[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 <linux/mutex.h>

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

static DEFINE_MUTEX(filter_mutex);

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);

static 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);
	}
}

void filter_print_preds(struct ftrace_event_call *call, struct trace_seq *s)
{
	mutex_lock(&filter_mutex);
	__filter_print_preds(call->preds, call->n_preds, s);
	mutex_unlock(&filter_mutex);
}

void filter_print_subsystem_preds(struct event_subsystem *system,
				  struct trace_seq *s)
{
	mutex_lock(&filter_mutex);
	__filter_print_preds(system->preds, system->n_preds, s);
	mutex_unlock(&filter_mutex);
}

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;
}

static 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;
}

void filter_disable_preds(struct ftrace_event_call *call)
{
	mutex_lock(&filter_mutex);
	__filter_disable_preds(call);
	mutex_unlock(&filter_mutex);
}

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);

static 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);
	}
}

void filter_free_subsystem_preds(struct event_subsystem *system)
{
	mutex_lock(&filter_mutex);
	__filter_free_subsystem_preds(system);
	mutex_unlock(&filter_mutex);
}

static int filter_add_pred_fn(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;
}

static int __filter_add_pred(struct ftrace_event_call *call,
			     struct filter_pred *pred)
{
	struct ftrace_event_field *field;
	filter_pred_fn_t fn;
	unsigned long long val;

	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)) {
		fn = filter_pred_string;
		pred->str_len = field->size;
		return filter_add_pred_fn(call, pred, fn);
	} else {
		if (strict_strtoull(pred->str_val, 0, &val))
			return -EINVAL;
		pred->val = val;
	}

	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_fn(call, pred, fn);
}

int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred)
{
	int err;

	mutex_lock(&filter_mutex);
	err = __filter_add_pred(call, pred);
	mutex_unlock(&filter_mutex);

	return err;
}

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

	mutex_lock(&filter_mutex);

	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) {
			mutex_unlock(&filter_mutex);
			return -ENOMEM;
		}
	}

	if (system->n_preds == MAX_FILTER_PRED) {
		mutex_unlock(&filter_mutex);
		return -ENOSPC;
	}

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

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

		if (!call->define_fields)
			continue;

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

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

	mutex_unlock(&filter_mutex);

	return 0;
}

/*
 * The filter format can be
 *   - 0, which means remove all filter preds
 *   - [||/&&] <field> ==/!= <val>
 */
int filter_parse(char **pbuf, struct filter_pred *pred)
{
	char *tok, *val_str = NULL;
	int tok_n = 0;

	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;
	}

	strcpy(pred->str_val, val_str);
	pred->str_len = strlen(val_str);

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

	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>
ac1adc55	25	#include <linux/mutex.h>
7ce7e424 TZ	26
7ce7e424 TZ	27	#include "trace.h"
4bda2d51	28	#include "trace_output.h"
7ce7e424	29
ac1adc55 TZ	30	static DEFINE_MUTEX(filter_mutex);
ac1adc55 TZ	31
7ce7e424 TZ	32	static int filter_pred_64(struct filter_pred pred, void event)
	33	{
	34	u64 addr = (u64 )(event + pred->offset);
	35	u64 val = (u64)pred->val;
	36	int match;
	37
	38	match = (val == *addr) ^ pred->not;
	39
	40	return match;
	41	}
	42
	43	static int filter_pred_32(struct filter_pred pred, void event)
	44	{
	45	u32 addr = (u32 )(event + pred->offset);
	46	u32 val = (u32)pred->val;
	47	int match;
	48
	49	match = (val == *addr) ^ pred->not;
	50
	51	return match;
	52	}
	53
	54	static int filter_pred_16(struct filter_pred pred, void event)
	55	{
	56	u16 addr = (u16 )(event + pred->offset);
	57	u16 val = (u16)pred->val;
	58	int match;
	59
	60	match = (val == *addr) ^ pred->not;
	61
	62	return match;
	63	}
	64
	65	static int filter_pred_8(struct filter_pred pred, void event)
	66	{
	67	u8 addr = (u8 )(event + pred->offset);
	68	u8 val = (u8)pred->val;
	69	int match;
	70
	71	match = (val == *addr) ^ pred->not;
	72
	73	return match;
	74	}
	75
	76	static int filter_pred_string(struct filter_pred pred, void event)
	77	{
	78	char addr = (char )(event + pred->offset);
	79	int cmp, match;
	80
	81	cmp = strncmp(addr, pred->str_val, pred->str_len);
	82
	83	match = (!cmp) ^ pred->not;
	84
	85	return match;
	86	}
	87
0a19e53c TZ	88	static int filter_pred_none(struct filter_pred pred, void event)
	89	{
	90	return 0;
	91	}
	92
7ce7e424 TZ	93	/* return 1 if event matches, 0 otherwise (discard) */
	94	int filter_match_preds(struct ftrace_event_call call, void rec)
	95	{
	96	int i, matched, and_failed = 0;
	97	struct filter_pred *pred;
	98
0a19e53c TZ	99	for (i = 0; i < call->n_preds; i++) {
	100	pred = call->preds[i];
	101	if (and_failed && !pred->or)
	102	continue;
	103	matched = pred->fn(pred, rec);
	104	if (!matched && !pred->or) {
	105	and_failed = 1;
	106	continue;
	107	} else if (matched && pred->or)
	108	return 1;
7ce7e424 TZ	109	}
	110
	111	if (and_failed)
	112	return 0;
	113
	114	return 1;
	115	}
17c873ec	116	EXPORT_SYMBOL_GPL(filter_match_preds);
7ce7e424	117
ac1adc55 TZ	118	static void __filter_print_preds(struct filter_pred **preds, int n_preds,
ac1adc55 TZ	119	struct trace_seq *s)
7ce7e424	120	{
7ce7e424 TZ	121	char *field_name;
	122	struct filter_pred *pred;
	123	int i;
	124
0a19e53c	125	if (!n_preds) {
4bda2d51 TZ	126	trace_seq_printf(s, "none\n");
4bda2d51 TZ	127	return;
7ce7e424 TZ	128	}
7ce7e424 TZ	129
0a19e53c TZ	130	for (i = 0; i < n_preds; i++) {
	131	pred = preds[i];
	132	field_name = pred->field_name;
	133	if (i)
	134	trace_seq_printf(s, pred->or ? "\|\| " : "&& ");
	135	trace_seq_printf(s, "%s ", field_name);
	136	trace_seq_printf(s, pred->not ? "!= " : "== ");
	137	if (pred->str_len)
	138	trace_seq_printf(s, "%s\n", pred->str_val);
	139	else
	140	trace_seq_printf(s, "%llu\n", pred->val);
7ce7e424	141	}
7ce7e424 TZ	142	}
7ce7e424 TZ	143
ac1adc55 TZ	144	void filter_print_preds(struct ftrace_event_call call, struct trace_seq s)
	145	{
	146	mutex_lock(&filter_mutex);
	147	__filter_print_preds(call->preds, call->n_preds, s);
	148	mutex_unlock(&filter_mutex);
	149	}
	150
	151	void filter_print_subsystem_preds(struct event_subsystem *system,
	152	struct trace_seq *s)
	153	{
	154	mutex_lock(&filter_mutex);
	155	__filter_print_preds(system->preds, system->n_preds, s);
	156	mutex_unlock(&filter_mutex);
	157	}
	158
7ce7e424 TZ	159	static struct ftrace_event_field *
	160	find_event_field(struct ftrace_event_call call, char name)
	161	{
1fc2d5c1	162	struct ftrace_event_field *field;
7ce7e424	163
1fc2d5c1	164	list_for_each_entry(field, &call->fields, link) {
7ce7e424 TZ	165	if (!strcmp(field->name, name))
	166	return field;
	167	}
	168
	169	return NULL;
	170	}
	171
	172	void filter_free_pred(struct filter_pred *pred)
	173	{
	174	if (!pred)
	175	return;
	176
	177	kfree(pred->field_name);
7ce7e424 TZ	178	kfree(pred);
	179	}
	180
0a19e53c TZ	181	static void filter_clear_pred(struct filter_pred *pred)
	182	{
	183	kfree(pred->field_name);
	184	pred->field_name = NULL;
	185	pred->str_len = 0;
	186	}
	187
	188	static int filter_set_pred(struct filter_pred *dest,
	189	struct filter_pred *src,
	190	filter_pred_fn_t fn)
	191	{
	192	dest = src;
	193	dest->field_name = kstrdup(src->field_name, GFP_KERNEL);
	194	if (!dest->field_name)
	195	return -ENOMEM;
	196	dest->fn = fn;
	197
	198	return 0;
	199	}
	200
ac1adc55	201	static void __filter_disable_preds(struct ftrace_event_call *call)
7ce7e424 TZ	202	{
	203	int i;
	204
0a19e53c TZ	205	call->n_preds = 0;
	206
	207	for (i = 0; i < MAX_FILTER_PRED; i++)
	208	call->preds[i]->fn = filter_pred_none;
	209	}
	210
ac1adc55 TZ	211	void filter_disable_preds(struct ftrace_event_call *call)
	212	{
	213	mutex_lock(&filter_mutex);
	214	__filter_disable_preds(call);
	215	mutex_unlock(&filter_mutex);
	216	}
	217
0a19e53c TZ	218	int init_preds(struct ftrace_event_call *call)
	219	{
	220	struct filter_pred *pred;
	221	int i;
	222
	223	call->n_preds = 0;
	224
	225	call->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
	226	if (!call->preds)
	227	return -ENOMEM;
	228
	229	for (i = 0; i < MAX_FILTER_PRED; i++) {
	230	pred = kzalloc(sizeof(*pred), GFP_KERNEL);
	231	if (!pred)
	232	goto oom;
	233	pred->fn = filter_pred_none;
	234	call->preds[i] = pred;
	235	}
	236
	237	return 0;
	238
	239	oom:
	240	for (i = 0; i < MAX_FILTER_PRED; i++) {
	241	if (call->preds[i])
7ce7e424	242	filter_free_pred(call->preds[i]);
7ce7e424	243	}
0a19e53c TZ	244	kfree(call->preds);
	245	call->preds = NULL;
	246
	247	return -ENOMEM;
7ce7e424	248	}
17c873ec	249	EXPORT_SYMBOL_GPL(init_preds);
7ce7e424	250
ac1adc55	251	static void __filter_free_subsystem_preds(struct event_subsystem *system)
cfb180f3	252	{
a59fd602	253	struct ftrace_event_call *call;
cfb180f3 TZ	254	int i;
cfb180f3 TZ	255
0a19e53c TZ	256	if (system->n_preds) {
0a19e53c TZ	257	for (i = 0; i < system->n_preds; i++)
cfb180f3 TZ	258	filter_free_pred(system->preds[i]);
	259	kfree(system->preds);
	260	system->preds = NULL;
0a19e53c	261	system->n_preds = 0;
cfb180f3 TZ	262	}
cfb180f3 TZ	263
a59fd602	264	list_for_each_entry(call, &ftrace_events, list) {
e1112b4d	265	if (!call->define_fields)
cfb180f3 TZ	266	continue;
	267
	268	if (!strcmp(call->system, system->name))
ac1adc55	269	__filter_disable_preds(call);
cfb180f3 TZ	270	}
	271	}
	272
ac1adc55 TZ	273	void filter_free_subsystem_preds(struct event_subsystem *system)
	274	{
	275	mutex_lock(&filter_mutex);
	276	__filter_free_subsystem_preds(system);
	277	mutex_unlock(&filter_mutex);
	278	}
	279
	280	static int filter_add_pred_fn(struct ftrace_event_call *call,
	281	struct filter_pred *pred,
	282	filter_pred_fn_t fn)
7ce7e424	283	{
0a19e53c	284	int idx, err;
7ce7e424	285
0a19e53c	286	if (call->n_preds && !pred->compound)
ac1adc55	287	__filter_disable_preds(call);
7ce7e424	288
0a19e53c TZ	289	if (call->n_preds == MAX_FILTER_PRED)
0a19e53c TZ	290	return -ENOSPC;
7ce7e424	291
0a19e53c TZ	292	idx = call->n_preds;
	293	filter_clear_pred(call->preds[idx]);
	294	err = filter_set_pred(call->preds[idx], pred, fn);
	295	if (err)
	296	return err;
	297
	298	call->n_preds++;
7ce7e424	299
0a19e53c	300	return 0;
7ce7e424 TZ	301	}
	302
	303	static int is_string_field(const char *type)
	304	{
	305	if (strchr(type, '[') && strstr(type, "char"))
	306	return 1;
	307
	308	return 0;
	309	}
	310
ac1adc55 TZ	311	static int __filter_add_pred(struct ftrace_event_call *call,
ac1adc55 TZ	312	struct filter_pred *pred)
7ce7e424 TZ	313	{
7ce7e424 TZ	314	struct ftrace_event_field *field;
0a19e53c	315	filter_pred_fn_t fn;
f66578a7	316	unsigned long long val;
7ce7e424 TZ	317
	318	field = find_event_field(call, pred->field_name);
	319	if (!field)
	320	return -EINVAL;
	321
0a19e53c	322	pred->fn = filter_pred_none;
7ce7e424 TZ	323	pred->offset = field->offset;
	324
	325	if (is_string_field(field->type)) {
0a19e53c	326	fn = filter_pred_string;
7ce7e424	327	pred->str_len = field->size;
ac1adc55	328	return filter_add_pred_fn(call, pred, fn);
9f58a159	329	} else {
f66578a7	330	if (strict_strtoull(pred->str_val, 0, &val))
9f58a159	331	return -EINVAL;
f66578a7	332	pred->val = val;
7ce7e424 TZ	333	}
	334
	335	switch (field->size) {
	336	case 8:
0a19e53c	337	fn = filter_pred_64;
7ce7e424 TZ	338	break;
7ce7e424 TZ	339	case 4:
0a19e53c	340	fn = filter_pred_32;
7ce7e424 TZ	341	break;
7ce7e424 TZ	342	case 2:
0a19e53c	343	fn = filter_pred_16;
7ce7e424 TZ	344	break;
7ce7e424 TZ	345	case 1:
0a19e53c	346	fn = filter_pred_8;
7ce7e424 TZ	347	break;
	348	default:
	349	return -EINVAL;
	350	}
	351
ac1adc55 TZ	352	return filter_add_pred_fn(call, pred, fn);
	353	}
	354
	355	int filter_add_pred(struct ftrace_event_call call, struct filter_pred pred)
	356	{
	357	int err;
	358
	359	mutex_lock(&filter_mutex);
	360	err = __filter_add_pred(call, pred);
	361	mutex_unlock(&filter_mutex);
	362
	363	return err;
cfb180f3 TZ	364	}
	365
	366	int filter_add_subsystem_pred(struct event_subsystem *system,
	367	struct filter_pred *pred)
	368	{
a59fd602	369	struct ftrace_event_call *call;
cfb180f3	370
ac1adc55 TZ	371	mutex_lock(&filter_mutex);
ac1adc55 TZ	372
0a19e53c	373	if (system->n_preds && !pred->compound)
ac1adc55	374	__filter_free_subsystem_preds(system);
cfb180f3	375
0a19e53c	376	if (!system->n_preds) {
cfb180f3 TZ	377	system->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
cfb180f3 TZ	378	GFP_KERNEL);
ac1adc55 TZ	379	if (!system->preds) {
ac1adc55 TZ	380	mutex_unlock(&filter_mutex);
cfb180f3	381	return -ENOMEM;
ac1adc55	382	}
cfb180f3 TZ	383	}
cfb180f3 TZ	384
ac1adc55 TZ	385	if (system->n_preds == MAX_FILTER_PRED) {
ac1adc55 TZ	386	mutex_unlock(&filter_mutex);
44e9c8b7	387	return -ENOSPC;
ac1adc55	388	}
c4cff064	389
0a19e53c	390	system->preds[system->n_preds] = pred;
ac1adc55	391	system->n_preds++;
0a19e53c	392
a59fd602	393	list_for_each_entry(call, &ftrace_events, list) {
c4cff064 TZ	394	int err;
c4cff064 TZ	395
e1112b4d	396	if (!call->define_fields)
cfb180f3 TZ	397	continue;
cfb180f3 TZ	398
c4cff064 TZ	399	if (strcmp(call->system, system->name))
	400	continue;
	401
ac1adc55	402	err = __filter_add_pred(call, pred);
0a19e53c TZ	403	if (err == -ENOMEM) {
0a19e53c TZ	404	system->preds[system->n_preds] = NULL;
ac1adc55 TZ	405	system->n_preds--;
ac1adc55 TZ	406	mutex_unlock(&filter_mutex);
0a19e53c TZ	407	return err;
0a19e53c TZ	408	}
cfb180f3 TZ	409	}
cfb180f3 TZ	410
ac1adc55	411	mutex_unlock(&filter_mutex);
c4cff064	412
0a19e53c	413	return 0;
cfb180f3 TZ	414	}
cfb180f3 TZ	415
f66578a7 LZ	416	/*
	417	* The filter format can be
	418	* - 0, which means remove all filter preds
	419	* - [\|\|/&&] <field> ==/!= <val>
	420	*/
7ce7e424 TZ	421	int filter_parse(char *pbuf, struct filter_pred pred)
7ce7e424 TZ	422	{
f66578a7	423	char tok, val_str = NULL;
7ce7e424 TZ	424	int tok_n = 0;
7ce7e424 TZ	425
7ce7e424 TZ	426	while ((tok = strsep(pbuf, " \n"))) {
	427	if (tok_n == 0) {
	428	if (!strcmp(tok, "0")) {
	429	pred->clear = 1;
	430	return 0;
	431	} else if (!strcmp(tok, "&&")) {
	432	pred->or = 0;
	433	pred->compound = 1;
	434	} else if (!strcmp(tok, "\|\|")) {
	435	pred->or = 1;
	436	pred->compound = 1;
	437	} else
	438	pred->field_name = tok;
	439	tok_n = 1;
	440	continue;
	441	}
	442	if (tok_n == 1) {
	443	if (!pred->field_name)
	444	pred->field_name = tok;
	445	else if (!strcmp(tok, "!="))
	446	pred->not = 1;
	447	else if (!strcmp(tok, "=="))
	448	pred->not = 0;
	449	else {
	450	pred->field_name = NULL;
	451	return -EINVAL;
	452	}
	453	tok_n = 2;
	454	continue;
	455	}
	456	if (tok_n == 2) {
	457	if (pred->compound) {
	458	if (!strcmp(tok, "!="))
	459	pred->not = 1;
	460	else if (!strcmp(tok, "=="))
	461	pred->not = 0;
	462	else {
	463	pred->field_name = NULL;
	464	return -EINVAL;
	465	}
	466	} else {
	467	val_str = tok;
	468	break; /* done */
	469	}
	470	tok_n = 3;
	471	continue;
	472	}
	473	if (tok_n == 3) {
	474	val_str = tok;
	475	break; /* done */
	476	}
	477	}
	478
0a19e53c TZ	479	if (!val_str \|\| !strlen(val_str)
0a19e53c TZ	480	\|\| strlen(val_str) >= MAX_FILTER_STR_VAL) {
bcabd91c LZ	481	pred->field_name = NULL;
	482	return -EINVAL;
	483	}
	484
f66578a7 LZ	485	strcpy(pred->str_val, val_str);
	486	pred->str_len = strlen(val_str);
	487
7ce7e424 TZ	488	pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
	489	if (!pred->field_name)
	490	return -ENOMEM;
	491
7ce7e424 TZ	492	return 0;
	493	}
	494
	495