1 // SPDX-License-Identifier: GPL-2.0
3 * trace_events_filter - generic event filtering
5 * Copyright (C) 2009 Tom Zanussi <tzanussi@gmail.com>
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>
15 #include "trace_output.h"
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"
23 /* Due to token parsing '<=' must be before '<' and '>=' must be before '>' */
38 enum filter_op_ids
{ OPS
};
43 static const char * ops
[] = { OPS
};
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.
49 #define PRED_FUNC_START OP_LE
50 #define PRED_FUNC_MAX (OP_BAND - PRED_FUNC_START)
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)?"), \
70 C(NO_FILTER, "No filter found")
73 #define C(a, b) FILT_ERR_##a
80 static const char *err_text
[] = { ERRORS
};
82 /* Called after a '!' character but "!=" and "!~" are not "not"s */
83 static bool is_not(const char *str
)
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.
102 struct filter_pred
*pred
;
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
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 "&&"
117 static void update_preds(struct prog_entry
*prog
, int N
, int invert
)
123 prog
[t
].when_to_branch
= invert
;
128 struct filter_parse_error
{
133 static void parse_error(struct filter_parse_error
*pe
, int err
, int pos
)
136 pe
->lasterr_pos
= pos
;
139 typedef int (*parse_pred_fn
)(const char *str
, void *data
, int pos
,
140 struct filter_parse_error
*pe
,
141 struct filter_pred
**pred
);
150 * Without going into a formal proof, this explains the method that is used in
151 * parsing the logical expressions.
153 * For example, if we have: "a && !(!b || (c && g)) || d || e && !f"
154 * The first pass will convert it into the following program:
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
166 * To do this, we use a data structure to represent each of the above
167 * predicate and conditions that has:
169 * predicate, when_to_branch, invert, target
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.
177 * A stack is created to hold values when parentheses are used.
179 * To simplify the logic, the labels will start at 0 and not 1.
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.
187 * The top of the stack and "invert" are initialized to zero.
191 * #1 A loop through all the tokens is done:
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"
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.
205 * The only other acceptable token is the predicate string.
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).
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".
214 * #6 The invert variable is reset to the current value saved on the top of
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.
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.
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
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 "&&".
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.
243 * #11 If this is the end of the input string "\0" then we break out of both
246 * #12 Otherwise, the next token is ")", where we pop the stack and continue
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 "||".
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
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;
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).
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
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 }
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:
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
314 * n0: r = a; if (r) goto T
315 * n1: r = b; if (!r) goto F
316 * n2: r = c; if (!r) goto F
320 * The First Pass is over the input string. The next too passes are over
321 * the program itself.
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:
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:
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:
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;
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;".
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
373 * Notice, all the "l#" labels are no longer used, and they can now
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
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
395 * n1: if (!a) goto n5;
396 * n2: if (!b) goto n5;
397 * n3: if (!c) goto T;
398 * n4: if (!g) goto T;
400 * n6: if (!e) goto F;
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.
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
)
414 struct prog_entry
*prog_stack
;
415 struct prog_entry
*prog
;
416 const char *ptr
= str
;
417 char *inverts
= NULL
;
426 nr_preds
+= 2; /* For TRUE and FALSE */
428 op_stack
= kmalloc_array(nr_parens
, sizeof(*op_stack
), GFP_KERNEL
);
430 return ERR_PTR(-ENOMEM
);
431 prog_stack
= kcalloc(nr_preds
, sizeof(*prog_stack
), GFP_KERNEL
);
433 parse_error(pe
, -ENOMEM
, 0);
436 inverts
= kmalloc_array(nr_preds
, sizeof(*inverts
), GFP_KERNEL
);
438 parse_error(pe
, -ENOMEM
, 0);
447 while (*ptr
) { /* #1 */
448 const char *next
= ptr
++;
455 if (top
- op_stack
> nr_parens
) {
469 parse_error(pe
, FILT_ERR_TOO_MANY_PREDS
, next
- str
);
473 inverts
[N
] = invert
; /* #4 */
474 prog
[N
].target
= N
-1;
476 len
= parse_pred(next
, data
, ptr
- str
, pe
, &prog
[N
].pred
);
497 /* accepting only "&&" or "||" */
498 if (next
[1] == next
[0]) {
504 parse_error(pe
, FILT_ERR_TOO_MANY_PREDS
,
509 invert
= *top
& INVERT
;
511 if (*top
& PROCESS_AND
) { /* #7 */
512 update_preds(prog
, N
- 1, invert
);
513 *top
&= ~PROCESS_AND
;
515 if (*next
== '&') { /* #8 */
519 if (*top
& PROCESS_OR
) { /* #9 */
520 update_preds(prog
, N
- 1, !invert
);
523 if (*next
== '|') { /* #10 */
527 if (!*next
) /* #11 */
530 if (top
== op_stack
) {
533 parse_error(pe
, FILT_ERR_TOO_MANY_CLOSE
, ptr
- str
);
540 if (top
!= op_stack
) {
542 parse_error(pe
, FILT_ERR_TOO_MANY_OPEN
, ptr
- str
);
549 parse_error(pe
, FILT_ERR_NO_FILTER
, ptr
- str
);
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;
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
;
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
)) {
585 for (i
= 0; prog_stack
[i
].pred
; i
++)
586 kfree(prog_stack
[i
].pred
);
592 #define DEFINE_COMPARISON_PRED(type) \
593 static int filter_pred_LT_##type(struct filter_pred *pred, void *event) \
595 type *addr = (type *)(event + pred->offset); \
596 type val = (type)pred->val; \
597 return *addr < val; \
599 static int filter_pred_LE_##type(struct filter_pred *pred, void *event) \
601 type *addr = (type *)(event + pred->offset); \
602 type val = (type)pred->val; \
603 return *addr <= val; \
605 static int filter_pred_GT_##type(struct filter_pred *pred, void *event) \
607 type *addr = (type *)(event + pred->offset); \
608 type val = (type)pred->val; \
609 return *addr > val; \
611 static int filter_pred_GE_##type(struct filter_pred *pred, void *event) \
613 type *addr = (type *)(event + pred->offset); \
614 type val = (type)pred->val; \
615 return *addr >= val; \
617 static int filter_pred_BAND_##type(struct filter_pred *pred, void *event) \
619 type *addr = (type *)(event + pred->offset); \
620 type val = (type)pred->val; \
621 return !!(*addr & val); \
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, \
631 #define DEFINE_EQUALITY_PRED(size) \
632 static int filter_pred_##size(struct filter_pred *pred, void *event) \
634 u##size *addr = (u##size *)(event + pred->offset); \
635 u##size val = (u##size)pred->val; \
638 match = (val == *addr) ^ pred->not; \
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
);
652 DEFINE_EQUALITY_PRED(64);
653 DEFINE_EQUALITY_PRED(32);
654 DEFINE_EQUALITY_PRED(16);
655 DEFINE_EQUALITY_PRED(8);
657 /* Filter predicate for fixed sized arrays of characters */
658 static int filter_pred_string(struct filter_pred
*pred
, void *event
)
660 char *addr
= (char *)(event
+ pred
->offset
);
663 cmp
= pred
->regex
.match(addr
, &pred
->regex
, pred
->regex
.field_len
);
665 match
= cmp
^ pred
->not;
670 /* Filter predicate for char * pointers */
671 static int filter_pred_pchar(struct filter_pred
*pred
, void *event
)
673 char **addr
= (char **)(event
+ pred
->offset
);
675 int len
= strlen(*addr
) + 1; /* including tailing '\0' */
677 cmp
= pred
->regex
.match(*addr
, &pred
->regex
, len
);
679 match
= cmp
^ pred
->not;
685 * Filter predicate for dynamic sized arrays of characters.
686 * These are implemented through a list of strings at the end
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.
694 static int filter_pred_strloc(struct filter_pred
*pred
, void *event
)
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
);
702 cmp
= pred
->regex
.match(addr
, &pred
->regex
, str_len
);
704 match
= cmp
^ pred
->not;
709 /* Filter predicate for CPUs. */
710 static int filter_pred_cpu(struct filter_pred
*pred
, void *event
)
714 cpu
= raw_smp_processor_id();
735 /* Filter predicate for COMM. */
736 static int filter_pred_comm(struct filter_pred
*pred
, void *event
)
740 cmp
= pred
->regex
.match(current
->comm
, &pred
->regex
,
742 return cmp
^ pred
->not;
745 static int filter_pred_none(struct filter_pred
*pred
, void *event
)
751 * regex_match_foo - Basic regex callbacks
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')
758 * - @str might not be NULL-terminated if it's of type DYN_STRING
759 * or STATIC_STRING, unless @len is zero.
762 static int regex_match_full(char *str
, struct regex
*r
, int len
)
764 /* len of zero means str is dynamic and ends with '\0' */
766 return strcmp(str
, r
->pattern
) == 0;
768 return strncmp(str
, r
->pattern
, len
) == 0;
771 static int regex_match_front(char *str
, struct regex
*r
, int len
)
773 if (len
&& len
< r
->len
)
776 return strncmp(str
, r
->pattern
, r
->len
) == 0;
779 static int regex_match_middle(char *str
, struct regex
*r
, int len
)
782 return strstr(str
, r
->pattern
) != NULL
;
784 return strnstr(str
, r
->pattern
, len
) != NULL
;
787 static int regex_match_end(char *str
, struct regex
*r
, int len
)
789 int strlen
= len
- 1;
791 if (strlen
>= r
->len
&&
792 memcmp(str
+ strlen
- r
->len
, r
->pattern
, r
->len
) == 0)
797 static int regex_match_glob(char *str
, struct regex
*r
, int len __maybe_unused
)
799 if (glob_match(r
->pattern
, str
))
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
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.
817 * search returns the pointer to use for comparison.
818 * not returns 1 if buff started with a '!'
821 enum regex_type
filter_parse_regex(char *buff
, int len
, char **search
, int *not)
823 int type
= MATCH_FULL
;
826 if (buff
[0] == '!') {
835 if (isdigit(buff
[0]))
838 for (i
= 0; i
< len
; i
++) {
839 if (buff
[i
] == '*') {
841 type
= MATCH_END_ONLY
;
842 } else if (i
== len
- 1) {
843 if (type
== MATCH_END_ONLY
)
844 type
= MATCH_MIDDLE_ONLY
;
846 type
= MATCH_FRONT_ONLY
;
849 } else { /* pattern continues, use full glob */
852 } else if (strchr("[?\\", buff
[i
])) {
862 static void filter_build_regex(struct filter_pred
*pred
)
864 struct regex
*r
= &pred
->regex
;
866 enum regex_type type
= MATCH_FULL
;
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);
875 /* MATCH_INDEX should not happen, but if it does, match full */
878 r
->match
= regex_match_full
;
880 case MATCH_FRONT_ONLY
:
881 r
->match
= regex_match_front
;
883 case MATCH_MIDDLE_ONLY
:
884 r
->match
= regex_match_middle
;
887 r
->match
= regex_match_end
;
890 r
->match
= regex_match_glob
;
895 /* return 1 if event matches, 0 otherwise (discard) */
896 int filter_match_preds(struct event_filter
*filter
, void *rec
)
898 struct prog_entry
*prog
;
901 /* no filter is considered a match */
905 /* Protected by either SRCU(tracepoint_srcu) or preempt_disable */
906 prog
= rcu_dereference_raw(filter
->prog
);
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
)
916 return prog
[i
].target
;
918 EXPORT_SYMBOL_GPL(filter_match_preds
);
920 static void remove_filter_string(struct event_filter
*filter
)
925 kfree(filter
->filter_string
);
926 filter
->filter_string
= NULL
;
929 static void append_filter_err(struct trace_array
*tr
,
930 struct filter_parse_error
*pe
,
931 struct event_filter
*filter
)
934 int pos
= pe
->lasterr_pos
;
938 if (WARN_ON(!filter
->filter_string
))
941 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
946 len
= strlen(filter
->filter_string
);
950 /* indexing is off by one */
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
);
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
,
967 trace_seq_putc(s
, 0);
968 buf
= kmemdup_nul(s
->buffer
, s
->seq
.len
, GFP_KERNEL
);
970 kfree(filter
->filter_string
);
971 filter
->filter_string
= buf
;
976 static inline struct event_filter
*event_filter(struct trace_event_file
*file
)
981 /* caller must hold event_mutex */
982 void print_event_filter(struct trace_event_file
*file
, struct trace_seq
*s
)
984 struct event_filter
*filter
= event_filter(file
);
986 if (filter
&& filter
->filter_string
)
987 trace_seq_printf(s
, "%s\n", filter
->filter_string
);
989 trace_seq_puts(s
, "none\n");
992 void print_subsystem_event_filter(struct event_subsystem
*system
,
995 struct event_filter
*filter
;
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
);
1002 trace_seq_puts(s
, DEFAULT_SYS_FILTER_MESSAGE
"\n");
1003 mutex_unlock(&event_mutex
);
1006 static void free_prog(struct event_filter
*filter
)
1008 struct prog_entry
*prog
;
1011 prog
= rcu_access_pointer(filter
->prog
);
1015 for (i
= 0; prog
[i
].pred
; i
++)
1016 kfree(prog
[i
].pred
);
1020 static void filter_disable(struct trace_event_file
*file
)
1022 unsigned long old_flags
= file
->flags
;
1024 file
->flags
&= ~EVENT_FILE_FL_FILTERED
;
1026 if (old_flags
!= file
->flags
)
1027 trace_buffered_event_disable();
1030 static void __free_filter(struct event_filter
*filter
)
1036 kfree(filter
->filter_string
);
1040 void free_event_filter(struct event_filter
*filter
)
1042 __free_filter(filter
);
1045 static inline void __remove_filter(struct trace_event_file
*file
)
1047 filter_disable(file
);
1048 remove_filter_string(file
->filter
);
1051 static void filter_free_subsystem_preds(struct trace_subsystem_dir
*dir
,
1052 struct trace_array
*tr
)
1054 struct trace_event_file
*file
;
1056 list_for_each_entry(file
, &tr
->events
, list
) {
1057 if (file
->system
!= dir
)
1059 __remove_filter(file
);
1063 static inline void __free_subsystem_filter(struct trace_event_file
*file
)
1065 __free_filter(file
->filter
);
1066 file
->filter
= NULL
;
1069 static void filter_free_subsystem_filters(struct trace_subsystem_dir
*dir
,
1070 struct trace_array
*tr
)
1072 struct trace_event_file
*file
;
1074 list_for_each_entry(file
, &tr
->events
, list
) {
1075 if (file
->system
!= dir
)
1077 __free_subsystem_filter(file
);
1081 int filter_assign_type(const char *type
)
1083 if (strstr(type
, "__data_loc") && strstr(type
, "char"))
1084 return FILTER_DYN_STRING
;
1086 if (strchr(type
, '[') && strstr(type
, "char"))
1087 return FILTER_STATIC_STRING
;
1089 if (strcmp(type
, "char *") == 0 || strcmp(type
, "const char *") == 0)
1090 return FILTER_PTR_STRING
;
1092 return FILTER_OTHER
;
1095 static filter_pred_fn_t
select_comparison_fn(enum filter_op_ids op
,
1096 int field_size
, int field_is_signed
)
1098 filter_pred_fn_t fn
= NULL
;
1099 int pred_func_index
= -1;
1106 if (WARN_ON_ONCE(op
< PRED_FUNC_START
))
1108 pred_func_index
= op
- PRED_FUNC_START
;
1109 if (WARN_ON_ONCE(pred_func_index
> PRED_FUNC_MAX
))
1113 switch (field_size
) {
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
];
1120 fn
= pred_funcs_u64
[pred_func_index
];
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
];
1128 fn
= pred_funcs_u32
[pred_func_index
];
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
];
1136 fn
= pred_funcs_u16
[pred_func_index
];
1139 if (pred_func_index
< 0)
1141 else if (field_is_signed
)
1142 fn
= pred_funcs_s8
[pred_func_index
];
1144 fn
= pred_funcs_u8
[pred_func_index
];
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
)
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 */
1169 /* First find the field to associate to */
1170 while (isspace(str
[i
]))
1174 while (isalnum(str
[i
]) || str
[i
] == '_')
1182 field_name
= kmemdup_nul(str
+ s
, len
, GFP_KERNEL
);
1186 /* Make sure that the field exists */
1188 field
= trace_find_event_field(call
, field_name
);
1191 parse_error(pe
, FILT_ERR_FIELD_NOT_FOUND
, pos
+ i
);
1195 while (isspace(str
[i
]))
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)
1206 parse_error(pe
, FILT_ERR_INVALID_OP
, pos
+ i
);
1210 i
+= strlen(ops
[op
]);
1212 while (isspace(str
[i
]))
1217 pred
= kzalloc(sizeof(*pred
), GFP_KERNEL
);
1221 pred
->field
= field
;
1222 pred
->offset
= field
->offset
;
1225 if (ftrace_event_is_function(call
)) {
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.
1233 if (strcmp(field
->name
, "ip") != 0) {
1234 parse_error(pe
, FILT_ERR_IP_FIELD_ONLY
, pos
+ i
);
1237 pred
->fn
= filter_pred_none
;
1240 * Quotes are not required, but if they exist then we need
1241 * to read them till we hit a matching one.
1243 if (str
[i
] == '\'' || str
[i
] == '"')
1248 for (i
++; str
[i
]; i
++) {
1249 if (q
&& str
[i
] == q
)
1251 if (!q
&& (str
[i
] == ')' || str
[i
] == '&' ||
1259 if (len
>= MAX_FILTER_STR_VAL
) {
1260 parse_error(pe
, FILT_ERR_OPERAND_TOO_LONG
, pos
+ i
);
1264 pred
->regex
.len
= len
;
1265 strncpy(pred
->regex
.pattern
, str
+ s
, len
);
1266 pred
->regex
.pattern
[len
] = 0;
1268 /* This is either a string, or an integer */
1269 } else if (str
[i
] == '\'' || str
[i
] == '"') {
1272 /* Make sure the op is OK for strings */
1281 parse_error(pe
, FILT_ERR_ILLEGAL_FIELD_OP
, pos
+ i
);
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
);
1291 for (i
++; str
[i
]; i
++) {
1296 parse_error(pe
, FILT_ERR_MISSING_QUOTE
, pos
+ i
);
1303 if (len
>= MAX_FILTER_STR_VAL
) {
1304 parse_error(pe
, FILT_ERR_OPERAND_TOO_LONG
, pos
+ i
);
1308 pred
->regex
.len
= len
;
1309 strncpy(pred
->regex
.pattern
, str
+ s
, len
);
1310 pred
->regex
.pattern
[len
] = 0;
1312 filter_build_regex(pred
);
1314 if (field
->filter_type
== FILTER_COMM
) {
1315 pred
->fn
= filter_pred_comm
;
1317 } else if (field
->filter_type
== FILTER_STATIC_STRING
) {
1318 pred
->fn
= filter_pred_string
;
1319 pred
->regex
.field_len
= field
->size
;
1321 } else if (field
->filter_type
== FILTER_DYN_STRING
)
1322 pred
->fn
= filter_pred_strloc
;
1324 pred
->fn
= filter_pred_pchar
;
1325 /* go past the last quote */
1328 } else if (isdigit(str
[i
]) || str
[i
] == '-') {
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
);
1336 if (op
== OP_GLOB
) {
1337 parse_error(pe
, FILT_ERR_ILLEGAL_FIELD_OP
, pos
+ i
);
1344 /* We allow 0xDEADBEEF */
1345 while (isalnum(str
[i
]))
1349 /* 0xfeedfacedeadbeef is 18 chars max */
1350 if (len
>= sizeof(num_buf
)) {
1351 parse_error(pe
, FILT_ERR_OPERAND_TOO_LONG
, pos
+ i
);
1355 strncpy(num_buf
, str
+ s
, len
);
1358 /* Make sure it is a value */
1359 if (field
->is_signed
)
1360 ret
= kstrtoll(num_buf
, 0, &val
);
1362 ret
= kstrtoull(num_buf
, 0, &val
);
1364 parse_error(pe
, FILT_ERR_ILLEGAL_INTVAL
, pos
+ s
);
1370 if (field
->filter_type
== FILTER_CPU
)
1371 pred
->fn
= filter_pred_cpu
;
1373 pred
->fn
= select_comparison_fn(pred
->op
, field
->size
,
1375 if (pred
->op
== OP_NE
)
1380 parse_error(pe
, FILT_ERR_INVALID_VALUE
, pos
+ i
);
1393 TOO_MANY_CLOSE
= -1,
1399 * Read the filter string once to calculate the number of predicates
1400 * as well as how deep the parentheses go.
1403 * 0 - everything is fine (err is undefined)
1406 * -3 - No matching quote
1408 static int calc_stack(const char *str
, int *parens
, int *preds
, int *err
)
1410 bool is_pred
= false;
1412 int open
= 1; /* Count the expression as "(E)" */
1420 for (i
= 0; str
[i
]; i
++) {
1421 if (isspace(str
[i
]))
1424 if (str
[i
] == quote
)
1437 if (str
[i
+1] != str
[i
])
1444 if (open
> max_open
)
1451 return TOO_MANY_CLOSE
;
1464 return MISSING_QUOTE
;
1470 /* find the bad open */
1473 if (str
[i
] == quote
)
1479 if (level
== open
) {
1481 return TOO_MANY_OPEN
;
1494 /* First character is the '(' with missing ')' */
1496 return TOO_MANY_OPEN
;
1499 /* Set the size of the required stacks */
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
)
1510 struct prog_entry
*prog
;
1516 ret
= calc_stack(filter_string
, &nr_parens
, &nr_preds
, &index
);
1520 parse_error(pe
, FILT_ERR_MISSING_QUOTE
, index
);
1523 parse_error(pe
, FILT_ERR_TOO_MANY_OPEN
, index
);
1526 parse_error(pe
, FILT_ERR_TOO_MANY_CLOSE
, index
);
1534 prog
= predicate_parse(filter_string
, nr_parens
, nr_preds
,
1535 parse_pred
, call
, pe
);
1537 return PTR_ERR(prog
);
1539 rcu_assign_pointer(filter
->prog
, prog
);
1543 static inline void event_set_filtered_flag(struct trace_event_file
*file
)
1545 unsigned long old_flags
= file
->flags
;
1547 file
->flags
|= EVENT_FILE_FL_FILTERED
;
1549 if (old_flags
!= file
->flags
)
1550 trace_buffered_event_enable();
1553 static inline void event_set_filter(struct trace_event_file
*file
,
1554 struct event_filter
*filter
)
1556 rcu_assign_pointer(file
->filter
, filter
);
1559 static inline void event_clear_filter(struct trace_event_file
*file
)
1561 RCU_INIT_POINTER(file
->filter
, NULL
);
1564 struct filter_list
{
1565 struct list_head list
;
1566 struct event_filter
*filter
;
1569 static int process_system_preds(struct trace_subsystem_dir
*dir
,
1570 struct trace_array
*tr
,
1571 struct filter_parse_error
*pe
,
1572 char *filter_string
)
1574 struct trace_event_file
*file
;
1575 struct filter_list
*filter_item
;
1576 struct event_filter
*filter
= NULL
;
1577 struct filter_list
*tmp
;
1578 LIST_HEAD(filter_list
);
1582 list_for_each_entry(file
, &tr
->events
, list
) {
1584 if (file
->system
!= dir
)
1587 filter
= kzalloc(sizeof(*filter
), GFP_KERNEL
);
1591 filter
->filter_string
= kstrdup(filter_string
, GFP_KERNEL
);
1592 if (!filter
->filter_string
)
1595 err
= process_preds(file
->event_call
, filter_string
, filter
, pe
);
1597 filter_disable(file
);
1598 parse_error(pe
, FILT_ERR_BAD_SUBSYS_FILTER
, 0);
1599 append_filter_err(tr
, pe
, filter
);
1601 event_set_filtered_flag(file
);
1604 filter_item
= kzalloc(sizeof(*filter_item
), GFP_KERNEL
);
1608 list_add_tail(&filter_item
->list
, &filter_list
);
1610 * Regardless of if this returned an error, we still
1611 * replace the filter for the call.
1613 filter_item
->filter
= event_filter(file
);
1614 event_set_filter(file
, filter
);
1624 * The calls can still be using the old filters.
1625 * Do a synchronize_rcu() and to ensure all calls are
1626 * done with them before we free them.
1628 tracepoint_synchronize_unregister();
1629 list_for_each_entry_safe(filter_item
, tmp
, &filter_list
, list
) {
1630 __free_filter(filter_item
->filter
);
1631 list_del(&filter_item
->list
);
1636 /* No call succeeded */
1637 list_for_each_entry_safe(filter_item
, tmp
, &filter_list
, list
) {
1638 list_del(&filter_item
->list
);
1641 parse_error(pe
, FILT_ERR_BAD_SUBSYS_FILTER
, 0);
1644 __free_filter(filter
);
1645 /* If any call succeeded, we still need to sync */
1647 tracepoint_synchronize_unregister();
1648 list_for_each_entry_safe(filter_item
, tmp
, &filter_list
, list
) {
1649 __free_filter(filter_item
->filter
);
1650 list_del(&filter_item
->list
);
1656 static int create_filter_start(char *filter_string
, bool set_str
,
1657 struct filter_parse_error
**pse
,
1658 struct event_filter
**filterp
)
1660 struct event_filter
*filter
;
1661 struct filter_parse_error
*pe
= NULL
;
1664 if (WARN_ON_ONCE(*pse
|| *filterp
))
1667 filter
= kzalloc(sizeof(*filter
), GFP_KERNEL
);
1668 if (filter
&& set_str
) {
1669 filter
->filter_string
= kstrdup(filter_string
, GFP_KERNEL
);
1670 if (!filter
->filter_string
)
1674 pe
= kzalloc(sizeof(*pe
), GFP_KERNEL
);
1676 if (!filter
|| !pe
|| err
) {
1678 __free_filter(filter
);
1682 /* we're committed to creating a new filter */
1689 static void create_filter_finish(struct filter_parse_error
*pe
)
1695 * create_filter - create a filter for a trace_event_call
1696 * @call: trace_event_call to create a filter for
1697 * @filter_str: filter string
1698 * @set_str: remember @filter_str and enable detailed error in filter
1699 * @filterp: out param for created filter (always updated on return)
1700 * Must be a pointer that references a NULL pointer.
1702 * Creates a filter for @call with @filter_str. If @set_str is %true,
1703 * @filter_str is copied and recorded in the new filter.
1705 * On success, returns 0 and *@filterp points to the new filter. On
1706 * failure, returns -errno and *@filterp may point to %NULL or to a new
1707 * filter. In the latter case, the returned filter contains error
1708 * information if @set_str is %true and the caller is responsible for
1711 static int create_filter(struct trace_array
*tr
,
1712 struct trace_event_call
*call
,
1713 char *filter_string
, bool set_str
,
1714 struct event_filter
**filterp
)
1716 struct filter_parse_error
*pe
= NULL
;
1719 /* filterp must point to NULL */
1720 if (WARN_ON(*filterp
))
1723 err
= create_filter_start(filter_string
, set_str
, &pe
, filterp
);
1727 err
= process_preds(call
, filter_string
, *filterp
, pe
);
1729 append_filter_err(tr
, pe
, *filterp
);
1730 create_filter_finish(pe
);
1735 int create_event_filter(struct trace_array
*tr
,
1736 struct trace_event_call
*call
,
1737 char *filter_str
, bool set_str
,
1738 struct event_filter
**filterp
)
1740 return create_filter(tr
, call
, filter_str
, set_str
, filterp
);
1744 * create_system_filter - create a filter for an event_subsystem
1745 * @system: event_subsystem to create a filter for
1746 * @filter_str: filter string
1747 * @filterp: out param for created filter (always updated on return)
1749 * Identical to create_filter() except that it creates a subsystem filter
1750 * and always remembers @filter_str.
1752 static int create_system_filter(struct trace_subsystem_dir
*dir
,
1753 struct trace_array
*tr
,
1754 char *filter_str
, struct event_filter
**filterp
)
1756 struct filter_parse_error
*pe
= NULL
;
1759 err
= create_filter_start(filter_str
, true, &pe
, filterp
);
1761 err
= process_system_preds(dir
, tr
, pe
, filter_str
);
1763 /* System filters just show a default message */
1764 kfree((*filterp
)->filter_string
);
1765 (*filterp
)->filter_string
= NULL
;
1767 append_filter_err(tr
, pe
, *filterp
);
1770 create_filter_finish(pe
);
1775 /* caller must hold event_mutex */
1776 int apply_event_filter(struct trace_event_file
*file
, char *filter_string
)
1778 struct trace_event_call
*call
= file
->event_call
;
1779 struct event_filter
*filter
= NULL
;
1782 if (!strcmp(strstrip(filter_string
), "0")) {
1783 filter_disable(file
);
1784 filter
= event_filter(file
);
1789 event_clear_filter(file
);
1791 /* Make sure the filter is not being used */
1792 tracepoint_synchronize_unregister();
1793 __free_filter(filter
);
1798 err
= create_filter(file
->tr
, call
, filter_string
, true, &filter
);
1801 * Always swap the call filter with the new filter
1802 * even if there was an error. If there was an error
1803 * in the filter, we disable the filter and show the error
1807 struct event_filter
*tmp
;
1809 tmp
= event_filter(file
);
1811 event_set_filtered_flag(file
);
1813 filter_disable(file
);
1815 event_set_filter(file
, filter
);
1818 /* Make sure the call is done with the filter */
1819 tracepoint_synchronize_unregister();
1827 int apply_subsystem_event_filter(struct trace_subsystem_dir
*dir
,
1828 char *filter_string
)
1830 struct event_subsystem
*system
= dir
->subsystem
;
1831 struct trace_array
*tr
= dir
->tr
;
1832 struct event_filter
*filter
= NULL
;
1835 mutex_lock(&event_mutex
);
1837 /* Make sure the system still has events */
1838 if (!dir
->nr_events
) {
1843 if (!strcmp(strstrip(filter_string
), "0")) {
1844 filter_free_subsystem_preds(dir
, tr
);
1845 remove_filter_string(system
->filter
);
1846 filter
= system
->filter
;
1847 system
->filter
= NULL
;
1848 /* Ensure all filters are no longer used */
1849 tracepoint_synchronize_unregister();
1850 filter_free_subsystem_filters(dir
, tr
);
1851 __free_filter(filter
);
1855 err
= create_system_filter(dir
, tr
, filter_string
, &filter
);
1858 * No event actually uses the system filter
1859 * we can free it without synchronize_rcu().
1861 __free_filter(system
->filter
);
1862 system
->filter
= filter
;
1865 mutex_unlock(&event_mutex
);
1870 #ifdef CONFIG_PERF_EVENTS
1872 void ftrace_profile_free_filter(struct perf_event
*event
)
1874 struct event_filter
*filter
= event
->filter
;
1876 event
->filter
= NULL
;
1877 __free_filter(filter
);
1880 struct function_filter_data
{
1881 struct ftrace_ops
*ops
;
1886 #ifdef CONFIG_FUNCTION_TRACER
1888 ftrace_function_filter_re(char *buf
, int len
, int *count
)
1892 str
= kstrndup(buf
, len
, GFP_KERNEL
);
1897 * The argv_split function takes white space
1898 * as a separator, so convert ',' into spaces.
1900 strreplace(str
, ',', ' ');
1902 re
= argv_split(GFP_KERNEL
, str
, count
);
1907 static int ftrace_function_set_regexp(struct ftrace_ops
*ops
, int filter
,
1908 int reset
, char *re
, int len
)
1913 ret
= ftrace_set_filter(ops
, re
, len
, reset
);
1915 ret
= ftrace_set_notrace(ops
, re
, len
, reset
);
1920 static int __ftrace_function_set_filter(int filter
, char *buf
, int len
,
1921 struct function_filter_data
*data
)
1923 int i
, re_cnt
, ret
= -EINVAL
;
1927 reset
= filter
? &data
->first_filter
: &data
->first_notrace
;
1930 * The 'ip' field could have multiple filters set, separated
1931 * either by space or comma. We first cut the filter and apply
1932 * all pieces separately.
1934 re
= ftrace_function_filter_re(buf
, len
, &re_cnt
);
1938 for (i
= 0; i
< re_cnt
; i
++) {
1939 ret
= ftrace_function_set_regexp(data
->ops
, filter
, *reset
,
1940 re
[i
], strlen(re
[i
]));
1952 static int ftrace_function_check_pred(struct filter_pred
*pred
)
1954 struct ftrace_event_field
*field
= pred
->field
;
1957 * Check the predicate for function trace, verify:
1958 * - only '==' and '!=' is used
1959 * - the 'ip' field is used
1961 if ((pred
->op
!= OP_EQ
) && (pred
->op
!= OP_NE
))
1964 if (strcmp(field
->name
, "ip"))
1970 static int ftrace_function_set_filter_pred(struct filter_pred
*pred
,
1971 struct function_filter_data
*data
)
1975 /* Checking the node is valid for function trace. */
1976 ret
= ftrace_function_check_pred(pred
);
1980 return __ftrace_function_set_filter(pred
->op
== OP_EQ
,
1981 pred
->regex
.pattern
,
1986 static bool is_or(struct prog_entry
*prog
, int i
)
1991 * Only "||" is allowed for function events, thus,
1992 * all true branches should jump to true, and any
1993 * false branch should jump to false.
1995 target
= prog
[i
].target
+ 1;
1996 /* True and false have NULL preds (all prog entries should jump to one */
1997 if (prog
[target
].pred
)
2000 /* prog[target].target is 1 for TRUE, 0 for FALSE */
2001 return prog
[i
].when_to_branch
== prog
[target
].target
;
2004 static int ftrace_function_set_filter(struct perf_event
*event
,
2005 struct event_filter
*filter
)
2007 struct prog_entry
*prog
= rcu_dereference_protected(filter
->prog
,
2008 lockdep_is_held(&event_mutex
));
2009 struct function_filter_data data
= {
2012 .ops
= &event
->ftrace_ops
,
2016 for (i
= 0; prog
[i
].pred
; i
++) {
2017 struct filter_pred
*pred
= prog
[i
].pred
;
2019 if (!is_or(prog
, i
))
2022 if (ftrace_function_set_filter_pred(pred
, &data
) < 0)
2028 static int ftrace_function_set_filter(struct perf_event
*event
,
2029 struct event_filter
*filter
)
2033 #endif /* CONFIG_FUNCTION_TRACER */
2035 int ftrace_profile_set_filter(struct perf_event
*event
, int event_id
,
2039 struct event_filter
*filter
= NULL
;
2040 struct trace_event_call
*call
;
2042 mutex_lock(&event_mutex
);
2044 call
= event
->tp_event
;
2054 err
= create_filter(NULL
, call
, filter_str
, false, &filter
);
2058 if (ftrace_event_is_function(call
))
2059 err
= ftrace_function_set_filter(event
, filter
);
2061 event
->filter
= filter
;
2064 if (err
|| ftrace_event_is_function(call
))
2065 __free_filter(filter
);
2068 mutex_unlock(&event_mutex
);
2073 #endif /* CONFIG_PERF_EVENTS */
2075 #ifdef CONFIG_FTRACE_STARTUP_TEST
2077 #include <linux/types.h>
2078 #include <linux/tracepoint.h>
2080 #define CREATE_TRACE_POINTS
2081 #include "trace_events_filter_test.h"
2083 #define DATA_REC(m, va, vb, vc, vd, ve, vf, vg, vh, nvisit) \
2086 .rec = { .a = va, .b = vb, .c = vc, .d = vd, \
2087 .e = ve, .f = vf, .g = vg, .h = vh }, \
2089 .not_visited = nvisit, \
2094 static struct test_filter_data_t
{
2096 struct trace_event_raw_ftrace_test_filter rec
;
2099 } test_filter_data
[] = {
2100 #define FILTER "a == 1 && b == 1 && c == 1 && d == 1 && " \
2101 "e == 1 && f == 1 && g == 1 && h == 1"
2102 DATA_REC(YES
, 1, 1, 1, 1, 1, 1, 1, 1, ""),
2103 DATA_REC(NO
, 0, 1, 1, 1, 1, 1, 1, 1, "bcdefgh"),
2104 DATA_REC(NO
, 1, 1, 1, 1, 1, 1, 1, 0, ""),
2106 #define FILTER "a == 1 || b == 1 || c == 1 || d == 1 || " \
2107 "e == 1 || f == 1 || g == 1 || h == 1"
2108 DATA_REC(NO
, 0, 0, 0, 0, 0, 0, 0, 0, ""),
2109 DATA_REC(YES
, 0, 0, 0, 0, 0, 0, 0, 1, ""),
2110 DATA_REC(YES
, 1, 0, 0, 0, 0, 0, 0, 0, "bcdefgh"),
2112 #define FILTER "(a == 1 || b == 1) && (c == 1 || d == 1) && " \
2113 "(e == 1 || f == 1) && (g == 1 || h == 1)"
2114 DATA_REC(NO
, 0, 0, 1, 1, 1, 1, 1, 1, "dfh"),
2115 DATA_REC(YES
, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2116 DATA_REC(YES
, 1, 0, 1, 0, 0, 1, 0, 1, "bd"),
2117 DATA_REC(NO
, 1, 0, 1, 0, 0, 1, 0, 0, "bd"),
2119 #define FILTER "(a == 1 && b == 1) || (c == 1 && d == 1) || " \
2120 "(e == 1 && f == 1) || (g == 1 && h == 1)"
2121 DATA_REC(YES
, 1, 0, 1, 1, 1, 1, 1, 1, "efgh"),
2122 DATA_REC(YES
, 0, 0, 0, 0, 0, 0, 1, 1, ""),
2123 DATA_REC(NO
, 0, 0, 0, 0, 0, 0, 0, 1, ""),
2125 #define FILTER "(a == 1 && b == 1) && (c == 1 && d == 1) && " \
2126 "(e == 1 && f == 1) || (g == 1 && h == 1)"
2127 DATA_REC(YES
, 1, 1, 1, 1, 1, 1, 0, 0, "gh"),
2128 DATA_REC(NO
, 0, 0, 0, 0, 0, 0, 0, 1, ""),
2129 DATA_REC(YES
, 1, 1, 1, 1, 1, 0, 1, 1, ""),
2131 #define FILTER "((a == 1 || b == 1) || (c == 1 || d == 1) || " \
2132 "(e == 1 || f == 1)) && (g == 1 || h == 1)"
2133 DATA_REC(YES
, 1, 1, 1, 1, 1, 1, 0, 1, "bcdef"),
2134 DATA_REC(NO
, 0, 0, 0, 0, 0, 0, 0, 0, ""),
2135 DATA_REC(YES
, 1, 1, 1, 1, 1, 0, 1, 1, "h"),
2137 #define FILTER "((((((((a == 1) && (b == 1)) || (c == 1)) && (d == 1)) || " \
2138 "(e == 1)) && (f == 1)) || (g == 1)) && (h == 1))"
2139 DATA_REC(YES
, 1, 1, 1, 1, 1, 1, 1, 1, "ceg"),
2140 DATA_REC(NO
, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2141 DATA_REC(NO
, 1, 0, 1, 0, 1, 0, 1, 0, ""),
2143 #define FILTER "((((((((a == 1) || (b == 1)) && (c == 1)) || (d == 1)) && " \
2144 "(e == 1)) || (f == 1)) && (g == 1)) || (h == 1))"
2145 DATA_REC(YES
, 1, 1, 1, 1, 1, 1, 1, 1, "bdfh"),
2146 DATA_REC(YES
, 0, 1, 0, 1, 0, 1, 0, 1, ""),
2147 DATA_REC(YES
, 1, 0, 1, 0, 1, 0, 1, 0, "bdfh"),
2155 #define DATA_CNT ARRAY_SIZE(test_filter_data)
2157 static int test_pred_visited
;
2159 static int test_pred_visited_fn(struct filter_pred
*pred
, void *event
)
2161 struct ftrace_event_field
*field
= pred
->field
;
2163 test_pred_visited
= 1;
2164 printk(KERN_INFO
"\npred visited %s\n", field
->name
);
2168 static void update_pred_fn(struct event_filter
*filter
, char *fields
)
2170 struct prog_entry
*prog
= rcu_dereference_protected(filter
->prog
,
2171 lockdep_is_held(&event_mutex
));
2174 for (i
= 0; prog
[i
].pred
; i
++) {
2175 struct filter_pred
*pred
= prog
[i
].pred
;
2176 struct ftrace_event_field
*field
= pred
->field
;
2178 WARN_ON_ONCE(!pred
->fn
);
2181 WARN_ONCE(1, "all leafs should have field defined %d", i
);
2185 if (!strchr(fields
, *field
->name
))
2188 pred
->fn
= test_pred_visited_fn
;
2192 static __init
int ftrace_test_event_filter(void)
2196 printk(KERN_INFO
"Testing ftrace filter: ");
2198 for (i
= 0; i
< DATA_CNT
; i
++) {
2199 struct event_filter
*filter
= NULL
;
2200 struct test_filter_data_t
*d
= &test_filter_data
[i
];
2203 err
= create_filter(NULL
, &event_ftrace_test_filter
,
2204 d
->filter
, false, &filter
);
2207 "Failed to get filter for '%s', err %d\n",
2209 __free_filter(filter
);
2213 /* Needed to dereference filter->prog */
2214 mutex_lock(&event_mutex
);
2216 * The preemption disabling is not really needed for self
2217 * tests, but the rcu dereference will complain without it.
2220 if (*d
->not_visited
)
2221 update_pred_fn(filter
, d
->not_visited
);
2223 test_pred_visited
= 0;
2224 err
= filter_match_preds(filter
, &d
->rec
);
2227 mutex_unlock(&event_mutex
);
2229 __free_filter(filter
);
2231 if (test_pred_visited
) {
2233 "Failed, unwanted pred visited for filter %s\n",
2238 if (err
!= d
->match
) {
2240 "Failed to match filter '%s', expected %d\n",
2241 d
->filter
, d
->match
);
2247 printk(KERN_CONT
"OK\n");
2252 late_initcall(ftrace_test_event_filter
);
2254 #endif /* CONFIG_FTRACE_STARTUP_TEST */