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trace_events_filter.c
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2473 lines (2077 loc) · 54.7 KB
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/*
* trace_events_filter - generic event filtering
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) 2009 Tom Zanussi <[email protected]>
*/
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/mutex.h>
#include <linux/perf_event.h>
#include <linux/slab.h>
#include "trace.h"
#include "trace_output.h"
#define DEFAULT_SYS_FILTER_MESSAGE \
"### global filter ###\n" \
"# Use this to set filters for multiple events.\n" \
"# Only events with the given fields will be affected.\n" \
"# If no events are modified, an error message will be displayed here"
enum filter_op_ids
{
OP_OR,
OP_AND,
OP_GLOB,
OP_NE,
OP_EQ,
OP_LT,
OP_LE,
OP_GT,
OP_GE,
OP_BAND,
OP_NOT,
OP_NONE,
OP_OPEN_PAREN,
};
struct filter_op {
int id;
char *string;
int precedence;
};
/* Order must be the same as enum filter_op_ids above */
static struct filter_op filter_ops[] = {
{ OP_OR, "||", 1 },
{ OP_AND, "&&", 2 },
{ OP_GLOB, "~", 4 },
{ OP_NE, "!=", 4 },
{ OP_EQ, "==", 4 },
{ OP_LT, "<", 5 },
{ OP_LE, "<=", 5 },
{ OP_GT, ">", 5 },
{ OP_GE, ">=", 5 },
{ OP_BAND, "&", 6 },
{ OP_NOT, "!", 6 },
{ OP_NONE, "OP_NONE", 0 },
{ OP_OPEN_PAREN, "(", 0 },
};
enum {
FILT_ERR_NONE,
FILT_ERR_INVALID_OP,
FILT_ERR_UNBALANCED_PAREN,
FILT_ERR_TOO_MANY_OPERANDS,
FILT_ERR_OPERAND_TOO_LONG,
FILT_ERR_FIELD_NOT_FOUND,
FILT_ERR_ILLEGAL_FIELD_OP,
FILT_ERR_ILLEGAL_INTVAL,
FILT_ERR_BAD_SUBSYS_FILTER,
FILT_ERR_TOO_MANY_PREDS,
FILT_ERR_MISSING_FIELD,
FILT_ERR_INVALID_FILTER,
FILT_ERR_IP_FIELD_ONLY,
FILT_ERR_ILLEGAL_NOT_OP,
};
static char *err_text[] = {
"No error",
"Invalid operator",
"Unbalanced parens",
"Too many operands",
"Operand too long",
"Field not found",
"Illegal operation for field type",
"Illegal integer value",
"Couldn't find or set field in one of a subsystem's events",
"Too many terms in predicate expression",
"Missing field name and/or value",
"Meaningless filter expression",
"Only 'ip' field is supported for function trace",
"Illegal use of '!'",
};
struct opstack_op {
enum filter_op_ids op;
struct list_head list;
};
struct postfix_elt {
enum filter_op_ids op;
char *operand;
struct list_head list;
};
struct filter_parse_state {
struct filter_op *ops;
struct list_head opstack;
struct list_head postfix;
int lasterr;
int lasterr_pos;
struct {
char *string;
unsigned int cnt;
unsigned int tail;
} infix;
struct {
char string[MAX_FILTER_STR_VAL];
int pos;
unsigned int tail;
} operand;
};
struct pred_stack {
struct filter_pred **preds;
int index;
};
/* If not of not match is equal to not of not, then it is a match */
#define DEFINE_COMPARISON_PRED(type) \
static int filter_pred_LT_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
int match = (*addr < val); \
return !!match == !pred->not; \
} \
static int filter_pred_LE_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
int match = (*addr <= val); \
return !!match == !pred->not; \
} \
static int filter_pred_GT_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
int match = (*addr > val); \
return !!match == !pred->not; \
} \
static int filter_pred_GE_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
int match = (*addr >= val); \
return !!match == !pred->not; \
} \
static int filter_pred_BAND_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
int match = !!(*addr & val); \
return match == !pred->not; \
} \
static const filter_pred_fn_t pred_funcs_##type[] = { \
filter_pred_LT_##type, \
filter_pred_LE_##type, \
filter_pred_GT_##type, \
filter_pred_GE_##type, \
filter_pred_BAND_##type, \
};
#define PRED_FUNC_START OP_LT
#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);
/* 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;
}
/* Filter predicate for char * pointers */
static int filter_pred_pchar(struct filter_pred *pred, void *event)
{
char **addr = (char **)(event + pred->offset);
int cmp, match;
int len = strlen(*addr) + 1; /* including tailing '\0' */
cmp = pred->regex.match(*addr, &pred->regex, len);
match = cmp ^ pred->not;
return match;
}
/*
* 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 CPUs. */
static int filter_pred_cpu(struct filter_pred *pred, void *event)
{
int cpu, cmp;
int match = 0;
cpu = raw_smp_processor_id();
cmp = pred->val;
switch (pred->op) {
case OP_EQ:
match = cpu == cmp;
break;
case OP_LT:
match = cpu < cmp;
break;
case OP_LE:
match = cpu <= cmp;
break;
case OP_GT:
match = cpu > cmp;
break;
case OP_GE:
match = cpu >= cmp;
break;
default:
break;
}
return !!match == !pred->not;
}
/* Filter predicate for COMM. */
static int filter_pred_comm(struct filter_pred *pred, void *event)
{
int cmp, match;
cmp = pred->regex.match(current->comm, &pred->regex,
pred->regex.field_len);
match = cmp ^ pred->not;
return match;
}
static int filter_pred_none(struct filter_pred *pred, void *event)
{
return 0;
}
/*
* 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
* or STATIC_STRING
*/
static int regex_match_full(char *str, struct regex *r, int len)
{
if (strncmp(str, r->pattern, len) == 0)
return 1;
return 0;
}
static int regex_match_front(char *str, struct regex *r, int len)
{
if (strncmp(str, r->pattern, r->len) == 0)
return 1;
return 0;
}
static int regex_match_middle(char *str, struct regex *r, int len)
{
if (strnstr(str, r->pattern, len))
return 1;
return 0;
}
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;
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;
int not = 0;
if (pred->op == OP_GLOB) {
type = filter_parse_regex(r->pattern, r->len, &search, ¬);
r->len = strlen(search);
memmove(r->pattern, search, r->len+1);
}
switch (type) {
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;
}
pred->not ^= not;
}
enum move_type {
MOVE_DOWN,
MOVE_UP_FROM_LEFT,
MOVE_UP_FROM_RIGHT
};
static struct filter_pred *
get_pred_parent(struct filter_pred *pred, struct filter_pred *preds,
int index, enum move_type *move)
{
if (pred->parent & FILTER_PRED_IS_RIGHT)
*move = MOVE_UP_FROM_RIGHT;
else
*move = MOVE_UP_FROM_LEFT;
pred = &preds[pred->parent & ~FILTER_PRED_IS_RIGHT];
return pred;
}
enum walk_return {
WALK_PRED_ABORT,
WALK_PRED_PARENT,
WALK_PRED_DEFAULT,
};
typedef int (*filter_pred_walkcb_t) (enum move_type move,
struct filter_pred *pred,
int *err, void *data);
static int walk_pred_tree(struct filter_pred *preds,
struct filter_pred *root,
filter_pred_walkcb_t cb, void *data)
{
struct filter_pred *pred = root;
enum move_type move = MOVE_DOWN;
int done = 0;
if (!preds)
return -EINVAL;
do {
int err = 0, ret;
ret = cb(move, pred, &err, data);
if (ret == WALK_PRED_ABORT)
return err;
if (ret == WALK_PRED_PARENT)
goto get_parent;
switch (move) {
case MOVE_DOWN:
if (pred->left != FILTER_PRED_INVALID) {
pred = &preds[pred->left];
continue;
}
goto get_parent;
case MOVE_UP_FROM_LEFT:
pred = &preds[pred->right];
move = MOVE_DOWN;
continue;
case MOVE_UP_FROM_RIGHT:
get_parent:
if (pred == root)
break;
pred = get_pred_parent(pred, preds,
pred->parent,
&move);
continue;
}
done = 1;
} while (!done);
/* We are fine. */
return 0;
}
/*
* A series of AND or ORs where found together. Instead of
* climbing up and down the tree branches, an array of the
* ops were made in order of checks. We can just move across
* the array and short circuit if needed.
*/
static int process_ops(struct filter_pred *preds,
struct filter_pred *op, void *rec)
{
struct filter_pred *pred;
int match = 0;
int type;
int i;
/*
* Micro-optimization: We set type to true if op
* is an OR and false otherwise (AND). Then we
* just need to test if the match is equal to
* the type, and if it is, we can short circuit the
* rest of the checks:
*
* if ((match && op->op == OP_OR) ||
* (!match && op->op == OP_AND))
* return match;
*/
type = op->op == OP_OR;
for (i = 0; i < op->val; i++) {
pred = &preds[op->ops[i]];
if (!WARN_ON_ONCE(!pred->fn))
match = pred->fn(pred, rec);
if (!!match == type)
break;
}
/* If not of not match is equal to not of not, then it is a match */
return !!match == !op->not;
}
struct filter_match_preds_data {
struct filter_pred *preds;
int match;
void *rec;
};
static int filter_match_preds_cb(enum move_type move, struct filter_pred *pred,
int *err, void *data)
{
struct filter_match_preds_data *d = data;
*err = 0;
switch (move) {
case MOVE_DOWN:
/* only AND and OR have children */
if (pred->left != FILTER_PRED_INVALID) {
/* If ops is set, then it was folded. */
if (!pred->ops)
return WALK_PRED_DEFAULT;
/* We can treat folded ops as a leaf node */
d->match = process_ops(d->preds, pred, d->rec);
} else {
if (!WARN_ON_ONCE(!pred->fn))
d->match = pred->fn(pred, d->rec);
}
return WALK_PRED_PARENT;
case MOVE_UP_FROM_LEFT:
/*
* Check for short circuits.
*
* Optimization: !!match == (pred->op == OP_OR)
* is the same as:
* if ((match && pred->op == OP_OR) ||
* (!match && pred->op == OP_AND))
*/
if (!!d->match == (pred->op == OP_OR))
return WALK_PRED_PARENT;
break;
case MOVE_UP_FROM_RIGHT:
break;
}
return WALK_PRED_DEFAULT;
}
/* return 1 if event matches, 0 otherwise (discard) */
int filter_match_preds(struct event_filter *filter, void *rec)
{
struct filter_pred *preds;
struct filter_pred *root;
struct filter_match_preds_data data = {
/* match is currently meaningless */
.match = -1,
.rec = rec,
};
int n_preds, ret;
/* no filter is considered a match */
if (!filter)
return 1;
n_preds = filter->n_preds;
if (!n_preds)
return 1;
/*
* n_preds, root and filter->preds are protect with preemption disabled.
*/
root = rcu_dereference_sched(filter->root);
if (!root)
return 1;
data.preds = preds = rcu_dereference_sched(filter->preds);
ret = walk_pred_tree(preds, root, filter_match_preds_cb, &data);
WARN_ON(ret);
return data.match;
}
EXPORT_SYMBOL_GPL(filter_match_preds);
static void parse_error(struct filter_parse_state *ps, int err, int pos)
{
ps->lasterr = err;
ps->lasterr_pos = pos;
}
static void remove_filter_string(struct event_filter *filter)
{
if (!filter)
return;
kfree(filter->filter_string);
filter->filter_string = NULL;
}
static int replace_filter_string(struct event_filter *filter,
char *filter_string)
{
kfree(filter->filter_string);
filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
if (!filter->filter_string)
return -ENOMEM;
return 0;
}
static int append_filter_string(struct event_filter *filter,
char *string)
{
int newlen;
char *new_filter_string;
BUG_ON(!filter->filter_string);
newlen = strlen(filter->filter_string) + strlen(string) + 1;
new_filter_string = kmalloc(newlen, GFP_KERNEL);
if (!new_filter_string)
return -ENOMEM;
strcpy(new_filter_string, filter->filter_string);
strcat(new_filter_string, string);
kfree(filter->filter_string);
filter->filter_string = new_filter_string;
return 0;
}
static void append_filter_err(struct filter_parse_state *ps,
struct event_filter *filter)
{
int pos = ps->lasterr_pos;
char *buf, *pbuf;
buf = (char *)__get_free_page(GFP_KERNEL);
if (!buf)
return;
append_filter_string(filter, "\n");
memset(buf, ' ', PAGE_SIZE);
if (pos > PAGE_SIZE - 128)
pos = 0;
buf[pos] = '^';
pbuf = &buf[pos] + 1;
sprintf(pbuf, "\nparse_error: %s\n", err_text[ps->lasterr]);
append_filter_string(filter, buf);
free_page((unsigned long) buf);
}
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 int __alloc_pred_stack(struct pred_stack *stack, int n_preds)
{
stack->preds = kcalloc(n_preds + 1, sizeof(*stack->preds), GFP_KERNEL);
if (!stack->preds)
return -ENOMEM;
stack->index = n_preds;
return 0;
}
static void __free_pred_stack(struct pred_stack *stack)
{
kfree(stack->preds);
stack->index = 0;
}
static int __push_pred_stack(struct pred_stack *stack,
struct filter_pred *pred)
{
int index = stack->index;
if (WARN_ON(index == 0))
return -ENOSPC;
stack->preds[--index] = pred;
stack->index = index;
return 0;
}
static struct filter_pred *
__pop_pred_stack(struct pred_stack *stack)
{
struct filter_pred *pred;
int index = stack->index;
pred = stack->preds[index++];
if (!pred)
return NULL;
stack->index = index;
return pred;
}
static int filter_set_pred(struct event_filter *filter,
int idx,
struct pred_stack *stack,
struct filter_pred *src)
{
struct filter_pred *dest = &filter->preds[idx];
struct filter_pred *left;
struct filter_pred *right;
*dest = *src;
dest->index = idx;
if (dest->op == OP_OR || dest->op == OP_AND) {
right = __pop_pred_stack(stack);
left = __pop_pred_stack(stack);
if (!left || !right)
return -EINVAL;
/*
* If both children can be folded
* and they are the same op as this op or a leaf,
* then this op can be folded.
*/
if (left->index & FILTER_PRED_FOLD &&
((left->op == dest->op && !left->not) ||
left->left == FILTER_PRED_INVALID) &&
right->index & FILTER_PRED_FOLD &&
((right->op == dest->op && !right->not) ||
right->left == FILTER_PRED_INVALID))
dest->index |= FILTER_PRED_FOLD;
dest->left = left->index & ~FILTER_PRED_FOLD;
dest->right = right->index & ~FILTER_PRED_FOLD;
left->parent = dest->index & ~FILTER_PRED_FOLD;
right->parent = dest->index | FILTER_PRED_IS_RIGHT;
} else {
/*
* Make dest->left invalid to be used as a quick
* way to know this is a leaf node.
*/
dest->left = FILTER_PRED_INVALID;
/* All leafs allow folding the parent ops. */
dest->index |= FILTER_PRED_FOLD;
}
return __push_pred_stack(stack, dest);
}
static void __free_preds(struct event_filter *filter)
{
int i;
if (filter->preds) {
for (i = 0; i < filter->n_preds; i++)
kfree(filter->preds[i].ops);
kfree(filter->preds);
filter->preds = NULL;
}
filter->a_preds = 0;
filter->n_preds = 0;
}
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_preds(filter);
kfree(filter->filter_string);
kfree(filter);
}
void free_event_filter(struct event_filter *filter)
{
__free_filter(filter);
}
static struct event_filter *__alloc_filter(void)
{
struct event_filter *filter;
filter = kzalloc(sizeof(*filter), GFP_KERNEL);
return filter;
}
static int __alloc_preds(struct event_filter *filter, int n_preds)
{
struct filter_pred *pred;
int i;
if (filter->preds)
__free_preds(filter);
filter->preds = kcalloc(n_preds, sizeof(*filter->preds), GFP_KERNEL);
if (!filter->preds)
return -ENOMEM;
filter->a_preds = n_preds;
filter->n_preds = 0;
for (i = 0; i < n_preds; i++) {
pred = &filter->preds[i];
pred->fn = filter_pred_none;
}
return 0;
}
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);
}
}
static int filter_add_pred(struct filter_parse_state *ps,
struct event_filter *filter,
struct filter_pred *pred,
struct pred_stack *stack)
{
int err;
if (WARN_ON(filter->n_preds == filter->a_preds)) {
parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
return -ENOSPC;
}
err = filter_set_pred(filter, filter->n_preds, stack, pred);
if (err)
return err;
filter->n_preds++;
return 0;
}
int filter_assign_type(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 FILTER_OTHER;
}
static bool is_legal_op(struct ftrace_event_field *field, enum filter_op_ids op)
{
if (is_string_field(field) &&
(op != OP_EQ && op != OP_NE && op != OP_GLOB))
return false;
if (!is_string_field(field) && op == OP_GLOB)
return false;
return true;
}
static filter_pred_fn_t select_comparison_fn(enum filter_op_ids 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 = pred_funcs_s64[op - PRED_FUNC_START];