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/uaccess.h> |
9 | #include <linux/module.h> |
10 | #include <linux/ctype.h> |
11 | #include <linux/mutex.h> |
12 | #include <linux/perf_event.h> |
13 | #include <linux/slab.h> |
14 | |
15 | #include "trace.h" |
16 | #include "trace_output.h" |
17 | |
18 | #define DEFAULT_SYS_FILTER_MESSAGE \ |
19 | "### global filter ###\n" \ |
20 | "# Use this to set filters for multiple events.\n" \ |
21 | "# Only events with the given fields will be affected.\n" \ |
22 | "# If no events are modified, an error message will be displayed here" |
23 | |
24 | /* Due to token parsing '<=' must be before '<' and '>=' must be before '>' */ |
25 | #define OPS \ |
26 | C( OP_GLOB, "~" ), \ |
27 | C( OP_NE, "!=" ), \ |
28 | C( OP_EQ, "==" ), \ |
29 | C( OP_LE, "<=" ), \ |
30 | C( OP_LT, "<" ), \ |
31 | C( OP_GE, ">=" ), \ |
32 | C( OP_GT, ">" ), \ |
33 | C( OP_BAND, "&" ), \ |
34 | C( OP_MAX, NULL ) |
35 | |
36 | #undef C |
37 | #define C(a, b) a |
38 | |
39 | enum filter_op_ids { OPS }; |
40 | |
41 | #undef C |
42 | #define C(a, b) b |
43 | |
44 | static const char * ops[] = { OPS }; |
45 | |
46 | enum filter_pred_fn { |
47 | FILTER_PRED_FN_NOP, |
48 | FILTER_PRED_FN_64, |
49 | FILTER_PRED_FN_64_CPUMASK, |
50 | FILTER_PRED_FN_S64, |
51 | FILTER_PRED_FN_U64, |
52 | FILTER_PRED_FN_32, |
53 | FILTER_PRED_FN_32_CPUMASK, |
54 | FILTER_PRED_FN_S32, |
55 | FILTER_PRED_FN_U32, |
56 | FILTER_PRED_FN_16, |
57 | FILTER_PRED_FN_16_CPUMASK, |
58 | FILTER_PRED_FN_S16, |
59 | FILTER_PRED_FN_U16, |
60 | FILTER_PRED_FN_8, |
61 | FILTER_PRED_FN_8_CPUMASK, |
62 | FILTER_PRED_FN_S8, |
63 | FILTER_PRED_FN_U8, |
64 | FILTER_PRED_FN_COMM, |
65 | FILTER_PRED_FN_STRING, |
66 | FILTER_PRED_FN_STRLOC, |
67 | FILTER_PRED_FN_STRRELLOC, |
68 | FILTER_PRED_FN_PCHAR_USER, |
69 | FILTER_PRED_FN_PCHAR, |
70 | FILTER_PRED_FN_CPU, |
71 | FILTER_PRED_FN_CPU_CPUMASK, |
72 | FILTER_PRED_FN_CPUMASK, |
73 | FILTER_PRED_FN_CPUMASK_CPU, |
74 | FILTER_PRED_FN_FUNCTION, |
75 | FILTER_PRED_FN_, |
76 | FILTER_PRED_TEST_VISITED, |
77 | }; |
78 | |
79 | struct filter_pred { |
80 | struct regex *regex; |
81 | struct cpumask *mask; |
82 | unsigned short *ops; |
83 | struct ftrace_event_field *field; |
84 | u64 val; |
85 | u64 val2; |
86 | enum filter_pred_fn fn_num; |
87 | int offset; |
88 | int not; |
89 | int op; |
90 | }; |
91 | |
92 | /* |
93 | * pred functions are OP_LE, OP_LT, OP_GE, OP_GT, and OP_BAND |
94 | * pred_funcs_##type below must match the order of them above. |
95 | */ |
96 | #define PRED_FUNC_START OP_LE |
97 | #define PRED_FUNC_MAX (OP_BAND - PRED_FUNC_START) |
98 | |
99 | #define ERRORS \ |
100 | C(NONE, "No error"), \ |
101 | C(INVALID_OP, "Invalid operator"), \ |
102 | C(TOO_MANY_OPEN, "Too many '('"), \ |
103 | C(TOO_MANY_CLOSE, "Too few '('"), \ |
104 | C(MISSING_QUOTE, "Missing matching quote"), \ |
105 | C(MISSING_BRACE_OPEN, "Missing '{'"), \ |
106 | C(MISSING_BRACE_CLOSE, "Missing '}'"), \ |
107 | C(OPERAND_TOO_LONG, "Operand too long"), \ |
108 | C(EXPECT_STRING, "Expecting string field"), \ |
109 | C(EXPECT_DIGIT, "Expecting numeric field"), \ |
110 | C(ILLEGAL_FIELD_OP, "Illegal operation for field type"), \ |
111 | C(FIELD_NOT_FOUND, "Field not found"), \ |
112 | C(ILLEGAL_INTVAL, "Illegal integer value"), \ |
113 | C(BAD_SUBSYS_FILTER, "Couldn't find or set field in one of a subsystem's events"), \ |
114 | C(TOO_MANY_PREDS, "Too many terms in predicate expression"), \ |
115 | C(INVALID_FILTER, "Meaningless filter expression"), \ |
116 | C(INVALID_CPULIST, "Invalid cpulist"), \ |
117 | C(IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \ |
118 | C(INVALID_VALUE, "Invalid value (did you forget quotes)?"), \ |
119 | C(NO_FUNCTION, "Function not found"), \ |
120 | C(ERRNO, "Error"), \ |
121 | C(NO_FILTER, "No filter found") |
122 | |
123 | #undef C |
124 | #define C(a, b) FILT_ERR_##a |
125 | |
126 | enum { ERRORS }; |
127 | |
128 | #undef C |
129 | #define C(a, b) b |
130 | |
131 | static const char *err_text[] = { ERRORS }; |
132 | |
133 | /* Called after a '!' character but "!=" and "!~" are not "not"s */ |
134 | static bool is_not(const char *str) |
135 | { |
136 | switch (str[1]) { |
137 | case '=': |
138 | case '~': |
139 | return false; |
140 | } |
141 | return true; |
142 | } |
143 | |
144 | /** |
145 | * struct prog_entry - a singe entry in the filter program |
146 | * @target: Index to jump to on a branch (actually one minus the index) |
147 | * @when_to_branch: The value of the result of the predicate to do a branch |
148 | * @pred: The predicate to execute. |
149 | */ |
150 | struct prog_entry { |
151 | int target; |
152 | int when_to_branch; |
153 | struct filter_pred *pred; |
154 | }; |
155 | |
156 | /** |
157 | * update_preds - assign a program entry a label target |
158 | * @prog: The program array |
159 | * @N: The index of the current entry in @prog |
160 | * @invert: What to assign a program entry for its branch condition |
161 | * |
162 | * The program entry at @N has a target that points to the index of a program |
163 | * entry that can have its target and when_to_branch fields updated. |
164 | * Update the current program entry denoted by index @N target field to be |
165 | * that of the updated entry. This will denote the entry to update if |
166 | * we are processing an "||" after an "&&". |
167 | */ |
168 | static void update_preds(struct prog_entry *prog, int N, int invert) |
169 | { |
170 | int t, s; |
171 | |
172 | t = prog[N].target; |
173 | s = prog[t].target; |
174 | prog[t].when_to_branch = invert; |
175 | prog[t].target = N; |
176 | prog[N].target = s; |
177 | } |
178 | |
179 | struct filter_parse_error { |
180 | int lasterr; |
181 | int lasterr_pos; |
182 | }; |
183 | |
184 | static void parse_error(struct filter_parse_error *pe, int err, int pos) |
185 | { |
186 | pe->lasterr = err; |
187 | pe->lasterr_pos = pos; |
188 | } |
189 | |
190 | typedef int (*parse_pred_fn)(const char *str, void *data, int pos, |
191 | struct filter_parse_error *pe, |
192 | struct filter_pred **pred); |
193 | |
194 | enum { |
195 | INVERT = 1, |
196 | PROCESS_AND = 2, |
197 | PROCESS_OR = 4, |
198 | }; |
199 | |
200 | static void free_predicate(struct filter_pred *pred) |
201 | { |
202 | if (pred) { |
203 | kfree(objp: pred->regex); |
204 | kfree(objp: pred->mask); |
205 | kfree(objp: pred); |
206 | } |
207 | } |
208 | |
209 | /* |
210 | * Without going into a formal proof, this explains the method that is used in |
211 | * parsing the logical expressions. |
212 | * |
213 | * For example, if we have: "a && !(!b || (c && g)) || d || e && !f" |
214 | * The first pass will convert it into the following program: |
215 | * |
216 | * n1: r=a; l1: if (!r) goto l4; |
217 | * n2: r=b; l2: if (!r) goto l4; |
218 | * n3: r=c; r=!r; l3: if (r) goto l4; |
219 | * n4: r=g; r=!r; l4: if (r) goto l5; |
220 | * n5: r=d; l5: if (r) goto T |
221 | * n6: r=e; l6: if (!r) goto l7; |
222 | * n7: r=f; r=!r; l7: if (!r) goto F |
223 | * T: return TRUE |
224 | * F: return FALSE |
225 | * |
226 | * To do this, we use a data structure to represent each of the above |
227 | * predicate and conditions that has: |
228 | * |
229 | * predicate, when_to_branch, invert, target |
230 | * |
231 | * The "predicate" will hold the function to determine the result "r". |
232 | * The "when_to_branch" denotes what "r" should be if a branch is to be taken |
233 | * "&&" would contain "!r" or (0) and "||" would contain "r" or (1). |
234 | * The "invert" holds whether the value should be reversed before testing. |
235 | * The "target" contains the label "l#" to jump to. |
236 | * |
237 | * A stack is created to hold values when parentheses are used. |
238 | * |
239 | * To simplify the logic, the labels will start at 0 and not 1. |
240 | * |
241 | * The possible invert values are 1 and 0. The number of "!"s that are in scope |
242 | * before the predicate determines the invert value, if the number is odd then |
243 | * the invert value is 1 and 0 otherwise. This means the invert value only |
244 | * needs to be toggled when a new "!" is introduced compared to what is stored |
245 | * on the stack, where parentheses were used. |
246 | * |
247 | * The top of the stack and "invert" are initialized to zero. |
248 | * |
249 | * ** FIRST PASS ** |
250 | * |
251 | * #1 A loop through all the tokens is done: |
252 | * |
253 | * #2 If the token is an "(", the stack is push, and the current stack value |
254 | * gets the current invert value, and the loop continues to the next token. |
255 | * The top of the stack saves the "invert" value to keep track of what |
256 | * the current inversion is. As "!(a && !b || c)" would require all |
257 | * predicates being affected separately by the "!" before the parentheses. |
258 | * And that would end up being equivalent to "(!a || b) && !c" |
259 | * |
260 | * #3 If the token is an "!", the current "invert" value gets inverted, and |
261 | * the loop continues. Note, if the next token is a predicate, then |
262 | * this "invert" value is only valid for the current program entry, |
263 | * and does not affect other predicates later on. |
264 | * |
265 | * The only other acceptable token is the predicate string. |
266 | * |
267 | * #4 A new entry into the program is added saving: the predicate and the |
268 | * current value of "invert". The target is currently assigned to the |
269 | * previous program index (this will not be its final value). |
270 | * |
271 | * #5 We now enter another loop and look at the next token. The only valid |
272 | * tokens are ")", "&&", "||" or end of the input string "\0". |
273 | * |
274 | * #6 The invert variable is reset to the current value saved on the top of |
275 | * the stack. |
276 | * |
277 | * #7 The top of the stack holds not only the current invert value, but also |
278 | * if a "&&" or "||" needs to be processed. Note, the "&&" takes higher |
279 | * precedence than "||". That is "a && b || c && d" is equivalent to |
280 | * "(a && b) || (c && d)". Thus the first thing to do is to see if "&&" needs |
281 | * to be processed. This is the case if an "&&" was the last token. If it was |
282 | * then we call update_preds(). This takes the program, the current index in |
283 | * the program, and the current value of "invert". More will be described |
284 | * below about this function. |
285 | * |
286 | * #8 If the next token is "&&" then we set a flag in the top of the stack |
287 | * that denotes that "&&" needs to be processed, break out of this loop |
288 | * and continue with the outer loop. |
289 | * |
290 | * #9 Otherwise, if a "||" needs to be processed then update_preds() is called. |
291 | * This is called with the program, the current index in the program, but |
292 | * this time with an inverted value of "invert" (that is !invert). This is |
293 | * because the value taken will become the "when_to_branch" value of the |
294 | * program. |
295 | * Note, this is called when the next token is not an "&&". As stated before, |
296 | * "&&" takes higher precedence, and "||" should not be processed yet if the |
297 | * next logical operation is "&&". |
298 | * |
299 | * #10 If the next token is "||" then we set a flag in the top of the stack |
300 | * that denotes that "||" needs to be processed, break out of this loop |
301 | * and continue with the outer loop. |
302 | * |
303 | * #11 If this is the end of the input string "\0" then we break out of both |
304 | * loops. |
305 | * |
306 | * #12 Otherwise, the next token is ")", where we pop the stack and continue |
307 | * this inner loop. |
308 | * |
309 | * Now to discuss the update_pred() function, as that is key to the setting up |
310 | * of the program. Remember the "target" of the program is initialized to the |
311 | * previous index and not the "l" label. The target holds the index into the |
312 | * program that gets affected by the operand. Thus if we have something like |
313 | * "a || b && c", when we process "a" the target will be "-1" (undefined). |
314 | * When we process "b", its target is "0", which is the index of "a", as that's |
315 | * the predicate that is affected by "||". But because the next token after "b" |
316 | * is "&&" we don't call update_preds(). Instead continue to "c". As the |
317 | * next token after "c" is not "&&" but the end of input, we first process the |
318 | * "&&" by calling update_preds() for the "&&" then we process the "||" by |
319 | * calling updates_preds() with the values for processing "||". |
320 | * |
321 | * What does that mean? What update_preds() does is to first save the "target" |
322 | * of the program entry indexed by the current program entry's "target" |
323 | * (remember the "target" is initialized to previous program entry), and then |
324 | * sets that "target" to the current index which represents the label "l#". |
325 | * That entry's "when_to_branch" is set to the value passed in (the "invert" |
326 | * or "!invert"). Then it sets the current program entry's target to the saved |
327 | * "target" value (the old value of the program that had its "target" updated |
328 | * to the label). |
329 | * |
330 | * Looking back at "a || b && c", we have the following steps: |
331 | * "a" - prog[0] = { "a", X, -1 } // pred, when_to_branch, target |
332 | * "||" - flag that we need to process "||"; continue outer loop |
333 | * "b" - prog[1] = { "b", X, 0 } |
334 | * "&&" - flag that we need to process "&&"; continue outer loop |
335 | * (Notice we did not process "||") |
336 | * "c" - prog[2] = { "c", X, 1 } |
337 | * update_preds(prog, 2, 0); // invert = 0 as we are processing "&&" |
338 | * t = prog[2].target; // t = 1 |
339 | * s = prog[t].target; // s = 0 |
340 | * prog[t].target = 2; // Set target to "l2" |
341 | * prog[t].when_to_branch = 0; |
342 | * prog[2].target = s; |
343 | * update_preds(prog, 2, 1); // invert = 1 as we are now processing "||" |
344 | * t = prog[2].target; // t = 0 |
345 | * s = prog[t].target; // s = -1 |
346 | * prog[t].target = 2; // Set target to "l2" |
347 | * prog[t].when_to_branch = 1; |
348 | * prog[2].target = s; |
349 | * |
350 | * #13 Which brings us to the final step of the first pass, which is to set |
351 | * the last program entry's when_to_branch and target, which will be |
352 | * when_to_branch = 0; target = N; ( the label after the program entry after |
353 | * the last program entry processed above). |
354 | * |
355 | * If we denote "TRUE" to be the entry after the last program entry processed, |
356 | * and "FALSE" the program entry after that, we are now done with the first |
357 | * pass. |
358 | * |
359 | * Making the above "a || b && c" have a program of: |
360 | * prog[0] = { "a", 1, 2 } |
361 | * prog[1] = { "b", 0, 2 } |
362 | * prog[2] = { "c", 0, 3 } |
363 | * |
364 | * Which translates into: |
365 | * n0: r = a; l0: if (r) goto l2; |
366 | * n1: r = b; l1: if (!r) goto l2; |
367 | * n2: r = c; l2: if (!r) goto l3; // Which is the same as "goto F;" |
368 | * T: return TRUE; l3: |
369 | * F: return FALSE |
370 | * |
371 | * Although, after the first pass, the program is correct, it is |
372 | * inefficient. The simple sample of "a || b && c" could be easily been |
373 | * converted into: |
374 | * n0: r = a; if (r) goto T |
375 | * n1: r = b; if (!r) goto F |
376 | * n2: r = c; if (!r) goto F |
377 | * T: return TRUE; |
378 | * F: return FALSE; |
379 | * |
380 | * The First Pass is over the input string. The next too passes are over |
381 | * the program itself. |
382 | * |
383 | * ** SECOND PASS ** |
384 | * |
385 | * Which brings us to the second pass. If a jump to a label has the |
386 | * same condition as that label, it can instead jump to its target. |
387 | * The original example of "a && !(!b || (c && g)) || d || e && !f" |
388 | * where the first pass gives us: |
389 | * |
390 | * n1: r=a; l1: if (!r) goto l4; |
391 | * n2: r=b; l2: if (!r) goto l4; |
392 | * n3: r=c; r=!r; l3: if (r) goto l4; |
393 | * n4: r=g; r=!r; l4: if (r) goto l5; |
394 | * n5: r=d; l5: if (r) goto T |
395 | * n6: r=e; l6: if (!r) goto l7; |
396 | * n7: r=f; r=!r; l7: if (!r) goto F: |
397 | * T: return TRUE; |
398 | * F: return FALSE |
399 | * |
400 | * We can see that "l3: if (r) goto l4;" and at l4, we have "if (r) goto l5;". |
401 | * And "l5: if (r) goto T", we could optimize this by converting l3 and l4 |
402 | * to go directly to T. To accomplish this, we start from the last |
403 | * entry in the program and work our way back. If the target of the entry |
404 | * has the same "when_to_branch" then we could use that entry's target. |
405 | * Doing this, the above would end up as: |
406 | * |
407 | * n1: r=a; l1: if (!r) goto l4; |
408 | * n2: r=b; l2: if (!r) goto l4; |
409 | * n3: r=c; r=!r; l3: if (r) goto T; |
410 | * n4: r=g; r=!r; l4: if (r) goto T; |
411 | * n5: r=d; l5: if (r) goto T; |
412 | * n6: r=e; l6: if (!r) goto F; |
413 | * n7: r=f; r=!r; l7: if (!r) goto F; |
414 | * T: return TRUE |
415 | * F: return FALSE |
416 | * |
417 | * In that same pass, if the "when_to_branch" doesn't match, we can simply |
418 | * go to the program entry after the label. That is, "l2: if (!r) goto l4;" |
419 | * where "l4: if (r) goto T;", then we can convert l2 to be: |
420 | * "l2: if (!r) goto n5;". |
421 | * |
422 | * This will have the second pass give us: |
423 | * n1: r=a; l1: if (!r) goto n5; |
424 | * n2: r=b; l2: if (!r) goto n5; |
425 | * n3: r=c; r=!r; l3: if (r) goto T; |
426 | * n4: r=g; r=!r; l4: if (r) goto T; |
427 | * n5: r=d; l5: if (r) goto T |
428 | * n6: r=e; l6: if (!r) goto F; |
429 | * n7: r=f; r=!r; l7: if (!r) goto F |
430 | * T: return TRUE |
431 | * F: return FALSE |
432 | * |
433 | * Notice, all the "l#" labels are no longer used, and they can now |
434 | * be discarded. |
435 | * |
436 | * ** THIRD PASS ** |
437 | * |
438 | * For the third pass we deal with the inverts. As they simply just |
439 | * make the "when_to_branch" get inverted, a simple loop over the |
440 | * program to that does: "when_to_branch ^= invert;" will do the |
441 | * job, leaving us with: |
442 | * n1: r=a; if (!r) goto n5; |
443 | * n2: r=b; if (!r) goto n5; |
444 | * n3: r=c: if (!r) goto T; |
445 | * n4: r=g; if (!r) goto T; |
446 | * n5: r=d; if (r) goto T |
447 | * n6: r=e; if (!r) goto F; |
448 | * n7: r=f; if (r) goto F |
449 | * T: return TRUE |
450 | * F: return FALSE |
451 | * |
452 | * As "r = a; if (!r) goto n5;" is obviously the same as |
453 | * "if (!a) goto n5;" without doing anything we can interpret the |
454 | * program as: |
455 | * n1: if (!a) goto n5; |
456 | * n2: if (!b) goto n5; |
457 | * n3: if (!c) goto T; |
458 | * n4: if (!g) goto T; |
459 | * n5: if (d) goto T |
460 | * n6: if (!e) goto F; |
461 | * n7: if (f) goto F |
462 | * T: return TRUE |
463 | * F: return FALSE |
464 | * |
465 | * Since the inverts are discarded at the end, there's no reason to store |
466 | * them in the program array (and waste memory). A separate array to hold |
467 | * the inverts is used and freed at the end. |
468 | */ |
469 | static struct prog_entry * |
470 | predicate_parse(const char *str, int nr_parens, int nr_preds, |
471 | parse_pred_fn parse_pred, void *data, |
472 | struct filter_parse_error *pe) |
473 | { |
474 | struct prog_entry *prog_stack; |
475 | struct prog_entry *prog; |
476 | const char *ptr = str; |
477 | char *inverts = NULL; |
478 | int *op_stack; |
479 | int *top; |
480 | int invert = 0; |
481 | int ret = -ENOMEM; |
482 | int len; |
483 | int N = 0; |
484 | int i; |
485 | |
486 | nr_preds += 2; /* For TRUE and FALSE */ |
487 | |
488 | op_stack = kmalloc_array(n: nr_parens, size: sizeof(*op_stack), GFP_KERNEL); |
489 | if (!op_stack) |
490 | return ERR_PTR(error: -ENOMEM); |
491 | prog_stack = kcalloc(n: nr_preds, size: sizeof(*prog_stack), GFP_KERNEL); |
492 | if (!prog_stack) { |
493 | parse_error(pe, err: -ENOMEM, pos: 0); |
494 | goto out_free; |
495 | } |
496 | inverts = kmalloc_array(n: nr_preds, size: sizeof(*inverts), GFP_KERNEL); |
497 | if (!inverts) { |
498 | parse_error(pe, err: -ENOMEM, pos: 0); |
499 | goto out_free; |
500 | } |
501 | |
502 | top = op_stack; |
503 | prog = prog_stack; |
504 | *top = 0; |
505 | |
506 | /* First pass */ |
507 | while (*ptr) { /* #1 */ |
508 | const char *next = ptr++; |
509 | |
510 | if (isspace(*next)) |
511 | continue; |
512 | |
513 | switch (*next) { |
514 | case '(': /* #2 */ |
515 | if (top - op_stack > nr_parens) { |
516 | ret = -EINVAL; |
517 | goto out_free; |
518 | } |
519 | *(++top) = invert; |
520 | continue; |
521 | case '!': /* #3 */ |
522 | if (!is_not(str: next)) |
523 | break; |
524 | invert = !invert; |
525 | continue; |
526 | } |
527 | |
528 | if (N >= nr_preds) { |
529 | parse_error(pe, err: FILT_ERR_TOO_MANY_PREDS, pos: next - str); |
530 | goto out_free; |
531 | } |
532 | |
533 | inverts[N] = invert; /* #4 */ |
534 | prog[N].target = N-1; |
535 | |
536 | len = parse_pred(next, data, ptr - str, pe, &prog[N].pred); |
537 | if (len < 0) { |
538 | ret = len; |
539 | goto out_free; |
540 | } |
541 | ptr = next + len; |
542 | |
543 | N++; |
544 | |
545 | ret = -1; |
546 | while (1) { /* #5 */ |
547 | next = ptr++; |
548 | if (isspace(*next)) |
549 | continue; |
550 | |
551 | switch (*next) { |
552 | case ')': |
553 | case '\0': |
554 | break; |
555 | case '&': |
556 | case '|': |
557 | /* accepting only "&&" or "||" */ |
558 | if (next[1] == next[0]) { |
559 | ptr++; |
560 | break; |
561 | } |
562 | fallthrough; |
563 | default: |
564 | parse_error(pe, err: FILT_ERR_TOO_MANY_PREDS, |
565 | pos: next - str); |
566 | goto out_free; |
567 | } |
568 | |
569 | invert = *top & INVERT; |
570 | |
571 | if (*top & PROCESS_AND) { /* #7 */ |
572 | update_preds(prog, N: N - 1, invert); |
573 | *top &= ~PROCESS_AND; |
574 | } |
575 | if (*next == '&') { /* #8 */ |
576 | *top |= PROCESS_AND; |
577 | break; |
578 | } |
579 | if (*top & PROCESS_OR) { /* #9 */ |
580 | update_preds(prog, N: N - 1, invert: !invert); |
581 | *top &= ~PROCESS_OR; |
582 | } |
583 | if (*next == '|') { /* #10 */ |
584 | *top |= PROCESS_OR; |
585 | break; |
586 | } |
587 | if (!*next) /* #11 */ |
588 | goto out; |
589 | |
590 | if (top == op_stack) { |
591 | ret = -1; |
592 | /* Too few '(' */ |
593 | parse_error(pe, err: FILT_ERR_TOO_MANY_CLOSE, pos: ptr - str); |
594 | goto out_free; |
595 | } |
596 | top--; /* #12 */ |
597 | } |
598 | } |
599 | out: |
600 | if (top != op_stack) { |
601 | /* Too many '(' */ |
602 | parse_error(pe, err: FILT_ERR_TOO_MANY_OPEN, pos: ptr - str); |
603 | goto out_free; |
604 | } |
605 | |
606 | if (!N) { |
607 | /* No program? */ |
608 | ret = -EINVAL; |
609 | parse_error(pe, err: FILT_ERR_NO_FILTER, pos: ptr - str); |
610 | goto out_free; |
611 | } |
612 | |
613 | prog[N].pred = NULL; /* #13 */ |
614 | prog[N].target = 1; /* TRUE */ |
615 | prog[N+1].pred = NULL; |
616 | prog[N+1].target = 0; /* FALSE */ |
617 | prog[N-1].target = N; |
618 | prog[N-1].when_to_branch = false; |
619 | |
620 | /* Second Pass */ |
621 | for (i = N-1 ; i--; ) { |
622 | int target = prog[i].target; |
623 | if (prog[i].when_to_branch == prog[target].when_to_branch) |
624 | prog[i].target = prog[target].target; |
625 | } |
626 | |
627 | /* Third Pass */ |
628 | for (i = 0; i < N; i++) { |
629 | invert = inverts[i] ^ prog[i].when_to_branch; |
630 | prog[i].when_to_branch = invert; |
631 | /* Make sure the program always moves forward */ |
632 | if (WARN_ON(prog[i].target <= i)) { |
633 | ret = -EINVAL; |
634 | goto out_free; |
635 | } |
636 | } |
637 | |
638 | kfree(objp: op_stack); |
639 | kfree(objp: inverts); |
640 | return prog; |
641 | out_free: |
642 | kfree(objp: op_stack); |
643 | kfree(objp: inverts); |
644 | if (prog_stack) { |
645 | for (i = 0; prog_stack[i].pred; i++) |
646 | free_predicate(pred: prog_stack[i].pred); |
647 | kfree(objp: prog_stack); |
648 | } |
649 | return ERR_PTR(error: ret); |
650 | } |
651 | |
652 | static inline int |
653 | do_filter_cpumask(int op, const struct cpumask *mask, const struct cpumask *cmp) |
654 | { |
655 | switch (op) { |
656 | case OP_EQ: |
657 | return cpumask_equal(src1p: mask, src2p: cmp); |
658 | case OP_NE: |
659 | return !cpumask_equal(src1p: mask, src2p: cmp); |
660 | case OP_BAND: |
661 | return cpumask_intersects(src1p: mask, src2p: cmp); |
662 | default: |
663 | return 0; |
664 | } |
665 | } |
666 | |
667 | /* Optimisation of do_filter_cpumask() for scalar fields */ |
668 | static inline int |
669 | do_filter_scalar_cpumask(int op, unsigned int cpu, const struct cpumask *mask) |
670 | { |
671 | /* |
672 | * Per the weight-of-one cpumask optimisations, the mask passed in this |
673 | * function has a weight >= 2, so it is never equal to a single scalar. |
674 | */ |
675 | switch (op) { |
676 | case OP_EQ: |
677 | return false; |
678 | case OP_NE: |
679 | return true; |
680 | case OP_BAND: |
681 | return cpumask_test_cpu(cpu, cpumask: mask); |
682 | default: |
683 | return 0; |
684 | } |
685 | } |
686 | |
687 | static inline int |
688 | do_filter_cpumask_scalar(int op, const struct cpumask *mask, unsigned int cpu) |
689 | { |
690 | switch (op) { |
691 | case OP_EQ: |
692 | return cpumask_test_cpu(cpu, cpumask: mask) && |
693 | cpumask_nth(cpu: 1, srcp: mask) >= nr_cpu_ids; |
694 | case OP_NE: |
695 | return !cpumask_test_cpu(cpu, cpumask: mask) || |
696 | cpumask_nth(cpu: 1, srcp: mask) < nr_cpu_ids; |
697 | case OP_BAND: |
698 | return cpumask_test_cpu(cpu, cpumask: mask); |
699 | default: |
700 | return 0; |
701 | } |
702 | } |
703 | |
704 | enum pred_cmp_types { |
705 | PRED_CMP_TYPE_NOP, |
706 | PRED_CMP_TYPE_LT, |
707 | PRED_CMP_TYPE_LE, |
708 | PRED_CMP_TYPE_GT, |
709 | PRED_CMP_TYPE_GE, |
710 | PRED_CMP_TYPE_BAND, |
711 | }; |
712 | |
713 | #define DEFINE_COMPARISON_PRED(type) \ |
714 | static int filter_pred_##type(struct filter_pred *pred, void *event) \ |
715 | { \ |
716 | switch (pred->op) { \ |
717 | case OP_LT: { \ |
718 | type *addr = (type *)(event + pred->offset); \ |
719 | type val = (type)pred->val; \ |
720 | return *addr < val; \ |
721 | } \ |
722 | case OP_LE: { \ |
723 | type *addr = (type *)(event + pred->offset); \ |
724 | type val = (type)pred->val; \ |
725 | return *addr <= val; \ |
726 | } \ |
727 | case OP_GT: { \ |
728 | type *addr = (type *)(event + pred->offset); \ |
729 | type val = (type)pred->val; \ |
730 | return *addr > val; \ |
731 | } \ |
732 | case OP_GE: { \ |
733 | type *addr = (type *)(event + pred->offset); \ |
734 | type val = (type)pred->val; \ |
735 | return *addr >= val; \ |
736 | } \ |
737 | case OP_BAND: { \ |
738 | type *addr = (type *)(event + pred->offset); \ |
739 | type val = (type)pred->val; \ |
740 | return !!(*addr & val); \ |
741 | } \ |
742 | default: \ |
743 | return 0; \ |
744 | } \ |
745 | } |
746 | |
747 | #define DEFINE_CPUMASK_COMPARISON_PRED(size) \ |
748 | static int filter_pred_##size##_cpumask(struct filter_pred *pred, void *event) \ |
749 | { \ |
750 | u##size *addr = (u##size *)(event + pred->offset); \ |
751 | unsigned int cpu = *addr; \ |
752 | \ |
753 | if (cpu >= nr_cpu_ids) \ |
754 | return 0; \ |
755 | \ |
756 | return do_filter_scalar_cpumask(pred->op, cpu, pred->mask); \ |
757 | } |
758 | |
759 | #define DEFINE_EQUALITY_PRED(size) \ |
760 | static int filter_pred_##size(struct filter_pred *pred, void *event) \ |
761 | { \ |
762 | u##size *addr = (u##size *)(event + pred->offset); \ |
763 | u##size val = (u##size)pred->val; \ |
764 | int match; \ |
765 | \ |
766 | match = (val == *addr) ^ pred->not; \ |
767 | \ |
768 | return match; \ |
769 | } |
770 | |
771 | DEFINE_COMPARISON_PRED(s64); |
772 | DEFINE_COMPARISON_PRED(u64); |
773 | DEFINE_COMPARISON_PRED(s32); |
774 | DEFINE_COMPARISON_PRED(u32); |
775 | DEFINE_COMPARISON_PRED(s16); |
776 | DEFINE_COMPARISON_PRED(u16); |
777 | DEFINE_COMPARISON_PRED(s8); |
778 | DEFINE_COMPARISON_PRED(u8); |
779 | |
780 | DEFINE_CPUMASK_COMPARISON_PRED(64); |
781 | DEFINE_CPUMASK_COMPARISON_PRED(32); |
782 | DEFINE_CPUMASK_COMPARISON_PRED(16); |
783 | DEFINE_CPUMASK_COMPARISON_PRED(8); |
784 | |
785 | DEFINE_EQUALITY_PRED(64); |
786 | DEFINE_EQUALITY_PRED(32); |
787 | DEFINE_EQUALITY_PRED(16); |
788 | DEFINE_EQUALITY_PRED(8); |
789 | |
790 | /* user space strings temp buffer */ |
791 | #define USTRING_BUF_SIZE 1024 |
792 | |
793 | struct ustring_buffer { |
794 | char buffer[USTRING_BUF_SIZE]; |
795 | }; |
796 | |
797 | static __percpu struct ustring_buffer *ustring_per_cpu; |
798 | |
799 | static __always_inline char *test_string(char *str) |
800 | { |
801 | struct ustring_buffer *ubuf; |
802 | char *kstr; |
803 | |
804 | if (!ustring_per_cpu) |
805 | return NULL; |
806 | |
807 | ubuf = this_cpu_ptr(ustring_per_cpu); |
808 | kstr = ubuf->buffer; |
809 | |
810 | /* For safety, do not trust the string pointer */ |
811 | if (!strncpy_from_kernel_nofault(dst: kstr, unsafe_addr: str, USTRING_BUF_SIZE)) |
812 | return NULL; |
813 | return kstr; |
814 | } |
815 | |
816 | static __always_inline char *test_ustring(char *str) |
817 | { |
818 | struct ustring_buffer *ubuf; |
819 | char __user *ustr; |
820 | char *kstr; |
821 | |
822 | if (!ustring_per_cpu) |
823 | return NULL; |
824 | |
825 | ubuf = this_cpu_ptr(ustring_per_cpu); |
826 | kstr = ubuf->buffer; |
827 | |
828 | /* user space address? */ |
829 | ustr = (char __user *)str; |
830 | if (!strncpy_from_user_nofault(dst: kstr, unsafe_addr: ustr, USTRING_BUF_SIZE)) |
831 | return NULL; |
832 | |
833 | return kstr; |
834 | } |
835 | |
836 | /* Filter predicate for fixed sized arrays of characters */ |
837 | static int filter_pred_string(struct filter_pred *pred, void *event) |
838 | { |
839 | char *addr = (char *)(event + pred->offset); |
840 | int cmp, match; |
841 | |
842 | cmp = pred->regex->match(addr, pred->regex, pred->regex->field_len); |
843 | |
844 | match = cmp ^ pred->not; |
845 | |
846 | return match; |
847 | } |
848 | |
849 | static __always_inline int filter_pchar(struct filter_pred *pred, char *str) |
850 | { |
851 | int cmp, match; |
852 | int len; |
853 | |
854 | len = strlen(str) + 1; /* including tailing '\0' */ |
855 | cmp = pred->regex->match(str, pred->regex, len); |
856 | |
857 | match = cmp ^ pred->not; |
858 | |
859 | return match; |
860 | } |
861 | /* Filter predicate for char * pointers */ |
862 | static int filter_pred_pchar(struct filter_pred *pred, void *event) |
863 | { |
864 | char **addr = (char **)(event + pred->offset); |
865 | char *str; |
866 | |
867 | str = test_string(str: *addr); |
868 | if (!str) |
869 | return 0; |
870 | |
871 | return filter_pchar(pred, str); |
872 | } |
873 | |
874 | /* Filter predicate for char * pointers in user space*/ |
875 | static int filter_pred_pchar_user(struct filter_pred *pred, void *event) |
876 | { |
877 | char **addr = (char **)(event + pred->offset); |
878 | char *str; |
879 | |
880 | str = test_ustring(str: *addr); |
881 | if (!str) |
882 | return 0; |
883 | |
884 | return filter_pchar(pred, str); |
885 | } |
886 | |
887 | /* |
888 | * Filter predicate for dynamic sized arrays of characters. |
889 | * These are implemented through a list of strings at the end |
890 | * of the entry. |
891 | * Also each of these strings have a field in the entry which |
892 | * contains its offset from the beginning of the entry. |
893 | * We have then first to get this field, dereference it |
894 | * and add it to the address of the entry, and at last we have |
895 | * the address of the string. |
896 | */ |
897 | static int filter_pred_strloc(struct filter_pred *pred, void *event) |
898 | { |
899 | u32 str_item = *(u32 *)(event + pred->offset); |
900 | int str_loc = str_item & 0xffff; |
901 | int str_len = str_item >> 16; |
902 | char *addr = (char *)(event + str_loc); |
903 | int cmp, match; |
904 | |
905 | cmp = pred->regex->match(addr, pred->regex, str_len); |
906 | |
907 | match = cmp ^ pred->not; |
908 | |
909 | return match; |
910 | } |
911 | |
912 | /* |
913 | * Filter predicate for relative dynamic sized arrays of characters. |
914 | * These are implemented through a list of strings at the end |
915 | * of the entry as same as dynamic string. |
916 | * The difference is that the relative one records the location offset |
917 | * from the field itself, not the event entry. |
918 | */ |
919 | static int filter_pred_strrelloc(struct filter_pred *pred, void *event) |
920 | { |
921 | u32 *item = (u32 *)(event + pred->offset); |
922 | u32 str_item = *item; |
923 | int str_loc = str_item & 0xffff; |
924 | int str_len = str_item >> 16; |
925 | char *addr = (char *)(&item[1]) + str_loc; |
926 | int cmp, match; |
927 | |
928 | cmp = pred->regex->match(addr, pred->regex, str_len); |
929 | |
930 | match = cmp ^ pred->not; |
931 | |
932 | return match; |
933 | } |
934 | |
935 | /* Filter predicate for CPUs. */ |
936 | static int filter_pred_cpu(struct filter_pred *pred, void *event) |
937 | { |
938 | int cpu, cmp; |
939 | |
940 | cpu = raw_smp_processor_id(); |
941 | cmp = pred->val; |
942 | |
943 | switch (pred->op) { |
944 | case OP_EQ: |
945 | return cpu == cmp; |
946 | case OP_NE: |
947 | return cpu != cmp; |
948 | case OP_LT: |
949 | return cpu < cmp; |
950 | case OP_LE: |
951 | return cpu <= cmp; |
952 | case OP_GT: |
953 | return cpu > cmp; |
954 | case OP_GE: |
955 | return cpu >= cmp; |
956 | default: |
957 | return 0; |
958 | } |
959 | } |
960 | |
961 | /* Filter predicate for current CPU vs user-provided cpumask */ |
962 | static int filter_pred_cpu_cpumask(struct filter_pred *pred, void *event) |
963 | { |
964 | int cpu = raw_smp_processor_id(); |
965 | |
966 | return do_filter_scalar_cpumask(op: pred->op, cpu, mask: pred->mask); |
967 | } |
968 | |
969 | /* Filter predicate for cpumask field vs user-provided cpumask */ |
970 | static int filter_pred_cpumask(struct filter_pred *pred, void *event) |
971 | { |
972 | u32 item = *(u32 *)(event + pred->offset); |
973 | int loc = item & 0xffff; |
974 | const struct cpumask *mask = (event + loc); |
975 | const struct cpumask *cmp = pred->mask; |
976 | |
977 | return do_filter_cpumask(op: pred->op, mask, cmp); |
978 | } |
979 | |
980 | /* Filter predicate for cpumask field vs user-provided scalar */ |
981 | static int filter_pred_cpumask_cpu(struct filter_pred *pred, void *event) |
982 | { |
983 | u32 item = *(u32 *)(event + pred->offset); |
984 | int loc = item & 0xffff; |
985 | const struct cpumask *mask = (event + loc); |
986 | unsigned int cpu = pred->val; |
987 | |
988 | return do_filter_cpumask_scalar(op: pred->op, mask, cpu); |
989 | } |
990 | |
991 | /* Filter predicate for COMM. */ |
992 | static int filter_pred_comm(struct filter_pred *pred, void *event) |
993 | { |
994 | int cmp; |
995 | |
996 | cmp = pred->regex->match(current->comm, pred->regex, |
997 | TASK_COMM_LEN); |
998 | return cmp ^ pred->not; |
999 | } |
1000 | |
1001 | /* Filter predicate for functions. */ |
1002 | static int filter_pred_function(struct filter_pred *pred, void *event) |
1003 | { |
1004 | unsigned long *addr = (unsigned long *)(event + pred->offset); |
1005 | unsigned long start = (unsigned long)pred->val; |
1006 | unsigned long end = (unsigned long)pred->val2; |
1007 | int ret = *addr >= start && *addr < end; |
1008 | |
1009 | return pred->op == OP_EQ ? ret : !ret; |
1010 | } |
1011 | |
1012 | /* |
1013 | * regex_match_foo - Basic regex callbacks |
1014 | * |
1015 | * @str: the string to be searched |
1016 | * @r: the regex structure containing the pattern string |
1017 | * @len: the length of the string to be searched (including '\0') |
1018 | * |
1019 | * Note: |
1020 | * - @str might not be NULL-terminated if it's of type DYN_STRING |
1021 | * RDYN_STRING, or STATIC_STRING, unless @len is zero. |
1022 | */ |
1023 | |
1024 | static int regex_match_full(char *str, struct regex *r, int len) |
1025 | { |
1026 | /* len of zero means str is dynamic and ends with '\0' */ |
1027 | if (!len) |
1028 | return strcmp(str, r->pattern) == 0; |
1029 | |
1030 | return strncmp(str, r->pattern, len) == 0; |
1031 | } |
1032 | |
1033 | static int regex_match_front(char *str, struct regex *r, int len) |
1034 | { |
1035 | if (len && len < r->len) |
1036 | return 0; |
1037 | |
1038 | return strncmp(str, r->pattern, r->len) == 0; |
1039 | } |
1040 | |
1041 | static int regex_match_middle(char *str, struct regex *r, int len) |
1042 | { |
1043 | if (!len) |
1044 | return strstr(str, r->pattern) != NULL; |
1045 | |
1046 | return strnstr(str, r->pattern, len) != NULL; |
1047 | } |
1048 | |
1049 | static int regex_match_end(char *str, struct regex *r, int len) |
1050 | { |
1051 | int strlen = len - 1; |
1052 | |
1053 | if (strlen >= r->len && |
1054 | memcmp(p: str + strlen - r->len, q: r->pattern, size: r->len) == 0) |
1055 | return 1; |
1056 | return 0; |
1057 | } |
1058 | |
1059 | static int regex_match_glob(char *str, struct regex *r, int len __maybe_unused) |
1060 | { |
1061 | if (glob_match(pat: r->pattern, str)) |
1062 | return 1; |
1063 | return 0; |
1064 | } |
1065 | |
1066 | /** |
1067 | * filter_parse_regex - parse a basic regex |
1068 | * @buff: the raw regex |
1069 | * @len: length of the regex |
1070 | * @search: will point to the beginning of the string to compare |
1071 | * @not: tell whether the match will have to be inverted |
1072 | * |
1073 | * This passes in a buffer containing a regex and this function will |
1074 | * set search to point to the search part of the buffer and |
1075 | * return the type of search it is (see enum above). |
1076 | * This does modify buff. |
1077 | * |
1078 | * Returns enum type. |
1079 | * search returns the pointer to use for comparison. |
1080 | * not returns 1 if buff started with a '!' |
1081 | * 0 otherwise. |
1082 | */ |
1083 | enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not) |
1084 | { |
1085 | int type = MATCH_FULL; |
1086 | int i; |
1087 | |
1088 | if (buff[0] == '!') { |
1089 | *not = 1; |
1090 | buff++; |
1091 | len--; |
1092 | } else |
1093 | *not = 0; |
1094 | |
1095 | *search = buff; |
1096 | |
1097 | if (isdigit(c: buff[0])) |
1098 | return MATCH_INDEX; |
1099 | |
1100 | for (i = 0; i < len; i++) { |
1101 | if (buff[i] == '*') { |
1102 | if (!i) { |
1103 | type = MATCH_END_ONLY; |
1104 | } else if (i == len - 1) { |
1105 | if (type == MATCH_END_ONLY) |
1106 | type = MATCH_MIDDLE_ONLY; |
1107 | else |
1108 | type = MATCH_FRONT_ONLY; |
1109 | buff[i] = 0; |
1110 | break; |
1111 | } else { /* pattern continues, use full glob */ |
1112 | return MATCH_GLOB; |
1113 | } |
1114 | } else if (strchr("[?\\" , buff[i])) { |
1115 | return MATCH_GLOB; |
1116 | } |
1117 | } |
1118 | if (buff[0] == '*') |
1119 | *search = buff + 1; |
1120 | |
1121 | return type; |
1122 | } |
1123 | |
1124 | static void filter_build_regex(struct filter_pred *pred) |
1125 | { |
1126 | struct regex *r = pred->regex; |
1127 | char *search; |
1128 | enum regex_type type = MATCH_FULL; |
1129 | |
1130 | if (pred->op == OP_GLOB) { |
1131 | type = filter_parse_regex(buff: r->pattern, len: r->len, search: &search, not: &pred->not); |
1132 | r->len = strlen(search); |
1133 | memmove(r->pattern, search, r->len+1); |
1134 | } |
1135 | |
1136 | switch (type) { |
1137 | /* MATCH_INDEX should not happen, but if it does, match full */ |
1138 | case MATCH_INDEX: |
1139 | case MATCH_FULL: |
1140 | r->match = regex_match_full; |
1141 | break; |
1142 | case MATCH_FRONT_ONLY: |
1143 | r->match = regex_match_front; |
1144 | break; |
1145 | case MATCH_MIDDLE_ONLY: |
1146 | r->match = regex_match_middle; |
1147 | break; |
1148 | case MATCH_END_ONLY: |
1149 | r->match = regex_match_end; |
1150 | break; |
1151 | case MATCH_GLOB: |
1152 | r->match = regex_match_glob; |
1153 | break; |
1154 | } |
1155 | } |
1156 | |
1157 | |
1158 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
1159 | static int test_pred_visited_fn(struct filter_pred *pred, void *event); |
1160 | #else |
1161 | static int test_pred_visited_fn(struct filter_pred *pred, void *event) |
1162 | { |
1163 | return 0; |
1164 | } |
1165 | #endif |
1166 | |
1167 | |
1168 | static int filter_pred_fn_call(struct filter_pred *pred, void *event); |
1169 | |
1170 | /* return 1 if event matches, 0 otherwise (discard) */ |
1171 | int filter_match_preds(struct event_filter *filter, void *rec) |
1172 | { |
1173 | struct prog_entry *prog; |
1174 | int i; |
1175 | |
1176 | /* no filter is considered a match */ |
1177 | if (!filter) |
1178 | return 1; |
1179 | |
1180 | /* Protected by either SRCU(tracepoint_srcu) or preempt_disable */ |
1181 | prog = rcu_dereference_raw(filter->prog); |
1182 | if (!prog) |
1183 | return 1; |
1184 | |
1185 | for (i = 0; prog[i].pred; i++) { |
1186 | struct filter_pred *pred = prog[i].pred; |
1187 | int match = filter_pred_fn_call(pred, event: rec); |
1188 | if (match == prog[i].when_to_branch) |
1189 | i = prog[i].target; |
1190 | } |
1191 | return prog[i].target; |
1192 | } |
1193 | EXPORT_SYMBOL_GPL(filter_match_preds); |
1194 | |
1195 | static void remove_filter_string(struct event_filter *filter) |
1196 | { |
1197 | if (!filter) |
1198 | return; |
1199 | |
1200 | kfree(objp: filter->filter_string); |
1201 | filter->filter_string = NULL; |
1202 | } |
1203 | |
1204 | static void append_filter_err(struct trace_array *tr, |
1205 | struct filter_parse_error *pe, |
1206 | struct event_filter *filter) |
1207 | { |
1208 | struct trace_seq *s; |
1209 | int pos = pe->lasterr_pos; |
1210 | char *buf; |
1211 | int len; |
1212 | |
1213 | if (WARN_ON(!filter->filter_string)) |
1214 | return; |
1215 | |
1216 | s = kmalloc(size: sizeof(*s), GFP_KERNEL); |
1217 | if (!s) |
1218 | return; |
1219 | trace_seq_init(s); |
1220 | |
1221 | len = strlen(filter->filter_string); |
1222 | if (pos > len) |
1223 | pos = len; |
1224 | |
1225 | /* indexing is off by one */ |
1226 | if (pos) |
1227 | pos++; |
1228 | |
1229 | trace_seq_puts(s, str: filter->filter_string); |
1230 | if (pe->lasterr > 0) { |
1231 | trace_seq_printf(s, fmt: "\n%*s" , pos, "^" ); |
1232 | trace_seq_printf(s, fmt: "\nparse_error: %s\n" , err_text[pe->lasterr]); |
1233 | tracing_log_err(tr, loc: "event filter parse error" , |
1234 | cmd: filter->filter_string, errs: err_text, |
1235 | type: pe->lasterr, pos: pe->lasterr_pos); |
1236 | } else { |
1237 | trace_seq_printf(s, fmt: "\nError: (%d)\n" , pe->lasterr); |
1238 | tracing_log_err(tr, loc: "event filter parse error" , |
1239 | cmd: filter->filter_string, errs: err_text, |
1240 | type: FILT_ERR_ERRNO, pos: 0); |
1241 | } |
1242 | trace_seq_putc(s, c: 0); |
1243 | buf = kmemdup_nul(s: s->buffer, len: s->seq.len, GFP_KERNEL); |
1244 | if (buf) { |
1245 | kfree(objp: filter->filter_string); |
1246 | filter->filter_string = buf; |
1247 | } |
1248 | kfree(objp: s); |
1249 | } |
1250 | |
1251 | static inline struct event_filter *event_filter(struct trace_event_file *file) |
1252 | { |
1253 | return file->filter; |
1254 | } |
1255 | |
1256 | /* caller must hold event_mutex */ |
1257 | void print_event_filter(struct trace_event_file *file, struct trace_seq *s) |
1258 | { |
1259 | struct event_filter *filter = event_filter(file); |
1260 | |
1261 | if (filter && filter->filter_string) |
1262 | trace_seq_printf(s, fmt: "%s\n" , filter->filter_string); |
1263 | else |
1264 | trace_seq_puts(s, str: "none\n" ); |
1265 | } |
1266 | |
1267 | void print_subsystem_event_filter(struct event_subsystem *system, |
1268 | struct trace_seq *s) |
1269 | { |
1270 | struct event_filter *filter; |
1271 | |
1272 | mutex_lock(&event_mutex); |
1273 | filter = system->filter; |
1274 | if (filter && filter->filter_string) |
1275 | trace_seq_printf(s, fmt: "%s\n" , filter->filter_string); |
1276 | else |
1277 | trace_seq_puts(s, DEFAULT_SYS_FILTER_MESSAGE "\n" ); |
1278 | mutex_unlock(lock: &event_mutex); |
1279 | } |
1280 | |
1281 | static void free_prog(struct event_filter *filter) |
1282 | { |
1283 | struct prog_entry *prog; |
1284 | int i; |
1285 | |
1286 | prog = rcu_access_pointer(filter->prog); |
1287 | if (!prog) |
1288 | return; |
1289 | |
1290 | for (i = 0; prog[i].pred; i++) |
1291 | free_predicate(pred: prog[i].pred); |
1292 | kfree(objp: prog); |
1293 | } |
1294 | |
1295 | static void filter_disable(struct trace_event_file *file) |
1296 | { |
1297 | unsigned long old_flags = file->flags; |
1298 | |
1299 | file->flags &= ~EVENT_FILE_FL_FILTERED; |
1300 | |
1301 | if (old_flags != file->flags) |
1302 | trace_buffered_event_disable(); |
1303 | } |
1304 | |
1305 | static void __free_filter(struct event_filter *filter) |
1306 | { |
1307 | if (!filter) |
1308 | return; |
1309 | |
1310 | free_prog(filter); |
1311 | kfree(objp: filter->filter_string); |
1312 | kfree(objp: filter); |
1313 | } |
1314 | |
1315 | void free_event_filter(struct event_filter *filter) |
1316 | { |
1317 | __free_filter(filter); |
1318 | } |
1319 | |
1320 | static inline void __remove_filter(struct trace_event_file *file) |
1321 | { |
1322 | filter_disable(file); |
1323 | remove_filter_string(filter: file->filter); |
1324 | } |
1325 | |
1326 | static void filter_free_subsystem_preds(struct trace_subsystem_dir *dir, |
1327 | struct trace_array *tr) |
1328 | { |
1329 | struct trace_event_file *file; |
1330 | |
1331 | list_for_each_entry(file, &tr->events, list) { |
1332 | if (file->system != dir) |
1333 | continue; |
1334 | __remove_filter(file); |
1335 | } |
1336 | } |
1337 | |
1338 | static inline void __free_subsystem_filter(struct trace_event_file *file) |
1339 | { |
1340 | __free_filter(filter: file->filter); |
1341 | file->filter = NULL; |
1342 | } |
1343 | |
1344 | static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir, |
1345 | struct trace_array *tr) |
1346 | { |
1347 | struct trace_event_file *file; |
1348 | |
1349 | list_for_each_entry(file, &tr->events, list) { |
1350 | if (file->system != dir) |
1351 | continue; |
1352 | __free_subsystem_filter(file); |
1353 | } |
1354 | } |
1355 | |
1356 | int filter_assign_type(const char *type) |
1357 | { |
1358 | if (strstr(type, "__data_loc" )) { |
1359 | if (strstr(type, "char" )) |
1360 | return FILTER_DYN_STRING; |
1361 | if (strstr(type, "cpumask_t" )) |
1362 | return FILTER_CPUMASK; |
1363 | } |
1364 | |
1365 | if (strstr(type, "__rel_loc" ) && strstr(type, "char" )) |
1366 | return FILTER_RDYN_STRING; |
1367 | |
1368 | if (strchr(type, '[') && strstr(type, "char" )) |
1369 | return FILTER_STATIC_STRING; |
1370 | |
1371 | if (strcmp(type, "char *" ) == 0 || strcmp(type, "const char *" ) == 0) |
1372 | return FILTER_PTR_STRING; |
1373 | |
1374 | return FILTER_OTHER; |
1375 | } |
1376 | |
1377 | static enum filter_pred_fn select_comparison_fn(enum filter_op_ids op, |
1378 | int field_size, int field_is_signed) |
1379 | { |
1380 | enum filter_pred_fn fn = FILTER_PRED_FN_NOP; |
1381 | int pred_func_index = -1; |
1382 | |
1383 | switch (op) { |
1384 | case OP_EQ: |
1385 | case OP_NE: |
1386 | break; |
1387 | default: |
1388 | if (WARN_ON_ONCE(op < PRED_FUNC_START)) |
1389 | return fn; |
1390 | pred_func_index = op - PRED_FUNC_START; |
1391 | if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX)) |
1392 | return fn; |
1393 | } |
1394 | |
1395 | switch (field_size) { |
1396 | case 8: |
1397 | if (pred_func_index < 0) |
1398 | fn = FILTER_PRED_FN_64; |
1399 | else if (field_is_signed) |
1400 | fn = FILTER_PRED_FN_S64; |
1401 | else |
1402 | fn = FILTER_PRED_FN_U64; |
1403 | break; |
1404 | case 4: |
1405 | if (pred_func_index < 0) |
1406 | fn = FILTER_PRED_FN_32; |
1407 | else if (field_is_signed) |
1408 | fn = FILTER_PRED_FN_S32; |
1409 | else |
1410 | fn = FILTER_PRED_FN_U32; |
1411 | break; |
1412 | case 2: |
1413 | if (pred_func_index < 0) |
1414 | fn = FILTER_PRED_FN_16; |
1415 | else if (field_is_signed) |
1416 | fn = FILTER_PRED_FN_S16; |
1417 | else |
1418 | fn = FILTER_PRED_FN_U16; |
1419 | break; |
1420 | case 1: |
1421 | if (pred_func_index < 0) |
1422 | fn = FILTER_PRED_FN_8; |
1423 | else if (field_is_signed) |
1424 | fn = FILTER_PRED_FN_S8; |
1425 | else |
1426 | fn = FILTER_PRED_FN_U8; |
1427 | break; |
1428 | } |
1429 | |
1430 | return fn; |
1431 | } |
1432 | |
1433 | |
1434 | static int filter_pred_fn_call(struct filter_pred *pred, void *event) |
1435 | { |
1436 | switch (pred->fn_num) { |
1437 | case FILTER_PRED_FN_64: |
1438 | return filter_pred_64(pred, event); |
1439 | case FILTER_PRED_FN_64_CPUMASK: |
1440 | return filter_pred_64_cpumask(pred, event); |
1441 | case FILTER_PRED_FN_S64: |
1442 | return filter_pred_s64(pred, event); |
1443 | case FILTER_PRED_FN_U64: |
1444 | return filter_pred_u64(pred, event); |
1445 | case FILTER_PRED_FN_32: |
1446 | return filter_pred_32(pred, event); |
1447 | case FILTER_PRED_FN_32_CPUMASK: |
1448 | return filter_pred_32_cpumask(pred, event); |
1449 | case FILTER_PRED_FN_S32: |
1450 | return filter_pred_s32(pred, event); |
1451 | case FILTER_PRED_FN_U32: |
1452 | return filter_pred_u32(pred, event); |
1453 | case FILTER_PRED_FN_16: |
1454 | return filter_pred_16(pred, event); |
1455 | case FILTER_PRED_FN_16_CPUMASK: |
1456 | return filter_pred_16_cpumask(pred, event); |
1457 | case FILTER_PRED_FN_S16: |
1458 | return filter_pred_s16(pred, event); |
1459 | case FILTER_PRED_FN_U16: |
1460 | return filter_pred_u16(pred, event); |
1461 | case FILTER_PRED_FN_8: |
1462 | return filter_pred_8(pred, event); |
1463 | case FILTER_PRED_FN_8_CPUMASK: |
1464 | return filter_pred_8_cpumask(pred, event); |
1465 | case FILTER_PRED_FN_S8: |
1466 | return filter_pred_s8(pred, event); |
1467 | case FILTER_PRED_FN_U8: |
1468 | return filter_pred_u8(pred, event); |
1469 | case FILTER_PRED_FN_COMM: |
1470 | return filter_pred_comm(pred, event); |
1471 | case FILTER_PRED_FN_STRING: |
1472 | return filter_pred_string(pred, event); |
1473 | case FILTER_PRED_FN_STRLOC: |
1474 | return filter_pred_strloc(pred, event); |
1475 | case FILTER_PRED_FN_STRRELLOC: |
1476 | return filter_pred_strrelloc(pred, event); |
1477 | case FILTER_PRED_FN_PCHAR_USER: |
1478 | return filter_pred_pchar_user(pred, event); |
1479 | case FILTER_PRED_FN_PCHAR: |
1480 | return filter_pred_pchar(pred, event); |
1481 | case FILTER_PRED_FN_CPU: |
1482 | return filter_pred_cpu(pred, event); |
1483 | case FILTER_PRED_FN_CPU_CPUMASK: |
1484 | return filter_pred_cpu_cpumask(pred, event); |
1485 | case FILTER_PRED_FN_CPUMASK: |
1486 | return filter_pred_cpumask(pred, event); |
1487 | case FILTER_PRED_FN_CPUMASK_CPU: |
1488 | return filter_pred_cpumask_cpu(pred, event); |
1489 | case FILTER_PRED_FN_FUNCTION: |
1490 | return filter_pred_function(pred, event); |
1491 | case FILTER_PRED_TEST_VISITED: |
1492 | return test_pred_visited_fn(pred, event); |
1493 | default: |
1494 | return 0; |
1495 | } |
1496 | } |
1497 | |
1498 | /* Called when a predicate is encountered by predicate_parse() */ |
1499 | static int parse_pred(const char *str, void *data, |
1500 | int pos, struct filter_parse_error *pe, |
1501 | struct filter_pred **pred_ptr) |
1502 | { |
1503 | struct trace_event_call *call = data; |
1504 | struct ftrace_event_field *field; |
1505 | struct filter_pred *pred = NULL; |
1506 | unsigned long offset; |
1507 | unsigned long size; |
1508 | unsigned long ip; |
1509 | char num_buf[24]; /* Big enough to hold an address */ |
1510 | char *field_name; |
1511 | char *name; |
1512 | bool function = false; |
1513 | bool ustring = false; |
1514 | char q; |
1515 | u64 val; |
1516 | int len; |
1517 | int ret; |
1518 | int op; |
1519 | int s; |
1520 | int i = 0; |
1521 | |
1522 | /* First find the field to associate to */ |
1523 | while (isspace(str[i])) |
1524 | i++; |
1525 | s = i; |
1526 | |
1527 | while (isalnum(str[i]) || str[i] == '_') |
1528 | i++; |
1529 | |
1530 | len = i - s; |
1531 | |
1532 | if (!len) |
1533 | return -1; |
1534 | |
1535 | field_name = kmemdup_nul(s: str + s, len, GFP_KERNEL); |
1536 | if (!field_name) |
1537 | return -ENOMEM; |
1538 | |
1539 | /* Make sure that the field exists */ |
1540 | |
1541 | field = trace_find_event_field(call, name: field_name); |
1542 | kfree(objp: field_name); |
1543 | if (!field) { |
1544 | parse_error(pe, err: FILT_ERR_FIELD_NOT_FOUND, pos: pos + i); |
1545 | return -EINVAL; |
1546 | } |
1547 | |
1548 | /* See if the field is a user space string */ |
1549 | if ((len = str_has_prefix(str: str + i, prefix: ".ustring" ))) { |
1550 | ustring = true; |
1551 | i += len; |
1552 | } |
1553 | |
1554 | /* See if the field is a kernel function name */ |
1555 | if ((len = str_has_prefix(str: str + i, prefix: ".function" ))) { |
1556 | function = true; |
1557 | i += len; |
1558 | } |
1559 | |
1560 | while (isspace(str[i])) |
1561 | i++; |
1562 | |
1563 | /* Make sure this op is supported */ |
1564 | for (op = 0; ops[op]; op++) { |
1565 | /* This is why '<=' must come before '<' in ops[] */ |
1566 | if (strncmp(str + i, ops[op], strlen(ops[op])) == 0) |
1567 | break; |
1568 | } |
1569 | |
1570 | if (!ops[op]) { |
1571 | parse_error(pe, err: FILT_ERR_INVALID_OP, pos: pos + i); |
1572 | goto err_free; |
1573 | } |
1574 | |
1575 | i += strlen(ops[op]); |
1576 | |
1577 | while (isspace(str[i])) |
1578 | i++; |
1579 | |
1580 | s = i; |
1581 | |
1582 | pred = kzalloc(size: sizeof(*pred), GFP_KERNEL); |
1583 | if (!pred) |
1584 | return -ENOMEM; |
1585 | |
1586 | pred->field = field; |
1587 | pred->offset = field->offset; |
1588 | pred->op = op; |
1589 | |
1590 | if (function) { |
1591 | /* The field must be the same size as long */ |
1592 | if (field->size != sizeof(long)) { |
1593 | parse_error(pe, err: FILT_ERR_ILLEGAL_FIELD_OP, pos: pos + i); |
1594 | goto err_free; |
1595 | } |
1596 | |
1597 | /* Function only works with '==' or '!=' and an unquoted string */ |
1598 | switch (op) { |
1599 | case OP_NE: |
1600 | case OP_EQ: |
1601 | break; |
1602 | default: |
1603 | parse_error(pe, err: FILT_ERR_INVALID_OP, pos: pos + i); |
1604 | goto err_free; |
1605 | } |
1606 | |
1607 | if (isdigit(c: str[i])) { |
1608 | /* We allow 0xDEADBEEF */ |
1609 | while (isalnum(str[i])) |
1610 | i++; |
1611 | |
1612 | len = i - s; |
1613 | /* 0xfeedfacedeadbeef is 18 chars max */ |
1614 | if (len >= sizeof(num_buf)) { |
1615 | parse_error(pe, err: FILT_ERR_OPERAND_TOO_LONG, pos: pos + i); |
1616 | goto err_free; |
1617 | } |
1618 | |
1619 | strncpy(p: num_buf, q: str + s, size: len); |
1620 | num_buf[len] = 0; |
1621 | |
1622 | ret = kstrtoul(s: num_buf, base: 0, res: &ip); |
1623 | if (ret) { |
1624 | parse_error(pe, err: FILT_ERR_INVALID_VALUE, pos: pos + i); |
1625 | goto err_free; |
1626 | } |
1627 | } else { |
1628 | s = i; |
1629 | for (; str[i] && !isspace(str[i]); i++) |
1630 | ; |
1631 | |
1632 | len = i - s; |
1633 | name = kmemdup_nul(s: str + s, len, GFP_KERNEL); |
1634 | if (!name) |
1635 | goto err_mem; |
1636 | ip = kallsyms_lookup_name(name); |
1637 | kfree(objp: name); |
1638 | if (!ip) { |
1639 | parse_error(pe, err: FILT_ERR_NO_FUNCTION, pos: pos + i); |
1640 | goto err_free; |
1641 | } |
1642 | } |
1643 | |
1644 | /* Now find the function start and end address */ |
1645 | if (!kallsyms_lookup_size_offset(addr: ip, symbolsize: &size, offset: &offset)) { |
1646 | parse_error(pe, err: FILT_ERR_NO_FUNCTION, pos: pos + i); |
1647 | goto err_free; |
1648 | } |
1649 | |
1650 | pred->fn_num = FILTER_PRED_FN_FUNCTION; |
1651 | pred->val = ip - offset; |
1652 | pred->val2 = pred->val + size; |
1653 | |
1654 | } else if (ftrace_event_is_function(call)) { |
1655 | /* |
1656 | * Perf does things different with function events. |
1657 | * It only allows an "ip" field, and expects a string. |
1658 | * But the string does not need to be surrounded by quotes. |
1659 | * If it is a string, the assigned function as a nop, |
1660 | * (perf doesn't use it) and grab everything. |
1661 | */ |
1662 | if (strcmp(field->name, "ip" ) != 0) { |
1663 | parse_error(pe, err: FILT_ERR_IP_FIELD_ONLY, pos: pos + i); |
1664 | goto err_free; |
1665 | } |
1666 | pred->fn_num = FILTER_PRED_FN_NOP; |
1667 | |
1668 | /* |
1669 | * Quotes are not required, but if they exist then we need |
1670 | * to read them till we hit a matching one. |
1671 | */ |
1672 | if (str[i] == '\'' || str[i] == '"') |
1673 | q = str[i]; |
1674 | else |
1675 | q = 0; |
1676 | |
1677 | for (i++; str[i]; i++) { |
1678 | if (q && str[i] == q) |
1679 | break; |
1680 | if (!q && (str[i] == ')' || str[i] == '&' || |
1681 | str[i] == '|')) |
1682 | break; |
1683 | } |
1684 | /* Skip quotes */ |
1685 | if (q) |
1686 | s++; |
1687 | len = i - s; |
1688 | if (len >= MAX_FILTER_STR_VAL) { |
1689 | parse_error(pe, err: FILT_ERR_OPERAND_TOO_LONG, pos: pos + i); |
1690 | goto err_free; |
1691 | } |
1692 | |
1693 | pred->regex = kzalloc(size: sizeof(*pred->regex), GFP_KERNEL); |
1694 | if (!pred->regex) |
1695 | goto err_mem; |
1696 | pred->regex->len = len; |
1697 | strncpy(p: pred->regex->pattern, q: str + s, size: len); |
1698 | pred->regex->pattern[len] = 0; |
1699 | |
1700 | } else if (!strncmp(str + i, "CPUS" , 4)) { |
1701 | unsigned int maskstart; |
1702 | bool single; |
1703 | char *tmp; |
1704 | |
1705 | switch (field->filter_type) { |
1706 | case FILTER_CPUMASK: |
1707 | case FILTER_CPU: |
1708 | case FILTER_OTHER: |
1709 | break; |
1710 | default: |
1711 | parse_error(pe, err: FILT_ERR_ILLEGAL_FIELD_OP, pos: pos + i); |
1712 | goto err_free; |
1713 | } |
1714 | |
1715 | switch (op) { |
1716 | case OP_EQ: |
1717 | case OP_NE: |
1718 | case OP_BAND: |
1719 | break; |
1720 | default: |
1721 | parse_error(pe, err: FILT_ERR_ILLEGAL_FIELD_OP, pos: pos + i); |
1722 | goto err_free; |
1723 | } |
1724 | |
1725 | /* Skip CPUS */ |
1726 | i += 4; |
1727 | if (str[i++] != '{') { |
1728 | parse_error(pe, err: FILT_ERR_MISSING_BRACE_OPEN, pos: pos + i); |
1729 | goto err_free; |
1730 | } |
1731 | maskstart = i; |
1732 | |
1733 | /* Walk the cpulist until closing } */ |
1734 | for (; str[i] && str[i] != '}'; i++) |
1735 | ; |
1736 | |
1737 | if (str[i] != '}') { |
1738 | parse_error(pe, err: FILT_ERR_MISSING_BRACE_CLOSE, pos: pos + i); |
1739 | goto err_free; |
1740 | } |
1741 | |
1742 | if (maskstart == i) { |
1743 | parse_error(pe, err: FILT_ERR_INVALID_CPULIST, pos: pos + i); |
1744 | goto err_free; |
1745 | } |
1746 | |
1747 | /* Copy the cpulist between { and } */ |
1748 | tmp = kmalloc(size: (i - maskstart) + 1, GFP_KERNEL); |
1749 | if (!tmp) |
1750 | goto err_mem; |
1751 | |
1752 | strscpy(p: tmp, q: str + maskstart, size: (i - maskstart) + 1); |
1753 | pred->mask = kzalloc(size: cpumask_size(), GFP_KERNEL); |
1754 | if (!pred->mask) { |
1755 | kfree(objp: tmp); |
1756 | goto err_mem; |
1757 | } |
1758 | |
1759 | /* Now parse it */ |
1760 | if (cpulist_parse(buf: tmp, dstp: pred->mask)) { |
1761 | kfree(objp: tmp); |
1762 | parse_error(pe, err: FILT_ERR_INVALID_CPULIST, pos: pos + i); |
1763 | goto err_free; |
1764 | } |
1765 | kfree(objp: tmp); |
1766 | |
1767 | /* Move along */ |
1768 | i++; |
1769 | |
1770 | /* |
1771 | * Optimisation: if the user-provided mask has a weight of one |
1772 | * then we can treat it as a scalar input. |
1773 | */ |
1774 | single = cpumask_weight(srcp: pred->mask) == 1; |
1775 | if (single) { |
1776 | pred->val = cpumask_first(srcp: pred->mask); |
1777 | kfree(objp: pred->mask); |
1778 | pred->mask = NULL; |
1779 | } |
1780 | |
1781 | if (field->filter_type == FILTER_CPUMASK) { |
1782 | pred->fn_num = single ? |
1783 | FILTER_PRED_FN_CPUMASK_CPU : |
1784 | FILTER_PRED_FN_CPUMASK; |
1785 | } else if (field->filter_type == FILTER_CPU) { |
1786 | if (single) { |
1787 | if (pred->op == OP_BAND) |
1788 | pred->op = OP_EQ; |
1789 | |
1790 | pred->fn_num = FILTER_PRED_FN_CPU; |
1791 | } else { |
1792 | pred->fn_num = FILTER_PRED_FN_CPU_CPUMASK; |
1793 | } |
1794 | } else if (single) { |
1795 | if (pred->op == OP_BAND) |
1796 | pred->op = OP_EQ; |
1797 | |
1798 | pred->fn_num = select_comparison_fn(op: pred->op, field_size: field->size, field_is_signed: false); |
1799 | if (pred->op == OP_NE) |
1800 | pred->not = 1; |
1801 | } else { |
1802 | switch (field->size) { |
1803 | case 8: |
1804 | pred->fn_num = FILTER_PRED_FN_64_CPUMASK; |
1805 | break; |
1806 | case 4: |
1807 | pred->fn_num = FILTER_PRED_FN_32_CPUMASK; |
1808 | break; |
1809 | case 2: |
1810 | pred->fn_num = FILTER_PRED_FN_16_CPUMASK; |
1811 | break; |
1812 | case 1: |
1813 | pred->fn_num = FILTER_PRED_FN_8_CPUMASK; |
1814 | break; |
1815 | } |
1816 | } |
1817 | |
1818 | /* This is either a string, or an integer */ |
1819 | } else if (str[i] == '\'' || str[i] == '"') { |
1820 | char q = str[i]; |
1821 | |
1822 | /* Make sure the op is OK for strings */ |
1823 | switch (op) { |
1824 | case OP_NE: |
1825 | pred->not = 1; |
1826 | fallthrough; |
1827 | case OP_GLOB: |
1828 | case OP_EQ: |
1829 | break; |
1830 | default: |
1831 | parse_error(pe, err: FILT_ERR_ILLEGAL_FIELD_OP, pos: pos + i); |
1832 | goto err_free; |
1833 | } |
1834 | |
1835 | /* Make sure the field is OK for strings */ |
1836 | if (!is_string_field(field)) { |
1837 | parse_error(pe, err: FILT_ERR_EXPECT_DIGIT, pos: pos + i); |
1838 | goto err_free; |
1839 | } |
1840 | |
1841 | for (i++; str[i]; i++) { |
1842 | if (str[i] == q) |
1843 | break; |
1844 | } |
1845 | if (!str[i]) { |
1846 | parse_error(pe, err: FILT_ERR_MISSING_QUOTE, pos: pos + i); |
1847 | goto err_free; |
1848 | } |
1849 | |
1850 | /* Skip quotes */ |
1851 | s++; |
1852 | len = i - s; |
1853 | if (len >= MAX_FILTER_STR_VAL) { |
1854 | parse_error(pe, err: FILT_ERR_OPERAND_TOO_LONG, pos: pos + i); |
1855 | goto err_free; |
1856 | } |
1857 | |
1858 | pred->regex = kzalloc(size: sizeof(*pred->regex), GFP_KERNEL); |
1859 | if (!pred->regex) |
1860 | goto err_mem; |
1861 | pred->regex->len = len; |
1862 | strncpy(p: pred->regex->pattern, q: str + s, size: len); |
1863 | pred->regex->pattern[len] = 0; |
1864 | |
1865 | filter_build_regex(pred); |
1866 | |
1867 | if (field->filter_type == FILTER_COMM) { |
1868 | pred->fn_num = FILTER_PRED_FN_COMM; |
1869 | |
1870 | } else if (field->filter_type == FILTER_STATIC_STRING) { |
1871 | pred->fn_num = FILTER_PRED_FN_STRING; |
1872 | pred->regex->field_len = field->size; |
1873 | |
1874 | } else if (field->filter_type == FILTER_DYN_STRING) { |
1875 | pred->fn_num = FILTER_PRED_FN_STRLOC; |
1876 | } else if (field->filter_type == FILTER_RDYN_STRING) |
1877 | pred->fn_num = FILTER_PRED_FN_STRRELLOC; |
1878 | else { |
1879 | |
1880 | if (!ustring_per_cpu) { |
1881 | /* Once allocated, keep it around for good */ |
1882 | ustring_per_cpu = alloc_percpu(struct ustring_buffer); |
1883 | if (!ustring_per_cpu) |
1884 | goto err_mem; |
1885 | } |
1886 | |
1887 | if (ustring) |
1888 | pred->fn_num = FILTER_PRED_FN_PCHAR_USER; |
1889 | else |
1890 | pred->fn_num = FILTER_PRED_FN_PCHAR; |
1891 | } |
1892 | /* go past the last quote */ |
1893 | i++; |
1894 | |
1895 | } else if (isdigit(c: str[i]) || str[i] == '-') { |
1896 | |
1897 | /* Make sure the field is not a string */ |
1898 | if (is_string_field(field)) { |
1899 | parse_error(pe, err: FILT_ERR_EXPECT_STRING, pos: pos + i); |
1900 | goto err_free; |
1901 | } |
1902 | |
1903 | if (op == OP_GLOB) { |
1904 | parse_error(pe, err: FILT_ERR_ILLEGAL_FIELD_OP, pos: pos + i); |
1905 | goto err_free; |
1906 | } |
1907 | |
1908 | if (str[i] == '-') |
1909 | i++; |
1910 | |
1911 | /* We allow 0xDEADBEEF */ |
1912 | while (isalnum(str[i])) |
1913 | i++; |
1914 | |
1915 | len = i - s; |
1916 | /* 0xfeedfacedeadbeef is 18 chars max */ |
1917 | if (len >= sizeof(num_buf)) { |
1918 | parse_error(pe, err: FILT_ERR_OPERAND_TOO_LONG, pos: pos + i); |
1919 | goto err_free; |
1920 | } |
1921 | |
1922 | strncpy(p: num_buf, q: str + s, size: len); |
1923 | num_buf[len] = 0; |
1924 | |
1925 | /* Make sure it is a value */ |
1926 | if (field->is_signed) |
1927 | ret = kstrtoll(s: num_buf, base: 0, res: &val); |
1928 | else |
1929 | ret = kstrtoull(s: num_buf, base: 0, res: &val); |
1930 | if (ret) { |
1931 | parse_error(pe, err: FILT_ERR_ILLEGAL_INTVAL, pos: pos + s); |
1932 | goto err_free; |
1933 | } |
1934 | |
1935 | pred->val = val; |
1936 | |
1937 | if (field->filter_type == FILTER_CPU) |
1938 | pred->fn_num = FILTER_PRED_FN_CPU; |
1939 | else { |
1940 | pred->fn_num = select_comparison_fn(op: pred->op, field_size: field->size, |
1941 | field_is_signed: field->is_signed); |
1942 | if (pred->op == OP_NE) |
1943 | pred->not = 1; |
1944 | } |
1945 | |
1946 | } else { |
1947 | parse_error(pe, err: FILT_ERR_INVALID_VALUE, pos: pos + i); |
1948 | goto err_free; |
1949 | } |
1950 | |
1951 | *pred_ptr = pred; |
1952 | return i; |
1953 | |
1954 | err_free: |
1955 | free_predicate(pred); |
1956 | return -EINVAL; |
1957 | err_mem: |
1958 | free_predicate(pred); |
1959 | return -ENOMEM; |
1960 | } |
1961 | |
1962 | enum { |
1963 | TOO_MANY_CLOSE = -1, |
1964 | TOO_MANY_OPEN = -2, |
1965 | MISSING_QUOTE = -3, |
1966 | }; |
1967 | |
1968 | /* |
1969 | * Read the filter string once to calculate the number of predicates |
1970 | * as well as how deep the parentheses go. |
1971 | * |
1972 | * Returns: |
1973 | * 0 - everything is fine (err is undefined) |
1974 | * -1 - too many ')' |
1975 | * -2 - too many '(' |
1976 | * -3 - No matching quote |
1977 | */ |
1978 | static int calc_stack(const char *str, int *parens, int *preds, int *err) |
1979 | { |
1980 | bool is_pred = false; |
1981 | int nr_preds = 0; |
1982 | int open = 1; /* Count the expression as "(E)" */ |
1983 | int last_quote = 0; |
1984 | int max_open = 1; |
1985 | int quote = 0; |
1986 | int i; |
1987 | |
1988 | *err = 0; |
1989 | |
1990 | for (i = 0; str[i]; i++) { |
1991 | if (isspace(str[i])) |
1992 | continue; |
1993 | if (quote) { |
1994 | if (str[i] == quote) |
1995 | quote = 0; |
1996 | continue; |
1997 | } |
1998 | |
1999 | switch (str[i]) { |
2000 | case '\'': |
2001 | case '"': |
2002 | quote = str[i]; |
2003 | last_quote = i; |
2004 | break; |
2005 | case '|': |
2006 | case '&': |
2007 | if (str[i+1] != str[i]) |
2008 | break; |
2009 | is_pred = false; |
2010 | continue; |
2011 | case '(': |
2012 | is_pred = false; |
2013 | open++; |
2014 | if (open > max_open) |
2015 | max_open = open; |
2016 | continue; |
2017 | case ')': |
2018 | is_pred = false; |
2019 | if (open == 1) { |
2020 | *err = i; |
2021 | return TOO_MANY_CLOSE; |
2022 | } |
2023 | open--; |
2024 | continue; |
2025 | } |
2026 | if (!is_pred) { |
2027 | nr_preds++; |
2028 | is_pred = true; |
2029 | } |
2030 | } |
2031 | |
2032 | if (quote) { |
2033 | *err = last_quote; |
2034 | return MISSING_QUOTE; |
2035 | } |
2036 | |
2037 | if (open != 1) { |
2038 | int level = open; |
2039 | |
2040 | /* find the bad open */ |
2041 | for (i--; i; i--) { |
2042 | if (quote) { |
2043 | if (str[i] == quote) |
2044 | quote = 0; |
2045 | continue; |
2046 | } |
2047 | switch (str[i]) { |
2048 | case '(': |
2049 | if (level == open) { |
2050 | *err = i; |
2051 | return TOO_MANY_OPEN; |
2052 | } |
2053 | level--; |
2054 | break; |
2055 | case ')': |
2056 | level++; |
2057 | break; |
2058 | case '\'': |
2059 | case '"': |
2060 | quote = str[i]; |
2061 | break; |
2062 | } |
2063 | } |
2064 | /* First character is the '(' with missing ')' */ |
2065 | *err = 0; |
2066 | return TOO_MANY_OPEN; |
2067 | } |
2068 | |
2069 | /* Set the size of the required stacks */ |
2070 | *parens = max_open; |
2071 | *preds = nr_preds; |
2072 | return 0; |
2073 | } |
2074 | |
2075 | static int process_preds(struct trace_event_call *call, |
2076 | const char *filter_string, |
2077 | struct event_filter *filter, |
2078 | struct filter_parse_error *pe) |
2079 | { |
2080 | struct prog_entry *prog; |
2081 | int nr_parens; |
2082 | int nr_preds; |
2083 | int index; |
2084 | int ret; |
2085 | |
2086 | ret = calc_stack(str: filter_string, parens: &nr_parens, preds: &nr_preds, err: &index); |
2087 | if (ret < 0) { |
2088 | switch (ret) { |
2089 | case MISSING_QUOTE: |
2090 | parse_error(pe, err: FILT_ERR_MISSING_QUOTE, pos: index); |
2091 | break; |
2092 | case TOO_MANY_OPEN: |
2093 | parse_error(pe, err: FILT_ERR_TOO_MANY_OPEN, pos: index); |
2094 | break; |
2095 | default: |
2096 | parse_error(pe, err: FILT_ERR_TOO_MANY_CLOSE, pos: index); |
2097 | } |
2098 | return ret; |
2099 | } |
2100 | |
2101 | if (!nr_preds) |
2102 | return -EINVAL; |
2103 | |
2104 | prog = predicate_parse(str: filter_string, nr_parens, nr_preds, |
2105 | parse_pred, data: call, pe); |
2106 | if (IS_ERR(ptr: prog)) |
2107 | return PTR_ERR(ptr: prog); |
2108 | |
2109 | rcu_assign_pointer(filter->prog, prog); |
2110 | return 0; |
2111 | } |
2112 | |
2113 | static inline void event_set_filtered_flag(struct trace_event_file *file) |
2114 | { |
2115 | unsigned long old_flags = file->flags; |
2116 | |
2117 | file->flags |= EVENT_FILE_FL_FILTERED; |
2118 | |
2119 | if (old_flags != file->flags) |
2120 | trace_buffered_event_enable(); |
2121 | } |
2122 | |
2123 | static inline void event_set_filter(struct trace_event_file *file, |
2124 | struct event_filter *filter) |
2125 | { |
2126 | rcu_assign_pointer(file->filter, filter); |
2127 | } |
2128 | |
2129 | static inline void event_clear_filter(struct trace_event_file *file) |
2130 | { |
2131 | RCU_INIT_POINTER(file->filter, NULL); |
2132 | } |
2133 | |
2134 | struct filter_list { |
2135 | struct list_head list; |
2136 | struct event_filter *filter; |
2137 | }; |
2138 | |
2139 | static int process_system_preds(struct trace_subsystem_dir *dir, |
2140 | struct trace_array *tr, |
2141 | struct filter_parse_error *pe, |
2142 | char *filter_string) |
2143 | { |
2144 | struct trace_event_file *file; |
2145 | struct filter_list *filter_item; |
2146 | struct event_filter *filter = NULL; |
2147 | struct filter_list *tmp; |
2148 | LIST_HEAD(filter_list); |
2149 | bool fail = true; |
2150 | int err; |
2151 | |
2152 | list_for_each_entry(file, &tr->events, list) { |
2153 | |
2154 | if (file->system != dir) |
2155 | continue; |
2156 | |
2157 | filter = kzalloc(size: sizeof(*filter), GFP_KERNEL); |
2158 | if (!filter) |
2159 | goto fail_mem; |
2160 | |
2161 | filter->filter_string = kstrdup(s: filter_string, GFP_KERNEL); |
2162 | if (!filter->filter_string) |
2163 | goto fail_mem; |
2164 | |
2165 | err = process_preds(call: file->event_call, filter_string, filter, pe); |
2166 | if (err) { |
2167 | filter_disable(file); |
2168 | parse_error(pe, err: FILT_ERR_BAD_SUBSYS_FILTER, pos: 0); |
2169 | append_filter_err(tr, pe, filter); |
2170 | } else |
2171 | event_set_filtered_flag(file); |
2172 | |
2173 | |
2174 | filter_item = kzalloc(size: sizeof(*filter_item), GFP_KERNEL); |
2175 | if (!filter_item) |
2176 | goto fail_mem; |
2177 | |
2178 | list_add_tail(new: &filter_item->list, head: &filter_list); |
2179 | /* |
2180 | * Regardless of if this returned an error, we still |
2181 | * replace the filter for the call. |
2182 | */ |
2183 | filter_item->filter = event_filter(file); |
2184 | event_set_filter(file, filter); |
2185 | filter = NULL; |
2186 | |
2187 | fail = false; |
2188 | } |
2189 | |
2190 | if (fail) |
2191 | goto fail; |
2192 | |
2193 | /* |
2194 | * The calls can still be using the old filters. |
2195 | * Do a synchronize_rcu() and to ensure all calls are |
2196 | * done with them before we free them. |
2197 | */ |
2198 | tracepoint_synchronize_unregister(); |
2199 | list_for_each_entry_safe(filter_item, tmp, &filter_list, list) { |
2200 | __free_filter(filter: filter_item->filter); |
2201 | list_del(entry: &filter_item->list); |
2202 | kfree(objp: filter_item); |
2203 | } |
2204 | return 0; |
2205 | fail: |
2206 | /* No call succeeded */ |
2207 | list_for_each_entry_safe(filter_item, tmp, &filter_list, list) { |
2208 | list_del(entry: &filter_item->list); |
2209 | kfree(objp: filter_item); |
2210 | } |
2211 | parse_error(pe, err: FILT_ERR_BAD_SUBSYS_FILTER, pos: 0); |
2212 | return -EINVAL; |
2213 | fail_mem: |
2214 | __free_filter(filter); |
2215 | /* If any call succeeded, we still need to sync */ |
2216 | if (!fail) |
2217 | tracepoint_synchronize_unregister(); |
2218 | list_for_each_entry_safe(filter_item, tmp, &filter_list, list) { |
2219 | __free_filter(filter: filter_item->filter); |
2220 | list_del(entry: &filter_item->list); |
2221 | kfree(objp: filter_item); |
2222 | } |
2223 | return -ENOMEM; |
2224 | } |
2225 | |
2226 | static int create_filter_start(char *filter_string, bool set_str, |
2227 | struct filter_parse_error **pse, |
2228 | struct event_filter **filterp) |
2229 | { |
2230 | struct event_filter *filter; |
2231 | struct filter_parse_error *pe = NULL; |
2232 | int err = 0; |
2233 | |
2234 | if (WARN_ON_ONCE(*pse || *filterp)) |
2235 | return -EINVAL; |
2236 | |
2237 | filter = kzalloc(size: sizeof(*filter), GFP_KERNEL); |
2238 | if (filter && set_str) { |
2239 | filter->filter_string = kstrdup(s: filter_string, GFP_KERNEL); |
2240 | if (!filter->filter_string) |
2241 | err = -ENOMEM; |
2242 | } |
2243 | |
2244 | pe = kzalloc(size: sizeof(*pe), GFP_KERNEL); |
2245 | |
2246 | if (!filter || !pe || err) { |
2247 | kfree(objp: pe); |
2248 | __free_filter(filter); |
2249 | return -ENOMEM; |
2250 | } |
2251 | |
2252 | /* we're committed to creating a new filter */ |
2253 | *filterp = filter; |
2254 | *pse = pe; |
2255 | |
2256 | return 0; |
2257 | } |
2258 | |
2259 | static void create_filter_finish(struct filter_parse_error *pe) |
2260 | { |
2261 | kfree(objp: pe); |
2262 | } |
2263 | |
2264 | /** |
2265 | * create_filter - create a filter for a trace_event_call |
2266 | * @tr: the trace array associated with these events |
2267 | * @call: trace_event_call to create a filter for |
2268 | * @filter_string: filter string |
2269 | * @set_str: remember @filter_str and enable detailed error in filter |
2270 | * @filterp: out param for created filter (always updated on return) |
2271 | * Must be a pointer that references a NULL pointer. |
2272 | * |
2273 | * Creates a filter for @call with @filter_str. If @set_str is %true, |
2274 | * @filter_str is copied and recorded in the new filter. |
2275 | * |
2276 | * On success, returns 0 and *@filterp points to the new filter. On |
2277 | * failure, returns -errno and *@filterp may point to %NULL or to a new |
2278 | * filter. In the latter case, the returned filter contains error |
2279 | * information if @set_str is %true and the caller is responsible for |
2280 | * freeing it. |
2281 | */ |
2282 | static int create_filter(struct trace_array *tr, |
2283 | struct trace_event_call *call, |
2284 | char *filter_string, bool set_str, |
2285 | struct event_filter **filterp) |
2286 | { |
2287 | struct filter_parse_error *pe = NULL; |
2288 | int err; |
2289 | |
2290 | /* filterp must point to NULL */ |
2291 | if (WARN_ON(*filterp)) |
2292 | *filterp = NULL; |
2293 | |
2294 | err = create_filter_start(filter_string, set_str, pse: &pe, filterp); |
2295 | if (err) |
2296 | return err; |
2297 | |
2298 | err = process_preds(call, filter_string, filter: *filterp, pe); |
2299 | if (err && set_str) |
2300 | append_filter_err(tr, pe, filter: *filterp); |
2301 | create_filter_finish(pe); |
2302 | |
2303 | return err; |
2304 | } |
2305 | |
2306 | int create_event_filter(struct trace_array *tr, |
2307 | struct trace_event_call *call, |
2308 | char *filter_str, bool set_str, |
2309 | struct event_filter **filterp) |
2310 | { |
2311 | return create_filter(tr, call, filter_string: filter_str, set_str, filterp); |
2312 | } |
2313 | |
2314 | /** |
2315 | * create_system_filter - create a filter for an event subsystem |
2316 | * @dir: the descriptor for the subsystem directory |
2317 | * @filter_str: filter string |
2318 | * @filterp: out param for created filter (always updated on return) |
2319 | * |
2320 | * Identical to create_filter() except that it creates a subsystem filter |
2321 | * and always remembers @filter_str. |
2322 | */ |
2323 | static int create_system_filter(struct trace_subsystem_dir *dir, |
2324 | char *filter_str, struct event_filter **filterp) |
2325 | { |
2326 | struct filter_parse_error *pe = NULL; |
2327 | int err; |
2328 | |
2329 | err = create_filter_start(filter_string: filter_str, set_str: true, pse: &pe, filterp); |
2330 | if (!err) { |
2331 | err = process_system_preds(dir, tr: dir->tr, pe, filter_string: filter_str); |
2332 | if (!err) { |
2333 | /* System filters just show a default message */ |
2334 | kfree(objp: (*filterp)->filter_string); |
2335 | (*filterp)->filter_string = NULL; |
2336 | } else { |
2337 | append_filter_err(tr: dir->tr, pe, filter: *filterp); |
2338 | } |
2339 | } |
2340 | create_filter_finish(pe); |
2341 | |
2342 | return err; |
2343 | } |
2344 | |
2345 | /* caller must hold event_mutex */ |
2346 | int apply_event_filter(struct trace_event_file *file, char *filter_string) |
2347 | { |
2348 | struct trace_event_call *call = file->event_call; |
2349 | struct event_filter *filter = NULL; |
2350 | int err; |
2351 | |
2352 | if (file->flags & EVENT_FILE_FL_FREED) |
2353 | return -ENODEV; |
2354 | |
2355 | if (!strcmp(strstrip(str: filter_string), "0" )) { |
2356 | filter_disable(file); |
2357 | filter = event_filter(file); |
2358 | |
2359 | if (!filter) |
2360 | return 0; |
2361 | |
2362 | event_clear_filter(file); |
2363 | |
2364 | /* Make sure the filter is not being used */ |
2365 | tracepoint_synchronize_unregister(); |
2366 | __free_filter(filter); |
2367 | |
2368 | return 0; |
2369 | } |
2370 | |
2371 | err = create_filter(tr: file->tr, call, filter_string, set_str: true, filterp: &filter); |
2372 | |
2373 | /* |
2374 | * Always swap the call filter with the new filter |
2375 | * even if there was an error. If there was an error |
2376 | * in the filter, we disable the filter and show the error |
2377 | * string |
2378 | */ |
2379 | if (filter) { |
2380 | struct event_filter *tmp; |
2381 | |
2382 | tmp = event_filter(file); |
2383 | if (!err) |
2384 | event_set_filtered_flag(file); |
2385 | else |
2386 | filter_disable(file); |
2387 | |
2388 | event_set_filter(file, filter); |
2389 | |
2390 | if (tmp) { |
2391 | /* Make sure the call is done with the filter */ |
2392 | tracepoint_synchronize_unregister(); |
2393 | __free_filter(filter: tmp); |
2394 | } |
2395 | } |
2396 | |
2397 | return err; |
2398 | } |
2399 | |
2400 | int apply_subsystem_event_filter(struct trace_subsystem_dir *dir, |
2401 | char *filter_string) |
2402 | { |
2403 | struct event_subsystem *system = dir->subsystem; |
2404 | struct trace_array *tr = dir->tr; |
2405 | struct event_filter *filter = NULL; |
2406 | int err = 0; |
2407 | |
2408 | mutex_lock(&event_mutex); |
2409 | |
2410 | /* Make sure the system still has events */ |
2411 | if (!dir->nr_events) { |
2412 | err = -ENODEV; |
2413 | goto out_unlock; |
2414 | } |
2415 | |
2416 | if (!strcmp(strstrip(str: filter_string), "0" )) { |
2417 | filter_free_subsystem_preds(dir, tr); |
2418 | remove_filter_string(filter: system->filter); |
2419 | filter = system->filter; |
2420 | system->filter = NULL; |
2421 | /* Ensure all filters are no longer used */ |
2422 | tracepoint_synchronize_unregister(); |
2423 | filter_free_subsystem_filters(dir, tr); |
2424 | __free_filter(filter); |
2425 | goto out_unlock; |
2426 | } |
2427 | |
2428 | err = create_system_filter(dir, filter_str: filter_string, filterp: &filter); |
2429 | if (filter) { |
2430 | /* |
2431 | * No event actually uses the system filter |
2432 | * we can free it without synchronize_rcu(). |
2433 | */ |
2434 | __free_filter(filter: system->filter); |
2435 | system->filter = filter; |
2436 | } |
2437 | out_unlock: |
2438 | mutex_unlock(lock: &event_mutex); |
2439 | |
2440 | return err; |
2441 | } |
2442 | |
2443 | #ifdef CONFIG_PERF_EVENTS |
2444 | |
2445 | void ftrace_profile_free_filter(struct perf_event *event) |
2446 | { |
2447 | struct event_filter *filter = event->filter; |
2448 | |
2449 | event->filter = NULL; |
2450 | __free_filter(filter); |
2451 | } |
2452 | |
2453 | struct function_filter_data { |
2454 | struct ftrace_ops *ops; |
2455 | int first_filter; |
2456 | int first_notrace; |
2457 | }; |
2458 | |
2459 | #ifdef CONFIG_FUNCTION_TRACER |
2460 | static char ** |
2461 | ftrace_function_filter_re(char *buf, int len, int *count) |
2462 | { |
2463 | char *str, **re; |
2464 | |
2465 | str = kstrndup(s: buf, len, GFP_KERNEL); |
2466 | if (!str) |
2467 | return NULL; |
2468 | |
2469 | /* |
2470 | * The argv_split function takes white space |
2471 | * as a separator, so convert ',' into spaces. |
2472 | */ |
2473 | strreplace(str, old: ',', new: ' '); |
2474 | |
2475 | re = argv_split(GFP_KERNEL, str, argcp: count); |
2476 | kfree(objp: str); |
2477 | return re; |
2478 | } |
2479 | |
2480 | static int ftrace_function_set_regexp(struct ftrace_ops *ops, int filter, |
2481 | int reset, char *re, int len) |
2482 | { |
2483 | int ret; |
2484 | |
2485 | if (filter) |
2486 | ret = ftrace_set_filter(ops, buf: re, len, reset); |
2487 | else |
2488 | ret = ftrace_set_notrace(ops, buf: re, len, reset); |
2489 | |
2490 | return ret; |
2491 | } |
2492 | |
2493 | static int __ftrace_function_set_filter(int filter, char *buf, int len, |
2494 | struct function_filter_data *data) |
2495 | { |
2496 | int i, re_cnt, ret = -EINVAL; |
2497 | int *reset; |
2498 | char **re; |
2499 | |
2500 | reset = filter ? &data->first_filter : &data->first_notrace; |
2501 | |
2502 | /* |
2503 | * The 'ip' field could have multiple filters set, separated |
2504 | * either by space or comma. We first cut the filter and apply |
2505 | * all pieces separately. |
2506 | */ |
2507 | re = ftrace_function_filter_re(buf, len, count: &re_cnt); |
2508 | if (!re) |
2509 | return -EINVAL; |
2510 | |
2511 | for (i = 0; i < re_cnt; i++) { |
2512 | ret = ftrace_function_set_regexp(ops: data->ops, filter, reset: *reset, |
2513 | re: re[i], strlen(re[i])); |
2514 | if (ret) |
2515 | break; |
2516 | |
2517 | if (*reset) |
2518 | *reset = 0; |
2519 | } |
2520 | |
2521 | argv_free(argv: re); |
2522 | return ret; |
2523 | } |
2524 | |
2525 | static int ftrace_function_check_pred(struct filter_pred *pred) |
2526 | { |
2527 | struct ftrace_event_field *field = pred->field; |
2528 | |
2529 | /* |
2530 | * Check the predicate for function trace, verify: |
2531 | * - only '==' and '!=' is used |
2532 | * - the 'ip' field is used |
2533 | */ |
2534 | if ((pred->op != OP_EQ) && (pred->op != OP_NE)) |
2535 | return -EINVAL; |
2536 | |
2537 | if (strcmp(field->name, "ip" )) |
2538 | return -EINVAL; |
2539 | |
2540 | return 0; |
2541 | } |
2542 | |
2543 | static int ftrace_function_set_filter_pred(struct filter_pred *pred, |
2544 | struct function_filter_data *data) |
2545 | { |
2546 | int ret; |
2547 | |
2548 | /* Checking the node is valid for function trace. */ |
2549 | ret = ftrace_function_check_pred(pred); |
2550 | if (ret) |
2551 | return ret; |
2552 | |
2553 | return __ftrace_function_set_filter(filter: pred->op == OP_EQ, |
2554 | buf: pred->regex->pattern, |
2555 | len: pred->regex->len, |
2556 | data); |
2557 | } |
2558 | |
2559 | static bool is_or(struct prog_entry *prog, int i) |
2560 | { |
2561 | int target; |
2562 | |
2563 | /* |
2564 | * Only "||" is allowed for function events, thus, |
2565 | * all true branches should jump to true, and any |
2566 | * false branch should jump to false. |
2567 | */ |
2568 | target = prog[i].target + 1; |
2569 | /* True and false have NULL preds (all prog entries should jump to one */ |
2570 | if (prog[target].pred) |
2571 | return false; |
2572 | |
2573 | /* prog[target].target is 1 for TRUE, 0 for FALSE */ |
2574 | return prog[i].when_to_branch == prog[target].target; |
2575 | } |
2576 | |
2577 | static int ftrace_function_set_filter(struct perf_event *event, |
2578 | struct event_filter *filter) |
2579 | { |
2580 | struct prog_entry *prog = rcu_dereference_protected(filter->prog, |
2581 | lockdep_is_held(&event_mutex)); |
2582 | struct function_filter_data data = { |
2583 | .first_filter = 1, |
2584 | .first_notrace = 1, |
2585 | .ops = &event->ftrace_ops, |
2586 | }; |
2587 | int i; |
2588 | |
2589 | for (i = 0; prog[i].pred; i++) { |
2590 | struct filter_pred *pred = prog[i].pred; |
2591 | |
2592 | if (!is_or(prog, i)) |
2593 | return -EINVAL; |
2594 | |
2595 | if (ftrace_function_set_filter_pred(pred, data: &data) < 0) |
2596 | return -EINVAL; |
2597 | } |
2598 | return 0; |
2599 | } |
2600 | #else |
2601 | static int ftrace_function_set_filter(struct perf_event *event, |
2602 | struct event_filter *filter) |
2603 | { |
2604 | return -ENODEV; |
2605 | } |
2606 | #endif /* CONFIG_FUNCTION_TRACER */ |
2607 | |
2608 | int ftrace_profile_set_filter(struct perf_event *event, int event_id, |
2609 | char *filter_str) |
2610 | { |
2611 | int err; |
2612 | struct event_filter *filter = NULL; |
2613 | struct trace_event_call *call; |
2614 | |
2615 | mutex_lock(&event_mutex); |
2616 | |
2617 | call = event->tp_event; |
2618 | |
2619 | err = -EINVAL; |
2620 | if (!call) |
2621 | goto out_unlock; |
2622 | |
2623 | err = -EEXIST; |
2624 | if (event->filter) |
2625 | goto out_unlock; |
2626 | |
2627 | err = create_filter(NULL, call, filter_string: filter_str, set_str: false, filterp: &filter); |
2628 | if (err) |
2629 | goto free_filter; |
2630 | |
2631 | if (ftrace_event_is_function(call)) |
2632 | err = ftrace_function_set_filter(event, filter); |
2633 | else |
2634 | event->filter = filter; |
2635 | |
2636 | free_filter: |
2637 | if (err || ftrace_event_is_function(call)) |
2638 | __free_filter(filter); |
2639 | |
2640 | out_unlock: |
2641 | mutex_unlock(lock: &event_mutex); |
2642 | |
2643 | return err; |
2644 | } |
2645 | |
2646 | #endif /* CONFIG_PERF_EVENTS */ |
2647 | |
2648 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
2649 | |
2650 | #include <linux/types.h> |
2651 | #include <linux/tracepoint.h> |
2652 | |
2653 | #define CREATE_TRACE_POINTS |
2654 | #include "trace_events_filter_test.h" |
2655 | |
2656 | #define DATA_REC(m, va, vb, vc, vd, ve, vf, vg, vh, nvisit) \ |
2657 | { \ |
2658 | .filter = FILTER, \ |
2659 | .rec = { .a = va, .b = vb, .c = vc, .d = vd, \ |
2660 | .e = ve, .f = vf, .g = vg, .h = vh }, \ |
2661 | .match = m, \ |
2662 | .not_visited = nvisit, \ |
2663 | } |
2664 | #define YES 1 |
2665 | #define NO 0 |
2666 | |
2667 | static struct test_filter_data_t { |
2668 | char *filter; |
2669 | struct trace_event_raw_ftrace_test_filter rec; |
2670 | int match; |
2671 | char *not_visited; |
2672 | } test_filter_data[] = { |
2673 | #define FILTER "a == 1 && b == 1 && c == 1 && d == 1 && " \ |
2674 | "e == 1 && f == 1 && g == 1 && h == 1" |
2675 | DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "" ), |
2676 | DATA_REC(NO, 0, 1, 1, 1, 1, 1, 1, 1, "bcdefgh" ), |
2677 | DATA_REC(NO, 1, 1, 1, 1, 1, 1, 1, 0, "" ), |
2678 | #undef FILTER |
2679 | #define FILTER "a == 1 || b == 1 || c == 1 || d == 1 || " \ |
2680 | "e == 1 || f == 1 || g == 1 || h == 1" |
2681 | DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 0, "" ), |
2682 | DATA_REC(YES, 0, 0, 0, 0, 0, 0, 0, 1, "" ), |
2683 | DATA_REC(YES, 1, 0, 0, 0, 0, 0, 0, 0, "bcdefgh" ), |
2684 | #undef FILTER |
2685 | #define FILTER "(a == 1 || b == 1) && (c == 1 || d == 1) && " \ |
2686 | "(e == 1 || f == 1) && (g == 1 || h == 1)" |
2687 | DATA_REC(NO, 0, 0, 1, 1, 1, 1, 1, 1, "dfh" ), |
2688 | DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, "" ), |
2689 | DATA_REC(YES, 1, 0, 1, 0, 0, 1, 0, 1, "bd" ), |
2690 | DATA_REC(NO, 1, 0, 1, 0, 0, 1, 0, 0, "bd" ), |
2691 | #undef FILTER |
2692 | #define FILTER "(a == 1 && b == 1) || (c == 1 && d == 1) || " \ |
2693 | "(e == 1 && f == 1) || (g == 1 && h == 1)" |
2694 | DATA_REC(YES, 1, 0, 1, 1, 1, 1, 1, 1, "efgh" ), |
2695 | DATA_REC(YES, 0, 0, 0, 0, 0, 0, 1, 1, "" ), |
2696 | DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 1, "" ), |
2697 | #undef FILTER |
2698 | #define FILTER "(a == 1 && b == 1) && (c == 1 && d == 1) && " \ |
2699 | "(e == 1 && f == 1) || (g == 1 && h == 1)" |
2700 | DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 0, "gh" ), |
2701 | DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 1, "" ), |
2702 | DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, "" ), |
2703 | #undef FILTER |
2704 | #define FILTER "((a == 1 || b == 1) || (c == 1 || d == 1) || " \ |
2705 | "(e == 1 || f == 1)) && (g == 1 || h == 1)" |
2706 | DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 1, "bcdef" ), |
2707 | DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 0, "" ), |
2708 | DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, "h" ), |
2709 | #undef FILTER |
2710 | #define FILTER "((((((((a == 1) && (b == 1)) || (c == 1)) && (d == 1)) || " \ |
2711 | "(e == 1)) && (f == 1)) || (g == 1)) && (h == 1))" |
2712 | DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "ceg" ), |
2713 | DATA_REC(NO, 0, 1, 0, 1, 0, 1, 0, 1, "" ), |
2714 | DATA_REC(NO, 1, 0, 1, 0, 1, 0, 1, 0, "" ), |
2715 | #undef FILTER |
2716 | #define FILTER "((((((((a == 1) || (b == 1)) && (c == 1)) || (d == 1)) && " \ |
2717 | "(e == 1)) || (f == 1)) && (g == 1)) || (h == 1))" |
2718 | DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "bdfh" ), |
2719 | DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, "" ), |
2720 | DATA_REC(YES, 1, 0, 1, 0, 1, 0, 1, 0, "bdfh" ), |
2721 | }; |
2722 | |
2723 | #undef DATA_REC |
2724 | #undef FILTER |
2725 | #undef YES |
2726 | #undef NO |
2727 | |
2728 | #define DATA_CNT ARRAY_SIZE(test_filter_data) |
2729 | |
2730 | static int test_pred_visited; |
2731 | |
2732 | static int test_pred_visited_fn(struct filter_pred *pred, void *event) |
2733 | { |
2734 | struct ftrace_event_field *field = pred->field; |
2735 | |
2736 | test_pred_visited = 1; |
2737 | printk(KERN_INFO "\npred visited %s\n" , field->name); |
2738 | return 1; |
2739 | } |
2740 | |
2741 | static void update_pred_fn(struct event_filter *filter, char *fields) |
2742 | { |
2743 | struct prog_entry *prog = rcu_dereference_protected(filter->prog, |
2744 | lockdep_is_held(&event_mutex)); |
2745 | int i; |
2746 | |
2747 | for (i = 0; prog[i].pred; i++) { |
2748 | struct filter_pred *pred = prog[i].pred; |
2749 | struct ftrace_event_field *field = pred->field; |
2750 | |
2751 | WARN_ON_ONCE(pred->fn_num == FILTER_PRED_FN_NOP); |
2752 | |
2753 | if (!field) { |
2754 | WARN_ONCE(1, "all leafs should have field defined %d" , i); |
2755 | continue; |
2756 | } |
2757 | |
2758 | if (!strchr(fields, *field->name)) |
2759 | continue; |
2760 | |
2761 | pred->fn_num = FILTER_PRED_TEST_VISITED; |
2762 | } |
2763 | } |
2764 | |
2765 | static __init int ftrace_test_event_filter(void) |
2766 | { |
2767 | int i; |
2768 | |
2769 | printk(KERN_INFO "Testing ftrace filter: " ); |
2770 | |
2771 | for (i = 0; i < DATA_CNT; i++) { |
2772 | struct event_filter *filter = NULL; |
2773 | struct test_filter_data_t *d = &test_filter_data[i]; |
2774 | int err; |
2775 | |
2776 | err = create_filter(NULL, call: &event_ftrace_test_filter, |
2777 | filter_string: d->filter, set_str: false, filterp: &filter); |
2778 | if (err) { |
2779 | printk(KERN_INFO |
2780 | "Failed to get filter for '%s', err %d\n" , |
2781 | d->filter, err); |
2782 | __free_filter(filter); |
2783 | break; |
2784 | } |
2785 | |
2786 | /* Needed to dereference filter->prog */ |
2787 | mutex_lock(&event_mutex); |
2788 | /* |
2789 | * The preemption disabling is not really needed for self |
2790 | * tests, but the rcu dereference will complain without it. |
2791 | */ |
2792 | preempt_disable(); |
2793 | if (*d->not_visited) |
2794 | update_pred_fn(filter, fields: d->not_visited); |
2795 | |
2796 | test_pred_visited = 0; |
2797 | err = filter_match_preds(filter, &d->rec); |
2798 | preempt_enable(); |
2799 | |
2800 | mutex_unlock(lock: &event_mutex); |
2801 | |
2802 | __free_filter(filter); |
2803 | |
2804 | if (test_pred_visited) { |
2805 | printk(KERN_INFO |
2806 | "Failed, unwanted pred visited for filter %s\n" , |
2807 | d->filter); |
2808 | break; |
2809 | } |
2810 | |
2811 | if (err != d->match) { |
2812 | printk(KERN_INFO |
2813 | "Failed to match filter '%s', expected %d\n" , |
2814 | d->filter, d->match); |
2815 | break; |
2816 | } |
2817 | } |
2818 | |
2819 | if (i == DATA_CNT) |
2820 | printk(KERN_CONT "OK\n" ); |
2821 | |
2822 | return 0; |
2823 | } |
2824 | |
2825 | late_initcall(ftrace_test_event_filter); |
2826 | |
2827 | #endif /* CONFIG_FTRACE_STARTUP_TEST */ |
2828 | |