1f9963cbb0
Currently a subsystem filter should be applicable to all events under the subsystem, and if it failed, all the event filters will be cleared. Those behaviors make subsys filter much less useful: # echo 'vec == 1' > irq/softirq_entry/filter # echo 'irq == 5' > irq/filter bash: echo: write error: Invalid argument # cat irq/softirq_entry/filter none I'd expect it set the filter for irq_handler_entry/exit, and not touch softirq_entry/exit. The basic idea is, try to see if the filter can be applied to which events, and then just apply to the those events: # echo 'vec == 1' > softirq_entry/filter # echo 'irq == 5' > filter # cat irq_handler_entry/filter irq == 5 # cat softirq_entry/filter vec == 1 Changelog for v2: - do some cleanups to address Frederic's comments. Inspired-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A63D485.7030703@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
1170 lines
24 KiB
C
1170 lines
24 KiB
C
/*
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* trace_events_filter - generic event filtering
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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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/debugfs.h>
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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 "trace.h"
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#include "trace_output.h"
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enum filter_op_ids
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{
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OP_OR,
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OP_AND,
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OP_NE,
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OP_EQ,
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OP_LT,
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OP_LE,
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OP_GT,
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OP_GE,
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OP_NONE,
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OP_OPEN_PAREN,
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};
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struct filter_op {
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int id;
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char *string;
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int precedence;
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};
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static struct filter_op filter_ops[] = {
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{ OP_OR, "||", 1 },
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{ OP_AND, "&&", 2 },
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{ OP_NE, "!=", 4 },
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{ OP_EQ, "==", 4 },
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{ OP_LT, "<", 5 },
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{ OP_LE, "<=", 5 },
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{ OP_GT, ">", 5 },
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{ OP_GE, ">=", 5 },
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{ OP_NONE, "OP_NONE", 0 },
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{ OP_OPEN_PAREN, "(", 0 },
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};
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enum {
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FILT_ERR_NONE,
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FILT_ERR_INVALID_OP,
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FILT_ERR_UNBALANCED_PAREN,
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FILT_ERR_TOO_MANY_OPERANDS,
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FILT_ERR_OPERAND_TOO_LONG,
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FILT_ERR_FIELD_NOT_FOUND,
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FILT_ERR_ILLEGAL_FIELD_OP,
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FILT_ERR_ILLEGAL_INTVAL,
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FILT_ERR_BAD_SUBSYS_FILTER,
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FILT_ERR_TOO_MANY_PREDS,
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FILT_ERR_MISSING_FIELD,
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FILT_ERR_INVALID_FILTER,
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};
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static char *err_text[] = {
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"No error",
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"Invalid operator",
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"Unbalanced parens",
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"Too many operands",
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"Operand too long",
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"Field not found",
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"Illegal operation for field type",
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"Illegal integer value",
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"Couldn't find or set field in one of a subsystem's events",
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"Too many terms in predicate expression",
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"Missing field name and/or value",
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"Meaningless filter expression",
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};
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struct opstack_op {
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int op;
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struct list_head list;
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};
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struct postfix_elt {
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int op;
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char *operand;
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struct list_head list;
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};
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struct filter_parse_state {
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struct filter_op *ops;
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struct list_head opstack;
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struct list_head postfix;
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int lasterr;
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int lasterr_pos;
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struct {
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char *string;
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unsigned int cnt;
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unsigned int tail;
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} infix;
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struct {
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char string[MAX_FILTER_STR_VAL];
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int pos;
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unsigned int tail;
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} operand;
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};
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DEFINE_COMPARISON_PRED(s64);
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DEFINE_COMPARISON_PRED(u64);
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DEFINE_COMPARISON_PRED(s32);
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DEFINE_COMPARISON_PRED(u32);
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DEFINE_COMPARISON_PRED(s16);
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DEFINE_COMPARISON_PRED(u16);
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DEFINE_COMPARISON_PRED(s8);
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DEFINE_COMPARISON_PRED(u8);
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DEFINE_EQUALITY_PRED(64);
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DEFINE_EQUALITY_PRED(32);
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DEFINE_EQUALITY_PRED(16);
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DEFINE_EQUALITY_PRED(8);
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static int filter_pred_and(struct filter_pred *pred __attribute((unused)),
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void *event __attribute((unused)),
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int val1, int val2)
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{
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return val1 && val2;
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}
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static int filter_pred_or(struct filter_pred *pred __attribute((unused)),
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void *event __attribute((unused)),
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int val1, int val2)
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{
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return val1 || val2;
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}
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/* Filter predicate for fixed sized arrays of characters */
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static int filter_pred_string(struct filter_pred *pred, void *event,
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int val1, int val2)
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{
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char *addr = (char *)(event + pred->offset);
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int cmp, match;
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cmp = strncmp(addr, pred->str_val, pred->str_len);
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match = (!cmp) ^ pred->not;
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return match;
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}
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/*
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* Filter predicate for dynamic sized arrays of characters.
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* These are implemented through a list of strings at the end
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* of the entry.
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* Also each of these strings have a field in the entry which
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* contains its offset from the beginning of the entry.
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* We have then first to get this field, dereference it
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* and add it to the address of the entry, and at last we have
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* the address of the string.
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*/
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static int filter_pred_strloc(struct filter_pred *pred, void *event,
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int val1, int val2)
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{
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u32 str_item = *(u32 *)(event + pred->offset);
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int str_loc = str_item & 0xffff;
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int str_len = str_item >> 16;
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char *addr = (char *)(event + str_loc);
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int cmp, match;
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cmp = strncmp(addr, pred->str_val, str_len);
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match = (!cmp) ^ pred->not;
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return match;
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}
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static int filter_pred_none(struct filter_pred *pred, void *event,
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int val1, int val2)
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{
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return 0;
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}
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/* return 1 if event matches, 0 otherwise (discard) */
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int filter_match_preds(struct ftrace_event_call *call, void *rec)
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{
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struct event_filter *filter = call->filter;
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int match, top = 0, val1 = 0, val2 = 0;
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int stack[MAX_FILTER_PRED];
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struct filter_pred *pred;
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int i;
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for (i = 0; i < filter->n_preds; i++) {
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pred = filter->preds[i];
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if (!pred->pop_n) {
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match = pred->fn(pred, rec, val1, val2);
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stack[top++] = match;
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continue;
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}
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if (pred->pop_n > top) {
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WARN_ON_ONCE(1);
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return 0;
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}
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val1 = stack[--top];
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val2 = stack[--top];
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match = pred->fn(pred, rec, val1, val2);
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stack[top++] = match;
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}
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return stack[--top];
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}
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EXPORT_SYMBOL_GPL(filter_match_preds);
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static void parse_error(struct filter_parse_state *ps, int err, int pos)
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{
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ps->lasterr = err;
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ps->lasterr_pos = pos;
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}
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static void remove_filter_string(struct event_filter *filter)
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{
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kfree(filter->filter_string);
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filter->filter_string = NULL;
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}
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static int replace_filter_string(struct event_filter *filter,
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char *filter_string)
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{
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kfree(filter->filter_string);
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filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
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if (!filter->filter_string)
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return -ENOMEM;
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return 0;
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}
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static int append_filter_string(struct event_filter *filter,
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char *string)
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{
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int newlen;
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char *new_filter_string;
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BUG_ON(!filter->filter_string);
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newlen = strlen(filter->filter_string) + strlen(string) + 1;
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new_filter_string = kmalloc(newlen, GFP_KERNEL);
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if (!new_filter_string)
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return -ENOMEM;
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strcpy(new_filter_string, filter->filter_string);
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strcat(new_filter_string, string);
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kfree(filter->filter_string);
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filter->filter_string = new_filter_string;
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return 0;
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}
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static void append_filter_err(struct filter_parse_state *ps,
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struct event_filter *filter)
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{
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int pos = ps->lasterr_pos;
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char *buf, *pbuf;
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buf = (char *)__get_free_page(GFP_TEMPORARY);
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if (!buf)
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return;
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append_filter_string(filter, "\n");
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memset(buf, ' ', PAGE_SIZE);
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if (pos > PAGE_SIZE - 128)
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pos = 0;
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buf[pos] = '^';
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pbuf = &buf[pos] + 1;
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sprintf(pbuf, "\nparse_error: %s\n", err_text[ps->lasterr]);
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append_filter_string(filter, buf);
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free_page((unsigned long) buf);
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}
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void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s)
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{
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struct event_filter *filter = call->filter;
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mutex_lock(&event_mutex);
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if (filter->filter_string)
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trace_seq_printf(s, "%s\n", filter->filter_string);
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else
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trace_seq_printf(s, "none\n");
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mutex_unlock(&event_mutex);
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}
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void print_subsystem_event_filter(struct event_subsystem *system,
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struct trace_seq *s)
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{
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struct event_filter *filter = system->filter;
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mutex_lock(&event_mutex);
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if (filter->filter_string)
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trace_seq_printf(s, "%s\n", filter->filter_string);
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else
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trace_seq_printf(s, "none\n");
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mutex_unlock(&event_mutex);
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}
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static struct ftrace_event_field *
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find_event_field(struct ftrace_event_call *call, char *name)
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{
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struct ftrace_event_field *field;
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list_for_each_entry(field, &call->fields, link) {
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if (!strcmp(field->name, name))
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return field;
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}
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return NULL;
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}
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static void filter_free_pred(struct filter_pred *pred)
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{
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if (!pred)
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return;
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kfree(pred->field_name);
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kfree(pred);
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}
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static void filter_clear_pred(struct filter_pred *pred)
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{
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kfree(pred->field_name);
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pred->field_name = NULL;
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pred->str_len = 0;
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}
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static int filter_set_pred(struct filter_pred *dest,
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struct filter_pred *src,
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filter_pred_fn_t fn)
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{
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*dest = *src;
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if (src->field_name) {
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dest->field_name = kstrdup(src->field_name, GFP_KERNEL);
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if (!dest->field_name)
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return -ENOMEM;
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}
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dest->fn = fn;
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return 0;
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}
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|
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static void filter_disable_preds(struct ftrace_event_call *call)
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{
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struct event_filter *filter = call->filter;
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int i;
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call->filter_active = 0;
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filter->n_preds = 0;
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for (i = 0; i < MAX_FILTER_PRED; i++)
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filter->preds[i]->fn = filter_pred_none;
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}
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|
|
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void destroy_preds(struct ftrace_event_call *call)
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{
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struct event_filter *filter = call->filter;
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int i;
|
|
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for (i = 0; i < MAX_FILTER_PRED; i++) {
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if (filter->preds[i])
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filter_free_pred(filter->preds[i]);
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}
|
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kfree(filter->preds);
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kfree(filter->filter_string);
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kfree(filter);
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call->filter = NULL;
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}
|
|
|
|
int init_preds(struct ftrace_event_call *call)
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{
|
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struct event_filter *filter;
|
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struct filter_pred *pred;
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int i;
|
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filter = call->filter = kzalloc(sizeof(*filter), GFP_KERNEL);
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if (!call->filter)
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return -ENOMEM;
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|
|
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call->filter_active = 0;
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filter->n_preds = 0;
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|
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filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
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if (!filter->preds)
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goto oom;
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|
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for (i = 0; i < MAX_FILTER_PRED; i++) {
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pred = kzalloc(sizeof(*pred), GFP_KERNEL);
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if (!pred)
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goto oom;
|
|
pred->fn = filter_pred_none;
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filter->preds[i] = pred;
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}
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|
|
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return 0;
|
|
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|
oom:
|
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destroy_preds(call);
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|
|
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return -ENOMEM;
|
|
}
|
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EXPORT_SYMBOL_GPL(init_preds);
|
|
|
|
enum {
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FILTER_DISABLE_ALL,
|
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FILTER_INIT_NO_RESET,
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FILTER_SKIP_NO_RESET,
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};
|
|
|
|
static void filter_free_subsystem_preds(struct event_subsystem *system,
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int flag)
|
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{
|
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struct ftrace_event_call *call;
|
|
|
|
list_for_each_entry(call, &ftrace_events, list) {
|
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if (!call->define_fields)
|
|
continue;
|
|
|
|
if (flag == FILTER_INIT_NO_RESET) {
|
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call->filter->no_reset = false;
|
|
continue;
|
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}
|
|
|
|
if (flag == FILTER_SKIP_NO_RESET && call->filter->no_reset)
|
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continue;
|
|
|
|
if (!strcmp(call->system, system->name)) {
|
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filter_disable_preds(call);
|
|
remove_filter_string(call->filter);
|
|
}
|
|
}
|
|
}
|
|
|
|
static int filter_add_pred_fn(struct filter_parse_state *ps,
|
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struct ftrace_event_call *call,
|
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struct filter_pred *pred,
|
|
filter_pred_fn_t fn)
|
|
{
|
|
struct event_filter *filter = call->filter;
|
|
int idx, err;
|
|
|
|
if (filter->n_preds == MAX_FILTER_PRED) {
|
|
parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
|
|
return -ENOSPC;
|
|
}
|
|
|
|
idx = filter->n_preds;
|
|
filter_clear_pred(filter->preds[idx]);
|
|
err = filter_set_pred(filter->preds[idx], pred, fn);
|
|
if (err)
|
|
return err;
|
|
|
|
filter->n_preds++;
|
|
call->filter_active = 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
enum {
|
|
FILTER_STATIC_STRING = 1,
|
|
FILTER_DYN_STRING
|
|
};
|
|
|
|
static int is_string_field(const char *type)
|
|
{
|
|
if (strstr(type, "__data_loc") && strstr(type, "char"))
|
|
return FILTER_DYN_STRING;
|
|
|
|
if (strchr(type, '[') && strstr(type, "char"))
|
|
return FILTER_STATIC_STRING;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int is_legal_op(struct ftrace_event_field *field, int op)
|
|
{
|
|
if (is_string_field(field->type) && (op != OP_EQ && op != OP_NE))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static filter_pred_fn_t select_comparison_fn(int op, int field_size,
|
|
int field_is_signed)
|
|
{
|
|
filter_pred_fn_t fn = NULL;
|
|
|
|
switch (field_size) {
|
|
case 8:
|
|
if (op == OP_EQ || op == OP_NE)
|
|
fn = filter_pred_64;
|
|
else if (field_is_signed)
|
|
fn = filter_pred_s64;
|
|
else
|
|
fn = filter_pred_u64;
|
|
break;
|
|
case 4:
|
|
if (op == OP_EQ || op == OP_NE)
|
|
fn = filter_pred_32;
|
|
else if (field_is_signed)
|
|
fn = filter_pred_s32;
|
|
else
|
|
fn = filter_pred_u32;
|
|
break;
|
|
case 2:
|
|
if (op == OP_EQ || op == OP_NE)
|
|
fn = filter_pred_16;
|
|
else if (field_is_signed)
|
|
fn = filter_pred_s16;
|
|
else
|
|
fn = filter_pred_u16;
|
|
break;
|
|
case 1:
|
|
if (op == OP_EQ || op == OP_NE)
|
|
fn = filter_pred_8;
|
|
else if (field_is_signed)
|
|
fn = filter_pred_s8;
|
|
else
|
|
fn = filter_pred_u8;
|
|
break;
|
|
}
|
|
|
|
return fn;
|
|
}
|
|
|
|
static int filter_add_pred(struct filter_parse_state *ps,
|
|
struct ftrace_event_call *call,
|
|
struct filter_pred *pred,
|
|
bool dry_run)
|
|
{
|
|
struct ftrace_event_field *field;
|
|
filter_pred_fn_t fn;
|
|
unsigned long long val;
|
|
int string_type;
|
|
int ret;
|
|
|
|
pred->fn = filter_pred_none;
|
|
|
|
if (pred->op == OP_AND) {
|
|
pred->pop_n = 2;
|
|
fn = filter_pred_and;
|
|
goto add_pred_fn;
|
|
} else if (pred->op == OP_OR) {
|
|
pred->pop_n = 2;
|
|
fn = filter_pred_or;
|
|
goto add_pred_fn;
|
|
}
|
|
|
|
field = find_event_field(call, pred->field_name);
|
|
if (!field) {
|
|
parse_error(ps, FILT_ERR_FIELD_NOT_FOUND, 0);
|
|
return -EINVAL;
|
|
}
|
|
|
|
pred->offset = field->offset;
|
|
|
|
if (!is_legal_op(field, pred->op)) {
|
|
parse_error(ps, FILT_ERR_ILLEGAL_FIELD_OP, 0);
|
|
return -EINVAL;
|
|
}
|
|
|
|
string_type = is_string_field(field->type);
|
|
if (string_type) {
|
|
if (string_type == FILTER_STATIC_STRING)
|
|
fn = filter_pred_string;
|
|
else
|
|
fn = filter_pred_strloc;
|
|
pred->str_len = field->size;
|
|
} else {
|
|
if (field->is_signed)
|
|
ret = strict_strtoll(pred->str_val, 0, &val);
|
|
else
|
|
ret = strict_strtoull(pred->str_val, 0, &val);
|
|
if (ret) {
|
|
parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0);
|
|
return -EINVAL;
|
|
}
|
|
pred->val = val;
|
|
|
|
fn = select_comparison_fn(pred->op, field->size,
|
|
field->is_signed);
|
|
if (!fn) {
|
|
parse_error(ps, FILT_ERR_INVALID_OP, 0);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
if (pred->op == OP_NE)
|
|
pred->not = 1;
|
|
|
|
add_pred_fn:
|
|
if (!dry_run)
|
|
return filter_add_pred_fn(ps, call, pred, fn);
|
|
return 0;
|
|
}
|
|
|
|
static int filter_add_subsystem_pred(struct filter_parse_state *ps,
|
|
struct event_subsystem *system,
|
|
struct filter_pred *pred,
|
|
char *filter_string,
|
|
bool dry_run)
|
|
{
|
|
struct ftrace_event_call *call;
|
|
int err = 0;
|
|
bool fail = true;
|
|
|
|
list_for_each_entry(call, &ftrace_events, list) {
|
|
|
|
if (!call->define_fields)
|
|
continue;
|
|
|
|
if (strcmp(call->system, system->name))
|
|
continue;
|
|
|
|
if (call->filter->no_reset)
|
|
continue;
|
|
|
|
err = filter_add_pred(ps, call, pred, dry_run);
|
|
if (err)
|
|
call->filter->no_reset = true;
|
|
else
|
|
fail = false;
|
|
|
|
if (!dry_run)
|
|
replace_filter_string(call->filter, filter_string);
|
|
}
|
|
|
|
if (fail) {
|
|
parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void parse_init(struct filter_parse_state *ps,
|
|
struct filter_op *ops,
|
|
char *infix_string)
|
|
{
|
|
memset(ps, '\0', sizeof(*ps));
|
|
|
|
ps->infix.string = infix_string;
|
|
ps->infix.cnt = strlen(infix_string);
|
|
ps->ops = ops;
|
|
|
|
INIT_LIST_HEAD(&ps->opstack);
|
|
INIT_LIST_HEAD(&ps->postfix);
|
|
}
|
|
|
|
static char infix_next(struct filter_parse_state *ps)
|
|
{
|
|
ps->infix.cnt--;
|
|
|
|
return ps->infix.string[ps->infix.tail++];
|
|
}
|
|
|
|
static char infix_peek(struct filter_parse_state *ps)
|
|
{
|
|
if (ps->infix.tail == strlen(ps->infix.string))
|
|
return 0;
|
|
|
|
return ps->infix.string[ps->infix.tail];
|
|
}
|
|
|
|
static void infix_advance(struct filter_parse_state *ps)
|
|
{
|
|
ps->infix.cnt--;
|
|
ps->infix.tail++;
|
|
}
|
|
|
|
static inline int is_precedence_lower(struct filter_parse_state *ps,
|
|
int a, int b)
|
|
{
|
|
return ps->ops[a].precedence < ps->ops[b].precedence;
|
|
}
|
|
|
|
static inline int is_op_char(struct filter_parse_state *ps, char c)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
|
|
if (ps->ops[i].string[0] == c)
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int infix_get_op(struct filter_parse_state *ps, char firstc)
|
|
{
|
|
char nextc = infix_peek(ps);
|
|
char opstr[3];
|
|
int i;
|
|
|
|
opstr[0] = firstc;
|
|
opstr[1] = nextc;
|
|
opstr[2] = '\0';
|
|
|
|
for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
|
|
if (!strcmp(opstr, ps->ops[i].string)) {
|
|
infix_advance(ps);
|
|
return ps->ops[i].id;
|
|
}
|
|
}
|
|
|
|
opstr[1] = '\0';
|
|
|
|
for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
|
|
if (!strcmp(opstr, ps->ops[i].string))
|
|
return ps->ops[i].id;
|
|
}
|
|
|
|
return OP_NONE;
|
|
}
|
|
|
|
static inline void clear_operand_string(struct filter_parse_state *ps)
|
|
{
|
|
memset(ps->operand.string, '\0', MAX_FILTER_STR_VAL);
|
|
ps->operand.tail = 0;
|
|
}
|
|
|
|
static inline int append_operand_char(struct filter_parse_state *ps, char c)
|
|
{
|
|
if (ps->operand.tail == MAX_FILTER_STR_VAL - 1)
|
|
return -EINVAL;
|
|
|
|
ps->operand.string[ps->operand.tail++] = c;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int filter_opstack_push(struct filter_parse_state *ps, int op)
|
|
{
|
|
struct opstack_op *opstack_op;
|
|
|
|
opstack_op = kmalloc(sizeof(*opstack_op), GFP_KERNEL);
|
|
if (!opstack_op)
|
|
return -ENOMEM;
|
|
|
|
opstack_op->op = op;
|
|
list_add(&opstack_op->list, &ps->opstack);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int filter_opstack_empty(struct filter_parse_state *ps)
|
|
{
|
|
return list_empty(&ps->opstack);
|
|
}
|
|
|
|
static int filter_opstack_top(struct filter_parse_state *ps)
|
|
{
|
|
struct opstack_op *opstack_op;
|
|
|
|
if (filter_opstack_empty(ps))
|
|
return OP_NONE;
|
|
|
|
opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list);
|
|
|
|
return opstack_op->op;
|
|
}
|
|
|
|
static int filter_opstack_pop(struct filter_parse_state *ps)
|
|
{
|
|
struct opstack_op *opstack_op;
|
|
int op;
|
|
|
|
if (filter_opstack_empty(ps))
|
|
return OP_NONE;
|
|
|
|
opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list);
|
|
op = opstack_op->op;
|
|
list_del(&opstack_op->list);
|
|
|
|
kfree(opstack_op);
|
|
|
|
return op;
|
|
}
|
|
|
|
static void filter_opstack_clear(struct filter_parse_state *ps)
|
|
{
|
|
while (!filter_opstack_empty(ps))
|
|
filter_opstack_pop(ps);
|
|
}
|
|
|
|
static char *curr_operand(struct filter_parse_state *ps)
|
|
{
|
|
return ps->operand.string;
|
|
}
|
|
|
|
static int postfix_append_operand(struct filter_parse_state *ps, char *operand)
|
|
{
|
|
struct postfix_elt *elt;
|
|
|
|
elt = kmalloc(sizeof(*elt), GFP_KERNEL);
|
|
if (!elt)
|
|
return -ENOMEM;
|
|
|
|
elt->op = OP_NONE;
|
|
elt->operand = kstrdup(operand, GFP_KERNEL);
|
|
if (!elt->operand) {
|
|
kfree(elt);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
list_add_tail(&elt->list, &ps->postfix);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int postfix_append_op(struct filter_parse_state *ps, int op)
|
|
{
|
|
struct postfix_elt *elt;
|
|
|
|
elt = kmalloc(sizeof(*elt), GFP_KERNEL);
|
|
if (!elt)
|
|
return -ENOMEM;
|
|
|
|
elt->op = op;
|
|
elt->operand = NULL;
|
|
|
|
list_add_tail(&elt->list, &ps->postfix);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void postfix_clear(struct filter_parse_state *ps)
|
|
{
|
|
struct postfix_elt *elt;
|
|
|
|
while (!list_empty(&ps->postfix)) {
|
|
elt = list_first_entry(&ps->postfix, struct postfix_elt, list);
|
|
kfree(elt->operand);
|
|
list_del(&elt->list);
|
|
}
|
|
}
|
|
|
|
static int filter_parse(struct filter_parse_state *ps)
|
|
{
|
|
int in_string = 0;
|
|
int op, top_op;
|
|
char ch;
|
|
|
|
while ((ch = infix_next(ps))) {
|
|
if (ch == '"') {
|
|
in_string ^= 1;
|
|
continue;
|
|
}
|
|
|
|
if (in_string)
|
|
goto parse_operand;
|
|
|
|
if (isspace(ch))
|
|
continue;
|
|
|
|
if (is_op_char(ps, ch)) {
|
|
op = infix_get_op(ps, ch);
|
|
if (op == OP_NONE) {
|
|
parse_error(ps, FILT_ERR_INVALID_OP, 0);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (strlen(curr_operand(ps))) {
|
|
postfix_append_operand(ps, curr_operand(ps));
|
|
clear_operand_string(ps);
|
|
}
|
|
|
|
while (!filter_opstack_empty(ps)) {
|
|
top_op = filter_opstack_top(ps);
|
|
if (!is_precedence_lower(ps, top_op, op)) {
|
|
top_op = filter_opstack_pop(ps);
|
|
postfix_append_op(ps, top_op);
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
|
|
filter_opstack_push(ps, op);
|
|
continue;
|
|
}
|
|
|
|
if (ch == '(') {
|
|
filter_opstack_push(ps, OP_OPEN_PAREN);
|
|
continue;
|
|
}
|
|
|
|
if (ch == ')') {
|
|
if (strlen(curr_operand(ps))) {
|
|
postfix_append_operand(ps, curr_operand(ps));
|
|
clear_operand_string(ps);
|
|
}
|
|
|
|
top_op = filter_opstack_pop(ps);
|
|
while (top_op != OP_NONE) {
|
|
if (top_op == OP_OPEN_PAREN)
|
|
break;
|
|
postfix_append_op(ps, top_op);
|
|
top_op = filter_opstack_pop(ps);
|
|
}
|
|
if (top_op == OP_NONE) {
|
|
parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0);
|
|
return -EINVAL;
|
|
}
|
|
continue;
|
|
}
|
|
parse_operand:
|
|
if (append_operand_char(ps, ch)) {
|
|
parse_error(ps, FILT_ERR_OPERAND_TOO_LONG, 0);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
if (strlen(curr_operand(ps)))
|
|
postfix_append_operand(ps, curr_operand(ps));
|
|
|
|
while (!filter_opstack_empty(ps)) {
|
|
top_op = filter_opstack_pop(ps);
|
|
if (top_op == OP_NONE)
|
|
break;
|
|
if (top_op == OP_OPEN_PAREN) {
|
|
parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0);
|
|
return -EINVAL;
|
|
}
|
|
postfix_append_op(ps, top_op);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct filter_pred *create_pred(int op, char *operand1, char *operand2)
|
|
{
|
|
struct filter_pred *pred;
|
|
|
|
pred = kzalloc(sizeof(*pred), GFP_KERNEL);
|
|
if (!pred)
|
|
return NULL;
|
|
|
|
pred->field_name = kstrdup(operand1, GFP_KERNEL);
|
|
if (!pred->field_name) {
|
|
kfree(pred);
|
|
return NULL;
|
|
}
|
|
|
|
strcpy(pred->str_val, operand2);
|
|
pred->str_len = strlen(operand2);
|
|
|
|
pred->op = op;
|
|
|
|
return pred;
|
|
}
|
|
|
|
static struct filter_pred *create_logical_pred(int op)
|
|
{
|
|
struct filter_pred *pred;
|
|
|
|
pred = kzalloc(sizeof(*pred), GFP_KERNEL);
|
|
if (!pred)
|
|
return NULL;
|
|
|
|
pred->op = op;
|
|
|
|
return pred;
|
|
}
|
|
|
|
static int check_preds(struct filter_parse_state *ps)
|
|
{
|
|
int n_normal_preds = 0, n_logical_preds = 0;
|
|
struct postfix_elt *elt;
|
|
|
|
list_for_each_entry(elt, &ps->postfix, list) {
|
|
if (elt->op == OP_NONE)
|
|
continue;
|
|
|
|
if (elt->op == OP_AND || elt->op == OP_OR) {
|
|
n_logical_preds++;
|
|
continue;
|
|
}
|
|
n_normal_preds++;
|
|
}
|
|
|
|
if (!n_normal_preds || n_logical_preds >= n_normal_preds) {
|
|
parse_error(ps, FILT_ERR_INVALID_FILTER, 0);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int replace_preds(struct event_subsystem *system,
|
|
struct ftrace_event_call *call,
|
|
struct filter_parse_state *ps,
|
|
char *filter_string,
|
|
bool dry_run)
|
|
{
|
|
char *operand1 = NULL, *operand2 = NULL;
|
|
struct filter_pred *pred;
|
|
struct postfix_elt *elt;
|
|
int err;
|
|
int n_preds = 0;
|
|
|
|
err = check_preds(ps);
|
|
if (err)
|
|
return err;
|
|
|
|
list_for_each_entry(elt, &ps->postfix, list) {
|
|
if (elt->op == OP_NONE) {
|
|
if (!operand1)
|
|
operand1 = elt->operand;
|
|
else if (!operand2)
|
|
operand2 = elt->operand;
|
|
else {
|
|
parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0);
|
|
return -EINVAL;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
if (n_preds++ == MAX_FILTER_PRED) {
|
|
parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
|
|
return -ENOSPC;
|
|
}
|
|
|
|
if (elt->op == OP_AND || elt->op == OP_OR) {
|
|
pred = create_logical_pred(elt->op);
|
|
goto add_pred;
|
|
}
|
|
|
|
if (!operand1 || !operand2) {
|
|
parse_error(ps, FILT_ERR_MISSING_FIELD, 0);
|
|
return -EINVAL;
|
|
}
|
|
|
|
pred = create_pred(elt->op, operand1, operand2);
|
|
add_pred:
|
|
if (call)
|
|
err = filter_add_pred(ps, call, pred, false);
|
|
else
|
|
err = filter_add_subsystem_pred(ps, system, pred,
|
|
filter_string, dry_run);
|
|
filter_free_pred(pred);
|
|
if (err)
|
|
return err;
|
|
|
|
operand1 = operand2 = NULL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
|
|
{
|
|
int err;
|
|
|
|
struct filter_parse_state *ps;
|
|
|
|
mutex_lock(&event_mutex);
|
|
|
|
if (!strcmp(strstrip(filter_string), "0")) {
|
|
filter_disable_preds(call);
|
|
remove_filter_string(call->filter);
|
|
mutex_unlock(&event_mutex);
|
|
return 0;
|
|
}
|
|
|
|
err = -ENOMEM;
|
|
ps = kzalloc(sizeof(*ps), GFP_KERNEL);
|
|
if (!ps)
|
|
goto out_unlock;
|
|
|
|
filter_disable_preds(call);
|
|
replace_filter_string(call->filter, filter_string);
|
|
|
|
parse_init(ps, filter_ops, filter_string);
|
|
err = filter_parse(ps);
|
|
if (err) {
|
|
append_filter_err(ps, call->filter);
|
|
goto out;
|
|
}
|
|
|
|
err = replace_preds(NULL, call, ps, filter_string, false);
|
|
if (err)
|
|
append_filter_err(ps, call->filter);
|
|
|
|
out:
|
|
filter_opstack_clear(ps);
|
|
postfix_clear(ps);
|
|
kfree(ps);
|
|
out_unlock:
|
|
mutex_unlock(&event_mutex);
|
|
|
|
return err;
|
|
}
|
|
|
|
int apply_subsystem_event_filter(struct event_subsystem *system,
|
|
char *filter_string)
|
|
{
|
|
int err;
|
|
|
|
struct filter_parse_state *ps;
|
|
|
|
mutex_lock(&event_mutex);
|
|
|
|
if (!strcmp(strstrip(filter_string), "0")) {
|
|
filter_free_subsystem_preds(system, FILTER_DISABLE_ALL);
|
|
remove_filter_string(system->filter);
|
|
mutex_unlock(&event_mutex);
|
|
return 0;
|
|
}
|
|
|
|
err = -ENOMEM;
|
|
ps = kzalloc(sizeof(*ps), GFP_KERNEL);
|
|
if (!ps)
|
|
goto out_unlock;
|
|
|
|
replace_filter_string(system->filter, filter_string);
|
|
|
|
parse_init(ps, filter_ops, filter_string);
|
|
err = filter_parse(ps);
|
|
if (err) {
|
|
append_filter_err(ps, system->filter);
|
|
goto out;
|
|
}
|
|
|
|
filter_free_subsystem_preds(system, FILTER_INIT_NO_RESET);
|
|
|
|
/* try to see the filter can be applied to which events */
|
|
err = replace_preds(system, NULL, ps, filter_string, true);
|
|
if (err) {
|
|
append_filter_err(ps, system->filter);
|
|
goto out;
|
|
}
|
|
|
|
filter_free_subsystem_preds(system, FILTER_SKIP_NO_RESET);
|
|
|
|
/* really apply the filter to the events */
|
|
err = replace_preds(system, NULL, ps, filter_string, false);
|
|
if (err) {
|
|
append_filter_err(ps, system->filter);
|
|
filter_free_subsystem_preds(system, 2);
|
|
}
|
|
|
|
out:
|
|
filter_opstack_clear(ps);
|
|
postfix_clear(ps);
|
|
kfree(ps);
|
|
out_unlock:
|
|
mutex_unlock(&event_mutex);
|
|
|
|
return err;
|
|
}
|
|
|