0 : break;
526 : }
527 0 : if (!*next) /* #11 */
528 0 : goto out;
529 :
530 0 : if (top == op_stack) {
531 0 : ret = -1;
532 : /* Too few '(' */
533 0 : parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, ptr - str);
534 0 : goto out_free;
535 : }
536 0 : top--; /* #12 */
537 : }
538 : }
539 0 : out:
540 0 : if (top != op_stack) {
541 : /* Too many '(' */
542 0 : parse_error(pe, FILT_ERR_TOO_MANY_OPEN, ptr - str);
543 0 : goto out_free;
544 : }
545 :
546 0 : if (!N) {
547 : /* No program? */
548 0 : ret = -EINVAL;
549 0 : parse_error(pe, FILT_ERR_NO_FILTER, ptr - str);
550 0 : goto out_free;
551 : }
552 :
553 0 : prog[N].pred = NULL; /* #13 */
554 0 : prog[N].target = 1; /* TRUE */
555 0 : prog[N+1].pred = NULL;
556 0 : prog[N+1].target = 0; /* FALSE */
557 0 : prog[N-1].target = N;
558 0 : prog[N-1].when_to_branch = false;
559 :
560 : /* Second Pass */
561 0 : for (i = N-1 ; i--; ) {
562 0 : int target = prog[i].target;
563 0 : if (prog[i].when_to_branch == prog[target].when_to_branch)
564 0 : prog[i].target = prog[target].target;
565 : }
566 :
567 : /* Third Pass */
568 0 : for (i = 0; i < N; i++) {
569 0 : invert = inverts[i] ^ prog[i].when_to_branch;
570 0 : prog[i].when_to_branch = invert;
571 : /* Make sure the program always moves forward */
572 0 : if (WARN_ON(prog[i].target <= i)) {
573 0 : ret = -EINVAL;
574 0 : goto out_free;
575 : }
576 : }
577 :
578 0 : kfree(op_stack);
579 0 : kfree(inverts);
580 0 : return prog;
581 0 : out_free:
582 0 : kfree(op_stack);
583 0 : kfree(inverts);
584 0 : if (prog_stack) {
585 0 : for (i = 0; prog_stack[i].pred; i++)
586 0 : kfree(prog_stack[i].pred);
587 0 : kfree(prog_stack);
588 : }
589 0 : 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 0 : DEFINE_COMPARISON_PRED(s64);
644 0 : DEFINE_COMPARISON_PRED(u64);
645 0 : DEFINE_COMPARISON_PRED(s32);
646 0 : DEFINE_COMPARISON_PRED(u32);
647 0 : DEFINE_COMPARISON_PRED(s16);
648 0 : DEFINE_COMPARISON_PRED(u16);
649 0 : DEFINE_COMPARISON_PRED(s8);
650 0 : DEFINE_COMPARISON_PRED(u8);
651 :
652 0 : DEFINE_EQUALITY_PRED(64);
653 0 : DEFINE_EQUALITY_PRED(32);
654 0 : DEFINE_EQUALITY_PRED(16);
655 0 : DEFINE_EQUALITY_PRED(8);
656 :
657 : /* Filter predicate for fixed sized arrays of characters */
658 0 : static int filter_pred_string(struct filter_pred *pred, void *event)
659 : {
660 0 : char *addr = (char *)(event + pred->offset);
661 0 : int cmp, match;
662 :
663 0 : cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len);
664 :
665 0 : match = cmp ^ pred->not;
666 :
667 0 : return match;
668 : }
669 :
670 : /* Filter predicate for char * pointers */
671 0 : static int filter_pred_pchar(struct filter_pred *pred, void *event)
672 : {
673 0 : char **addr = (char **)(event + pred->offset);
674 0 : int cmp, match;
675 0 : int len = strlen(*addr) + 1; /* including tailing '\0' */
676 :
677 0 : cmp = pred->regex.match(*addr, &pred->regex, len);
678 :
679 0 : match = cmp ^ pred->not;
680 :
681 0 : 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 0 : static int filter_pred_strloc(struct filter_pred *pred, void *event)
695 : {
696 0 : u32 str_item = *(u32 *)(event + pred->offset);
697 0 : int str_loc = str_item & 0xffff;
698 0 : int str_len = str_item >> 16;
699 0 : char *addr = (char *)(event + str_loc);
700 0 : int cmp, match;
701 :
702 0 : cmp = pred->regex.match(addr, &pred->regex, str_len);
703 :
704 0 : match = cmp ^ pred->not;
705 :
706 0 : return match;
707 : }
708 :
709 : /* Filter predicate for CPUs. */
710 0 : static int filter_pred_cpu(struct filter_pred *pred, void *event)
711 : {
712 0 : int cpu, cmp;
713 :
714 0 : cpu = raw_smp_processor_id();
715 0 : cmp = pred->val;
716 :
717 0 : switch (pred->op) {
718 0 : case OP_EQ:
719 0 : return cpu == cmp;
720 0 : case OP_NE:
721 0 : return cpu != cmp;
722 0 : case OP_LT:
723 0 : return cpu < cmp;
724 0 : case OP_LE:
725 0 : return cpu <= cmp;
726 0 : case OP_GT:
727 0 : return cpu > cmp;
728 0 : case OP_GE:
729 0 : return cpu >= cmp;
730 : default:
731 : return 0;
732 : }
733 : }
734 :
735 : /* Filter predicate for COMM. */
736 0 : static int filter_pred_comm(struct filter_pred *pred, void *event)
737 : {
738 0 : int cmp;
739 :
740 0 : cmp = pred->regex.match(current->comm, &pred->regex,
741 : TASK_COMM_LEN);
742 0 : return cmp ^ pred->not;
743 : }
744 :
745 0 : static int filter_pred_none(struct filter_pred *pred, void *event)
746 : {
747 0 : 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 0 : 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 0 : if (!len)
766 0 : return strcmp(str, r->pattern) == 0;
767 :
768 0 : return strncmp(str, r->pattern, len) == 0;
769 : }
770 :
771 0 : static int regex_match_front(char *str, struct regex *r, int len)
772 : {
773 0 : if (len && len < r->len)
774 : return 0;
775 :
776 0 : return strncmp(str, r->pattern, r->len) == 0;
777 : }
778 :
779 0 : static int regex_match_middle(char *str, struct regex *r, int len)
780 : {
781 0 : if (!len)
782 0 : return strstr(str, r->pattern) != NULL;
783 :
784 0 : return strnstr(str, r->pattern, len) != NULL;
785 : }
786 :
787 0 : static int regex_match_end(char *str, struct regex *r, int len)
788 : {
789 0 : int strlen = len - 1;
790 :
791 0 : if (strlen >= r->len &&
792 0 : memcmp(str + strlen - r->len, r->pattern, r->len) == 0)
793 0 : return 1;
794 : return 0;
795 : }
796 :
797 0 : static int regex_match_glob(char *str, struct regex *r, int len __maybe_unused)
798 : {
799 0 : if (glob_match(r->pattern, str))
800 0 : 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 0 : enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not)
822 : {
823 0 : int type = MATCH_FULL;
824 0 : int i;
825 :
826 0 : if (buff[0] == '!') {
827 0 : *not = 1;
828 0 : buff++;
829 0 : len--;
830 : } else
831 0 : *not = 0;
832 :
833 0 : *search = buff;
834 :
835 0 : if (isdigit(buff[0]))
836 : return MATCH_INDEX;
837 :
838 0 : for (i = 0; i < len; i++) {
839 0 : if (buff[i] == '*') {
840 0 : if (!i) {
841 : type = MATCH_END_ONLY;
842 0 : } else if (i == len - 1) {
843 0 : if (type == MATCH_END_ONLY)
844 : type = MATCH_MIDDLE_ONLY;
845 : else
846 0 : type = MATCH_FRONT_ONLY;
847 0 : buff[i] = 0;
848 0 : break;
849 : } else { /* pattern continues, use full glob */
850 : return MATCH_GLOB;
851 : }
852 0 : } else if (strchr("[?\\", buff[i])) {
853 : return MATCH_GLOB;
854 : }
855 : }
856 0 : if (buff[0] == '*')
857 0 : *search = buff + 1;
858 :
859 0 : return type;
860 : }
861 :
862 0 : static void filter_build_regex(struct filter_pred *pred)
863 : {
864 0 : struct regex *r = &pred->regex;
865 0 : char *search;
866 0 : enum regex_type type = MATCH_FULL;
867 :
868 0 : if (pred->op == OP_GLOB) {
869 0 : type = filter_parse_regex(r->pattern, r->len, &search, &pred->not);
870 0 : r->len = strlen(search);
871 0 : memmove(r->pattern, search, r->len+1);
872 : }
873 :
874 0 : switch (type) {
875 : /* MATCH_INDEX should not happen, but if it does, match full */
876 0 : case MATCH_INDEX:
877 : case MATCH_FULL:
878 0 : r->match = regex_match_full;
879 0 : break;
880 0 : case MATCH_FRONT_ONLY:
881 0 : r->match = regex_match_front;
882 0 : break;
883 0 : case MATCH_MIDDLE_ONLY:
884 0 : r->match = regex_match_middle;
885 0 : break;
886 0 : case MATCH_END_ONLY:
887 0 : r->match = regex_match_end;
888 0 : break;
889 0 : case MATCH_GLOB:
890 0 : r->match = regex_match_glob;
891 0 : break;
892 : }
893 0 : }
894 :
895 : /* return 1 if event matches, 0 otherwise (discard) */
896 0 : int filter_match_preds(struct event_filter *filter, void *rec)
897 : {
898 0 : struct prog_entry *prog;
899 0 : int i;
900 :
901 : /* no filter is considered a match */
902 0 : if (!filter)
903 : return 1;
904 :
905 : /* Protected by either SRCU(tracepoint_srcu) or preempt_disable */
906 0 : prog = rcu_dereference_raw(filter->prog);
907 0 : if (!prog)
908 : return 1;
909 :
910 0 : for (i = 0; prog[i].pred; i++) {
911 0 : struct filter_pred *pred = prog[i].pred;
912 0 : int match = pred->fn(pred, rec);
913 0 : if (match == prog[i].when_to_branch)
914 0 : i = prog[i].target;
915 : }
916 0 : return prog[i].target;
917 : }
918 : EXPORT_SYMBOL_GPL(filter_match_preds);
919 :
920 0 : static void remove_filter_string(struct event_filter *filter)
921 : {
922 0 : if (!filter)
923 : return;
924 :
925 0 : kfree(filter->filter_string);
926 0 : filter->filter_string = NULL;
927 : }
928 :
929 0 : static void append_filter_err(struct trace_array *tr,
930 : struct filter_parse_error *pe,
931 : struct event_filter *filter)
932 : {
933 0 : struct trace_seq *s;
934 0 : int pos = pe->lasterr_pos;
935 0 : char *buf;
936 0 : int len;
937 :
938 0 : if (WARN_ON(!filter->filter_string))
939 : return;
940 :
941 0 : s = kmalloc(sizeof(*s), GFP_KERNEL);
942 0 : if (!s)
943 : return;
944 0 : trace_seq_init(s);
945 :
946 0 : len = strlen(filter->filter_string);
947 0 : if (pos > len)
948 : pos = len;
949 :
950 : /* indexing is off by one */
951 0 : if (pos)
952 0 : pos++;
953 :
954 0 : trace_seq_puts(s, filter->filter_string);
955 0 : if (pe->lasterr > 0) {
956 0 : trace_seq_printf(s, "\n%*s", pos, "^");
957 0 : trace_seq_printf(s, "\nparse_error: %s\n", err_text[pe->lasterr]);
958 0 : tracing_log_err(tr, "event filter parse error",
959 0 : filter->filter_string, err_text,
960 0 : pe->lasterr, pe->lasterr_pos);
961 : } else {
962 0 : trace_seq_printf(s, "\nError: (%d)\n", pe->lasterr);
963 0 : tracing_log_err(tr, "event filter parse error",
964 0 : filter->filter_string, err_text,
965 : FILT_ERR_ERRNO, 0);
966 : }
967 0 : trace_seq_putc(s, 0);
968 0 : buf = kmemdup_nul(s->buffer, s->seq.len, GFP_KERNEL);
969 0 : if (buf) {
970 0 : kfree(filter->filter_string);
971 0 : filter->filter_string = buf;
972 : }
973 0 : kfree(s);
974 : }
975 :
976 0 : static inline struct event_filter *event_filter(struct trace_event_file *file)
977 : {
978 0 : return file->filter;
979 : }
980 :
981 : /* caller must hold event_mutex */
982 0 : void print_event_filter(struct trace_event_file *file, struct trace_seq *s)
983 : {
984 0 : struct event_filter *filter = event_filter(file);
985 :
986 0 : if (filter && filter->filter_string)
987 0 : trace_seq_printf(s, "%s\n", filter->filter_string);
988 : else
989 0 : trace_seq_puts(s, "none\n");
990 0 : }
991 :
992 0 : void print_subsystem_event_filter(struct event_subsystem *system,
993 : struct trace_seq *s)
994 : {
995 0 : struct event_filter *filter;
996 :
997 0 : mutex_lock(&event_mutex);
998 0 : filter = system->filter;
999 0 : if (filter && filter->filter_string)
1000 0 : trace_seq_printf(s, "%s\n", filter->filter_string);
1001 : else
1002 0 : trace_seq_puts(s, DEFAULT_SYS_FILTER_MESSAGE "\n");
1003 0 : mutex_unlock(&event_mutex);
1004 0 : }
1005 :
1006 0 : static void free_prog(struct event_filter *filter)
1007 : {
1008 0 : struct prog_entry *prog;
1009 0 : int i;
1010 :
1011 0 : prog = rcu_access_pointer(filter->prog);
1012 0 : if (!prog)
1013 : return;
1014 :
1015 0 : for (i = 0; prog[i].pred; i++)
1016 0 : kfree(prog[i].pred);
1017 0 : kfree(prog);
1018 : }
1019 :
1020 0 : static void filter_disable(struct trace_event_file *file)
1021 : {
1022 0 : unsigned long old_flags = file->flags;
1023 :
1024 0 : file->flags &= ~EVENT_FILE_FL_FILTERED;
1025 :
1026 0 : if (old_flags != file->flags)
1027 0 : trace_buffered_event_disable();
1028 : }
1029 :
1030 0 : static void __free_filter(struct event_filter *filter)
1031 : {
1032 0 : if (!filter)
1033 : return;
1034 :
1035 0 : free_prog(filter);
1036 0 : kfree(filter->filter_string);
1037 0 : kfree(filter);
1038 : }
1039 :
1040 0 : void free_event_filter(struct event_filter *filter)
1041 : {
1042 0 : __free_filter(filter);
1043 0 : }
1044 :
1045 0 : static inline void __remove_filter(struct trace_event_file *file)
1046 : {
1047 0 : filter_disable(file);
1048 0 : remove_filter_string(file->filter);
1049 0 : }
1050 :
1051 0 : static void filter_free_subsystem_preds(struct trace_subsystem_dir *dir,
1052 : struct trace_array *tr)
1053 : {
1054 0 : struct trace_event_file *file;
1055 :
1056 0 : list_for_each_entry(file, &tr->events, list) {
1057 0 : if (file->system != dir)
1058 0 : continue;
1059 0 : __remove_filter(file);
1060 : }
1061 0 : }
1062 :
1063 0 : static inline void __free_subsystem_filter(struct trace_event_file *file)
1064 : {
1065 0 : __free_filter(file->filter);
1066 0 : file->filter = NULL;
1067 0 : }
1068 :
1069 0 : static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir,
1070 : struct trace_array *tr)
1071 : {
1072 0 : struct trace_event_file *file;
1073 :
1074 0 : list_for_each_entry(file, &tr->events, list) {
1075 0 : if (file->system != dir)
1076 0 : continue;
1077 0 : __free_subsystem_filter(file);
1078 : }
1079 0 : }
1080 :
1081 1680 : int filter_assign_type(const char *type)
1082 : {
1083 1680 : if (strstr(type, "__data_loc") && strstr(type, "char"))
1084 : return FILTER_DYN_STRING;
1085 :
1086 1629 : if (strchr(type, '[') && strstr(type, "char"))
1087 : return FILTER_STATIC_STRING;
1088 :
1089 1582 : if (strcmp(type, "char *") == 0 || strcmp(type, "const char *") == 0)
1090 12 : return FILTER_PTR_STRING;
1091 :
1092 : return FILTER_OTHER;
1093 : }
1094 :
1095 0 : static filter_pred_fn_t select_comparison_fn(enum filter_op_ids op,
1096 : int field_size, int field_is_signed)
1097 : {
1098 0 : filter_pred_fn_t fn = NULL;
1099 0 : int pred_func_index = -1;
1100 :
1101 0 : switch (op) {
1102 : case OP_EQ:
1103 : case OP_NE:
1104 : break;
1105 0 : default:
1106 0 : if (WARN_ON_ONCE(op < PRED_FUNC_START))
1107 : return NULL;
1108 0 : pred_func_index = op - PRED_FUNC_START;
1109 0 : if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX))
1110 : return NULL;
1111 : }
1112 :
1113 0 : switch (field_size) {
1114 0 : case 8:
1115 0 : if (pred_func_index < 0)
1116 : fn = filter_pred_64;
1117 0 : else if (field_is_signed)
1118 0 : fn = pred_funcs_s64[pred_func_index];
1119 : else
1120 0 : fn = pred_funcs_u64[pred_func_index];
1121 : break;
1122 0 : case 4:
1123 0 : if (pred_func_index < 0)
1124 : fn = filter_pred_32;
1125 0 : else if (field_is_signed)
1126 0 : fn = pred_funcs_s32[pred_func_index];
1127 : else
1128 0 : fn = pred_funcs_u32[pred_func_index];
1129 : break;
1130 0 : case 2:
1131 0 : if (pred_func_index < 0)
1132 : fn = filter_pred_16;
1133 0 : else if (field_is_signed)
1134 0 : fn = pred_funcs_s16[pred_func_index];
1135 : else
1136 0 : fn = pred_funcs_u16[pred_func_index];
1137 : break;
1138 0 : case 1:
1139 0 : if (pred_func_index < 0)
1140 : fn = filter_pred_8;
1141 0 : else if (field_is_signed)
1142 0 : fn = pred_funcs_s8[pred_func_index];
1143 : else
1144 0 : 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 0 : 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 0 : struct trace_event_call *call = data;
1157 0 : struct ftrace_event_field *field;
1158 0 : struct filter_pred *pred = NULL;
1159 0 : char num_buf[24]; /* Big enough to hold an address */
1160 0 : char *field_name;
1161 0 : char q;
1162 0 : u64 val;
1163 0 : int len;
1164 0 : int ret;
1165 0 : int op;
1166 0 : int s;
1167 0 : int i = 0;
1168 :
1169 : /* First find the field to associate to */
1170 0 : while (isspace(str[i]))
1171 0 : i++;
1172 0 : s = i;
1173 :
1174 0 : while (isalnum(str[i]) || str[i] == '_')
1175 0 : i++;
1176 :
1177 0 : len = i - s;
1178 :
1179 0 : if (!len)
1180 : return -1;
1181 :
1182 0 : field_name = kmemdup_nul(str + s, len, GFP_KERNEL);
1183 0 : if (!field_name)
1184 : return -ENOMEM;
1185 :
1186 : /* Make sure that the field exists */
1187 :
1188 0 : field = trace_find_event_field(call, field_name);
1189 0 : kfree(field_name);
1190 0 : if (!field) {
1191 0 : parse_error(pe, FILT_ERR_FIELD_NOT_FOUND, pos + i);
1192 0 : return -EINVAL;
1193 : }
1194 :
1195 0 : while (isspace(str[i]))
1196 0 : i++;
1197 :
1198 : /* Make sure this op is supported */
1199 0 : for (op = 0; ops[op]; op++) {
1200 : /* This is why '<=' must come before '<' in ops[] */
1201 0 : if (strncmp(str + i, ops[op], strlen(ops[op])) == 0)
1202 : break;
1203 : }
1204 :
1205 0 : if (!ops[op]) {
1206 0 : parse_error(pe, FILT_ERR_INVALID_OP, pos + i);
1207 0 : goto err_free;
1208 : }
1209 :
1210 0 : i += strlen(ops[op]);
1211 :
1212 0 : while (isspace(str[i]))
1213 0 : i++;
1214 :
1215 0 : s = i;
1216 :
1217 0 : pred = kzalloc(sizeof(*pred), GFP_KERNEL);
1218 0 : if (!pred)
1219 : return -ENOMEM;
1220 :
1221 0 : pred->field = field;
1222 0 : pred->offset = field->offset;
1223 0 : pred->op = op;
1224 :
1225 0 : 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 0 : if (strcmp(field->name, "ip") != 0) {
1234 0 : parse_error(pe, FILT_ERR_IP_FIELD_ONLY, pos + i);
1235 0 : goto err_free;
1236 : }
1237 0 : 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 0 : if (str[i] == '\'' || str[i] == '"')
1244 0 : q = str[i];
1245 : else
1246 : q = 0;
1247 :
1248 0 : for (i++; str[i]; i++) {
1249 0 : if (q && str[i] == q)
1250 : break;
1251 0 : if (!q && (str[i] == ')' || str[i] == '&' ||
1252 : str[i] == '|'))
1253 : break;
1254 : }
1255 : /* Skip quotes */
1256 0 : if (q)
1257 0 : s++;
1258 0 : len = i - s;
1259 0 : if (len >= MAX_FILTER_STR_VAL) {
1260 0 : parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
1261 0 : goto err_free;
1262 : }
1263 :
1264 0 : pred->regex.len = len;
1265 0 : strncpy(pred->regex.pattern, str + s, len);
1266 0 : pred->regex.pattern[len] = 0;
1267 :
1268 : /* This is either a string, or an integer */
1269 0 : } else if (str[i] == '\'' || str[i] == '"') {
1270 0 : char q = str[i];
1271 :
1272 : /* Make sure the op is OK for strings */
1273 0 : switch (op) {
1274 0 : case OP_NE:
1275 0 : pred->not = 1;
1276 0 : fallthrough;
1277 : case OP_GLOB:
1278 : case OP_EQ:
1279 0 : break;
1280 0 : default:
1281 0 : parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
1282 0 : goto err_free;
1283 : }
1284 :
1285 : /* Make sure the field is OK for strings */
1286 0 : if (!is_string_field(field)) {
1287 0 : parse_error(pe, FILT_ERR_EXPECT_DIGIT, pos + i);
1288 0 : goto err_free;
1289 : }
1290 :
1291 0 : for (i++; str[i]; i++) {
1292 0 : if (str[i] == q)
1293 : break;
1294 : }
1295 0 : if (!str[i]) {
1296 0 : parse_error(pe, FILT_ERR_MISSING_QUOTE, pos + i);
1297 0 : goto err_free;
1298 : }
1299 :
1300 : /* Skip quotes */
1301 0 : s++;
1302 0 : len = i - s;
1303 0 : if (len >= MAX_FILTER_STR_VAL) {
1304 0 : parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
1305 0 : goto err_free;
1306 : }
1307 :
1308 0 : pred->regex.len = len;
1309 0 : strncpy(pred->regex.pattern, str + s, len);
1310 0 : pred->regex.pattern[len] = 0;
1311 :
1312 0 : filter_build_regex(pred);
1313 :
1314 0 : if (field->filter_type == FILTER_COMM) {
1315 0 : pred->fn = filter_pred_comm;
1316 :
1317 0 : } else if (field->filter_type == FILTER_STATIC_STRING) {
1318 0 : pred->fn = filter_pred_string;
1319 0 : pred->regex.field_len = field->size;
1320 :
1321 0 : } else if (field->filter_type == FILTER_DYN_STRING)
1322 0 : pred->fn = filter_pred_strloc;
1323 : else
1324 0 : pred->fn = filter_pred_pchar;
1325 : /* go past the last quote */
1326 0 : i++;
1327 :
1328 0 : } else if (isdigit(str[i]) || str[i] == '-') {
1329 :
1330 : /* Make sure the field is not a string */
1331 0 : if (is_string_field(field)) {
1332 0 : parse_error(pe, FILT_ERR_EXPECT_STRING, pos + i);
1333 0 : goto err_free;
1334 : }
1335 :
1336 0 : if (op == OP_GLOB) {
1337 0 : parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
1338 0 : goto err_free;
1339 : }
1340 :
1341 0 : if (str[i] == '-')
1342 0 : i++;
1343 :
1344 : /* We allow 0xDEADBEEF */
1345 0 : while (isalnum(str[i]))
1346 0 : i++;
1347 :
1348 0 : len = i - s;
1349 : /* 0xfeedfacedeadbeef is 18 chars max */
1350 0 : if (len >= sizeof(num_buf)) {
1351 0 : parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
1352 0 : goto err_free;
1353 : }
1354 :
1355 0 : strncpy(num_buf, str + s, len);
1356 0 : num_buf[len] = 0;
1357 :
1358 : /* Make sure it is a value */
1359 0 : if (field->is_signed)
1360 0 : ret = kstrtoll(num_buf, 0, &val);
1361 : else
1362 0 : ret = kstrtoull(num_buf, 0, &val);
1363 0 : if (ret) {
1364 0 : parse_error(pe, FILT_ERR_ILLEGAL_INTVAL, pos + s);
1365 0 : goto err_free;
1366 : }
1367 :
1368 0 : pred->val = val;
1369 :
1370 0 : if (field->filter_type == FILTER_CPU)
1371 0 : pred->fn = filter_pred_cpu;
1372 : else {
1373 0 : pred->fn = select_comparison_fn(pred->op, field->size,
1374 : field->is_signed);
1375 0 : if (pred->op == OP_NE)
1376 0 : pred->not = 1;
1377 : }
1378 :
1379 : } else {
1380 0 : parse_error(pe, FILT_ERR_INVALID_VALUE, pos + i);
1381 0 : goto err_free;
1382 : }
1383 :
1384 0 : *pred_ptr = pred;
1385 0 : return i;
1386 :
1387 0 : err_free:
1388 0 : kfree(pred);
1389 0 : 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 0 : static int calc_stack(const char *str, int *parens, int *preds, int *err)
1409 : {
1410 0 : bool is_pred = false;
1411 0 : int nr_preds = 0;
1412 0 : int open = 1; /* Count the expression as "(E)" */
1413 0 : int last_quote = 0;
1414 0 : int max_open = 1;
1415 0 : int quote = 0;
1416 0 : int i;
1417 :
1418 0 : *err = 0;
1419 :
1420 0 : for (i = 0; str[i]; i++) {
1421 0 : if (isspace(str[i]))
1422 0 : continue;
1423 0 : if (quote) {
1424 0 : if (str[i] == quote)
1425 0 : quote = 0;
1426 0 : continue;
1427 : }
1428 :
1429 0 : switch (str[i]) {
1430 0 : case '\'':
1431 : case '"':
1432 0 : quote = str[i];
1433 0 : last_quote = i;
1434 0 : break;
1435 0 : case '|':
1436 : case '&':
1437 0 : if (str[i+1] != str[i])
1438 : break;
1439 0 : is_pred = false;
1440 0 : continue;
1441 0 : case '(':
1442 0 : is_pred = false;
1443 0 : open++;
1444 0 : if (open > max_open)
1445 : max_open = open;
1446 0 : continue;
1447 0 : case ')':
1448 0 : is_pred = false;
1449 0 : if (open == 1) {
1450 0 : *err = i;
1451 0 : return TOO_MANY_CLOSE;
1452 : }
1453 0 : open--;
1454 0 : continue;
1455 : }
1456 0 : if (!is_pred) {
1457 0 : nr_preds++;
1458 0 : is_pred = true;
1459 : }
1460 : }
1461 :
1462 0 : if (quote) {
1463 0 : *err = last_quote;
1464 0 : return MISSING_QUOTE;
1465 : }
1466 :
1467 0 : if (open != 1) {
1468 0 : int level = open;
1469 :
1470 : /* find the bad open */
1471 0 : for (i--; i; i--) {
1472 0 : if (quote) {
1473 0 : if (str[i] == quote)
1474 0 : quote = 0;
1475 0 : continue;
1476 : }
1477 0 : switch (str[i]) {
1478 0 : case '(':
1479 0 : if (level == open) {
1480 0 : *err = i;
1481 0 : return TOO_MANY_OPEN;
1482 : }
1483 0 : level--;
1484 0 : break;
1485 0 : case ')':
1486 0 : level++;
1487 0 : break;
1488 0 : case '\'':
1489 : case '"':
1490 0 : quote = str[i];
1491 0 : break;
1492 : }
1493 0 : }
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 0 : *parens = max_open;
1501 0 : *preds = nr_preds;
1502 0 : return 0;
1503 : }
1504 :
1505 0 : 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 0 : struct prog_entry *prog;
1511 0 : int nr_parens;
1512 0 : int nr_preds;
1513 0 : int index;
1514 0 : int ret;
1515 :
1516 0 : ret = calc_stack(filter_string, &nr_parens, &nr_preds, &index);
1517 0 : if (ret < 0) {
1518 0 : switch (ret) {
1519 0 : case MISSING_QUOTE:
1520 0 : parse_error(pe, FILT_ERR_MISSING_QUOTE, index);
1521 : break;
1522 0 : case TOO_MANY_OPEN:
1523 0 : parse_error(pe, FILT_ERR_TOO_MANY_OPEN, index);
1524 : break;
1525 0 : default:
1526 0 : parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, index);
1527 : }
1528 0 : return ret;
1529 : }
1530 :
1531 0 : if (!nr_preds)
1532 : return -EINVAL;
1533 :
1534 0 : prog = predicate_parse(filter_string, nr_parens, nr_preds,
1535 : parse_pred, call, pe);
1536 0 : if (IS_ERR(prog))
1537 0 : return PTR_ERR(prog);
1538 :
1539 0 : rcu_assign_pointer(filter->prog, prog);
1540 0 : return 0;
1541 : }
1542 :
1543 0 : static inline void event_set_filtered_flag(struct trace_event_file *file)
1544 : {
1545 0 : unsigned long old_flags = file->flags;
1546 :
1547 0 : file->flags |= EVENT_FILE_FL_FILTERED;
1548 :
1549 0 : if (old_flags != file->flags)
1550 0 : trace_buffered_event_enable();
1551 : }
1552 :
1553 0 : static inline void event_set_filter(struct trace_event_file *file,
1554 : struct event_filter *filter)
1555 : {
1556 0 : rcu_assign_pointer(file->filter, filter);
1557 : }
1558 :
1559 0 : static inline void event_clear_filter(struct trace_event_file *file)
1560 : {
1561 0 : RCU_INIT_POINTER(file->filter, NULL);
1562 : }
1563 :
1564 : struct filter_list {
1565 : struct list_head list;
1566 : struct event_filter *filter;
1567 : };
1568 :
1569 0 : static int process_system_preds(struct trace_subsystem_dir *dir,
1570 : struct trace_array *tr,
1571 : struct filter_parse_error *pe,
1572 : char *filter_string)
1573 : {
1574 0 : struct trace_event_file *file;
1575 0 : struct filter_list *filter_item;
1576 0 : struct event_filter *filter = NULL;
1577 0 : struct filter_list *tmp;
1578 0 : LIST_HEAD(filter_list);
1579 0 : bool fail = true;
1580 0 : int err;
1581 :
1582 0 : list_for_each_entry(file, &tr->events, list) {
1583 :
1584 0 : if (file->system != dir)
1585 0 : continue;
1586 :
1587 0 : filter = kzalloc(sizeof(*filter), GFP_KERNEL);
1588 0 : if (!filter)
1589 0 : goto fail_mem;
1590 :
1591 0 : filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
1592 0 : if (!filter->filter_string)
1593 0 : goto fail_mem;
1594 :
1595 0 : err = process_preds(file->event_call, filter_string, filter, pe);
1596 0 : if (err) {
1597 0 : filter_disable(file);
1598 0 : parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0);
1599 0 : append_filter_err(tr, pe, filter);
1600 : } else
1601 0 : event_set_filtered_flag(file);
1602 :
1603 :
1604 0 : filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL);
1605 0 : if (!filter_item)
1606 0 : goto fail_mem;
1607 :
1608 0 : list_add_tail(&filter_item->list, &filter_list);
1609 : /*
1610 : * Regardless of if this returned an error, we still
1611 : * replace the filter for the call.
1612 : */
1613 0 : filter_item->filter = event_filter(file);
1614 0 : event_set_filter(file, filter);
1615 0 : filter = NULL;
1616 :
1617 0 : fail = false;
1618 : }
1619 :
1620 0 : if (fail)
1621 0 : goto fail;
1622 :
1623 : /*
1624 : * The calls can still be using the old filters.
1625 : * Do a synchronize_rcu() and to ensure all calls are
1626 : * done with them before we free them.
1627 : */
1628 0 : tracepoint_synchronize_unregister();
1629 0 : list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
1630 0 : __free_filter(filter_item->filter);
1631 0 : list_del(&filter_item->list);
1632 0 : kfree(filter_item);
1633 : }
1634 : return 0;
1635 0 : fail:
1636 : /* No call succeeded */
1637 0 : list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
1638 0 : list_del(&filter_item->list);
1639 0 : kfree(filter_item);
1640 : }
1641 0 : parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0);
1642 0 : return -EINVAL;
1643 0 : fail_mem:
1644 0 : __free_filter(filter);
1645 : /* If any call succeeded, we still need to sync */
1646 0 : if (!fail)
1647 0 : tracepoint_synchronize_unregister();
1648 0 : list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
1649 0 : __free_filter(filter_item->filter);
1650 0 : list_del(&filter_item->list);
1651 0 : kfree(filter_item);
1652 : }
1653 : return -ENOMEM;
1654 : }
1655 :
1656 0 : static int create_filter_start(char *filter_string, bool set_str,
1657 : struct filter_parse_error **pse,
1658 : struct event_filter **filterp)
1659 : {
1660 0 : struct event_filter *filter;
1661 0 : struct filter_parse_error *pe = NULL;
1662 0 : int err = 0;
1663 :
1664 0 : if (WARN_ON_ONCE(*pse || *filterp))
1665 : return -EINVAL;
1666 :
1667 0 : filter = kzalloc(sizeof(*filter), GFP_KERNEL);
1668 0 : if (filter && set_str) {
1669 0 : filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
1670 0 : if (!filter->filter_string)
1671 0 : err = -ENOMEM;
1672 : }
1673 :
1674 0 : pe = kzalloc(sizeof(*pe), GFP_KERNEL);
1675 :
1676 0 : if (!filter || !pe || err) {
1677 0 : kfree(pe);
1678 0 : __free_filter(filter);
1679 0 : return -ENOMEM;
1680 : }
1681 :
1682 : /* we're committed to creating a new filter */
1683 0 : *filterp = filter;
1684 0 : *pse = pe;
1685 :
1686 0 : return 0;
1687 : }
1688 :
1689 0 : static void create_filter_finish(struct filter_parse_error *pe)
1690 : {
1691 0 : kfree(pe);
1692 : }
1693 :
1694 : /**
1695 : * create_filter - create a filter for a trace_event_call
1696 : * @call: trace_event_call to create a filter for
1697 : * @filter_str: filter string
1698 : * @set_str: remember @filter_str and enable detailed error in filter
1699 : * @filterp: out param for created filter (always updated on return)
1700 : * Must be a pointer that references a NULL pointer.
1701 : *
1702 : * Creates a filter for @call with @filter_str. If @set_str is %true,
1703 : * @filter_str is copied and recorded in the new filter.
1704 : *
1705 : * On success, returns 0 and *@filterp points to the new filter. On
1706 : * failure, returns -errno and *@filterp may point to %NULL or to a new
1707 : * filter. In the latter case, the returned filter contains error
1708 : * information if @set_str is %true and the caller is responsible for
1709 : * freeing it.
1710 : */
1711 0 : static int create_filter(struct trace_array *tr,
1712 : struct trace_event_call *call,
1713 : char *filter_string, bool set_str,
1714 : struct event_filter **filterp)
1715 : {
1716 0 : struct filter_parse_error *pe = NULL;
1717 0 : int err;
1718 :
1719 : /* filterp must point to NULL */
1720 0 : if (WARN_ON(*filterp))
1721 0 : *filterp = NULL;
1722 :
1723 0 : err = create_filter_start(filter_string, set_str, &pe, filterp);
1724 0 : if (err)
1725 : return err;
1726 :
1727 0 : err = process_preds(call, filter_string, *filterp, pe);
1728 0 : if (err && set_str)
1729 0 : append_filter_err(tr, pe, *filterp);
1730 0 : create_filter_finish(pe);
1731 :
1732 0 : return err;
1733 : }
1734 :
1735 0 : int create_event_filter(struct trace_array *tr,
1736 : struct trace_event_call *call,
1737 : char *filter_str, bool set_str,
1738 : struct event_filter **filterp)
1739 : {
1740 0 : return create_filter(tr, call, filter_str, set_str, filterp);
1741 : }
1742 :
1743 : /**
1744 : * create_system_filter - create a filter for an event_subsystem
1745 : * @system: event_subsystem to create a filter for
1746 : * @filter_str: filter string
1747 : * @filterp: out param for created filter (always updated on return)
1748 : *
1749 : * Identical to create_filter() except that it creates a subsystem filter
1750 : * and always remembers @filter_str.
1751 : */
1752 0 : static int create_system_filter(struct trace_subsystem_dir *dir,
1753 : struct trace_array *tr,
1754 : char *filter_str, struct event_filter **filterp)
1755 : {
1756 0 : struct filter_parse_error *pe = NULL;
1757 0 : int err;
1758 :
1759 0 : err = create_filter_start(filter_str, true, &pe, filterp);
1760 0 : if (!err) {
1761 0 : err = process_system_preds(dir, tr, pe, filter_str);
1762 0 : if (!err) {
1763 : /* System filters just show a default message */
1764 0 : kfree((*filterp)->filter_string);
1765 0 : (*filterp)->filter_string = NULL;
1766 : } else {
1767 0 : append_filter_err(tr, pe, *filterp);
1768 : }
1769 : }
1770 0 : create_filter_finish(pe);
1771 :
1772 0 : return err;
1773 : }
1774 :
1775 : /* caller must hold event_mutex */
1776 0 : int apply_event_filter(struct trace_event_file *file, char *filter_string)
1777 : {
1778 0 : struct trace_event_call *call = file->event_call;
1779 0 : struct event_filter *filter = NULL;
1780 0 : int err;
1781 :
1782 0 : if (!strcmp(strstrip(filter_string), "0")) {
1783 0 : filter_disable(file);
1784 0 : filter = event_filter(file);
1785 :
1786 0 : if (!filter)
1787 : return 0;
1788 :
1789 0 : event_clear_filter(file);
1790 :
1791 : /* Make sure the filter is not being used */
1792 0 : tracepoint_synchronize_unregister();
1793 0 : __free_filter(filter);
1794 :
1795 0 : return 0;
1796 : }
1797 :
1798 0 : err = create_filter(file->tr, call, filter_string, true, &filter);
1799 :
1800 : /*
1801 : * Always swap the call filter with the new filter
1802 : * even if there was an error. If there was an error
1803 : * in the filter, we disable the filter and show the error
1804 : * string
1805 : */
1806 0 : if (filter) {
1807 0 : struct event_filter *tmp;
1808 :
1809 0 : tmp = event_filter(file);
1810 0 : if (!err)
1811 0 : event_set_filtered_flag(file);
1812 : else
1813 0 : filter_disable(file);
1814 :
1815 0 : event_set_filter(file, filter);
1816 :
1817 0 : if (tmp) {
1818 : /* Make sure the call is done with the filter */
1819 0 : tracepoint_synchronize_unregister();
1820 0 : __free_filter(tmp);
1821 : }
1822 : }
1823 :
1824 : return err;
1825 : }
1826 :
1827 0 : int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1828 : char *filter_string)
1829 : {
1830 0 : struct event_subsystem *system = dir->subsystem;
1831 0 : struct trace_array *tr = dir->tr;
1832 0 : struct event_filter *filter = NULL;
1833 0 : int err = 0;
1834 :
1835 0 : mutex_lock(&event_mutex);
1836 :
1837 : /* Make sure the system still has events */
1838 0 : if (!dir->nr_events) {
1839 0 : err = -ENODEV;
1840 0 : goto out_unlock;
1841 : }
1842 :
1843 0 : if (!strcmp(strstrip(filter_string), "0")) {
1844 0 : filter_free_subsystem_preds(dir, tr);
1845 0 : remove_filter_string(system->filter);
1846 0 : filter = system->filter;
1847 0 : system->filter = NULL;
1848 : /* Ensure all filters are no longer used */
1849 0 : tracepoint_synchronize_unregister();
1850 0 : filter_free_subsystem_filters(dir, tr);
1851 0 : __free_filter(filter);
1852 0 : goto out_unlock;
1853 : }
1854 :
1855 0 : err = create_system_filter(dir, tr, filter_string, &filter);
1856 0 : if (filter) {
1857 : /*
1858 : * No event actually uses the system filter
1859 : * we can free it without synchronize_rcu().
1860 : */
1861 0 : __free_filter(system->filter);
1862 0 : system->filter = filter;
1863 : }
1864 0 : out_unlock:
1865 0 : mutex_unlock(&event_mutex);
1866 :
1867 0 : return err;
1868 : }
1869 :
1870 : #ifdef CONFIG_PERF_EVENTS
1871 :
1872 0 : void ftrace_profile_free_filter(struct perf_event *event)
1873 : {
1874 0 : struct event_filter *filter = event->filter;
1875 :
1876 0 : event->filter = NULL;
1877 0 : __free_filter(filter);
1878 0 : }
1879 :
1880 : struct function_filter_data {
1881 : struct ftrace_ops *ops;
1882 : int first_filter;
1883 : int first_notrace;
1884 : };
1885 :
1886 : #ifdef CONFIG_FUNCTION_TRACER
1887 : static char **
1888 : ftrace_function_filter_re(char *buf, int len, int *count)
1889 : {
1890 : char *str, **re;
1891 :
1892 : str = kstrndup(buf, len, GFP_KERNEL);
1893 : if (!str)
1894 : return NULL;
1895 :
1896 : /*
1897 : * The argv_split function takes white space
1898 : * as a separator, so convert ',' into spaces.
1899 : */
1900 : strreplace(str, ',', ' ');
1901 :
1902 : re = argv_split(GFP_KERNEL, str, count);
1903 : kfree(str);
1904 : return re;
1905 : }
1906 :
1907 : static int ftrace_function_set_regexp(struct ftrace_ops *ops, int filter,
1908 : int reset, char *re, int len)
1909 : {
1910 : int ret;
1911 :
1912 : if (filter)
1913 : ret = ftrace_set_filter(ops, re, len, reset);
1914 : else
1915 : ret = ftrace_set_notrace(ops, re, len, reset);
1916 :
1917 : return ret;
1918 : }
1919 :
1920 : static int __ftrace_function_set_filter(int filter, char *buf, int len,
1921 : struct function_filter_data *data)
1922 : {
1923 : int i, re_cnt, ret = -EINVAL;
1924 : int *reset;
1925 : char **re;
1926 :
1927 : reset = filter ? &data->first_filter : &data->first_notrace;
1928 :
1929 : /*
1930 : * The 'ip' field could have multiple filters set, separated
1931 : * either by space or comma. We first cut the filter and apply
1932 : * all pieces separately.
1933 : */
1934 : re = ftrace_function_filter_re(buf, len, &re_cnt);
1935 : if (!re)
1936 : return -EINVAL;
1937 :
1938 : for (i = 0; i < re_cnt; i++) {
1939 : ret = ftrace_function_set_regexp(data->ops, filter, *reset,
1940 : re[i], strlen(re[i]));
1941 : if (ret)
1942 : break;
1943 :
1944 : if (*reset)
1945 : *reset = 0;
1946 : }
1947 :
1948 : argv_free(re);
1949 : return ret;
1950 : }
1951 :
1952 : static int ftrace_function_check_pred(struct filter_pred *pred)
1953 : {
1954 : struct ftrace_event_field *field = pred->field;
1955 :
1956 : /*
1957 : * Check the predicate for function trace, verify:
1958 : * - only '==' and '!=' is used
1959 : * - the 'ip' field is used
1960 : */
1961 : if ((pred->op != OP_EQ) && (pred->op != OP_NE))
1962 : return -EINVAL;
1963 :
1964 : if (strcmp(field->name, "ip"))
1965 : return -EINVAL;
1966 :
1967 : return 0;
1968 : }
1969 :
1970 : static int ftrace_function_set_filter_pred(struct filter_pred *pred,
1971 : struct function_filter_data *data)
1972 : {
1973 : int ret;
1974 :
1975 : /* Checking the node is valid for function trace. */
1976 : ret = ftrace_function_check_pred(pred);
1977 : if (ret)
1978 : return ret;
1979 :
1980 : return __ftrace_function_set_filter(pred->op == OP_EQ,
1981 : pred->regex.pattern,
1982 : pred->regex.len,
1983 : data);
1984 : }
1985 :
1986 : static bool is_or(struct prog_entry *prog, int i)
1987 : {
1988 : int target;
1989 :
1990 : /*
1991 : * Only "||" is allowed for function events, thus,
1992 : * all true branches should jump to true, and any
1993 : * false branch should jump to false.
1994 : */
1995 : target = prog[i].target + 1;
1996 : /* True and false have NULL preds (all prog entries should jump to one */
1997 : if (prog[target].pred)
1998 : return false;
1999 :
2000 : /* prog[target].target is 1 for TRUE, 0 for FALSE */
2001 : return prog[i].when_to_branch == prog[target].target;
2002 : }
2003 :
2004 : static int ftrace_function_set_filter(struct perf_event *event,
2005 : struct event_filter *filter)
2006 : {
2007 : struct prog_entry *prog = rcu_dereference_protected(filter->prog,
2008 : lockdep_is_held(&event_mutex));
2009 : struct function_filter_data data = {
2010 : .first_filter = 1,
2011 : .first_notrace = 1,
2012 : .ops = &event->ftrace_ops,
2013 : };
2014 : int i;
2015 :
2016 : for (i = 0; prog[i].pred; i++) {
2017 : struct filter_pred *pred = prog[i].pred;
2018 :
2019 : if (!is_or(prog, i))
2020 : return -EINVAL;
2021 :
2022 : if (ftrace_function_set_filter_pred(pred, &data) < 0)
2023 : return -EINVAL;
2024 : }
2025 : return 0;
2026 : }
2027 : #else
2028 : static int ftrace_function_set_filter(struct perf_event *event,
2029 : struct event_filter *filter)
2030 : {
2031 : return -ENODEV;
2032 : }
2033 : #endif /* CONFIG_FUNCTION_TRACER */
2034 :
2035 0 : int ftrace_profile_set_filter(struct perf_event *event, int event_id,
2036 : char *filter_str)
2037 : {
2038 0 : int err;
2039 0 : struct event_filter *filter = NULL;
2040 0 : struct trace_event_call *call;
2041 :
2042 0 : mutex_lock(&event_mutex);
2043 :
2044 0 : call = event->tp_event;
2045 :
2046 0 : err = -EINVAL;
2047 0 : if (!call)
2048 0 : goto out_unlock;
2049 :
2050 0 : err = -EEXIST;
2051 0 : if (event->filter)
2052 0 : goto out_unlock;
2053 :
2054 0 : err = create_filter(NULL, call, filter_str, false, &filter);
2055 0 : if (err)
2056 0 : goto free_filter;
2057 :
2058 0 : if (ftrace_event_is_function(call))
2059 0 : err = ftrace_function_set_filter(event, filter);
2060 : else
2061 0 : event->filter = filter;
2062 :
2063 0 : free_filter:
2064 0 : if (err || ftrace_event_is_function(call))
2065 0 : __free_filter(filter);
2066 :
2067 0 : out_unlock:
2068 0 : mutex_unlock(&event_mutex);
2069 :
2070 0 : return err;
2071 : }
2072 :
2073 : #endif /* CONFIG_PERF_EVENTS */
2074 :
2075 : #ifdef CONFIG_FTRACE_STARTUP_TEST
2076 :
2077 : #include <linux/types.h>
2078 : #include <linux/tracepoint.h>
2079 :
2080 : #define CREATE_TRACE_POINTS
2081 : #include "trace_events_filter_test.h"
2082 :
2083 : #define DATA_REC(m, va, vb, vc, vd, ve, vf, vg, vh, nvisit) \
2084 : { \
2085 : .filter = FILTER, \
2086 : .rec = { .a = va, .b = vb, .c = vc, .d = vd, \
2087 : .e = ve, .f = vf, .g = vg, .h = vh }, \
2088 : .match = m, \
2089 : .not_visited = nvisit, \
2090 : }
2091 : #define YES 1
2092 : #define NO 0
2093 :
2094 : static struct test_filter_data_t {
2095 : char *filter;
2096 : struct trace_event_raw_ftrace_test_filter rec;
2097 : int match;
2098 : char *not_visited;
2099 : } test_filter_data[] = {
2100 : #define FILTER "a == 1 && b == 1 && c == 1 && d == 1 && " \
2101 : "e == 1 && f == 1 && g == 1 && h == 1"
2102 : DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, ""),
2103 : DATA_REC(NO, 0, 1, 1, 1, 1, 1, 1, 1, "bcdefgh"),
2104 : DATA_REC(NO, 1, 1, 1, 1, 1, 1, 1, 0, ""),
2105 : #undef FILTER
2106 : #define FILTER "a == 1 || b == 1 || c == 1 || d == 1 || " \
2107 : "e == 1 || f == 1 || g == 1 || h == 1"
2108 : DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 0, ""),
2109 : DATA_REC(YES, 0, 0, 0, 0, 0, 0, 0, 1, ""),
2110 : DATA_REC(YES, 1, 0, 0, 0, 0, 0, 0, 0, "bcdefgh"),
2111 : #undef FILTER
2112 : #define FILTER "(a == 1 || b == 1) && (c == 1 || d == 1) && " \
2113 : "(e == 1 || f == 1) && (g == 1 || h == 1)"
2114 : DATA_REC(NO, 0, 0, 1, 1, 1, 1, 1, 1, "dfh"),
2115 : DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2116 : DATA_REC(YES, 1, 0, 1, 0, 0, 1, 0, 1, "bd"),
2117 : DATA_REC(NO, 1, 0, 1, 0, 0, 1, 0, 0, "bd"),
2118 : #undef FILTER
2119 : #define FILTER "(a == 1 && b == 1) || (c == 1 && d == 1) || " \
2120 : "(e == 1 && f == 1) || (g == 1 && h == 1)"
2121 : DATA_REC(YES, 1, 0, 1, 1, 1, 1, 1, 1, "efgh"),
2122 : DATA_REC(YES, 0, 0, 0, 0, 0, 0, 1, 1, ""),
2123 : DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 1, ""),
2124 : #undef FILTER
2125 : #define FILTER "(a == 1 && b == 1) && (c == 1 && d == 1) && " \
2126 : "(e == 1 && f == 1) || (g == 1 && h == 1)"
2127 : DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 0, "gh"),
2128 : DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 1, ""),
2129 : DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, ""),
2130 : #undef FILTER
2131 : #define FILTER "((a == 1 || b == 1) || (c == 1 || d == 1) || " \
2132 : "(e == 1 || f == 1)) && (g == 1 || h == 1)"
2133 : DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 1, "bcdef"),
2134 : DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 0, ""),
2135 : DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, "h"),
2136 : #undef FILTER
2137 : #define FILTER "((((((((a == 1) && (b == 1)) || (c == 1)) && (d == 1)) || " \
2138 : "(e == 1)) && (f == 1)) || (g == 1)) && (h == 1))"
2139 : DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "ceg"),
2140 : DATA_REC(NO, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2141 : DATA_REC(NO, 1, 0, 1, 0, 1, 0, 1, 0, ""),
2142 : #undef FILTER
2143 : #define FILTER "((((((((a == 1) || (b == 1)) && (c == 1)) || (d == 1)) && " \
2144 : "(e == 1)) || (f == 1)) && (g == 1)) || (h == 1))"
2145 : DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "bdfh"),
2146 : DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2147 : DATA_REC(YES, 1, 0, 1, 0, 1, 0, 1, 0, "bdfh"),
2148 : };
2149 :
2150 : #undef DATA_REC
2151 : #undef FILTER
2152 : #undef YES
2153 : #undef NO
2154 :
2155 : #define DATA_CNT ARRAY_SIZE(test_filter_data)
2156 :
2157 : static int test_pred_visited;
2158 :
2159 : static int test_pred_visited_fn(struct filter_pred *pred, void *event)
2160 : {
2161 : struct ftrace_event_field *field = pred->field;
2162 :
2163 : test_pred_visited = 1;
2164 : printk(KERN_INFO "\npred visited %s\n", field->name);
2165 : return 1;
2166 : }
2167 :
2168 : static void update_pred_fn(struct event_filter *filter, char *fields)
2169 : {
2170 : struct prog_entry *prog = rcu_dereference_protected(filter->prog,
2171 : lockdep_is_held(&event_mutex));
2172 : int i;
2173 :
2174 : for (i = 0; prog[i].pred; i++) {
2175 : struct filter_pred *pred = prog[i].pred;
2176 : struct ftrace_event_field *field = pred->field;
2177 :
2178 : WARN_ON_ONCE(!pred->fn);
2179 :
2180 : if (!field) {
2181 : WARN_ONCE(1, "all leafs should have field defined %d", i);
2182 : continue;
2183 : }
2184 :
2185 : if (!strchr(fields, *field->name))
2186 : continue;
2187 :
2188 : pred->fn = test_pred_visited_fn;
2189 : }
2190 : }
2191 :
2192 : static __init int ftrace_test_event_filter(void)
2193 : {
2194 : int i;
2195 :
2196 : printk(KERN_INFO "Testing ftrace filter: ");
2197 :
2198 : for (i = 0; i < DATA_CNT; i++) {
2199 : struct event_filter *filter = NULL;
2200 : struct test_filter_data_t *d = &test_filter_data[i];
2201 : int err;
2202 :
2203 : err = create_filter(NULL, &event_ftrace_test_filter,
2204 : d->filter, false, &filter);
2205 : if (err) {
2206 : printk(KERN_INFO
2207 : "Failed to get filter for '%s', err %d\n",
2208 : d->filter, err);
2209 : __free_filter(filter);
2210 : break;
2211 : }
2212 :
2213 : /* Needed to dereference filter->prog */
2214 : mutex_lock(&event_mutex);
2215 : /*
2216 : * The preemption disabling is not really needed for self
2217 : * tests, but the rcu dereference will complain without it.
2218 : */
2219 : preempt_disable();
2220 : if (*d->not_visited)
2221 : update_pred_fn(filter, d->not_visited);
2222 :
2223 : test_pred_visited = 0;
2224 : err = filter_match_preds(filter, &d->rec);
2225 : preempt_enable();
2226 :
2227 : mutex_unlock(&event_mutex);
2228 :
2229 : __free_filter(filter);
2230 :
2231 : if (test_pred_visited) {
2232 : printk(KERN_INFO
2233 : "Failed, unwanted pred visited for filter %s\n",
2234 : d->filter);
2235 : break;
2236 : }
2237 :
2238 : if (err != d->match) {
2239 : printk(KERN_INFO
2240 : "Failed to match filter '%s', expected %d\n",
2241 : d->filter, d->match);
2242 : break;
2243 : }
2244 : }
2245 :
2246 : if (i == DATA_CNT)
2247 : printk(KERN_CONT "OK\n");
2248 :
2249 : return 0;
2250 : }
2251 :
2252 : late_initcall(ftrace_test_event_filter);
2253 :
2254 : #endif /* CONFIG_FTRACE_STARTUP_TEST */
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