[mirror_ubuntu-hirsute-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 "trace.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;
}

/* 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 < MAX_FILTER_PRED; i++) {
		if (call->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;
		} else
			break;
	}

	if (and_failed)
		return 0;

	return 1;
}

int filter_print_preds(struct filter_pred **preds, char *buf)
{
	ssize_t this_len = 0;
	char *field_name;
	struct filter_pred *pred;
	int i;

	if (!preds) {
		this_len += sprintf(buf + this_len, "none\n");
		return this_len;
	}

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

	return this_len;
}

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

	list_for_each_entry_safe(field, next, &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->str_val);
	kfree(pred);
}

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

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

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

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

	events_for_each(call) {
		if (!call->name || !call->regfunc)
			continue;

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

static int __filter_add_pred(struct ftrace_event_call *call,
			     struct filter_pred *pred)
{
	int i;

	if (call->preds && !pred->compound)
		filter_free_preds(call);

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

	for (i = 0; i < MAX_FILTER_PRED; i++) {
		if (!call->preds[i]) {
			call->preds[i] = pred;
			return 0;
		}
	}

	return -ENOMEM;
}

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;

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

	pred->offset = field->offset;

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

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

	return __filter_add_pred(call, pred);
}

static struct filter_pred *copy_pred(struct filter_pred *pred)
{
	struct filter_pred *new_pred = kmalloc(sizeof(*pred), GFP_KERNEL);
	if (!new_pred)
		return NULL;

	memcpy(new_pred, pred, sizeof(*pred));

	if (pred->field_name) {
		new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
		if (!new_pred->field_name) {
			kfree(new_pred);
			return NULL;
		}
	}

	if (pred->str_val) {
		new_pred->str_val = kstrdup(pred->str_val, GFP_KERNEL);
		if (!new_pred->str_val) {
			filter_free_pred(new_pred);
			return NULL;
		}
	}

	return new_pred;
}

int filter_add_subsystem_pred(struct event_subsystem *system,
			      struct filter_pred *pred)
{
	struct ftrace_event_call *call = __start_ftrace_events;
	struct filter_pred *event_pred;
	int i;

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

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

	for (i = 0; i < MAX_FILTER_PRED; i++) {
		if (!system->preds[i]) {
			system->preds[i] = pred;
			break;
		}
	}

	if (i == MAX_FILTER_PRED)
		return -EINVAL;

	events_for_each(call) {
		int err;

		if (!call->name || !call->regfunc)
			continue;

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

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

		event_pred = copy_pred(pred);
		if (!event_pred)
			goto oom;

		err = filter_add_pred(call, event_pred);
		if (err)
			filter_free_pred(event_pred);
		if (err == -ENOMEM)
			goto oom;
	}

	return 0;

oom:
	system->preds[i] = NULL;
	return -ENOMEM;
}

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 */
		}
	}

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

	pred->val = simple_strtoull(val_str, &tmp, 10);
	if (tmp == val_str) {
		pred->str_val = kstrdup(val_str, GFP_KERNEL);
		if (!pred->str_val)
			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>
	25
	26	#include "trace.h"
	27
	28	static int filter_pred_64(struct filter_pred pred, void event)
	29	{
	30	u64 addr = (u64 )(event + pred->offset);
	31	u64 val = (u64)pred->val;
	32	int match;
	33
	34	match = (val == *addr) ^ pred->not;
	35
	36	return match;
	37	}
	38
	39	static int filter_pred_32(struct filter_pred pred, void event)
	40	{
	41	u32 addr = (u32 )(event + pred->offset);
	42	u32 val = (u32)pred->val;
	43	int match;
	44
	45	match = (val == *addr) ^ pred->not;
	46
	47	return match;
	48	}
	49
	50	static int filter_pred_16(struct filter_pred pred, void event)
	51	{
	52	u16 addr = (u16 )(event + pred->offset);
	53	u16 val = (u16)pred->val;
	54	int match;
	55
	56	match = (val == *addr) ^ pred->not;
	57
	58	return match;
	59	}
	60
	61	static int filter_pred_8(struct filter_pred pred, void event)
	62	{
	63	u8 addr = (u8 )(event + pred->offset);
	64	u8 val = (u8)pred->val;
65	int match;
66
67	match = (val == *addr) ^ pred->not;
68
69	return match;
70	}
71
72	static int filter_pred_string(struct filter_pred pred, void event)
73	{
74	char addr = (char )(event + pred->offset);
75	int cmp, match;
76
77	cmp = strncmp(addr, pred->str_val, pred->str_len);
78
79	match = (!cmp) ^ pred->not;
80
81	return match;
82	}
83
84	/* return 1 if event matches, 0 otherwise (discard) */
85	int filter_match_preds(struct ftrace_event_call call, void rec)
86	{
87	int i, matched, and_failed = 0;
88	struct filter_pred *pred;
89
90	for (i = 0; i < MAX_FILTER_PRED; i++) {
91	if (call->preds[i]) {
92	pred = call->preds[i];
93	if (and_failed && !pred->or)
94	continue;
95	matched = pred->fn(pred, rec);
96	if (!matched && !pred->or) {
97	and_failed = 1;
98	continue;
99	} else if (matched && pred->or)
100	return 1;
101	} else
102	break;
103	}
104
105	if (and_failed)
106	return 0;
107
108	return 1;
109	}
110
111	int filter_print_preds(struct filter_pred *preds, char buf)
112	{
113	ssize_t this_len = 0;
114	char *field_name;
115	struct filter_pred *pred;
116	int i;
117
118	if (!preds) {
119	this_len += sprintf(buf + this_len, "none\n");
120	return this_len;
121	}
122
123	for (i = 0; i < MAX_FILTER_PRED; i++) {
124	if (preds[i]) {
125	pred = preds[i];
126	field_name = pred->field_name;
127	if (i)
128	this_len += sprintf(buf + this_len,
129	pred->or ? "\|\| " : "&& ");
130	this_len += sprintf(buf + this_len,
131	"%s ", field_name);
132	this_len += sprintf(buf + this_len,
133	pred->not ? "!= " : "== ");
134	if (pred->str_val)
135	this_len += sprintf(buf + this_len,
136	"%s\n", pred->str_val);
137	else
138	this_len += sprintf(buf + this_len,
139	"%llu\n", pred->val);
140	} else
141	break;
142	}
143
144	return this_len;
145	}
146
147	static struct ftrace_event_field *
148	find_event_field(struct ftrace_event_call call, char name)
149	{
75c8b417	150	struct ftrace_event_field field, next;
7ce7e424	151
75c8b417	152	list_for_each_entry_safe(field, next, &call->fields, link) {
7ce7e424 TZ	153	if (!strcmp(field->name, name))
	154	return field;
	155	}
	156
	157	return NULL;
	158	}
	159
	160	void filter_free_pred(struct filter_pred *pred)
	161	{
	162	if (!pred)
	163	return;
	164
	165	kfree(pred->field_name);
	166	kfree(pred->str_val);
	167	kfree(pred);
	168	}
	169
	170	void filter_free_preds(struct ftrace_event_call *call)
	171	{
	172	int i;
	173
	174	if (call->preds) {
	175	for (i = 0; i < MAX_FILTER_PRED; i++)
	176	filter_free_pred(call->preds[i]);
	177	kfree(call->preds);
	178	call->preds = NULL;
	179	}
	180	}
	181
cfb180f3 TZ	182	void filter_free_subsystem_preds(struct event_subsystem *system)
	183	{
	184	struct ftrace_event_call *call = __start_ftrace_events;
	185	int i;
	186
	187	if (system->preds) {
	188	for (i = 0; i < MAX_FILTER_PRED; i++)
	189	filter_free_pred(system->preds[i]);
	190	kfree(system->preds);
	191	system->preds = NULL;
	192	}
	193
	194	events_for_each(call) {
	195	if (!call->name \|\| !call->regfunc)
	196	continue;
	197
	198	if (!strcmp(call->system, system->name))
	199	filter_free_preds(call);
	200	}
	201	}
	202
7ce7e424 TZ	203	static int __filter_add_pred(struct ftrace_event_call *call,
	204	struct filter_pred *pred)
	205	{
	206	int i;
	207
	208	if (call->preds && !pred->compound)
	209	filter_free_preds(call);
	210
	211	if (!call->preds) {
	212	call->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
	213	GFP_KERNEL);
	214	if (!call->preds)
	215	return -ENOMEM;
	216	}
	217
	218	for (i = 0; i < MAX_FILTER_PRED; i++) {
	219	if (!call->preds[i]) {
	220	call->preds[i] = pred;
	221	return 0;
	222	}
	223	}
	224
	225	return -ENOMEM;
	226	}
	227
	228	static int is_string_field(const char *type)
	229	{
	230	if (strchr(type, '[') && strstr(type, "char"))
	231	return 1;
	232
	233	return 0;
	234	}
	235
	236	int filter_add_pred(struct ftrace_event_call call, struct filter_pred pred)
	237	{
	238	struct ftrace_event_field *field;
	239
	240	field = find_event_field(call, pred->field_name);
	241	if (!field)
	242	return -EINVAL;
	243
	244	pred->offset = field->offset;
	245
	246	if (is_string_field(field->type)) {
	247	pred->fn = filter_pred_string;
	248	pred->str_len = field->size;
	249	return __filter_add_pred(call, pred);
	250	}
	251
	252	switch (field->size) {
	253	case 8:
	254	pred->fn = filter_pred_64;
	255	break;
	256	case 4:
	257	pred->fn = filter_pred_32;
	258	break;
	259	case 2:
	260	pred->fn = filter_pred_16;
	261	break;
	262	case 1:
	263	pred->fn = filter_pred_8;
	264	break;
	265	default:
	266	return -EINVAL;
267	}
268
269	return __filter_add_pred(call, pred);
270	}
271
cfb180f3 TZ	272	static struct filter_pred copy_pred(struct filter_pred pred)
	273	{
	274	struct filter_pred new_pred = kmalloc(sizeof(pred), GFP_KERNEL);
	275	if (!new_pred)
	276	return NULL;
	277
	278	memcpy(new_pred, pred, sizeof(*pred));
ee6cdabc TZ	279
	280	if (pred->field_name) {
	281	new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
	282	if (!new_pred->field_name) {
	283	kfree(new_pred);
	284	return NULL;
	285	}
	286	}
	287
cfb180f3 TZ	288	if (pred->str_val) {
cfb180f3 TZ	289	new_pred->str_val = kstrdup(pred->str_val, GFP_KERNEL);
cfb180f3	290	if (!new_pred->str_val) {
ee6cdabc	291	filter_free_pred(new_pred);
cfb180f3 TZ	292	return NULL;
	293	}
	294	}
	295
	296	return new_pred;
	297	}
	298
	299	int filter_add_subsystem_pred(struct event_subsystem *system,
	300	struct filter_pred *pred)
	301	{
	302	struct ftrace_event_call *call = __start_ftrace_events;
	303	struct filter_pred *event_pred;
	304	int i;
	305
	306	if (system->preds && !pred->compound)
	307	filter_free_subsystem_preds(system);
	308
	309	if (!system->preds) {
	310	system->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
	311	GFP_KERNEL);
	312	if (!system->preds)
	313	return -ENOMEM;
	314	}
	315
	316	for (i = 0; i < MAX_FILTER_PRED; i++) {
	317	if (!system->preds[i]) {
	318	system->preds[i] = pred;
	319	break;
	320	}
cfb180f3 TZ	321	}
cfb180f3 TZ	322
c4cff064 TZ	323	if (i == MAX_FILTER_PRED)
	324	return -EINVAL;
	325
cfb180f3	326	events_for_each(call) {
c4cff064 TZ	327	int err;
c4cff064 TZ	328
cfb180f3 TZ	329	if (!call->name \|\| !call->regfunc)
	330	continue;
	331
c4cff064 TZ	332	if (strcmp(call->system, system->name))
	333	continue;
	334
	335	if (!find_event_field(call, pred->field_name))
	336	continue;
	337
	338	event_pred = copy_pred(pred);
	339	if (!event_pred)
	340	goto oom;
	341
	342	err = filter_add_pred(call, event_pred);
	343	if (err)
	344	filter_free_pred(event_pred);
	345	if (err == -ENOMEM)
	346	goto oom;
cfb180f3 TZ	347	}
	348
	349	return 0;
c4cff064 TZ	350
	351	oom:
	352	system->preds[i] = NULL;
	353	return -ENOMEM;
cfb180f3 TZ	354	}
cfb180f3 TZ	355
7ce7e424 TZ	356	int filter_parse(char *pbuf, struct filter_pred pred)
	357	{
	358	char tmp, tok, *val_str = NULL;
	359	int tok_n = 0;
	360
	361	/* field ==/!= number, or/and field ==/!= number, number */
	362	while ((tok = strsep(pbuf, " \n"))) {
	363	if (tok_n == 0) {
	364	if (!strcmp(tok, "0")) {
	365	pred->clear = 1;
	366	return 0;
	367	} else if (!strcmp(tok, "&&")) {
	368	pred->or = 0;
	369	pred->compound = 1;
	370	} else if (!strcmp(tok, "\|\|")) {
	371	pred->or = 1;
	372	pred->compound = 1;
	373	} else
	374	pred->field_name = tok;
	375	tok_n = 1;
	376	continue;
	377	}
	378	if (tok_n == 1) {
	379	if (!pred->field_name)
	380	pred->field_name = tok;
	381	else if (!strcmp(tok, "!="))
	382	pred->not = 1;
	383	else if (!strcmp(tok, "=="))
	384	pred->not = 0;
	385	else {
	386	pred->field_name = NULL;
	387	return -EINVAL;
	388	}
	389	tok_n = 2;
	390	continue;
	391	}
	392	if (tok_n == 2) {
	393	if (pred->compound) {
	394	if (!strcmp(tok, "!="))
	395	pred->not = 1;
	396	else if (!strcmp(tok, "=="))
	397	pred->not = 0;
	398	else {
	399	pred->field_name = NULL;
	400	return -EINVAL;
	401	}
	402	} else {
	403	val_str = tok;
	404	break; /* done */
	405	}
	406	tok_n = 3;
	407	continue;
	408	}
	409	if (tok_n == 3) {
	410	val_str = tok;
	411	break; /* done */
	412	}
	413	}
	414
	415	pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
	416	if (!pred->field_name)
	417	return -ENOMEM;
	418
	419	pred->val = simple_strtoull(val_str, &tmp, 10);
420	if (tmp == val_str) {
421	pred->str_val = kstrdup(val_str, GFP_KERNEL);
422	if (!pred->str_val)
423	return -ENOMEM;
424	}
425
426	return 0;
427	}
428
429