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![Randy Dunlap](/assets/img/avatar_default.png)
Use the 'struct' keyword for a struct's kernel-doc notation and use the correct function parameter name to eliminate kernel-doc warnings: kernel/trace/trace_events_filter.c:136: warning: cannot understand function prototype: 'struct prog_entry ' kerne/trace/trace_events_filter.c:155: warning: Excess function parameter 'when_to_branch' description in 'update_preds' Also correct some trivial punctuation problems. Link: https://lkml.kernel.org/r/20230108021238.16398-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2472 lines
60 KiB
C
2472 lines
60 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* trace_events_filter - generic event filtering
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*
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* Copyright (C) 2009 Tom Zanussi <tzanussi@gmail.com>
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*/
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#include <linux/uaccess.h>
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#include <linux/module.h>
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#include <linux/ctype.h>
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#include <linux/mutex.h>
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#include <linux/perf_event.h>
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#include <linux/slab.h>
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#include "trace.h"
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#include "trace_output.h"
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#define DEFAULT_SYS_FILTER_MESSAGE \
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"### global filter ###\n" \
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"# Use this to set filters for multiple events.\n" \
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"# Only events with the given fields will be affected.\n" \
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"# If no events are modified, an error message will be displayed here"
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/* Due to token parsing '<=' must be before '<' and '>=' must be before '>' */
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#define OPS \
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C( OP_GLOB, "~" ), \
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C( OP_NE, "!=" ), \
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C( OP_EQ, "==" ), \
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C( OP_LE, "<=" ), \
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C( OP_LT, "<" ), \
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C( OP_GE, ">=" ), \
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C( OP_GT, ">" ), \
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C( OP_BAND, "&" ), \
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C( OP_MAX, NULL )
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#undef C
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#define C(a, b) a
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enum filter_op_ids { OPS };
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#undef C
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#define C(a, b) b
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static const char * ops[] = { OPS };
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enum filter_pred_fn {
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FILTER_PRED_FN_NOP,
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FILTER_PRED_FN_64,
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FILTER_PRED_FN_S64,
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FILTER_PRED_FN_U64,
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FILTER_PRED_FN_32,
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FILTER_PRED_FN_S32,
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FILTER_PRED_FN_U32,
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FILTER_PRED_FN_16,
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FILTER_PRED_FN_S16,
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FILTER_PRED_FN_U16,
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FILTER_PRED_FN_8,
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FILTER_PRED_FN_S8,
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FILTER_PRED_FN_U8,
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FILTER_PRED_FN_COMM,
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FILTER_PRED_FN_STRING,
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FILTER_PRED_FN_STRLOC,
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FILTER_PRED_FN_STRRELLOC,
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FILTER_PRED_FN_PCHAR_USER,
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FILTER_PRED_FN_PCHAR,
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FILTER_PRED_FN_CPU,
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FILTER_PRED_FN_,
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FILTER_PRED_TEST_VISITED,
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};
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struct filter_pred {
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enum filter_pred_fn fn_num;
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u64 val;
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struct regex regex;
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unsigned short *ops;
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struct ftrace_event_field *field;
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int offset;
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int not;
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int op;
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};
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/*
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* pred functions are OP_LE, OP_LT, OP_GE, OP_GT, and OP_BAND
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* pred_funcs_##type below must match the order of them above.
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*/
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#define PRED_FUNC_START OP_LE
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#define PRED_FUNC_MAX (OP_BAND - PRED_FUNC_START)
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#define ERRORS \
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C(NONE, "No error"), \
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C(INVALID_OP, "Invalid operator"), \
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C(TOO_MANY_OPEN, "Too many '('"), \
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C(TOO_MANY_CLOSE, "Too few '('"), \
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C(MISSING_QUOTE, "Missing matching quote"), \
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C(OPERAND_TOO_LONG, "Operand too long"), \
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C(EXPECT_STRING, "Expecting string field"), \
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C(EXPECT_DIGIT, "Expecting numeric field"), \
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C(ILLEGAL_FIELD_OP, "Illegal operation for field type"), \
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C(FIELD_NOT_FOUND, "Field not found"), \
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C(ILLEGAL_INTVAL, "Illegal integer value"), \
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C(BAD_SUBSYS_FILTER, "Couldn't find or set field in one of a subsystem's events"), \
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C(TOO_MANY_PREDS, "Too many terms in predicate expression"), \
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C(INVALID_FILTER, "Meaningless filter expression"), \
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C(IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \
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C(INVALID_VALUE, "Invalid value (did you forget quotes)?"), \
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C(ERRNO, "Error"), \
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C(NO_FILTER, "No filter found")
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#undef C
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#define C(a, b) FILT_ERR_##a
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enum { ERRORS };
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#undef C
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#define C(a, b) b
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static const char *err_text[] = { ERRORS };
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/* Called after a '!' character but "!=" and "!~" are not "not"s */
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static bool is_not(const char *str)
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{
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switch (str[1]) {
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case '=':
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case '~':
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return false;
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}
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return true;
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}
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/**
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* struct prog_entry - a singe entry in the filter program
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* @target: Index to jump to on a branch (actually one minus the index)
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* @when_to_branch: The value of the result of the predicate to do a branch
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* @pred: The predicate to execute.
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*/
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struct prog_entry {
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int target;
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int when_to_branch;
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struct filter_pred *pred;
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};
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/**
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* update_preds - assign a program entry a label target
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* @prog: The program array
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* @N: The index of the current entry in @prog
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* @invert: What to assign a program entry for its branch condition
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*
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* The program entry at @N has a target that points to the index of a program
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* entry that can have its target and when_to_branch fields updated.
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* Update the current program entry denoted by index @N target field to be
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* that of the updated entry. This will denote the entry to update if
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* we are processing an "||" after an "&&".
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*/
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static void update_preds(struct prog_entry *prog, int N, int invert)
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{
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int t, s;
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t = prog[N].target;
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s = prog[t].target;
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prog[t].when_to_branch = invert;
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prog[t].target = N;
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prog[N].target = s;
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}
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struct filter_parse_error {
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int lasterr;
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int lasterr_pos;
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};
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static void parse_error(struct filter_parse_error *pe, int err, int pos)
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{
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pe->lasterr = err;
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pe->lasterr_pos = pos;
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}
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typedef int (*parse_pred_fn)(const char *str, void *data, int pos,
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struct filter_parse_error *pe,
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struct filter_pred **pred);
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enum {
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INVERT = 1,
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PROCESS_AND = 2,
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PROCESS_OR = 4,
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};
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/*
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* Without going into a formal proof, this explains the method that is used in
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* parsing the logical expressions.
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*
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* For example, if we have: "a && !(!b || (c && g)) || d || e && !f"
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* The first pass will convert it into the following program:
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*
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* n1: r=a; l1: if (!r) goto l4;
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* n2: r=b; l2: if (!r) goto l4;
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* n3: r=c; r=!r; l3: if (r) goto l4;
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* n4: r=g; r=!r; l4: if (r) goto l5;
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* n5: r=d; l5: if (r) goto T
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* n6: r=e; l6: if (!r) goto l7;
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* n7: r=f; r=!r; l7: if (!r) goto F
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* T: return TRUE
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* F: return FALSE
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*
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* To do this, we use a data structure to represent each of the above
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* predicate and conditions that has:
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*
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* predicate, when_to_branch, invert, target
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*
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* The "predicate" will hold the function to determine the result "r".
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* The "when_to_branch" denotes what "r" should be if a branch is to be taken
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* "&&" would contain "!r" or (0) and "||" would contain "r" or (1).
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* The "invert" holds whether the value should be reversed before testing.
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* The "target" contains the label "l#" to jump to.
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*
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* A stack is created to hold values when parentheses are used.
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*
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* To simplify the logic, the labels will start at 0 and not 1.
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*
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* The possible invert values are 1 and 0. The number of "!"s that are in scope
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* before the predicate determines the invert value, if the number is odd then
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* the invert value is 1 and 0 otherwise. This means the invert value only
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* needs to be toggled when a new "!" is introduced compared to what is stored
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* on the stack, where parentheses were used.
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*
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* The top of the stack and "invert" are initialized to zero.
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*
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* ** FIRST PASS **
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*
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* #1 A loop through all the tokens is done:
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*
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* #2 If the token is an "(", the stack is push, and the current stack value
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* gets the current invert value, and the loop continues to the next token.
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* The top of the stack saves the "invert" value to keep track of what
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* the current inversion is. As "!(a && !b || c)" would require all
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* predicates being affected separately by the "!" before the parentheses.
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* And that would end up being equivalent to "(!a || b) && !c"
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*
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* #3 If the token is an "!", the current "invert" value gets inverted, and
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* the loop continues. Note, if the next token is a predicate, then
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* this "invert" value is only valid for the current program entry,
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* and does not affect other predicates later on.
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*
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* The only other acceptable token is the predicate string.
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*
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* #4 A new entry into the program is added saving: the predicate and the
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* current value of "invert". The target is currently assigned to the
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* previous program index (this will not be its final value).
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*
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* #5 We now enter another loop and look at the next token. The only valid
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* tokens are ")", "&&", "||" or end of the input string "\0".
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*
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* #6 The invert variable is reset to the current value saved on the top of
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* the stack.
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*
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* #7 The top of the stack holds not only the current invert value, but also
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* if a "&&" or "||" needs to be processed. Note, the "&&" takes higher
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* precedence than "||". That is "a && b || c && d" is equivalent to
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* "(a && b) || (c && d)". Thus the first thing to do is to see if "&&" needs
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* to be processed. This is the case if an "&&" was the last token. If it was
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* then we call update_preds(). This takes the program, the current index in
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* the program, and the current value of "invert". More will be described
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* below about this function.
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*
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* #8 If the next token is "&&" then we set a flag in the top of the stack
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* that denotes that "&&" needs to be processed, break out of this loop
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* and continue with the outer loop.
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*
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* #9 Otherwise, if a "||" needs to be processed then update_preds() is called.
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* This is called with the program, the current index in the program, but
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* this time with an inverted value of "invert" (that is !invert). This is
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* because the value taken will become the "when_to_branch" value of the
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* program.
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* Note, this is called when the next token is not an "&&". As stated before,
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* "&&" takes higher precedence, and "||" should not be processed yet if the
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* next logical operation is "&&".
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*
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* #10 If the next token is "||" then we set a flag in the top of the stack
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* that denotes that "||" needs to be processed, break out of this loop
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* and continue with the outer loop.
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*
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* #11 If this is the end of the input string "\0" then we break out of both
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* loops.
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*
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* #12 Otherwise, the next token is ")", where we pop the stack and continue
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* this inner loop.
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*
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* Now to discuss the update_pred() function, as that is key to the setting up
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* of the program. Remember the "target" of the program is initialized to the
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* previous index and not the "l" label. The target holds the index into the
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* program that gets affected by the operand. Thus if we have something like
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* "a || b && c", when we process "a" the target will be "-1" (undefined).
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* When we process "b", its target is "0", which is the index of "a", as that's
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* the predicate that is affected by "||". But because the next token after "b"
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* is "&&" we don't call update_preds(). Instead continue to "c". As the
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* next token after "c" is not "&&" but the end of input, we first process the
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* "&&" by calling update_preds() for the "&&" then we process the "||" by
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* calling updates_preds() with the values for processing "||".
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*
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* What does that mean? What update_preds() does is to first save the "target"
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* of the program entry indexed by the current program entry's "target"
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* (remember the "target" is initialized to previous program entry), and then
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* sets that "target" to the current index which represents the label "l#".
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* That entry's "when_to_branch" is set to the value passed in (the "invert"
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* or "!invert"). Then it sets the current program entry's target to the saved
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* "target" value (the old value of the program that had its "target" updated
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* to the label).
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*
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* Looking back at "a || b && c", we have the following steps:
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* "a" - prog[0] = { "a", X, -1 } // pred, when_to_branch, target
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* "||" - flag that we need to process "||"; continue outer loop
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* "b" - prog[1] = { "b", X, 0 }
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* "&&" - flag that we need to process "&&"; continue outer loop
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* (Notice we did not process "||")
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* "c" - prog[2] = { "c", X, 1 }
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* update_preds(prog, 2, 0); // invert = 0 as we are processing "&&"
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* t = prog[2].target; // t = 1
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* s = prog[t].target; // s = 0
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* prog[t].target = 2; // Set target to "l2"
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* prog[t].when_to_branch = 0;
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* prog[2].target = s;
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* update_preds(prog, 2, 1); // invert = 1 as we are now processing "||"
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* t = prog[2].target; // t = 0
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* s = prog[t].target; // s = -1
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* prog[t].target = 2; // Set target to "l2"
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* prog[t].when_to_branch = 1;
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* prog[2].target = s;
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*
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* #13 Which brings us to the final step of the first pass, which is to set
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* the last program entry's when_to_branch and target, which will be
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* when_to_branch = 0; target = N; ( the label after the program entry after
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* the last program entry processed above).
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*
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* If we denote "TRUE" to be the entry after the last program entry processed,
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* and "FALSE" the program entry after that, we are now done with the first
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* pass.
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*
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* Making the above "a || b && c" have a program of:
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* prog[0] = { "a", 1, 2 }
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* prog[1] = { "b", 0, 2 }
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* prog[2] = { "c", 0, 3 }
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*
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* Which translates into:
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* n0: r = a; l0: if (r) goto l2;
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* n1: r = b; l1: if (!r) goto l2;
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* n2: r = c; l2: if (!r) goto l3; // Which is the same as "goto F;"
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* T: return TRUE; l3:
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* F: return FALSE
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*
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* Although, after the first pass, the program is correct, it is
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* inefficient. The simple sample of "a || b && c" could be easily been
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* converted into:
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* n0: r = a; if (r) goto T
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* n1: r = b; if (!r) goto F
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* n2: r = c; if (!r) goto F
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* T: return TRUE;
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* F: return FALSE;
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*
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* The First Pass is over the input string. The next too passes are over
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* the program itself.
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*
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* ** SECOND PASS **
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*
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* Which brings us to the second pass. If a jump to a label has the
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* same condition as that label, it can instead jump to its target.
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* The original example of "a && !(!b || (c && g)) || d || e && !f"
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* where the first pass gives us:
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*
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* n1: r=a; l1: if (!r) goto l4;
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* n2: r=b; l2: if (!r) goto l4;
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* n3: r=c; r=!r; l3: if (r) goto l4;
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* n4: r=g; r=!r; l4: if (r) goto l5;
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* n5: r=d; l5: if (r) goto T
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* n6: r=e; l6: if (!r) goto l7;
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* n7: r=f; r=!r; l7: if (!r) goto F:
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* T: return TRUE;
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* F: return FALSE
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*
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* We can see that "l3: if (r) goto l4;" and at l4, we have "if (r) goto l5;".
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* And "l5: if (r) goto T", we could optimize this by converting l3 and l4
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* to go directly to T. To accomplish this, we start from the last
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* entry in the program and work our way back. If the target of the entry
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* has the same "when_to_branch" then we could use that entry's target.
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* Doing this, the above would end up as:
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*
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* n1: r=a; l1: if (!r) goto l4;
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* n2: r=b; l2: if (!r) goto l4;
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* n3: r=c; r=!r; l3: if (r) goto T;
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* n4: r=g; r=!r; l4: if (r) goto T;
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* n5: r=d; l5: if (r) goto T;
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* n6: r=e; l6: if (!r) goto F;
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* n7: r=f; r=!r; l7: if (!r) goto F;
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* T: return TRUE
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* F: return FALSE
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*
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* In that same pass, if the "when_to_branch" doesn't match, we can simply
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* go to the program entry after the label. That is, "l2: if (!r) goto l4;"
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* where "l4: if (r) goto T;", then we can convert l2 to be:
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* "l2: if (!r) goto n5;".
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*
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* This will have the second pass give us:
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* n1: r=a; l1: if (!r) goto n5;
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* n2: r=b; l2: if (!r) goto n5;
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* n3: r=c; r=!r; l3: if (r) goto T;
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* n4: r=g; r=!r; l4: if (r) goto T;
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* n5: r=d; l5: if (r) goto T
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* n6: r=e; l6: if (!r) goto F;
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* n7: r=f; r=!r; l7: if (!r) goto F
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* T: return TRUE
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* F: return FALSE
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*
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* Notice, all the "l#" labels are no longer used, and they can now
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* be discarded.
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*
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* ** THIRD PASS **
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*
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* For the third pass we deal with the inverts. As they simply just
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* make the "when_to_branch" get inverted, a simple loop over the
|
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* program to that does: "when_to_branch ^= invert;" will do the
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* job, leaving us with:
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* n1: r=a; if (!r) goto n5;
|
|
* n2: r=b; if (!r) goto n5;
|
|
* n3: r=c: if (!r) goto T;
|
|
* n4: r=g; if (!r) goto T;
|
|
* n5: r=d; if (r) goto T
|
|
* n6: r=e; if (!r) goto F;
|
|
* n7: r=f; if (r) goto F
|
|
* T: return TRUE
|
|
* F: return FALSE
|
|
*
|
|
* As "r = a; if (!r) goto n5;" is obviously the same as
|
|
* "if (!a) goto n5;" without doing anything we can interpret the
|
|
* program as:
|
|
* n1: if (!a) goto n5;
|
|
* n2: if (!b) goto n5;
|
|
* n3: if (!c) goto T;
|
|
* n4: if (!g) goto T;
|
|
* n5: if (d) goto T
|
|
* n6: if (!e) goto F;
|
|
* n7: if (f) goto F
|
|
* T: return TRUE
|
|
* F: return FALSE
|
|
*
|
|
* Since the inverts are discarded at the end, there's no reason to store
|
|
* them in the program array (and waste memory). A separate array to hold
|
|
* the inverts is used and freed at the end.
|
|
*/
|
|
static struct prog_entry *
|
|
predicate_parse(const char *str, int nr_parens, int nr_preds,
|
|
parse_pred_fn parse_pred, void *data,
|
|
struct filter_parse_error *pe)
|
|
{
|
|
struct prog_entry *prog_stack;
|
|
struct prog_entry *prog;
|
|
const char *ptr = str;
|
|
char *inverts = NULL;
|
|
int *op_stack;
|
|
int *top;
|
|
int invert = 0;
|
|
int ret = -ENOMEM;
|
|
int len;
|
|
int N = 0;
|
|
int i;
|
|
|
|
nr_preds += 2; /* For TRUE and FALSE */
|
|
|
|
op_stack = kmalloc_array(nr_parens, sizeof(*op_stack), GFP_KERNEL);
|
|
if (!op_stack)
|
|
return ERR_PTR(-ENOMEM);
|
|
prog_stack = kcalloc(nr_preds, sizeof(*prog_stack), GFP_KERNEL);
|
|
if (!prog_stack) {
|
|
parse_error(pe, -ENOMEM, 0);
|
|
goto out_free;
|
|
}
|
|
inverts = kmalloc_array(nr_preds, sizeof(*inverts), GFP_KERNEL);
|
|
if (!inverts) {
|
|
parse_error(pe, -ENOMEM, 0);
|
|
goto out_free;
|
|
}
|
|
|
|
top = op_stack;
|
|
prog = prog_stack;
|
|
*top = 0;
|
|
|
|
/* First pass */
|
|
while (*ptr) { /* #1 */
|
|
const char *next = ptr++;
|
|
|
|
if (isspace(*next))
|
|
continue;
|
|
|
|
switch (*next) {
|
|
case '(': /* #2 */
|
|
if (top - op_stack > nr_parens) {
|
|
ret = -EINVAL;
|
|
goto out_free;
|
|
}
|
|
*(++top) = invert;
|
|
continue;
|
|
case '!': /* #3 */
|
|
if (!is_not(next))
|
|
break;
|
|
invert = !invert;
|
|
continue;
|
|
}
|
|
|
|
if (N >= nr_preds) {
|
|
parse_error(pe, FILT_ERR_TOO_MANY_PREDS, next - str);
|
|
goto out_free;
|
|
}
|
|
|
|
inverts[N] = invert; /* #4 */
|
|
prog[N].target = N-1;
|
|
|
|
len = parse_pred(next, data, ptr - str, pe, &prog[N].pred);
|
|
if (len < 0) {
|
|
ret = len;
|
|
goto out_free;
|
|
}
|
|
ptr = next + len;
|
|
|
|
N++;
|
|
|
|
ret = -1;
|
|
while (1) { /* #5 */
|
|
next = ptr++;
|
|
if (isspace(*next))
|
|
continue;
|
|
|
|
switch (*next) {
|
|
case ')':
|
|
case '\0':
|
|
break;
|
|
case '&':
|
|
case '|':
|
|
/* accepting only "&&" or "||" */
|
|
if (next[1] == next[0]) {
|
|
ptr++;
|
|
break;
|
|
}
|
|
fallthrough;
|
|
default:
|
|
parse_error(pe, FILT_ERR_TOO_MANY_PREDS,
|
|
next - str);
|
|
goto out_free;
|
|
}
|
|
|
|
invert = *top & INVERT;
|
|
|
|
if (*top & PROCESS_AND) { /* #7 */
|
|
update_preds(prog, N - 1, invert);
|
|
*top &= ~PROCESS_AND;
|
|
}
|
|
if (*next == '&') { /* #8 */
|
|
*top |= PROCESS_AND;
|
|
break;
|
|
}
|
|
if (*top & PROCESS_OR) { /* #9 */
|
|
update_preds(prog, N - 1, !invert);
|
|
*top &= ~PROCESS_OR;
|
|
}
|
|
if (*next == '|') { /* #10 */
|
|
*top |= PROCESS_OR;
|
|
break;
|
|
}
|
|
if (!*next) /* #11 */
|
|
goto out;
|
|
|
|
if (top == op_stack) {
|
|
ret = -1;
|
|
/* Too few '(' */
|
|
parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, ptr - str);
|
|
goto out_free;
|
|
}
|
|
top--; /* #12 */
|
|
}
|
|
}
|
|
out:
|
|
if (top != op_stack) {
|
|
/* Too many '(' */
|
|
parse_error(pe, FILT_ERR_TOO_MANY_OPEN, ptr - str);
|
|
goto out_free;
|
|
}
|
|
|
|
if (!N) {
|
|
/* No program? */
|
|
ret = -EINVAL;
|
|
parse_error(pe, FILT_ERR_NO_FILTER, ptr - str);
|
|
goto out_free;
|
|
}
|
|
|
|
prog[N].pred = NULL; /* #13 */
|
|
prog[N].target = 1; /* TRUE */
|
|
prog[N+1].pred = NULL;
|
|
prog[N+1].target = 0; /* FALSE */
|
|
prog[N-1].target = N;
|
|
prog[N-1].when_to_branch = false;
|
|
|
|
/* Second Pass */
|
|
for (i = N-1 ; i--; ) {
|
|
int target = prog[i].target;
|
|
if (prog[i].when_to_branch == prog[target].when_to_branch)
|
|
prog[i].target = prog[target].target;
|
|
}
|
|
|
|
/* Third Pass */
|
|
for (i = 0; i < N; i++) {
|
|
invert = inverts[i] ^ prog[i].when_to_branch;
|
|
prog[i].when_to_branch = invert;
|
|
/* Make sure the program always moves forward */
|
|
if (WARN_ON(prog[i].target <= i)) {
|
|
ret = -EINVAL;
|
|
goto out_free;
|
|
}
|
|
}
|
|
|
|
kfree(op_stack);
|
|
kfree(inverts);
|
|
return prog;
|
|
out_free:
|
|
kfree(op_stack);
|
|
kfree(inverts);
|
|
if (prog_stack) {
|
|
for (i = 0; prog_stack[i].pred; i++)
|
|
kfree(prog_stack[i].pred);
|
|
kfree(prog_stack);
|
|
}
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
enum pred_cmp_types {
|
|
PRED_CMP_TYPE_NOP,
|
|
PRED_CMP_TYPE_LT,
|
|
PRED_CMP_TYPE_LE,
|
|
PRED_CMP_TYPE_GT,
|
|
PRED_CMP_TYPE_GE,
|
|
PRED_CMP_TYPE_BAND,
|
|
};
|
|
|
|
#define DEFINE_COMPARISON_PRED(type) \
|
|
static int filter_pred_##type(struct filter_pred *pred, void *event) \
|
|
{ \
|
|
switch (pred->op) { \
|
|
case OP_LT: { \
|
|
type *addr = (type *)(event + pred->offset); \
|
|
type val = (type)pred->val; \
|
|
return *addr < val; \
|
|
} \
|
|
case OP_LE: { \
|
|
type *addr = (type *)(event + pred->offset); \
|
|
type val = (type)pred->val; \
|
|
return *addr <= val; \
|
|
} \
|
|
case OP_GT: { \
|
|
type *addr = (type *)(event + pred->offset); \
|
|
type val = (type)pred->val; \
|
|
return *addr > val; \
|
|
} \
|
|
case OP_GE: { \
|
|
type *addr = (type *)(event + pred->offset); \
|
|
type val = (type)pred->val; \
|
|
return *addr >= val; \
|
|
} \
|
|
case OP_BAND: { \
|
|
type *addr = (type *)(event + pred->offset); \
|
|
type val = (type)pred->val; \
|
|
return !!(*addr & val); \
|
|
} \
|
|
default: \
|
|
return 0; \
|
|
} \
|
|
}
|
|
|
|
#define DEFINE_EQUALITY_PRED(size) \
|
|
static int filter_pred_##size(struct filter_pred *pred, void *event) \
|
|
{ \
|
|
u##size *addr = (u##size *)(event + pred->offset); \
|
|
u##size val = (u##size)pred->val; \
|
|
int match; \
|
|
\
|
|
match = (val == *addr) ^ pred->not; \
|
|
\
|
|
return match; \
|
|
}
|
|
|
|
DEFINE_COMPARISON_PRED(s64);
|
|
DEFINE_COMPARISON_PRED(u64);
|
|
DEFINE_COMPARISON_PRED(s32);
|
|
DEFINE_COMPARISON_PRED(u32);
|
|
DEFINE_COMPARISON_PRED(s16);
|
|
DEFINE_COMPARISON_PRED(u16);
|
|
DEFINE_COMPARISON_PRED(s8);
|
|
DEFINE_COMPARISON_PRED(u8);
|
|
|
|
DEFINE_EQUALITY_PRED(64);
|
|
DEFINE_EQUALITY_PRED(32);
|
|
DEFINE_EQUALITY_PRED(16);
|
|
DEFINE_EQUALITY_PRED(8);
|
|
|
|
/* user space strings temp buffer */
|
|
#define USTRING_BUF_SIZE 1024
|
|
|
|
struct ustring_buffer {
|
|
char buffer[USTRING_BUF_SIZE];
|
|
};
|
|
|
|
static __percpu struct ustring_buffer *ustring_per_cpu;
|
|
|
|
static __always_inline char *test_string(char *str)
|
|
{
|
|
struct ustring_buffer *ubuf;
|
|
char *kstr;
|
|
|
|
if (!ustring_per_cpu)
|
|
return NULL;
|
|
|
|
ubuf = this_cpu_ptr(ustring_per_cpu);
|
|
kstr = ubuf->buffer;
|
|
|
|
/* For safety, do not trust the string pointer */
|
|
if (!strncpy_from_kernel_nofault(kstr, str, USTRING_BUF_SIZE))
|
|
return NULL;
|
|
return kstr;
|
|
}
|
|
|
|
static __always_inline char *test_ustring(char *str)
|
|
{
|
|
struct ustring_buffer *ubuf;
|
|
char __user *ustr;
|
|
char *kstr;
|
|
|
|
if (!ustring_per_cpu)
|
|
return NULL;
|
|
|
|
ubuf = this_cpu_ptr(ustring_per_cpu);
|
|
kstr = ubuf->buffer;
|
|
|
|
/* user space address? */
|
|
ustr = (char __user *)str;
|
|
if (!strncpy_from_user_nofault(kstr, ustr, USTRING_BUF_SIZE))
|
|
return NULL;
|
|
|
|
return kstr;
|
|
}
|
|
|
|
/* Filter predicate for fixed sized arrays of characters */
|
|
static int filter_pred_string(struct filter_pred *pred, void *event)
|
|
{
|
|
char *addr = (char *)(event + pred->offset);
|
|
int cmp, match;
|
|
|
|
cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len);
|
|
|
|
match = cmp ^ pred->not;
|
|
|
|
return match;
|
|
}
|
|
|
|
static __always_inline int filter_pchar(struct filter_pred *pred, char *str)
|
|
{
|
|
int cmp, match;
|
|
int len;
|
|
|
|
len = strlen(str) + 1; /* including tailing '\0' */
|
|
cmp = pred->regex.match(str, &pred->regex, len);
|
|
|
|
match = cmp ^ pred->not;
|
|
|
|
return match;
|
|
}
|
|
/* Filter predicate for char * pointers */
|
|
static int filter_pred_pchar(struct filter_pred *pred, void *event)
|
|
{
|
|
char **addr = (char **)(event + pred->offset);
|
|
char *str;
|
|
|
|
str = test_string(*addr);
|
|
if (!str)
|
|
return 0;
|
|
|
|
return filter_pchar(pred, str);
|
|
}
|
|
|
|
/* Filter predicate for char * pointers in user space*/
|
|
static int filter_pred_pchar_user(struct filter_pred *pred, void *event)
|
|
{
|
|
char **addr = (char **)(event + pred->offset);
|
|
char *str;
|
|
|
|
str = test_ustring(*addr);
|
|
if (!str)
|
|
return 0;
|
|
|
|
return filter_pchar(pred, str);
|
|
}
|
|
|
|
/*
|
|
* Filter predicate for dynamic sized arrays of characters.
|
|
* These are implemented through a list of strings at the end
|
|
* of the entry.
|
|
* Also each of these strings have a field in the entry which
|
|
* contains its offset from the beginning of the entry.
|
|
* We have then first to get this field, dereference it
|
|
* and add it to the address of the entry, and at last we have
|
|
* the address of the string.
|
|
*/
|
|
static int filter_pred_strloc(struct filter_pred *pred, void *event)
|
|
{
|
|
u32 str_item = *(u32 *)(event + pred->offset);
|
|
int str_loc = str_item & 0xffff;
|
|
int str_len = str_item >> 16;
|
|
char *addr = (char *)(event + str_loc);
|
|
int cmp, match;
|
|
|
|
cmp = pred->regex.match(addr, &pred->regex, str_len);
|
|
|
|
match = cmp ^ pred->not;
|
|
|
|
return match;
|
|
}
|
|
|
|
/*
|
|
* Filter predicate for relative dynamic sized arrays of characters.
|
|
* These are implemented through a list of strings at the end
|
|
* of the entry as same as dynamic string.
|
|
* The difference is that the relative one records the location offset
|
|
* from the field itself, not the event entry.
|
|
*/
|
|
static int filter_pred_strrelloc(struct filter_pred *pred, void *event)
|
|
{
|
|
u32 *item = (u32 *)(event + pred->offset);
|
|
u32 str_item = *item;
|
|
int str_loc = str_item & 0xffff;
|
|
int str_len = str_item >> 16;
|
|
char *addr = (char *)(&item[1]) + str_loc;
|
|
int cmp, match;
|
|
|
|
cmp = pred->regex.match(addr, &pred->regex, str_len);
|
|
|
|
match = cmp ^ pred->not;
|
|
|
|
return match;
|
|
}
|
|
|
|
/* Filter predicate for CPUs. */
|
|
static int filter_pred_cpu(struct filter_pred *pred, void *event)
|
|
{
|
|
int cpu, cmp;
|
|
|
|
cpu = raw_smp_processor_id();
|
|
cmp = pred->val;
|
|
|
|
switch (pred->op) {
|
|
case OP_EQ:
|
|
return cpu == cmp;
|
|
case OP_NE:
|
|
return cpu != cmp;
|
|
case OP_LT:
|
|
return cpu < cmp;
|
|
case OP_LE:
|
|
return cpu <= cmp;
|
|
case OP_GT:
|
|
return cpu > cmp;
|
|
case OP_GE:
|
|
return cpu >= cmp;
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* Filter predicate for COMM. */
|
|
static int filter_pred_comm(struct filter_pred *pred, void *event)
|
|
{
|
|
int cmp;
|
|
|
|
cmp = pred->regex.match(current->comm, &pred->regex,
|
|
TASK_COMM_LEN);
|
|
return cmp ^ pred->not;
|
|
}
|
|
|
|
/*
|
|
* regex_match_foo - Basic regex callbacks
|
|
*
|
|
* @str: the string to be searched
|
|
* @r: the regex structure containing the pattern string
|
|
* @len: the length of the string to be searched (including '\0')
|
|
*
|
|
* Note:
|
|
* - @str might not be NULL-terminated if it's of type DYN_STRING
|
|
* RDYN_STRING, or STATIC_STRING, unless @len is zero.
|
|
*/
|
|
|
|
static int regex_match_full(char *str, struct regex *r, int len)
|
|
{
|
|
/* len of zero means str is dynamic and ends with '\0' */
|
|
if (!len)
|
|
return strcmp(str, r->pattern) == 0;
|
|
|
|
return strncmp(str, r->pattern, len) == 0;
|
|
}
|
|
|
|
static int regex_match_front(char *str, struct regex *r, int len)
|
|
{
|
|
if (len && len < r->len)
|
|
return 0;
|
|
|
|
return strncmp(str, r->pattern, r->len) == 0;
|
|
}
|
|
|
|
static int regex_match_middle(char *str, struct regex *r, int len)
|
|
{
|
|
if (!len)
|
|
return strstr(str, r->pattern) != NULL;
|
|
|
|
return strnstr(str, r->pattern, len) != NULL;
|
|
}
|
|
|
|
static int regex_match_end(char *str, struct regex *r, int len)
|
|
{
|
|
int strlen = len - 1;
|
|
|
|
if (strlen >= r->len &&
|
|
memcmp(str + strlen - r->len, r->pattern, r->len) == 0)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static int regex_match_glob(char *str, struct regex *r, int len __maybe_unused)
|
|
{
|
|
if (glob_match(r->pattern, str))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* filter_parse_regex - parse a basic regex
|
|
* @buff: the raw regex
|
|
* @len: length of the regex
|
|
* @search: will point to the beginning of the string to compare
|
|
* @not: tell whether the match will have to be inverted
|
|
*
|
|
* This passes in a buffer containing a regex and this function will
|
|
* set search to point to the search part of the buffer and
|
|
* return the type of search it is (see enum above).
|
|
* This does modify buff.
|
|
*
|
|
* Returns enum type.
|
|
* search returns the pointer to use for comparison.
|
|
* not returns 1 if buff started with a '!'
|
|
* 0 otherwise.
|
|
*/
|
|
enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not)
|
|
{
|
|
int type = MATCH_FULL;
|
|
int i;
|
|
|
|
if (buff[0] == '!') {
|
|
*not = 1;
|
|
buff++;
|
|
len--;
|
|
} else
|
|
*not = 0;
|
|
|
|
*search = buff;
|
|
|
|
if (isdigit(buff[0]))
|
|
return MATCH_INDEX;
|
|
|
|
for (i = 0; i < len; i++) {
|
|
if (buff[i] == '*') {
|
|
if (!i) {
|
|
type = MATCH_END_ONLY;
|
|
} else if (i == len - 1) {
|
|
if (type == MATCH_END_ONLY)
|
|
type = MATCH_MIDDLE_ONLY;
|
|
else
|
|
type = MATCH_FRONT_ONLY;
|
|
buff[i] = 0;
|
|
break;
|
|
} else { /* pattern continues, use full glob */
|
|
return MATCH_GLOB;
|
|
}
|
|
} else if (strchr("[?\\", buff[i])) {
|
|
return MATCH_GLOB;
|
|
}
|
|
}
|
|
if (buff[0] == '*')
|
|
*search = buff + 1;
|
|
|
|
return type;
|
|
}
|
|
|
|
static void filter_build_regex(struct filter_pred *pred)
|
|
{
|
|
struct regex *r = &pred->regex;
|
|
char *search;
|
|
enum regex_type type = MATCH_FULL;
|
|
|
|
if (pred->op == OP_GLOB) {
|
|
type = filter_parse_regex(r->pattern, r->len, &search, &pred->not);
|
|
r->len = strlen(search);
|
|
memmove(r->pattern, search, r->len+1);
|
|
}
|
|
|
|
switch (type) {
|
|
/* MATCH_INDEX should not happen, but if it does, match full */
|
|
case MATCH_INDEX:
|
|
case MATCH_FULL:
|
|
r->match = regex_match_full;
|
|
break;
|
|
case MATCH_FRONT_ONLY:
|
|
r->match = regex_match_front;
|
|
break;
|
|
case MATCH_MIDDLE_ONLY:
|
|
r->match = regex_match_middle;
|
|
break;
|
|
case MATCH_END_ONLY:
|
|
r->match = regex_match_end;
|
|
break;
|
|
case MATCH_GLOB:
|
|
r->match = regex_match_glob;
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_FTRACE_STARTUP_TEST
|
|
static int test_pred_visited_fn(struct filter_pred *pred, void *event);
|
|
#else
|
|
static int test_pred_visited_fn(struct filter_pred *pred, void *event)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
|
|
static int filter_pred_fn_call(struct filter_pred *pred, void *event);
|
|
|
|
/* return 1 if event matches, 0 otherwise (discard) */
|
|
int filter_match_preds(struct event_filter *filter, void *rec)
|
|
{
|
|
struct prog_entry *prog;
|
|
int i;
|
|
|
|
/* no filter is considered a match */
|
|
if (!filter)
|
|
return 1;
|
|
|
|
/* Protected by either SRCU(tracepoint_srcu) or preempt_disable */
|
|
prog = rcu_dereference_raw(filter->prog);
|
|
if (!prog)
|
|
return 1;
|
|
|
|
for (i = 0; prog[i].pred; i++) {
|
|
struct filter_pred *pred = prog[i].pred;
|
|
int match = filter_pred_fn_call(pred, rec);
|
|
if (match == prog[i].when_to_branch)
|
|
i = prog[i].target;
|
|
}
|
|
return prog[i].target;
|
|
}
|
|
EXPORT_SYMBOL_GPL(filter_match_preds);
|
|
|
|
static void remove_filter_string(struct event_filter *filter)
|
|
{
|
|
if (!filter)
|
|
return;
|
|
|
|
kfree(filter->filter_string);
|
|
filter->filter_string = NULL;
|
|
}
|
|
|
|
static void append_filter_err(struct trace_array *tr,
|
|
struct filter_parse_error *pe,
|
|
struct event_filter *filter)
|
|
{
|
|
struct trace_seq *s;
|
|
int pos = pe->lasterr_pos;
|
|
char *buf;
|
|
int len;
|
|
|
|
if (WARN_ON(!filter->filter_string))
|
|
return;
|
|
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL);
|
|
if (!s)
|
|
return;
|
|
trace_seq_init(s);
|
|
|
|
len = strlen(filter->filter_string);
|
|
if (pos > len)
|
|
pos = len;
|
|
|
|
/* indexing is off by one */
|
|
if (pos)
|
|
pos++;
|
|
|
|
trace_seq_puts(s, filter->filter_string);
|
|
if (pe->lasterr > 0) {
|
|
trace_seq_printf(s, "\n%*s", pos, "^");
|
|
trace_seq_printf(s, "\nparse_error: %s\n", err_text[pe->lasterr]);
|
|
tracing_log_err(tr, "event filter parse error",
|
|
filter->filter_string, err_text,
|
|
pe->lasterr, pe->lasterr_pos);
|
|
} else {
|
|
trace_seq_printf(s, "\nError: (%d)\n", pe->lasterr);
|
|
tracing_log_err(tr, "event filter parse error",
|
|
filter->filter_string, err_text,
|
|
FILT_ERR_ERRNO, 0);
|
|
}
|
|
trace_seq_putc(s, 0);
|
|
buf = kmemdup_nul(s->buffer, s->seq.len, GFP_KERNEL);
|
|
if (buf) {
|
|
kfree(filter->filter_string);
|
|
filter->filter_string = buf;
|
|
}
|
|
kfree(s);
|
|
}
|
|
|
|
static inline struct event_filter *event_filter(struct trace_event_file *file)
|
|
{
|
|
return file->filter;
|
|
}
|
|
|
|
/* caller must hold event_mutex */
|
|
void print_event_filter(struct trace_event_file *file, struct trace_seq *s)
|
|
{
|
|
struct event_filter *filter = event_filter(file);
|
|
|
|
if (filter && filter->filter_string)
|
|
trace_seq_printf(s, "%s\n", filter->filter_string);
|
|
else
|
|
trace_seq_puts(s, "none\n");
|
|
}
|
|
|
|
void print_subsystem_event_filter(struct event_subsystem *system,
|
|
struct trace_seq *s)
|
|
{
|
|
struct event_filter *filter;
|
|
|
|
mutex_lock(&event_mutex);
|
|
filter = system->filter;
|
|
if (filter && filter->filter_string)
|
|
trace_seq_printf(s, "%s\n", filter->filter_string);
|
|
else
|
|
trace_seq_puts(s, DEFAULT_SYS_FILTER_MESSAGE "\n");
|
|
mutex_unlock(&event_mutex);
|
|
}
|
|
|
|
static void free_prog(struct event_filter *filter)
|
|
{
|
|
struct prog_entry *prog;
|
|
int i;
|
|
|
|
prog = rcu_access_pointer(filter->prog);
|
|
if (!prog)
|
|
return;
|
|
|
|
for (i = 0; prog[i].pred; i++)
|
|
kfree(prog[i].pred);
|
|
kfree(prog);
|
|
}
|
|
|
|
static void filter_disable(struct trace_event_file *file)
|
|
{
|
|
unsigned long old_flags = file->flags;
|
|
|
|
file->flags &= ~EVENT_FILE_FL_FILTERED;
|
|
|
|
if (old_flags != file->flags)
|
|
trace_buffered_event_disable();
|
|
}
|
|
|
|
static void __free_filter(struct event_filter *filter)
|
|
{
|
|
if (!filter)
|
|
return;
|
|
|
|
free_prog(filter);
|
|
kfree(filter->filter_string);
|
|
kfree(filter);
|
|
}
|
|
|
|
void free_event_filter(struct event_filter *filter)
|
|
{
|
|
__free_filter(filter);
|
|
}
|
|
|
|
static inline void __remove_filter(struct trace_event_file *file)
|
|
{
|
|
filter_disable(file);
|
|
remove_filter_string(file->filter);
|
|
}
|
|
|
|
static void filter_free_subsystem_preds(struct trace_subsystem_dir *dir,
|
|
struct trace_array *tr)
|
|
{
|
|
struct trace_event_file *file;
|
|
|
|
list_for_each_entry(file, &tr->events, list) {
|
|
if (file->system != dir)
|
|
continue;
|
|
__remove_filter(file);
|
|
}
|
|
}
|
|
|
|
static inline void __free_subsystem_filter(struct trace_event_file *file)
|
|
{
|
|
__free_filter(file->filter);
|
|
file->filter = NULL;
|
|
}
|
|
|
|
static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir,
|
|
struct trace_array *tr)
|
|
{
|
|
struct trace_event_file *file;
|
|
|
|
list_for_each_entry(file, &tr->events, list) {
|
|
if (file->system != dir)
|
|
continue;
|
|
__free_subsystem_filter(file);
|
|
}
|
|
}
|
|
|
|
int filter_assign_type(const char *type)
|
|
{
|
|
if (strstr(type, "__data_loc") && strstr(type, "char"))
|
|
return FILTER_DYN_STRING;
|
|
|
|
if (strstr(type, "__rel_loc") && strstr(type, "char"))
|
|
return FILTER_RDYN_STRING;
|
|
|
|
if (strchr(type, '[') && strstr(type, "char"))
|
|
return FILTER_STATIC_STRING;
|
|
|
|
if (strcmp(type, "char *") == 0 || strcmp(type, "const char *") == 0)
|
|
return FILTER_PTR_STRING;
|
|
|
|
return FILTER_OTHER;
|
|
}
|
|
|
|
static enum filter_pred_fn select_comparison_fn(enum filter_op_ids op,
|
|
int field_size, int field_is_signed)
|
|
{
|
|
enum filter_pred_fn fn = FILTER_PRED_FN_NOP;
|
|
int pred_func_index = -1;
|
|
|
|
switch (op) {
|
|
case OP_EQ:
|
|
case OP_NE:
|
|
break;
|
|
default:
|
|
if (WARN_ON_ONCE(op < PRED_FUNC_START))
|
|
return fn;
|
|
pred_func_index = op - PRED_FUNC_START;
|
|
if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX))
|
|
return fn;
|
|
}
|
|
|
|
switch (field_size) {
|
|
case 8:
|
|
if (pred_func_index < 0)
|
|
fn = FILTER_PRED_FN_64;
|
|
else if (field_is_signed)
|
|
fn = FILTER_PRED_FN_S64;
|
|
else
|
|
fn = FILTER_PRED_FN_U64;
|
|
break;
|
|
case 4:
|
|
if (pred_func_index < 0)
|
|
fn = FILTER_PRED_FN_32;
|
|
else if (field_is_signed)
|
|
fn = FILTER_PRED_FN_S32;
|
|
else
|
|
fn = FILTER_PRED_FN_U32;
|
|
break;
|
|
case 2:
|
|
if (pred_func_index < 0)
|
|
fn = FILTER_PRED_FN_16;
|
|
else if (field_is_signed)
|
|
fn = FILTER_PRED_FN_S16;
|
|
else
|
|
fn = FILTER_PRED_FN_U16;
|
|
break;
|
|
case 1:
|
|
if (pred_func_index < 0)
|
|
fn = FILTER_PRED_FN_8;
|
|
else if (field_is_signed)
|
|
fn = FILTER_PRED_FN_S8;
|
|
else
|
|
fn = FILTER_PRED_FN_U8;
|
|
break;
|
|
}
|
|
|
|
return fn;
|
|
}
|
|
|
|
|
|
static int filter_pred_fn_call(struct filter_pred *pred, void *event)
|
|
{
|
|
switch (pred->fn_num) {
|
|
case FILTER_PRED_FN_64:
|
|
return filter_pred_64(pred, event);
|
|
case FILTER_PRED_FN_S64:
|
|
return filter_pred_s64(pred, event);
|
|
case FILTER_PRED_FN_U64:
|
|
return filter_pred_u64(pred, event);
|
|
case FILTER_PRED_FN_32:
|
|
return filter_pred_32(pred, event);
|
|
case FILTER_PRED_FN_S32:
|
|
return filter_pred_s32(pred, event);
|
|
case FILTER_PRED_FN_U32:
|
|
return filter_pred_u32(pred, event);
|
|
case FILTER_PRED_FN_16:
|
|
return filter_pred_16(pred, event);
|
|
case FILTER_PRED_FN_S16:
|
|
return filter_pred_s16(pred, event);
|
|
case FILTER_PRED_FN_U16:
|
|
return filter_pred_u16(pred, event);
|
|
case FILTER_PRED_FN_8:
|
|
return filter_pred_8(pred, event);
|
|
case FILTER_PRED_FN_S8:
|
|
return filter_pred_s8(pred, event);
|
|
case FILTER_PRED_FN_U8:
|
|
return filter_pred_u8(pred, event);
|
|
case FILTER_PRED_FN_COMM:
|
|
return filter_pred_comm(pred, event);
|
|
case FILTER_PRED_FN_STRING:
|
|
return filter_pred_string(pred, event);
|
|
case FILTER_PRED_FN_STRLOC:
|
|
return filter_pred_strloc(pred, event);
|
|
case FILTER_PRED_FN_STRRELLOC:
|
|
return filter_pred_strrelloc(pred, event);
|
|
case FILTER_PRED_FN_PCHAR_USER:
|
|
return filter_pred_pchar_user(pred, event);
|
|
case FILTER_PRED_FN_PCHAR:
|
|
return filter_pred_pchar(pred, event);
|
|
case FILTER_PRED_FN_CPU:
|
|
return filter_pred_cpu(pred, event);
|
|
case FILTER_PRED_TEST_VISITED:
|
|
return test_pred_visited_fn(pred, event);
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* Called when a predicate is encountered by predicate_parse() */
|
|
static int parse_pred(const char *str, void *data,
|
|
int pos, struct filter_parse_error *pe,
|
|
struct filter_pred **pred_ptr)
|
|
{
|
|
struct trace_event_call *call = data;
|
|
struct ftrace_event_field *field;
|
|
struct filter_pred *pred = NULL;
|
|
char num_buf[24]; /* Big enough to hold an address */
|
|
char *field_name;
|
|
bool ustring = false;
|
|
char q;
|
|
u64 val;
|
|
int len;
|
|
int ret;
|
|
int op;
|
|
int s;
|
|
int i = 0;
|
|
|
|
/* First find the field to associate to */
|
|
while (isspace(str[i]))
|
|
i++;
|
|
s = i;
|
|
|
|
while (isalnum(str[i]) || str[i] == '_')
|
|
i++;
|
|
|
|
len = i - s;
|
|
|
|
if (!len)
|
|
return -1;
|
|
|
|
field_name = kmemdup_nul(str + s, len, GFP_KERNEL);
|
|
if (!field_name)
|
|
return -ENOMEM;
|
|
|
|
/* Make sure that the field exists */
|
|
|
|
field = trace_find_event_field(call, field_name);
|
|
kfree(field_name);
|
|
if (!field) {
|
|
parse_error(pe, FILT_ERR_FIELD_NOT_FOUND, pos + i);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* See if the field is a user space string */
|
|
if ((len = str_has_prefix(str + i, ".ustring"))) {
|
|
ustring = true;
|
|
i += len;
|
|
}
|
|
|
|
while (isspace(str[i]))
|
|
i++;
|
|
|
|
/* Make sure this op is supported */
|
|
for (op = 0; ops[op]; op++) {
|
|
/* This is why '<=' must come before '<' in ops[] */
|
|
if (strncmp(str + i, ops[op], strlen(ops[op])) == 0)
|
|
break;
|
|
}
|
|
|
|
if (!ops[op]) {
|
|
parse_error(pe, FILT_ERR_INVALID_OP, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
i += strlen(ops[op]);
|
|
|
|
while (isspace(str[i]))
|
|
i++;
|
|
|
|
s = i;
|
|
|
|
pred = kzalloc(sizeof(*pred), GFP_KERNEL);
|
|
if (!pred)
|
|
return -ENOMEM;
|
|
|
|
pred->field = field;
|
|
pred->offset = field->offset;
|
|
pred->op = op;
|
|
|
|
if (ftrace_event_is_function(call)) {
|
|
/*
|
|
* Perf does things different with function events.
|
|
* It only allows an "ip" field, and expects a string.
|
|
* But the string does not need to be surrounded by quotes.
|
|
* If it is a string, the assigned function as a nop,
|
|
* (perf doesn't use it) and grab everything.
|
|
*/
|
|
if (strcmp(field->name, "ip") != 0) {
|
|
parse_error(pe, FILT_ERR_IP_FIELD_ONLY, pos + i);
|
|
goto err_free;
|
|
}
|
|
pred->fn_num = FILTER_PRED_FN_NOP;
|
|
|
|
/*
|
|
* Quotes are not required, but if they exist then we need
|
|
* to read them till we hit a matching one.
|
|
*/
|
|
if (str[i] == '\'' || str[i] == '"')
|
|
q = str[i];
|
|
else
|
|
q = 0;
|
|
|
|
for (i++; str[i]; i++) {
|
|
if (q && str[i] == q)
|
|
break;
|
|
if (!q && (str[i] == ')' || str[i] == '&' ||
|
|
str[i] == '|'))
|
|
break;
|
|
}
|
|
/* Skip quotes */
|
|
if (q)
|
|
s++;
|
|
len = i - s;
|
|
if (len >= MAX_FILTER_STR_VAL) {
|
|
parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
pred->regex.len = len;
|
|
strncpy(pred->regex.pattern, str + s, len);
|
|
pred->regex.pattern[len] = 0;
|
|
|
|
/* This is either a string, or an integer */
|
|
} else if (str[i] == '\'' || str[i] == '"') {
|
|
char q = str[i];
|
|
|
|
/* Make sure the op is OK for strings */
|
|
switch (op) {
|
|
case OP_NE:
|
|
pred->not = 1;
|
|
fallthrough;
|
|
case OP_GLOB:
|
|
case OP_EQ:
|
|
break;
|
|
default:
|
|
parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
/* Make sure the field is OK for strings */
|
|
if (!is_string_field(field)) {
|
|
parse_error(pe, FILT_ERR_EXPECT_DIGIT, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
for (i++; str[i]; i++) {
|
|
if (str[i] == q)
|
|
break;
|
|
}
|
|
if (!str[i]) {
|
|
parse_error(pe, FILT_ERR_MISSING_QUOTE, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
/* Skip quotes */
|
|
s++;
|
|
len = i - s;
|
|
if (len >= MAX_FILTER_STR_VAL) {
|
|
parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
pred->regex.len = len;
|
|
strncpy(pred->regex.pattern, str + s, len);
|
|
pred->regex.pattern[len] = 0;
|
|
|
|
filter_build_regex(pred);
|
|
|
|
if (field->filter_type == FILTER_COMM) {
|
|
pred->fn_num = FILTER_PRED_FN_COMM;
|
|
|
|
} else if (field->filter_type == FILTER_STATIC_STRING) {
|
|
pred->fn_num = FILTER_PRED_FN_STRING;
|
|
pred->regex.field_len = field->size;
|
|
|
|
} else if (field->filter_type == FILTER_DYN_STRING) {
|
|
pred->fn_num = FILTER_PRED_FN_STRLOC;
|
|
} else if (field->filter_type == FILTER_RDYN_STRING)
|
|
pred->fn_num = FILTER_PRED_FN_STRRELLOC;
|
|
else {
|
|
|
|
if (!ustring_per_cpu) {
|
|
/* Once allocated, keep it around for good */
|
|
ustring_per_cpu = alloc_percpu(struct ustring_buffer);
|
|
if (!ustring_per_cpu)
|
|
goto err_mem;
|
|
}
|
|
|
|
if (ustring)
|
|
pred->fn_num = FILTER_PRED_FN_PCHAR_USER;
|
|
else
|
|
pred->fn_num = FILTER_PRED_FN_PCHAR;
|
|
}
|
|
/* go past the last quote */
|
|
i++;
|
|
|
|
} else if (isdigit(str[i]) || str[i] == '-') {
|
|
|
|
/* Make sure the field is not a string */
|
|
if (is_string_field(field)) {
|
|
parse_error(pe, FILT_ERR_EXPECT_STRING, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
if (op == OP_GLOB) {
|
|
parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
if (str[i] == '-')
|
|
i++;
|
|
|
|
/* We allow 0xDEADBEEF */
|
|
while (isalnum(str[i]))
|
|
i++;
|
|
|
|
len = i - s;
|
|
/* 0xfeedfacedeadbeef is 18 chars max */
|
|
if (len >= sizeof(num_buf)) {
|
|
parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
strncpy(num_buf, str + s, len);
|
|
num_buf[len] = 0;
|
|
|
|
/* Make sure it is a value */
|
|
if (field->is_signed)
|
|
ret = kstrtoll(num_buf, 0, &val);
|
|
else
|
|
ret = kstrtoull(num_buf, 0, &val);
|
|
if (ret) {
|
|
parse_error(pe, FILT_ERR_ILLEGAL_INTVAL, pos + s);
|
|
goto err_free;
|
|
}
|
|
|
|
pred->val = val;
|
|
|
|
if (field->filter_type == FILTER_CPU)
|
|
pred->fn_num = FILTER_PRED_FN_CPU;
|
|
else {
|
|
pred->fn_num = select_comparison_fn(pred->op, field->size,
|
|
field->is_signed);
|
|
if (pred->op == OP_NE)
|
|
pred->not = 1;
|
|
}
|
|
|
|
} else {
|
|
parse_error(pe, FILT_ERR_INVALID_VALUE, pos + i);
|
|
goto err_free;
|
|
}
|
|
|
|
*pred_ptr = pred;
|
|
return i;
|
|
|
|
err_free:
|
|
kfree(pred);
|
|
return -EINVAL;
|
|
err_mem:
|
|
kfree(pred);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
enum {
|
|
TOO_MANY_CLOSE = -1,
|
|
TOO_MANY_OPEN = -2,
|
|
MISSING_QUOTE = -3,
|
|
};
|
|
|
|
/*
|
|
* Read the filter string once to calculate the number of predicates
|
|
* as well as how deep the parentheses go.
|
|
*
|
|
* Returns:
|
|
* 0 - everything is fine (err is undefined)
|
|
* -1 - too many ')'
|
|
* -2 - too many '('
|
|
* -3 - No matching quote
|
|
*/
|
|
static int calc_stack(const char *str, int *parens, int *preds, int *err)
|
|
{
|
|
bool is_pred = false;
|
|
int nr_preds = 0;
|
|
int open = 1; /* Count the expression as "(E)" */
|
|
int last_quote = 0;
|
|
int max_open = 1;
|
|
int quote = 0;
|
|
int i;
|
|
|
|
*err = 0;
|
|
|
|
for (i = 0; str[i]; i++) {
|
|
if (isspace(str[i]))
|
|
continue;
|
|
if (quote) {
|
|
if (str[i] == quote)
|
|
quote = 0;
|
|
continue;
|
|
}
|
|
|
|
switch (str[i]) {
|
|
case '\'':
|
|
case '"':
|
|
quote = str[i];
|
|
last_quote = i;
|
|
break;
|
|
case '|':
|
|
case '&':
|
|
if (str[i+1] != str[i])
|
|
break;
|
|
is_pred = false;
|
|
continue;
|
|
case '(':
|
|
is_pred = false;
|
|
open++;
|
|
if (open > max_open)
|
|
max_open = open;
|
|
continue;
|
|
case ')':
|
|
is_pred = false;
|
|
if (open == 1) {
|
|
*err = i;
|
|
return TOO_MANY_CLOSE;
|
|
}
|
|
open--;
|
|
continue;
|
|
}
|
|
if (!is_pred) {
|
|
nr_preds++;
|
|
is_pred = true;
|
|
}
|
|
}
|
|
|
|
if (quote) {
|
|
*err = last_quote;
|
|
return MISSING_QUOTE;
|
|
}
|
|
|
|
if (open != 1) {
|
|
int level = open;
|
|
|
|
/* find the bad open */
|
|
for (i--; i; i--) {
|
|
if (quote) {
|
|
if (str[i] == quote)
|
|
quote = 0;
|
|
continue;
|
|
}
|
|
switch (str[i]) {
|
|
case '(':
|
|
if (level == open) {
|
|
*err = i;
|
|
return TOO_MANY_OPEN;
|
|
}
|
|
level--;
|
|
break;
|
|
case ')':
|
|
level++;
|
|
break;
|
|
case '\'':
|
|
case '"':
|
|
quote = str[i];
|
|
break;
|
|
}
|
|
}
|
|
/* First character is the '(' with missing ')' */
|
|
*err = 0;
|
|
return TOO_MANY_OPEN;
|
|
}
|
|
|
|
/* Set the size of the required stacks */
|
|
*parens = max_open;
|
|
*preds = nr_preds;
|
|
return 0;
|
|
}
|
|
|
|
static int process_preds(struct trace_event_call *call,
|
|
const char *filter_string,
|
|
struct event_filter *filter,
|
|
struct filter_parse_error *pe)
|
|
{
|
|
struct prog_entry *prog;
|
|
int nr_parens;
|
|
int nr_preds;
|
|
int index;
|
|
int ret;
|
|
|
|
ret = calc_stack(filter_string, &nr_parens, &nr_preds, &index);
|
|
if (ret < 0) {
|
|
switch (ret) {
|
|
case MISSING_QUOTE:
|
|
parse_error(pe, FILT_ERR_MISSING_QUOTE, index);
|
|
break;
|
|
case TOO_MANY_OPEN:
|
|
parse_error(pe, FILT_ERR_TOO_MANY_OPEN, index);
|
|
break;
|
|
default:
|
|
parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, index);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
if (!nr_preds)
|
|
return -EINVAL;
|
|
|
|
prog = predicate_parse(filter_string, nr_parens, nr_preds,
|
|
parse_pred, call, pe);
|
|
if (IS_ERR(prog))
|
|
return PTR_ERR(prog);
|
|
|
|
rcu_assign_pointer(filter->prog, prog);
|
|
return 0;
|
|
}
|
|
|
|
static inline void event_set_filtered_flag(struct trace_event_file *file)
|
|
{
|
|
unsigned long old_flags = file->flags;
|
|
|
|
file->flags |= EVENT_FILE_FL_FILTERED;
|
|
|
|
if (old_flags != file->flags)
|
|
trace_buffered_event_enable();
|
|
}
|
|
|
|
static inline void event_set_filter(struct trace_event_file *file,
|
|
struct event_filter *filter)
|
|
{
|
|
rcu_assign_pointer(file->filter, filter);
|
|
}
|
|
|
|
static inline void event_clear_filter(struct trace_event_file *file)
|
|
{
|
|
RCU_INIT_POINTER(file->filter, NULL);
|
|
}
|
|
|
|
struct filter_list {
|
|
struct list_head list;
|
|
struct event_filter *filter;
|
|
};
|
|
|
|
static int process_system_preds(struct trace_subsystem_dir *dir,
|
|
struct trace_array *tr,
|
|
struct filter_parse_error *pe,
|
|
char *filter_string)
|
|
{
|
|
struct trace_event_file *file;
|
|
struct filter_list *filter_item;
|
|
struct event_filter *filter = NULL;
|
|
struct filter_list *tmp;
|
|
LIST_HEAD(filter_list);
|
|
bool fail = true;
|
|
int err;
|
|
|
|
list_for_each_entry(file, &tr->events, list) {
|
|
|
|
if (file->system != dir)
|
|
continue;
|
|
|
|
filter = kzalloc(sizeof(*filter), GFP_KERNEL);
|
|
if (!filter)
|
|
goto fail_mem;
|
|
|
|
filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
|
|
if (!filter->filter_string)
|
|
goto fail_mem;
|
|
|
|
err = process_preds(file->event_call, filter_string, filter, pe);
|
|
if (err) {
|
|
filter_disable(file);
|
|
parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0);
|
|
append_filter_err(tr, pe, filter);
|
|
} else
|
|
event_set_filtered_flag(file);
|
|
|
|
|
|
filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL);
|
|
if (!filter_item)
|
|
goto fail_mem;
|
|
|
|
list_add_tail(&filter_item->list, &filter_list);
|
|
/*
|
|
* Regardless of if this returned an error, we still
|
|
* replace the filter for the call.
|
|
*/
|
|
filter_item->filter = event_filter(file);
|
|
event_set_filter(file, filter);
|
|
filter = NULL;
|
|
|
|
fail = false;
|
|
}
|
|
|
|
if (fail)
|
|
goto fail;
|
|
|
|
/*
|
|
* The calls can still be using the old filters.
|
|
* Do a synchronize_rcu() and to ensure all calls are
|
|
* done with them before we free them.
|
|
*/
|
|
tracepoint_synchronize_unregister();
|
|
list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
|
|
__free_filter(filter_item->filter);
|
|
list_del(&filter_item->list);
|
|
kfree(filter_item);
|
|
}
|
|
return 0;
|
|
fail:
|
|
/* No call succeeded */
|
|
list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
|
|
list_del(&filter_item->list);
|
|
kfree(filter_item);
|
|
}
|
|
parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0);
|
|
return -EINVAL;
|
|
fail_mem:
|
|
__free_filter(filter);
|
|
/* If any call succeeded, we still need to sync */
|
|
if (!fail)
|
|
tracepoint_synchronize_unregister();
|
|
list_for_each_entry_safe(filter_item, tmp, &filter_list, list) {
|
|
__free_filter(filter_item->filter);
|
|
list_del(&filter_item->list);
|
|
kfree(filter_item);
|
|
}
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int create_filter_start(char *filter_string, bool set_str,
|
|
struct filter_parse_error **pse,
|
|
struct event_filter **filterp)
|
|
{
|
|
struct event_filter *filter;
|
|
struct filter_parse_error *pe = NULL;
|
|
int err = 0;
|
|
|
|
if (WARN_ON_ONCE(*pse || *filterp))
|
|
return -EINVAL;
|
|
|
|
filter = kzalloc(sizeof(*filter), GFP_KERNEL);
|
|
if (filter && set_str) {
|
|
filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
|
|
if (!filter->filter_string)
|
|
err = -ENOMEM;
|
|
}
|
|
|
|
pe = kzalloc(sizeof(*pe), GFP_KERNEL);
|
|
|
|
if (!filter || !pe || err) {
|
|
kfree(pe);
|
|
__free_filter(filter);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* we're committed to creating a new filter */
|
|
*filterp = filter;
|
|
*pse = pe;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void create_filter_finish(struct filter_parse_error *pe)
|
|
{
|
|
kfree(pe);
|
|
}
|
|
|
|
/**
|
|
* create_filter - create a filter for a trace_event_call
|
|
* @tr: the trace array associated with these events
|
|
* @call: trace_event_call to create a filter for
|
|
* @filter_string: filter string
|
|
* @set_str: remember @filter_str and enable detailed error in filter
|
|
* @filterp: out param for created filter (always updated on return)
|
|
* Must be a pointer that references a NULL pointer.
|
|
*
|
|
* Creates a filter for @call with @filter_str. If @set_str is %true,
|
|
* @filter_str is copied and recorded in the new filter.
|
|
*
|
|
* On success, returns 0 and *@filterp points to the new filter. On
|
|
* failure, returns -errno and *@filterp may point to %NULL or to a new
|
|
* filter. In the latter case, the returned filter contains error
|
|
* information if @set_str is %true and the caller is responsible for
|
|
* freeing it.
|
|
*/
|
|
static int create_filter(struct trace_array *tr,
|
|
struct trace_event_call *call,
|
|
char *filter_string, bool set_str,
|
|
struct event_filter **filterp)
|
|
{
|
|
struct filter_parse_error *pe = NULL;
|
|
int err;
|
|
|
|
/* filterp must point to NULL */
|
|
if (WARN_ON(*filterp))
|
|
*filterp = NULL;
|
|
|
|
err = create_filter_start(filter_string, set_str, &pe, filterp);
|
|
if (err)
|
|
return err;
|
|
|
|
err = process_preds(call, filter_string, *filterp, pe);
|
|
if (err && set_str)
|
|
append_filter_err(tr, pe, *filterp);
|
|
create_filter_finish(pe);
|
|
|
|
return err;
|
|
}
|
|
|
|
int create_event_filter(struct trace_array *tr,
|
|
struct trace_event_call *call,
|
|
char *filter_str, bool set_str,
|
|
struct event_filter **filterp)
|
|
{
|
|
return create_filter(tr, call, filter_str, set_str, filterp);
|
|
}
|
|
|
|
/**
|
|
* create_system_filter - create a filter for an event subsystem
|
|
* @dir: the descriptor for the subsystem directory
|
|
* @filter_str: filter string
|
|
* @filterp: out param for created filter (always updated on return)
|
|
*
|
|
* Identical to create_filter() except that it creates a subsystem filter
|
|
* and always remembers @filter_str.
|
|
*/
|
|
static int create_system_filter(struct trace_subsystem_dir *dir,
|
|
char *filter_str, struct event_filter **filterp)
|
|
{
|
|
struct filter_parse_error *pe = NULL;
|
|
int err;
|
|
|
|
err = create_filter_start(filter_str, true, &pe, filterp);
|
|
if (!err) {
|
|
err = process_system_preds(dir, dir->tr, pe, filter_str);
|
|
if (!err) {
|
|
/* System filters just show a default message */
|
|
kfree((*filterp)->filter_string);
|
|
(*filterp)->filter_string = NULL;
|
|
} else {
|
|
append_filter_err(dir->tr, pe, *filterp);
|
|
}
|
|
}
|
|
create_filter_finish(pe);
|
|
|
|
return err;
|
|
}
|
|
|
|
/* caller must hold event_mutex */
|
|
int apply_event_filter(struct trace_event_file *file, char *filter_string)
|
|
{
|
|
struct trace_event_call *call = file->event_call;
|
|
struct event_filter *filter = NULL;
|
|
int err;
|
|
|
|
if (!strcmp(strstrip(filter_string), "0")) {
|
|
filter_disable(file);
|
|
filter = event_filter(file);
|
|
|
|
if (!filter)
|
|
return 0;
|
|
|
|
event_clear_filter(file);
|
|
|
|
/* Make sure the filter is not being used */
|
|
tracepoint_synchronize_unregister();
|
|
__free_filter(filter);
|
|
|
|
return 0;
|
|
}
|
|
|
|
err = create_filter(file->tr, call, filter_string, true, &filter);
|
|
|
|
/*
|
|
* Always swap the call filter with the new filter
|
|
* even if there was an error. If there was an error
|
|
* in the filter, we disable the filter and show the error
|
|
* string
|
|
*/
|
|
if (filter) {
|
|
struct event_filter *tmp;
|
|
|
|
tmp = event_filter(file);
|
|
if (!err)
|
|
event_set_filtered_flag(file);
|
|
else
|
|
filter_disable(file);
|
|
|
|
event_set_filter(file, filter);
|
|
|
|
if (tmp) {
|
|
/* Make sure the call is done with the filter */
|
|
tracepoint_synchronize_unregister();
|
|
__free_filter(tmp);
|
|
}
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
|
|
char *filter_string)
|
|
{
|
|
struct event_subsystem *system = dir->subsystem;
|
|
struct trace_array *tr = dir->tr;
|
|
struct event_filter *filter = NULL;
|
|
int err = 0;
|
|
|
|
mutex_lock(&event_mutex);
|
|
|
|
/* Make sure the system still has events */
|
|
if (!dir->nr_events) {
|
|
err = -ENODEV;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (!strcmp(strstrip(filter_string), "0")) {
|
|
filter_free_subsystem_preds(dir, tr);
|
|
remove_filter_string(system->filter);
|
|
filter = system->filter;
|
|
system->filter = NULL;
|
|
/* Ensure all filters are no longer used */
|
|
tracepoint_synchronize_unregister();
|
|
filter_free_subsystem_filters(dir, tr);
|
|
__free_filter(filter);
|
|
goto out_unlock;
|
|
}
|
|
|
|
err = create_system_filter(dir, filter_string, &filter);
|
|
if (filter) {
|
|
/*
|
|
* No event actually uses the system filter
|
|
* we can free it without synchronize_rcu().
|
|
*/
|
|
__free_filter(system->filter);
|
|
system->filter = filter;
|
|
}
|
|
out_unlock:
|
|
mutex_unlock(&event_mutex);
|
|
|
|
return err;
|
|
}
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
|
|
void ftrace_profile_free_filter(struct perf_event *event)
|
|
{
|
|
struct event_filter *filter = event->filter;
|
|
|
|
event->filter = NULL;
|
|
__free_filter(filter);
|
|
}
|
|
|
|
struct function_filter_data {
|
|
struct ftrace_ops *ops;
|
|
int first_filter;
|
|
int first_notrace;
|
|
};
|
|
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
static char **
|
|
ftrace_function_filter_re(char *buf, int len, int *count)
|
|
{
|
|
char *str, **re;
|
|
|
|
str = kstrndup(buf, len, GFP_KERNEL);
|
|
if (!str)
|
|
return NULL;
|
|
|
|
/*
|
|
* The argv_split function takes white space
|
|
* as a separator, so convert ',' into spaces.
|
|
*/
|
|
strreplace(str, ',', ' ');
|
|
|
|
re = argv_split(GFP_KERNEL, str, count);
|
|
kfree(str);
|
|
return re;
|
|
}
|
|
|
|
static int ftrace_function_set_regexp(struct ftrace_ops *ops, int filter,
|
|
int reset, char *re, int len)
|
|
{
|
|
int ret;
|
|
|
|
if (filter)
|
|
ret = ftrace_set_filter(ops, re, len, reset);
|
|
else
|
|
ret = ftrace_set_notrace(ops, re, len, reset);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __ftrace_function_set_filter(int filter, char *buf, int len,
|
|
struct function_filter_data *data)
|
|
{
|
|
int i, re_cnt, ret = -EINVAL;
|
|
int *reset;
|
|
char **re;
|
|
|
|
reset = filter ? &data->first_filter : &data->first_notrace;
|
|
|
|
/*
|
|
* The 'ip' field could have multiple filters set, separated
|
|
* either by space or comma. We first cut the filter and apply
|
|
* all pieces separately.
|
|
*/
|
|
re = ftrace_function_filter_re(buf, len, &re_cnt);
|
|
if (!re)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < re_cnt; i++) {
|
|
ret = ftrace_function_set_regexp(data->ops, filter, *reset,
|
|
re[i], strlen(re[i]));
|
|
if (ret)
|
|
break;
|
|
|
|
if (*reset)
|
|
*reset = 0;
|
|
}
|
|
|
|
argv_free(re);
|
|
return ret;
|
|
}
|
|
|
|
static int ftrace_function_check_pred(struct filter_pred *pred)
|
|
{
|
|
struct ftrace_event_field *field = pred->field;
|
|
|
|
/*
|
|
* Check the predicate for function trace, verify:
|
|
* - only '==' and '!=' is used
|
|
* - the 'ip' field is used
|
|
*/
|
|
if ((pred->op != OP_EQ) && (pred->op != OP_NE))
|
|
return -EINVAL;
|
|
|
|
if (strcmp(field->name, "ip"))
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ftrace_function_set_filter_pred(struct filter_pred *pred,
|
|
struct function_filter_data *data)
|
|
{
|
|
int ret;
|
|
|
|
/* Checking the node is valid for function trace. */
|
|
ret = ftrace_function_check_pred(pred);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return __ftrace_function_set_filter(pred->op == OP_EQ,
|
|
pred->regex.pattern,
|
|
pred->regex.len,
|
|
data);
|
|
}
|
|
|
|
static bool is_or(struct prog_entry *prog, int i)
|
|
{
|
|
int target;
|
|
|
|
/*
|
|
* Only "||" is allowed for function events, thus,
|
|
* all true branches should jump to true, and any
|
|
* false branch should jump to false.
|
|
*/
|
|
target = prog[i].target + 1;
|
|
/* True and false have NULL preds (all prog entries should jump to one */
|
|
if (prog[target].pred)
|
|
return false;
|
|
|
|
/* prog[target].target is 1 for TRUE, 0 for FALSE */
|
|
return prog[i].when_to_branch == prog[target].target;
|
|
}
|
|
|
|
static int ftrace_function_set_filter(struct perf_event *event,
|
|
struct event_filter *filter)
|
|
{
|
|
struct prog_entry *prog = rcu_dereference_protected(filter->prog,
|
|
lockdep_is_held(&event_mutex));
|
|
struct function_filter_data data = {
|
|
.first_filter = 1,
|
|
.first_notrace = 1,
|
|
.ops = &event->ftrace_ops,
|
|
};
|
|
int i;
|
|
|
|
for (i = 0; prog[i].pred; i++) {
|
|
struct filter_pred *pred = prog[i].pred;
|
|
|
|
if (!is_or(prog, i))
|
|
return -EINVAL;
|
|
|
|
if (ftrace_function_set_filter_pred(pred, &data) < 0)
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
#else
|
|
static int ftrace_function_set_filter(struct perf_event *event,
|
|
struct event_filter *filter)
|
|
{
|
|
return -ENODEV;
|
|
}
|
|
#endif /* CONFIG_FUNCTION_TRACER */
|
|
|
|
int ftrace_profile_set_filter(struct perf_event *event, int event_id,
|
|
char *filter_str)
|
|
{
|
|
int err;
|
|
struct event_filter *filter = NULL;
|
|
struct trace_event_call *call;
|
|
|
|
mutex_lock(&event_mutex);
|
|
|
|
call = event->tp_event;
|
|
|
|
err = -EINVAL;
|
|
if (!call)
|
|
goto out_unlock;
|
|
|
|
err = -EEXIST;
|
|
if (event->filter)
|
|
goto out_unlock;
|
|
|
|
err = create_filter(NULL, call, filter_str, false, &filter);
|
|
if (err)
|
|
goto free_filter;
|
|
|
|
if (ftrace_event_is_function(call))
|
|
err = ftrace_function_set_filter(event, filter);
|
|
else
|
|
event->filter = filter;
|
|
|
|
free_filter:
|
|
if (err || ftrace_event_is_function(call))
|
|
__free_filter(filter);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&event_mutex);
|
|
|
|
return err;
|
|
}
|
|
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
#ifdef CONFIG_FTRACE_STARTUP_TEST
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/tracepoint.h>
|
|
|
|
#define CREATE_TRACE_POINTS
|
|
#include "trace_events_filter_test.h"
|
|
|
|
#define DATA_REC(m, va, vb, vc, vd, ve, vf, vg, vh, nvisit) \
|
|
{ \
|
|
.filter = FILTER, \
|
|
.rec = { .a = va, .b = vb, .c = vc, .d = vd, \
|
|
.e = ve, .f = vf, .g = vg, .h = vh }, \
|
|
.match = m, \
|
|
.not_visited = nvisit, \
|
|
}
|
|
#define YES 1
|
|
#define NO 0
|
|
|
|
static struct test_filter_data_t {
|
|
char *filter;
|
|
struct trace_event_raw_ftrace_test_filter rec;
|
|
int match;
|
|
char *not_visited;
|
|
} test_filter_data[] = {
|
|
#define FILTER "a == 1 && b == 1 && c == 1 && d == 1 && " \
|
|
"e == 1 && f == 1 && g == 1 && h == 1"
|
|
DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, ""),
|
|
DATA_REC(NO, 0, 1, 1, 1, 1, 1, 1, 1, "bcdefgh"),
|
|
DATA_REC(NO, 1, 1, 1, 1, 1, 1, 1, 0, ""),
|
|
#undef FILTER
|
|
#define FILTER "a == 1 || b == 1 || c == 1 || d == 1 || " \
|
|
"e == 1 || f == 1 || g == 1 || h == 1"
|
|
DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 0, ""),
|
|
DATA_REC(YES, 0, 0, 0, 0, 0, 0, 0, 1, ""),
|
|
DATA_REC(YES, 1, 0, 0, 0, 0, 0, 0, 0, "bcdefgh"),
|
|
#undef FILTER
|
|
#define FILTER "(a == 1 || b == 1) && (c == 1 || d == 1) && " \
|
|
"(e == 1 || f == 1) && (g == 1 || h == 1)"
|
|
DATA_REC(NO, 0, 0, 1, 1, 1, 1, 1, 1, "dfh"),
|
|
DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
|
|
DATA_REC(YES, 1, 0, 1, 0, 0, 1, 0, 1, "bd"),
|
|
DATA_REC(NO, 1, 0, 1, 0, 0, 1, 0, 0, "bd"),
|
|
#undef FILTER
|
|
#define FILTER "(a == 1 && b == 1) || (c == 1 && d == 1) || " \
|
|
"(e == 1 && f == 1) || (g == 1 && h == 1)"
|
|
DATA_REC(YES, 1, 0, 1, 1, 1, 1, 1, 1, "efgh"),
|
|
DATA_REC(YES, 0, 0, 0, 0, 0, 0, 1, 1, ""),
|
|
DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 1, ""),
|
|
#undef FILTER
|
|
#define FILTER "(a == 1 && b == 1) && (c == 1 && d == 1) && " \
|
|
"(e == 1 && f == 1) || (g == 1 && h == 1)"
|
|
DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 0, "gh"),
|
|
DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 1, ""),
|
|
DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, ""),
|
|
#undef FILTER
|
|
#define FILTER "((a == 1 || b == 1) || (c == 1 || d == 1) || " \
|
|
"(e == 1 || f == 1)) && (g == 1 || h == 1)"
|
|
DATA_REC(YES, 1, 1, 1, 1, 1, 1, 0, 1, "bcdef"),
|
|
DATA_REC(NO, 0, 0, 0, 0, 0, 0, 0, 0, ""),
|
|
DATA_REC(YES, 1, 1, 1, 1, 1, 0, 1, 1, "h"),
|
|
#undef FILTER
|
|
#define FILTER "((((((((a == 1) && (b == 1)) || (c == 1)) && (d == 1)) || " \
|
|
"(e == 1)) && (f == 1)) || (g == 1)) && (h == 1))"
|
|
DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "ceg"),
|
|
DATA_REC(NO, 0, 1, 0, 1, 0, 1, 0, 1, ""),
|
|
DATA_REC(NO, 1, 0, 1, 0, 1, 0, 1, 0, ""),
|
|
#undef FILTER
|
|
#define FILTER "((((((((a == 1) || (b == 1)) && (c == 1)) || (d == 1)) && " \
|
|
"(e == 1)) || (f == 1)) && (g == 1)) || (h == 1))"
|
|
DATA_REC(YES, 1, 1, 1, 1, 1, 1, 1, 1, "bdfh"),
|
|
DATA_REC(YES, 0, 1, 0, 1, 0, 1, 0, 1, ""),
|
|
DATA_REC(YES, 1, 0, 1, 0, 1, 0, 1, 0, "bdfh"),
|
|
};
|
|
|
|
#undef DATA_REC
|
|
#undef FILTER
|
|
#undef YES
|
|
#undef NO
|
|
|
|
#define DATA_CNT ARRAY_SIZE(test_filter_data)
|
|
|
|
static int test_pred_visited;
|
|
|
|
static int test_pred_visited_fn(struct filter_pred *pred, void *event)
|
|
{
|
|
struct ftrace_event_field *field = pred->field;
|
|
|
|
test_pred_visited = 1;
|
|
printk(KERN_INFO "\npred visited %s\n", field->name);
|
|
return 1;
|
|
}
|
|
|
|
static void update_pred_fn(struct event_filter *filter, char *fields)
|
|
{
|
|
struct prog_entry *prog = rcu_dereference_protected(filter->prog,
|
|
lockdep_is_held(&event_mutex));
|
|
int i;
|
|
|
|
for (i = 0; prog[i].pred; i++) {
|
|
struct filter_pred *pred = prog[i].pred;
|
|
struct ftrace_event_field *field = pred->field;
|
|
|
|
WARN_ON_ONCE(pred->fn_num == FILTER_PRED_FN_NOP);
|
|
|
|
if (!field) {
|
|
WARN_ONCE(1, "all leafs should have field defined %d", i);
|
|
continue;
|
|
}
|
|
|
|
if (!strchr(fields, *field->name))
|
|
continue;
|
|
|
|
pred->fn_num = FILTER_PRED_TEST_VISITED;
|
|
}
|
|
}
|
|
|
|
static __init int ftrace_test_event_filter(void)
|
|
{
|
|
int i;
|
|
|
|
printk(KERN_INFO "Testing ftrace filter: ");
|
|
|
|
for (i = 0; i < DATA_CNT; i++) {
|
|
struct event_filter *filter = NULL;
|
|
struct test_filter_data_t *d = &test_filter_data[i];
|
|
int err;
|
|
|
|
err = create_filter(NULL, &event_ftrace_test_filter,
|
|
d->filter, false, &filter);
|
|
if (err) {
|
|
printk(KERN_INFO
|
|
"Failed to get filter for '%s', err %d\n",
|
|
d->filter, err);
|
|
__free_filter(filter);
|
|
break;
|
|
}
|
|
|
|
/* Needed to dereference filter->prog */
|
|
mutex_lock(&event_mutex);
|
|
/*
|
|
* The preemption disabling is not really needed for self
|
|
* tests, but the rcu dereference will complain without it.
|
|
*/
|
|
preempt_disable();
|
|
if (*d->not_visited)
|
|
update_pred_fn(filter, d->not_visited);
|
|
|
|
test_pred_visited = 0;
|
|
err = filter_match_preds(filter, &d->rec);
|
|
preempt_enable();
|
|
|
|
mutex_unlock(&event_mutex);
|
|
|
|
__free_filter(filter);
|
|
|
|
if (test_pred_visited) {
|
|
printk(KERN_INFO
|
|
"Failed, unwanted pred visited for filter %s\n",
|
|
d->filter);
|
|
break;
|
|
}
|
|
|
|
if (err != d->match) {
|
|
printk(KERN_INFO
|
|
"Failed to match filter '%s', expected %d\n",
|
|
d->filter, d->match);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (i == DATA_CNT)
|
|
printk(KERN_CONT "OK\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(ftrace_test_event_filter);
|
|
|
|
#endif /* CONFIG_FTRACE_STARTUP_TEST */
|