[mirror_ubuntu-artful-kernel.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)
{
	struct event_filter *filter = call->filter;
	int i, matched, and_failed = 0;
	struct filter_pred *pred;

	for (i = 0; i < filter->n_preds; i++) {
		pred = filter->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 event_filter *filter,
				 struct trace_seq *s)
{
	struct filter_pred *pred;
	char *field_name;
	int i;

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

	for (i = 0; i < filter->n_preds; i++) {
		pred = filter->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->filter, 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->filter, 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)
{
	struct event_filter *filter = call->filter;
	int i;

	call->filter_active = 0;
	filter->n_preds = 0;

	for (i = 0; i < MAX_FILTER_PRED; i++)
		filter->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 event_filter *filter;
	struct filter_pred *pred;
	int i;

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

	call->filter_active = 0;
	filter->n_preds = 0;

	filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
	if (!filter->preds)
		goto oom;

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

	return 0;

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

	return -ENOMEM;
}
EXPORT_SYMBOL_GPL(init_preds);

static void __filter_free_subsystem_preds(struct event_subsystem *system)
{
	struct event_filter *filter = system->filter;
	struct ftrace_event_call *call;
	int i;

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

	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)
{
	struct event_filter *filter = call->filter;
	int idx, err;

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

	if (filter->n_preds == MAX_FILTER_PRED)
		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;
}

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 event_filter *filter = system->filter;
	struct ftrace_event_call *call;

	mutex_lock(&filter_mutex);

	if (filter && filter->n_preds && !pred->compound) {
		__filter_free_subsystem_preds(system);
		filter = NULL;
	}

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

		if (!filter->preds) {
			kfree(system->filter);
			system->filter = NULL;
			mutex_unlock(&filter_mutex);
			return -ENOMEM;
		}
	}

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

	filter->preds[filter->n_preds] = pred;
	filter->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) {
			filter->preds[filter->n_preds] = NULL;
			filter->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	{
30e673b2	96	struct event_filter *filter = call->filter;
7ce7e424 TZ	97	int i, matched, and_failed = 0;
	98	struct filter_pred *pred;
	99
30e673b2 TZ	100	for (i = 0; i < filter->n_preds; i++) {
30e673b2 TZ	101	pred = filter->preds[i];
0a19e53c TZ	102	if (and_failed && !pred->or)
	103	continue;
	104	matched = pred->fn(pred, rec);
	105	if (!matched && !pred->or) {
	106	and_failed = 1;
	107	continue;
	108	} else if (matched && pred->or)
	109	return 1;
7ce7e424 TZ	110	}
	111
	112	if (and_failed)
	113	return 0;
	114
	115	return 1;
	116	}
17c873ec	117	EXPORT_SYMBOL_GPL(filter_match_preds);
7ce7e424	118
30e673b2	119	static void __filter_print_preds(struct event_filter *filter,
ac1adc55	120	struct trace_seq *s)
7ce7e424	121	{
7ce7e424	122	struct filter_pred *pred;
30e673b2	123	char *field_name;
7ce7e424 TZ	124	int i;
7ce7e424 TZ	125
30e673b2	126	if (!filter \|\| !filter->n_preds) {
4bda2d51 TZ	127	trace_seq_printf(s, "none\n");
4bda2d51 TZ	128	return;
7ce7e424 TZ	129	}
7ce7e424 TZ	130
30e673b2 TZ	131	for (i = 0; i < filter->n_preds; i++) {
30e673b2 TZ	132	pred = filter->preds[i];
0a19e53c TZ	133	field_name = pred->field_name;
	134	if (i)
	135	trace_seq_printf(s, pred->or ? "\|\| " : "&& ");
	136	trace_seq_printf(s, "%s ", field_name);
	137	trace_seq_printf(s, pred->not ? "!= " : "== ");
	138	if (pred->str_len)
	139	trace_seq_printf(s, "%s\n", pred->str_val);
	140	else
	141	trace_seq_printf(s, "%llu\n", pred->val);
7ce7e424	142	}
7ce7e424 TZ	143	}
7ce7e424 TZ	144
ac1adc55 TZ	145	void filter_print_preds(struct ftrace_event_call call, struct trace_seq s)
	146	{
	147	mutex_lock(&filter_mutex);
30e673b2	148	__filter_print_preds(call->filter, s);
ac1adc55 TZ	149	mutex_unlock(&filter_mutex);
	150	}
	151
	152	void filter_print_subsystem_preds(struct event_subsystem *system,
	153	struct trace_seq *s)
	154	{
	155	mutex_lock(&filter_mutex);
30e673b2	156	__filter_print_preds(system->filter, s);
ac1adc55 TZ	157	mutex_unlock(&filter_mutex);
	158	}
	159
7ce7e424 TZ	160	static struct ftrace_event_field *
	161	find_event_field(struct ftrace_event_call call, char name)
	162	{
1fc2d5c1	163	struct ftrace_event_field *field;
7ce7e424	164
1fc2d5c1	165	list_for_each_entry(field, &call->fields, link) {
7ce7e424 TZ	166	if (!strcmp(field->name, name))
	167	return field;
	168	}
	169
	170	return NULL;
	171	}
	172
	173	void filter_free_pred(struct filter_pred *pred)
	174	{
	175	if (!pred)
	176	return;
	177
	178	kfree(pred->field_name);
7ce7e424 TZ	179	kfree(pred);
	180	}
	181
0a19e53c TZ	182	static void filter_clear_pred(struct filter_pred *pred)
	183	{
	184	kfree(pred->field_name);
	185	pred->field_name = NULL;
	186	pred->str_len = 0;
	187	}
	188
	189	static int filter_set_pred(struct filter_pred *dest,
	190	struct filter_pred *src,
	191	filter_pred_fn_t fn)
	192	{
	193	dest = src;
	194	dest->field_name = kstrdup(src->field_name, GFP_KERNEL);
	195	if (!dest->field_name)
	196	return -ENOMEM;
	197	dest->fn = fn;
	198
	199	return 0;
	200	}
	201
ac1adc55	202	static void __filter_disable_preds(struct ftrace_event_call *call)
7ce7e424	203	{
30e673b2	204	struct event_filter *filter = call->filter;
7ce7e424 TZ	205	int i;
7ce7e424 TZ	206
30e673b2 TZ	207	call->filter_active = 0;
30e673b2 TZ	208	filter->n_preds = 0;
0a19e53c TZ	209
0a19e53c TZ	210	for (i = 0; i < MAX_FILTER_PRED; i++)
30e673b2	211	filter->preds[i]->fn = filter_pred_none;
0a19e53c TZ	212	}
0a19e53c TZ	213
ac1adc55 TZ	214	void filter_disable_preds(struct ftrace_event_call *call)
	215	{
	216	mutex_lock(&filter_mutex);
	217	__filter_disable_preds(call);
	218	mutex_unlock(&filter_mutex);
	219	}
	220
0a19e53c TZ	221	int init_preds(struct ftrace_event_call *call)
0a19e53c TZ	222	{
30e673b2	223	struct event_filter *filter;
0a19e53c TZ	224	struct filter_pred *pred;
	225	int i;
	226
30e673b2 TZ	227	filter = call->filter = kzalloc(sizeof(*filter), GFP_KERNEL);
30e673b2 TZ	228	if (!call->filter)
0a19e53c TZ	229	return -ENOMEM;
0a19e53c TZ	230
30e673b2 TZ	231	call->filter_active = 0;
	232	filter->n_preds = 0;
	233
	234	filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
	235	if (!filter->preds)
	236	goto oom;
	237
0a19e53c TZ	238	for (i = 0; i < MAX_FILTER_PRED; i++) {
	239	pred = kzalloc(sizeof(*pred), GFP_KERNEL);
	240	if (!pred)
	241	goto oom;
	242	pred->fn = filter_pred_none;
30e673b2	243	filter->preds[i] = pred;
0a19e53c TZ	244	}
	245
	246	return 0;
	247
	248	oom:
	249	for (i = 0; i < MAX_FILTER_PRED; i++) {
30e673b2 TZ	250	if (filter->preds[i])
30e673b2 TZ	251	filter_free_pred(filter->preds[i]);
7ce7e424	252	}
30e673b2 TZ	253	kfree(filter->preds);
	254	kfree(call->filter);
	255	call->filter = NULL;
0a19e53c TZ	256
0a19e53c TZ	257	return -ENOMEM;
7ce7e424	258	}
17c873ec	259	EXPORT_SYMBOL_GPL(init_preds);
7ce7e424	260
ac1adc55	261	static void __filter_free_subsystem_preds(struct event_subsystem *system)
cfb180f3	262	{
30e673b2	263	struct event_filter *filter = system->filter;
a59fd602	264	struct ftrace_event_call *call;
cfb180f3 TZ	265	int i;
cfb180f3 TZ	266
30e673b2 TZ	267	if (filter && filter->n_preds) {
	268	for (i = 0; i < filter->n_preds; i++)
	269	filter_free_pred(filter->preds[i]);
	270	kfree(filter->preds);
	271	kfree(filter);
	272	system->filter = NULL;
cfb180f3 TZ	273	}
cfb180f3 TZ	274
a59fd602	275	list_for_each_entry(call, &ftrace_events, list) {
e1112b4d	276	if (!call->define_fields)
cfb180f3 TZ	277	continue;
	278
	279	if (!strcmp(call->system, system->name))
ac1adc55	280	__filter_disable_preds(call);
cfb180f3 TZ	281	}
	282	}
	283
ac1adc55 TZ	284	void filter_free_subsystem_preds(struct event_subsystem *system)
	285	{
	286	mutex_lock(&filter_mutex);
	287	__filter_free_subsystem_preds(system);
	288	mutex_unlock(&filter_mutex);
	289	}
	290
	291	static int filter_add_pred_fn(struct ftrace_event_call *call,
	292	struct filter_pred *pred,
	293	filter_pred_fn_t fn)
7ce7e424	294	{
30e673b2	295	struct event_filter *filter = call->filter;
0a19e53c	296	int idx, err;
7ce7e424	297
30e673b2	298	if (filter->n_preds && !pred->compound)
ac1adc55	299	__filter_disable_preds(call);
7ce7e424	300
30e673b2	301	if (filter->n_preds == MAX_FILTER_PRED)
0a19e53c	302	return -ENOSPC;
7ce7e424	303
30e673b2 TZ	304	idx = filter->n_preds;
	305	filter_clear_pred(filter->preds[idx]);
	306	err = filter_set_pred(filter->preds[idx], pred, fn);
0a19e53c TZ	307	if (err)
	308	return err;
	309
30e673b2 TZ	310	filter->n_preds++;
30e673b2 TZ	311	call->filter_active = 1;
7ce7e424	312
0a19e53c	313	return 0;
7ce7e424 TZ	314	}
	315
	316	static int is_string_field(const char *type)
	317	{
	318	if (strchr(type, '[') && strstr(type, "char"))
	319	return 1;
	320
	321	return 0;
	322	}
	323
ac1adc55 TZ	324	static int __filter_add_pred(struct ftrace_event_call *call,
ac1adc55 TZ	325	struct filter_pred *pred)
7ce7e424 TZ	326	{
7ce7e424 TZ	327	struct ftrace_event_field *field;
0a19e53c	328	filter_pred_fn_t fn;
f66578a7	329	unsigned long long val;
7ce7e424 TZ	330
	331	field = find_event_field(call, pred->field_name);
	332	if (!field)
	333	return -EINVAL;
	334
0a19e53c	335	pred->fn = filter_pred_none;
7ce7e424 TZ	336	pred->offset = field->offset;
	337
	338	if (is_string_field(field->type)) {
0a19e53c	339	fn = filter_pred_string;
7ce7e424	340	pred->str_len = field->size;
ac1adc55	341	return filter_add_pred_fn(call, pred, fn);
9f58a159	342	} else {
f66578a7	343	if (strict_strtoull(pred->str_val, 0, &val))
9f58a159	344	return -EINVAL;
f66578a7	345	pred->val = val;
7ce7e424 TZ	346	}
	347
	348	switch (field->size) {
	349	case 8:
0a19e53c	350	fn = filter_pred_64;
7ce7e424 TZ	351	break;
7ce7e424 TZ	352	case 4:
0a19e53c	353	fn = filter_pred_32;
7ce7e424 TZ	354	break;
7ce7e424 TZ	355	case 2:
0a19e53c	356	fn = filter_pred_16;
7ce7e424 TZ	357	break;
7ce7e424 TZ	358	case 1:
0a19e53c	359	fn = filter_pred_8;
7ce7e424 TZ	360	break;
	361	default:
	362	return -EINVAL;
	363	}
	364
ac1adc55 TZ	365	return filter_add_pred_fn(call, pred, fn);
	366	}
	367
	368	int filter_add_pred(struct ftrace_event_call call, struct filter_pred pred)
	369	{
	370	int err;
	371
	372	mutex_lock(&filter_mutex);
	373	err = __filter_add_pred(call, pred);
	374	mutex_unlock(&filter_mutex);
	375
	376	return err;
cfb180f3 TZ	377	}
	378
	379	int filter_add_subsystem_pred(struct event_subsystem *system,
	380	struct filter_pred *pred)
	381	{
30e673b2	382	struct event_filter *filter = system->filter;
a59fd602	383	struct ftrace_event_call *call;
cfb180f3	384
ac1adc55 TZ	385	mutex_lock(&filter_mutex);
ac1adc55 TZ	386
30e673b2	387	if (filter && filter->n_preds && !pred->compound) {
ac1adc55	388	__filter_free_subsystem_preds(system);
30e673b2 TZ	389	filter = NULL;
30e673b2 TZ	390	}
cfb180f3	391
30e673b2 TZ	392	if (!filter) {
	393	system->filter = kzalloc(sizeof(*filter), GFP_KERNEL);
	394	if (!system->filter) {
	395	mutex_unlock(&filter_mutex);
	396	return -ENOMEM;
	397	}
	398	filter = system->filter;
	399	filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
cfb180f3	400	GFP_KERNEL);
30e673b2 TZ	401
	402	if (!filter->preds) {
	403	kfree(system->filter);
	404	system->filter = NULL;
ac1adc55	405	mutex_unlock(&filter_mutex);
cfb180f3	406	return -ENOMEM;
ac1adc55	407	}
cfb180f3 TZ	408	}
cfb180f3 TZ	409
30e673b2	410	if (filter->n_preds == MAX_FILTER_PRED) {
ac1adc55	411	mutex_unlock(&filter_mutex);
44e9c8b7	412	return -ENOSPC;
ac1adc55	413	}
c4cff064	414
30e673b2 TZ	415	filter->preds[filter->n_preds] = pred;
30e673b2 TZ	416	filter->n_preds++;
0a19e53c	417
a59fd602	418	list_for_each_entry(call, &ftrace_events, list) {
c4cff064 TZ	419	int err;
c4cff064 TZ	420
e1112b4d	421	if (!call->define_fields)
cfb180f3 TZ	422	continue;
cfb180f3 TZ	423
c4cff064 TZ	424	if (strcmp(call->system, system->name))
	425	continue;
	426
ac1adc55	427	err = __filter_add_pred(call, pred);
0a19e53c	428	if (err == -ENOMEM) {
30e673b2 TZ	429	filter->preds[filter->n_preds] = NULL;
30e673b2 TZ	430	filter->n_preds--;
ac1adc55	431	mutex_unlock(&filter_mutex);
0a19e53c TZ	432	return err;
0a19e53c TZ	433	}
cfb180f3 TZ	434	}
cfb180f3 TZ	435
ac1adc55	436	mutex_unlock(&filter_mutex);
c4cff064	437
0a19e53c	438	return 0;
cfb180f3 TZ	439	}
cfb180f3 TZ	440
f66578a7 LZ	441	/*
	442	* The filter format can be
	443	* - 0, which means remove all filter preds
	444	* - [\|\|/&&] <field> ==/!= <val>
	445	*/
7ce7e424 TZ	446	int filter_parse(char *pbuf, struct filter_pred pred)
7ce7e424 TZ	447	{
f66578a7	448	char tok, val_str = NULL;
7ce7e424 TZ	449	int tok_n = 0;
7ce7e424 TZ	450
7ce7e424 TZ	451	while ((tok = strsep(pbuf, " \n"))) {
	452	if (tok_n == 0) {
	453	if (!strcmp(tok, "0")) {
	454	pred->clear = 1;
	455	return 0;
	456	} else if (!strcmp(tok, "&&")) {
	457	pred->or = 0;
	458	pred->compound = 1;
	459	} else if (!strcmp(tok, "\|\|")) {
	460	pred->or = 1;
	461	pred->compound = 1;
	462	} else
	463	pred->field_name = tok;
	464	tok_n = 1;
	465	continue;
	466	}
	467	if (tok_n == 1) {
	468	if (!pred->field_name)
	469	pred->field_name = tok;
	470	else if (!strcmp(tok, "!="))
	471	pred->not = 1;
	472	else if (!strcmp(tok, "=="))
	473	pred->not = 0;
	474	else {
	475	pred->field_name = NULL;
	476	return -EINVAL;
	477	}
	478	tok_n = 2;
	479	continue;
	480	}
	481	if (tok_n == 2) {
	482	if (pred->compound) {
	483	if (!strcmp(tok, "!="))
	484	pred->not = 1;
	485	else if (!strcmp(tok, "=="))
	486	pred->not = 0;
	487	else {
	488	pred->field_name = NULL;
	489	return -EINVAL;
	490	}
	491	} else {
	492	val_str = tok;
	493	break; /* done */
	494	}
	495	tok_n = 3;
	496	continue;
	497	}
	498	if (tok_n == 3) {
	499	val_str = tok;
	500	break; /* done */
	501	}
	502	}
	503
0a19e53c TZ	504	if (!val_str \|\| !strlen(val_str)
0a19e53c TZ	505	\|\| strlen(val_str) >= MAX_FILTER_STR_VAL) {
bcabd91c LZ	506	pred->field_name = NULL;
	507	return -EINVAL;
	508	}
	509
f66578a7 LZ	510	strcpy(pred->str_val, val_str);
	511	pred->str_len = strlen(val_str);
	512
7ce7e424 TZ	513	pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
	514	if (!pred->field_name)
	515	return -ENOMEM;
	516
7ce7e424 TZ	517	return 0;
	518	}
	519
	520