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