[deliverable/linux.git] / kernel / trace / trace_events_filter.c

/*
 * 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 <tzanussi@gmail.com>
 */

#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/ctype.h>

#include "trace.h"
#include "trace_output.h"

static int filter_pred_64(struct filter_pred *pred, void *event)
{
	u64 *addr = (u64 *)(event + pred->offset);
	u64 val = (u64)pred->val;
	int match;

	match = (val == *addr) ^ pred->not;

	return match;
}

static int filter_pred_32(struct filter_pred *pred, void *event)
{
	u32 *addr = (u32 *)(event + pred->offset);
	u32 val = (u32)pred->val;
	int match;

	match = (val == *addr) ^ pred->not;

	return match;
}

static int filter_pred_16(struct filter_pred *pred, void *event)
{
	u16 *addr = (u16 *)(event + pred->offset);
	u16 val = (u16)pred->val;
	int match;

	match = (val == *addr) ^ pred->not;

	return match;
}

static int filter_pred_8(struct filter_pred *pred, void *event)
{
	u8 *addr = (u8 *)(event + pred->offset);
	u8 val = (u8)pred->val;
	int match;

	match = (val == *addr) ^ pred->not;

	return match;
}

static int filter_pred_string(struct filter_pred *pred, void *event)
{
	char *addr = (char *)(event + pred->offset);
	int cmp, match;

	cmp = strncmp(addr, pred->str_val, pred->str_len);

	match = (!cmp) ^ pred->not;

	return match;
}

static int filter_pred_none(struct filter_pred *pred, void *event)
{
	return 0;
}

/* return 1 if event matches, 0 otherwise (discard) */
int filter_match_preds(struct ftrace_event_call *call, void *rec)
{
	int i, matched, and_failed = 0;
	struct filter_pred *pred;

	for (i = 0; i < call->n_preds; i++) {
		pred = call->preds[i];
		if (and_failed && !pred->or)
			continue;
		matched = pred->fn(pred, rec);
		if (!matched && !pred->or) {
			and_failed = 1;
			continue;
		} else if (matched && pred->or)
			return 1;
	}

	if (and_failed)
		return 0;

	return 1;
}
EXPORT_SYMBOL_GPL(filter_match_preds);

void filter_print_preds(struct filter_pred **preds, int n_preds,
			struct trace_seq *s)
{
	char *field_name;
	struct filter_pred *pred;
	int i;

	if (!n_preds) {
		trace_seq_printf(s, "none\n");
		return;
	}

	for (i = 0; i < n_preds; i++) {
		pred = preds[i];
		field_name = pred->field_name;
		if (i)
			trace_seq_printf(s, pred->or ? "|| " : "&& ");
		trace_seq_printf(s, "%s ", field_name);
		trace_seq_printf(s, pred->not ? "!= " : "== ");
		if (pred->str_len)
			trace_seq_printf(s, "%s\n", pred->str_val);
		else
			trace_seq_printf(s, "%llu\n", pred->val);
	}
}

static struct ftrace_event_field *
find_event_field(struct ftrace_event_call *call, char *name)
{
	struct ftrace_event_field *field;

	list_for_each_entry(field, &call->fields, link) {
		if (!strcmp(field->name, name))
			return field;
	}

	return NULL;
}

void filter_free_pred(struct filter_pred *pred)
{
	if (!pred)
		return;

	kfree(pred->field_name);
	kfree(pred);
}

static void filter_clear_pred(struct filter_pred *pred)
{
	kfree(pred->field_name);
	pred->field_name = NULL;
	pred->str_len = 0;
}

static int filter_set_pred(struct filter_pred *dest,
			   struct filter_pred *src,
			   filter_pred_fn_t fn)
{
	*dest = *src;
	dest->field_name = kstrdup(src->field_name, GFP_KERNEL);
	if (!dest->field_name)
		return -ENOMEM;
	dest->fn = fn;

	return 0;
}

void filter_disable_preds(struct ftrace_event_call *call)
{
	int i;

	call->n_preds = 0;

	for (i = 0; i < MAX_FILTER_PRED; i++)
		call->preds[i]->fn = filter_pred_none;
}

int init_preds(struct ftrace_event_call *call)
{
	struct filter_pred *pred;
	int i;

	call->n_preds = 0;

	call->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
	if (!call->preds)
		return -ENOMEM;

	for (i = 0; i < MAX_FILTER_PRED; i++) {
		pred = kzalloc(sizeof(*pred), GFP_KERNEL);
		if (!pred)
			goto oom;
		pred->fn = filter_pred_none;
		call->preds[i] = pred;
	}

	return 0;

oom:
	for (i = 0; i < MAX_FILTER_PRED; i++) {
		if (call->preds[i])
			filter_free_pred(call->preds[i]);
	}
	kfree(call->preds);
	call->preds = NULL;

	return -ENOMEM;
}
EXPORT_SYMBOL_GPL(init_preds);

void filter_free_subsystem_preds(struct event_subsystem *system)
{
	struct ftrace_event_call *call;
	int i;

	if (system->n_preds) {
		for (i = 0; i < system->n_preds; i++)
			filter_free_pred(system->preds[i]);
		kfree(system->preds);
		system->preds = NULL;
		system->n_preds = 0;
	}

	list_for_each_entry(call, &ftrace_events, list) {
		if (!call->define_fields)
			continue;

		if (!strcmp(call->system, system->name))
			filter_disable_preds(call);
	}
}

static int __filter_add_pred(struct ftrace_event_call *call,
			     struct filter_pred *pred,
			     filter_pred_fn_t fn)
{
	int idx, err;

	if (call->n_preds && !pred->compound)
		filter_disable_preds(call);

	if (call->n_preds == MAX_FILTER_PRED)
		return -ENOSPC;

	idx = call->n_preds;
	filter_clear_pred(call->preds[idx]);
	err = filter_set_pred(call->preds[idx], pred, fn);
	if (err)
		return err;

	call->n_preds++;

	return 0;
}

static int is_string_field(const char *type)
{
	if (strchr(type, '[') && strstr(type, "char"))
		return 1;

	return 0;
}

int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred)
{
	struct ftrace_event_field *field;
	filter_pred_fn_t fn;

	field = find_event_field(call, pred->field_name);
	if (!field)
		return -EINVAL;

	pred->fn = filter_pred_none;
	pred->offset = field->offset;

	if (is_string_field(field->type)) {
		if (!pred->str_len)
			return -EINVAL;
		fn = filter_pred_string;
		pred->str_len = field->size;
		return __filter_add_pred(call, pred, fn);
	} else {
		if (pred->str_len)
			return -EINVAL;
	}

	switch (field->size) {
	case 8:
		fn = filter_pred_64;
		break;
	case 4:
		fn = filter_pred_32;
		break;
	case 2:
		fn = filter_pred_16;
		break;
	case 1:
		fn = filter_pred_8;
		break;
	default:
		return -EINVAL;
	}

	return __filter_add_pred(call, pred, fn);
}

int filter_add_subsystem_pred(struct event_subsystem *system,
			      struct filter_pred *pred)
{
	struct ftrace_event_call *call;

	if (system->n_preds && !pred->compound)
		filter_free_subsystem_preds(system);

	if (!system->n_preds) {
		system->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
					GFP_KERNEL);
		if (!system->preds)
			return -ENOMEM;
	}

	if (system->n_preds == MAX_FILTER_PRED)
		return -ENOSPC;

	system->preds[system->n_preds] = pred;

	list_for_each_entry(call, &ftrace_events, list) {
		int err;

		if (!call->define_fields)
			continue;

		if (strcmp(call->system, system->name))
			continue;

		if (!find_event_field(call, pred->field_name))
			continue;

		err = filter_add_pred(call, pred);
		if (err == -ENOMEM) {
			system->preds[system->n_preds] = NULL;
			return err;
		}
	}

	system->n_preds++;

	return 0;
}

int filter_parse(char **pbuf, struct filter_pred *pred)
{
	char *tmp, *tok, *val_str = NULL;
	int tok_n = 0;

	/* field ==/!= number, or/and field ==/!= number, number */
	while ((tok = strsep(pbuf, " \n"))) {
		if (tok_n == 0) {
			if (!strcmp(tok, "0")) {
				pred->clear = 1;
				return 0;
			} else if (!strcmp(tok, "&&")) {
				pred->or = 0;
				pred->compound = 1;
			} else if (!strcmp(tok, "||")) {
				pred->or = 1;
				pred->compound = 1;
			} else
				pred->field_name = tok;
			tok_n = 1;
			continue;
		}
		if (tok_n == 1) {
			if (!pred->field_name)
				pred->field_name = tok;
			else if (!strcmp(tok, "!="))
				pred->not = 1;
			else if (!strcmp(tok, "=="))
				pred->not = 0;
			else {
				pred->field_name = NULL;
				return -EINVAL;
			}
			tok_n = 2;
			continue;
		}
		if (tok_n == 2) {
			if (pred->compound) {
				if (!strcmp(tok, "!="))
					pred->not = 1;
				else if (!strcmp(tok, "=="))
					pred->not = 0;
				else {
					pred->field_name = NULL;
					return -EINVAL;
				}
			} else {
				val_str = tok;
				break; /* done */
			}
			tok_n = 3;
			continue;
		}
		if (tok_n == 3) {
			val_str = tok;
			break; /* done */
		}
	}

	if (!val_str || !strlen(val_str)
	    || strlen(val_str) >= MAX_FILTER_STR_VAL) {
		pred->field_name = NULL;
		return -EINVAL;
	}

	pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
	if (!pred->field_name)
		return -ENOMEM;

	pred->str_len = 0;
	pred->val = simple_strtoull(val_str, &tmp, 0);
	if (tmp == val_str) {
		strncpy(pred->str_val, val_str, MAX_FILTER_STR_VAL);
		pred->str_len = strlen(val_str);
		pred->str_val[pred->str_len] = '\0';
	} else if (*tmp != '\0')
		return -EINVAL;

	return 0;
}
Commit	Line	Data
7ce7e424 TZ	1	/*
	2	* trace_events_filter - generic event filtering
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*
	18	* Copyright (C) 2009 Tom Zanussi <tzanussi@gmail.com>
	19	*/
	20
	21	#include <linux/debugfs.h>
	22	#include <linux/uaccess.h>
	23	#include <linux/module.h>
	24	#include <linux/ctype.h>
	25
	26	#include "trace.h"
4bda2d51	27	#include "trace_output.h"
7ce7e424 TZ	28
	29	static int filter_pred_64(struct filter_pred pred, void event)
	30	{
	31	u64 addr = (u64 )(event + pred->offset);
	32	u64 val = (u64)pred->val;
	33	int match;
	34
	35	match = (val == *addr) ^ pred->not;
	36
	37	return match;
	38	}
	39
	40	static int filter_pred_32(struct filter_pred pred, void event)
	41	{
	42	u32 addr = (u32 )(event + pred->offset);
	43	u32 val = (u32)pred->val;
	44	int match;
	45
	46	match = (val == *addr) ^ pred->not;
	47
	48	return match;
	49	}
	50
	51	static int filter_pred_16(struct filter_pred pred, void event)
	52	{
	53	u16 addr = (u16 )(event + pred->offset);
	54	u16 val = (u16)pred->val;
	55	int match;
	56
	57	match = (val == *addr) ^ pred->not;
	58
	59	return match;
	60	}
	61
	62	static int filter_pred_8(struct filter_pred pred, void event)
	63	{
	64	u8 addr = (u8 )(event + pred->offset);
	65	u8 val = (u8)pred->val;
	66	int match;
	67
	68	match = (val == *addr) ^ pred->not;
	69
	70	return match;
	71	}
	72
	73	static int filter_pred_string(struct filter_pred pred, void event)
	74	{
	75	char addr = (char )(event + pred->offset);
	76	int cmp, match;
	77
	78	cmp = strncmp(addr, pred->str_val, pred->str_len);
	79
	80	match = (!cmp) ^ pred->not;
	81
	82	return match;
	83	}
	84
0a19e53c TZ	85	static int filter_pred_none(struct filter_pred pred, void event)
	86	{
	87	return 0;
	88	}
	89
7ce7e424 TZ	90	/* return 1 if event matches, 0 otherwise (discard) */
	91	int filter_match_preds(struct ftrace_event_call call, void rec)
	92	{
	93	int i, matched, and_failed = 0;
	94	struct filter_pred *pred;
	95
0a19e53c TZ	96	for (i = 0; i < call->n_preds; i++) {
	97	pred = call->preds[i];
	98	if (and_failed && !pred->or)
	99	continue;
	100	matched = pred->fn(pred, rec);
	101	if (!matched && !pred->or) {
	102	and_failed = 1;
	103	continue;
	104	} else if (matched && pred->or)
	105	return 1;
7ce7e424 TZ	106	}
	107
	108	if (and_failed)
	109	return 0;
	110
	111	return 1;
	112	}
17c873ec	113	EXPORT_SYMBOL_GPL(filter_match_preds);
7ce7e424	114
0a19e53c TZ	115	void filter_print_preds(struct filter_pred **preds, int n_preds,
0a19e53c TZ	116	struct trace_seq *s)
7ce7e424	117	{
7ce7e424 TZ	118	char *field_name;
	119	struct filter_pred *pred;
	120	int i;
	121
0a19e53c	122	if (!n_preds) {
4bda2d51 TZ	123	trace_seq_printf(s, "none\n");
4bda2d51 TZ	124	return;
7ce7e424 TZ	125	}
7ce7e424 TZ	126
0a19e53c TZ	127	for (i = 0; i < n_preds; i++) {
	128	pred = preds[i];
	129	field_name = pred->field_name;
	130	if (i)
	131	trace_seq_printf(s, pred->or ? "\|\| " : "&& ");
	132	trace_seq_printf(s, "%s ", field_name);
	133	trace_seq_printf(s, pred->not ? "!= " : "== ");
	134	if (pred->str_len)
	135	trace_seq_printf(s, "%s\n", pred->str_val);
	136	else
	137	trace_seq_printf(s, "%llu\n", pred->val);
7ce7e424	138	}
7ce7e424 TZ	139	}
	140
	141	static struct ftrace_event_field *
	142	find_event_field(struct ftrace_event_call call, char name)
	143	{
1fc2d5c1	144	struct ftrace_event_field *field;
7ce7e424	145
1fc2d5c1	146	list_for_each_entry(field, &call->fields, link) {
7ce7e424 TZ	147	if (!strcmp(field->name, name))
	148	return field;
	149	}
	150
	151	return NULL;
	152	}
	153
	154	void filter_free_pred(struct filter_pred *pred)
	155	{
	156	if (!pred)
	157	return;
	158
	159	kfree(pred->field_name);
7ce7e424 TZ	160	kfree(pred);
	161	}
	162
0a19e53c TZ	163	static void filter_clear_pred(struct filter_pred *pred)
	164	{
	165	kfree(pred->field_name);
	166	pred->field_name = NULL;
	167	pred->str_len = 0;
	168	}
	169
	170	static int filter_set_pred(struct filter_pred *dest,
	171	struct filter_pred *src,
	172	filter_pred_fn_t fn)
	173	{
	174	dest = src;
	175	dest->field_name = kstrdup(src->field_name, GFP_KERNEL);
	176	if (!dest->field_name)
	177	return -ENOMEM;
	178	dest->fn = fn;
	179
	180	return 0;
	181	}
	182
	183	void filter_disable_preds(struct ftrace_event_call *call)
7ce7e424 TZ	184	{
	185	int i;
	186
0a19e53c TZ	187	call->n_preds = 0;
	188
	189	for (i = 0; i < MAX_FILTER_PRED; i++)
	190	call->preds[i]->fn = filter_pred_none;
	191	}
	192
	193	int init_preds(struct ftrace_event_call *call)
	194	{
	195	struct filter_pred *pred;
	196	int i;
	197
	198	call->n_preds = 0;
	199
	200	call->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
	201	if (!call->preds)
	202	return -ENOMEM;
	203
	204	for (i = 0; i < MAX_FILTER_PRED; i++) {
	205	pred = kzalloc(sizeof(*pred), GFP_KERNEL);
	206	if (!pred)
	207	goto oom;
	208	pred->fn = filter_pred_none;
	209	call->preds[i] = pred;
	210	}
	211
	212	return 0;
	213
	214	oom:
	215	for (i = 0; i < MAX_FILTER_PRED; i++) {
	216	if (call->preds[i])
7ce7e424	217	filter_free_pred(call->preds[i]);
7ce7e424	218	}
0a19e53c TZ	219	kfree(call->preds);
	220	call->preds = NULL;
	221
	222	return -ENOMEM;
7ce7e424	223	}
17c873ec	224	EXPORT_SYMBOL_GPL(init_preds);
7ce7e424	225
cfb180f3 TZ	226	void filter_free_subsystem_preds(struct event_subsystem *system)
cfb180f3 TZ	227	{
a59fd602	228	struct ftrace_event_call *call;
cfb180f3 TZ	229	int i;
cfb180f3 TZ	230
0a19e53c TZ	231	if (system->n_preds) {
0a19e53c TZ	232	for (i = 0; i < system->n_preds; i++)
cfb180f3 TZ	233	filter_free_pred(system->preds[i]);
	234	kfree(system->preds);
	235	system->preds = NULL;
0a19e53c	236	system->n_preds = 0;
cfb180f3 TZ	237	}
cfb180f3 TZ	238
a59fd602	239	list_for_each_entry(call, &ftrace_events, list) {
e1112b4d	240	if (!call->define_fields)
cfb180f3 TZ	241	continue;
	242
	243	if (!strcmp(call->system, system->name))
0a19e53c	244	filter_disable_preds(call);
cfb180f3 TZ	245	}
	246	}
	247
7ce7e424	248	static int __filter_add_pred(struct ftrace_event_call *call,
0a19e53c TZ	249	struct filter_pred *pred,
0a19e53c TZ	250	filter_pred_fn_t fn)
7ce7e424	251	{
0a19e53c	252	int idx, err;
7ce7e424	253
0a19e53c TZ	254	if (call->n_preds && !pred->compound)
0a19e53c TZ	255	filter_disable_preds(call);
7ce7e424	256
0a19e53c TZ	257	if (call->n_preds == MAX_FILTER_PRED)
0a19e53c TZ	258	return -ENOSPC;
7ce7e424	259
0a19e53c TZ	260	idx = call->n_preds;
	261	filter_clear_pred(call->preds[idx]);
	262	err = filter_set_pred(call->preds[idx], pred, fn);
	263	if (err)
	264	return err;
	265
	266	call->n_preds++;
7ce7e424	267
0a19e53c	268	return 0;
7ce7e424 TZ	269	}
	270
	271	static int is_string_field(const char *type)
	272	{
	273	if (strchr(type, '[') && strstr(type, "char"))
	274	return 1;
	275
	276	return 0;
	277	}
	278
	279	int filter_add_pred(struct ftrace_event_call call, struct filter_pred pred)
	280	{
	281	struct ftrace_event_field *field;
0a19e53c	282	filter_pred_fn_t fn;
7ce7e424 TZ	283
	284	field = find_event_field(call, pred->field_name);
	285	if (!field)
	286	return -EINVAL;
	287
0a19e53c	288	pred->fn = filter_pred_none;
7ce7e424 TZ	289	pred->offset = field->offset;
	290
	291	if (is_string_field(field->type)) {
0a19e53c	292	if (!pred->str_len)
9f58a159	293	return -EINVAL;
0a19e53c	294	fn = filter_pred_string;
7ce7e424	295	pred->str_len = field->size;
0a19e53c	296	return __filter_add_pred(call, pred, fn);
9f58a159	297	} else {
0a19e53c	298	if (pred->str_len)
9f58a159	299	return -EINVAL;
7ce7e424 TZ	300	}
	301
	302	switch (field->size) {
	303	case 8:
0a19e53c	304	fn = filter_pred_64;
7ce7e424 TZ	305	break;
7ce7e424 TZ	306	case 4:
0a19e53c	307	fn = filter_pred_32;
7ce7e424 TZ	308	break;
7ce7e424 TZ	309	case 2:
0a19e53c	310	fn = filter_pred_16;
7ce7e424 TZ	311	break;
7ce7e424 TZ	312	case 1:
0a19e53c	313	fn = filter_pred_8;
7ce7e424 TZ	314	break;
	315	default:
	316	return -EINVAL;
	317	}
	318
0a19e53c	319	return __filter_add_pred(call, pred, fn);
cfb180f3 TZ	320	}
	321
	322	int filter_add_subsystem_pred(struct event_subsystem *system,
	323	struct filter_pred *pred)
	324	{
a59fd602	325	struct ftrace_event_call *call;
cfb180f3	326
0a19e53c	327	if (system->n_preds && !pred->compound)
cfb180f3 TZ	328	filter_free_subsystem_preds(system);
cfb180f3 TZ	329
0a19e53c	330	if (!system->n_preds) {
cfb180f3 TZ	331	system->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
	332	GFP_KERNEL);
	333	if (!system->preds)
	334	return -ENOMEM;
	335	}
	336
0a19e53c	337	if (system->n_preds == MAX_FILTER_PRED)
44e9c8b7	338	return -ENOSPC;
c4cff064	339
0a19e53c TZ	340	system->preds[system->n_preds] = pred;
0a19e53c TZ	341
a59fd602	342	list_for_each_entry(call, &ftrace_events, list) {
c4cff064 TZ	343	int err;
c4cff064 TZ	344
e1112b4d	345	if (!call->define_fields)
cfb180f3 TZ	346	continue;
cfb180f3 TZ	347
c4cff064 TZ	348	if (strcmp(call->system, system->name))
	349	continue;
	350
	351	if (!find_event_field(call, pred->field_name))
	352	continue;
	353
0a19e53c TZ	354	err = filter_add_pred(call, pred);
	355	if (err == -ENOMEM) {
	356	system->preds[system->n_preds] = NULL;
	357	return err;
	358	}
cfb180f3 TZ	359	}
cfb180f3 TZ	360
0a19e53c	361	system->n_preds++;
c4cff064	362
0a19e53c	363	return 0;
cfb180f3 TZ	364	}
cfb180f3 TZ	365
7ce7e424 TZ	366	int filter_parse(char *pbuf, struct filter_pred pred)
	367	{
	368	char tmp, tok, *val_str = NULL;
	369	int tok_n = 0;
	370
	371	/* field ==/!= number, or/and field ==/!= number, number */
	372	while ((tok = strsep(pbuf, " \n"))) {
	373	if (tok_n == 0) {
	374	if (!strcmp(tok, "0")) {
	375	pred->clear = 1;
	376	return 0;
	377	} else if (!strcmp(tok, "&&")) {
	378	pred->or = 0;
	379	pred->compound = 1;
	380	} else if (!strcmp(tok, "\|\|")) {
	381	pred->or = 1;
	382	pred->compound = 1;
	383	} else
	384	pred->field_name = tok;
	385	tok_n = 1;
	386	continue;
	387	}
	388	if (tok_n == 1) {
	389	if (!pred->field_name)
	390	pred->field_name = tok;
	391	else if (!strcmp(tok, "!="))
	392	pred->not = 1;
	393	else if (!strcmp(tok, "=="))
	394	pred->not = 0;
	395	else {
	396	pred->field_name = NULL;
	397	return -EINVAL;
	398	}
	399	tok_n = 2;
	400	continue;
	401	}
	402	if (tok_n == 2) {
	403	if (pred->compound) {
	404	if (!strcmp(tok, "!="))
	405	pred->not = 1;
	406	else if (!strcmp(tok, "=="))
	407	pred->not = 0;
	408	else {
	409	pred->field_name = NULL;
	410	return -EINVAL;
	411	}
	412	} else {
	413	val_str = tok;
	414	break; /* done */
	415	}
	416	tok_n = 3;
	417	continue;
	418	}
	419	if (tok_n == 3) {
	420	val_str = tok;
	421	break; /* done */
	422	}
	423	}
	424
0a19e53c TZ	425	if (!val_str \|\| !strlen(val_str)
0a19e53c TZ	426	\|\| strlen(val_str) >= MAX_FILTER_STR_VAL) {
bcabd91c LZ	427	pred->field_name = NULL;
	428	return -EINVAL;
	429	}
	430
7ce7e424 TZ	431	pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
	432	if (!pred->field_name)
	433	return -ENOMEM;
	434
0a19e53c	435	pred->str_len = 0;
a3e0ab05	436	pred->val = simple_strtoull(val_str, &tmp, 0);
7ce7e424	437	if (tmp == val_str) {
0a19e53c TZ	438	strncpy(pred->str_val, val_str, MAX_FILTER_STR_VAL);
	439	pred->str_len = strlen(val_str);
	440	pred->str_val[pred->str_len] = '\0';
a3e0ab05 LZ	441	} else if (*tmp != '\0')
a3e0ab05 LZ	442	return -EINVAL;
7ce7e424 TZ	443
	444	return 0;
	445	}
	446
	447