X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Ftrace%2Ftrace_events_filter.c;h=60c2a4efad4a52aa1fe1dc173f5805f7b40a2fa9;hb=16da27a8bc7a0d050686d1b2e9efb53fab9ed226;hp=1ab20cee0e4c09a759da610393c63823f0564f1b;hpb=cfb180f3e71b2a280a254c8646a9ab1beab63f84;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 1ab20ce..60c2a4e 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -18,140 +18,478 @@
  * 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 <linux/perf_event.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
-static int filter_pred_64(struct filter_pred *pred, void *event)
+enum filter_op_ids
 {
-	u64 *addr = (u64 *)(event + pred->offset);
-	u64 val = (u64)pred->val;
-	int match;
+	OP_OR,
+	OP_AND,
+	OP_GLOB,
+	OP_NE,
+	OP_EQ,
+	OP_LT,
+	OP_LE,
+	OP_GT,
+	OP_GE,
+	OP_NONE,
+	OP_OPEN_PAREN,
+};
+
+struct filter_op {
+	int id;
+	char *string;
+	int precedence;
+};
+
+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_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,
+};
+
+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",
+};
+
+struct opstack_op {
+	int op;
+	struct list_head list;
+};
+
+struct postfix_elt {
+	int 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;
+};
+
+#define DEFINE_COMPARISON_PRED(type)					\
+static int filter_pred_##type(struct filter_pred *pred, void *event,	\
+			      int val1, int val2)			\
+{									\
+	type *addr = (type *)(event + pred->offset);			\
+	type val = (type)pred->val;					\
+	int match = 0;							\
+									\
+	switch (pred->op) {						\
+	case OP_LT:							\
+		match = (*addr < val);					\
+		break;							\
+	case OP_LE:							\
+		match = (*addr <= val);					\
+		break;							\
+	case OP_GT:							\
+		match = (*addr > val);					\
+		break;							\
+	case OP_GE:							\
+		match = (*addr >= val);					\
+		break;							\
+	default:							\
+		break;							\
+	}								\
+									\
+	return match;							\
+}
 
-	match = (val == *addr) ^ pred->not;
+#define DEFINE_EQUALITY_PRED(size)					\
+static int filter_pred_##size(struct filter_pred *pred, void *event,	\
+			      int val1, int val2)			\
+{									\
+	u##size *addr = (u##size *)(event + pred->offset);		\
+	u##size val = (u##size)pred->val;				\
+	int match;							\
+									\
+	match = (val == *addr) ^ pred->not;				\
+									\
+	return match;							\
+}
 
-	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);
+
+static int filter_pred_and(struct filter_pred *pred __attribute((unused)),
+			   void *event __attribute((unused)),
+			   int val1, int val2)
+{
+	return val1 && val2;
+}
+
+static int filter_pred_or(struct filter_pred *pred __attribute((unused)),
+			  void *event __attribute((unused)),
+			  int val1, int val2)
+{
+	return val1 || val2;
 }
 
-static int filter_pred_32(struct filter_pred *pred, void *event)
+/* Filter predicate for fixed sized arrays of characters */
+static int filter_pred_string(struct filter_pred *pred, void *event,
+			      int val1, int val2)
 {
-	u32 *addr = (u32 *)(event + pred->offset);
-	u32 val = (u32)pred->val;
-	int match;
+	char *addr = (char *)(event + pred->offset);
+	int cmp, match;
 
-	match = (val == *addr) ^ pred->not;
+	cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len);
+
+	match = cmp ^ pred->not;
 
 	return match;
 }
 
-static int filter_pred_16(struct filter_pred *pred, void *event)
+/* Filter predicate for char * pointers */
+static int filter_pred_pchar(struct filter_pred *pred, void *event,
+			     int val1, int val2)
 {
-	u16 *addr = (u16 *)(event + pred->offset);
-	u16 val = (u16)pred->val;
-	int match;
+	char **addr = (char **)(event + pred->offset);
+	int cmp, match;
+	int len = strlen(*addr) + 1;	/* including tailing '\0' */
 
-	match = (val == *addr) ^ pred->not;
+	cmp = pred->regex.match(*addr, &pred->regex, len);
+
+	match = cmp ^ pred->not;
 
 	return match;
 }
 
-static int filter_pred_8(struct filter_pred *pred, void *event)
+/*
+ * 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,
+			      int val1, int val2)
 {
-	u8 *addr = (u8 *)(event + pred->offset);
-	u8 val = (u8)pred->val;
-	int match;
+	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 = (val == *addr) ^ pred->not;
+	match = cmp ^ pred->not;
 
 	return match;
 }
 
-static int filter_pred_string(struct filter_pred *pred, void *event)
+static int filter_pred_none(struct filter_pred *pred, void *event,
+			    int val1, int val2)
 {
-	char *addr = (char *)(event + pred->offset);
-	int cmp, match;
+	return 0;
+}
+
+/* Basic regex callbacks */
+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;
+}
 
-	cmp = strncmp(addr, pred->str_val, pred->str_len);
+static int regex_match_middle(char *str, struct regex *r, int len)
+{
+	if (strnstr(str, r->pattern, len))
+		return 1;
+	return 0;
+}
 
-	match = (!cmp) ^ pred->not;
+static int regex_match_end(char *str, struct regex *r, int len)
+{
+	int strlen = len - 1;
 
-	return match;
+	if (strlen >= r->len &&
+	    memcmp(str + strlen - r->len, r->pattern, r->len) == 0)
+		return 1;
+	return 0;
 }
 
-/* return 1 if event matches, 0 otherwise (discard) */
-int filter_match_preds(struct ftrace_event_call *call, void *rec)
+/**
+ * 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 i, matched, and_failed = 0;
-	struct filter_pred *pred;
+	int type = MATCH_FULL;
+	int i;
 
-	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 (buff[0] == '!') {
+		*not = 1;
+		buff++;
+		len--;
+	} else
+		*not = 0;
+
+	*search = buff;
+
+	for (i = 0; i < len; i++) {
+		if (buff[i] == '*') {
+			if (!i) {
+				*search = buff + 1;
+				type = MATCH_END_ONLY;
+			} else {
+				if (type == MATCH_END_ONLY)
+					type = MATCH_MIDDLE_ONLY;
+				else
+					type = MATCH_FRONT_ONLY;
+				buff[i] = 0;
+				break;
+			}
+		}
 	}
 
-	if (and_failed)
-		return 0;
+	return type;
+}
 
-	return 1;
+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, &not);
+		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;
+	}
+
+	pred->not ^= not;
 }
 
-int filter_print_preds(struct filter_pred **preds, char *buf)
+/* return 1 if event matches, 0 otherwise (discard) */
+int filter_match_preds(struct event_filter *filter, void *rec)
 {
-	ssize_t this_len = 0;
-	char *field_name;
+	int match, top = 0, val1 = 0, val2 = 0;
+	int stack[MAX_FILTER_PRED];
 	struct filter_pred *pred;
 	int i;
 
-	if (!preds) {
-		this_len += sprintf(buf + this_len, "none\n");
-		return this_len;
+	for (i = 0; i < filter->n_preds; i++) {
+		pred = filter->preds[i];
+		if (!pred->pop_n) {
+			match = pred->fn(pred, rec, val1, val2);
+			stack[top++] = match;
+			continue;
+		}
+		if (pred->pop_n > top) {
+			WARN_ON_ONCE(1);
+			return 0;
+		}
+		val1 = stack[--top];
+		val2 = stack[--top];
+		match = pred->fn(pred, rec, val1, val2);
+		stack[top++] = match;
 	}
 
-	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 stack[--top];
+}
+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)
+{
+	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 this_len;
+	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_TEMPORARY);
+	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);
+}
+
+void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s)
+{
+	struct event_filter *filter = call->filter;
+
+	mutex_lock(&event_mutex);
+	if (filter && filter->filter_string)
+		trace_seq_printf(s, "%s\n", filter->filter_string);
+	else
+		trace_seq_printf(s, "none\n");
+	mutex_unlock(&event_mutex);
+}
+
+void print_subsystem_event_filter(struct event_subsystem *system,
+				  struct trace_seq *s)
+{
+	struct event_filter *filter = system->filter;
+
+	mutex_lock(&event_mutex);
+	if (filter && filter->filter_string)
+		trace_seq_printf(s, "%s\n", filter->filter_string);
+	else
+		trace_seq_printf(s, "none\n");
+	mutex_unlock(&event_mutex);
 }
 
 static struct ftrace_event_field *
 find_event_field(struct ftrace_event_call *call, char *name)
 {
 	struct ftrace_event_field *field;
-	struct list_head *entry, *tmp;
 
-	list_for_each_safe(entry, tmp, &call->fields) {
-		field = list_entry(entry, struct ftrace_event_field, link);
+	list_for_each_entry(field, &call->fields, link) {
 		if (!strcmp(field->name, name))
 			return field;
 	}
@@ -159,248 +497,936 @@ find_event_field(struct ftrace_event_call *call, char *name)
 	return NULL;
 }
 
-void filter_free_pred(struct filter_pred *pred)
+static 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)
+static void filter_clear_pred(struct filter_pred *pred)
+{
+	kfree(pred->field_name);
+	pred->field_name = NULL;
+	pred->regex.len = 0;
+}
+
+static int filter_set_pred(struct filter_pred *dest,
+			   struct filter_pred *src,
+			   filter_pred_fn_t fn)
+{
+	*dest = *src;
+	if (src->field_name) {
+		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;
+}
+
+static void __free_preds(struct event_filter *filter)
 {
 	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;
+	if (!filter)
+		return;
+
+	for (i = 0; i < MAX_FILTER_PRED; i++) {
+		if (filter->preds[i])
+			filter_free_pred(filter->preds[i]);
 	}
+	kfree(filter->preds);
+	kfree(filter->filter_string);
+	kfree(filter);
+}
+
+void destroy_preds(struct ftrace_event_call *call)
+{
+	__free_preds(call->filter);
+	call->filter = NULL;
+	call->filter_active = 0;
 }
 
-void filter_free_subsystem_preds(struct event_subsystem *system)
+static struct event_filter *__alloc_preds(void)
 {
-	struct ftrace_event_call *call = __start_ftrace_events;
+	struct event_filter *filter;
+	struct filter_pred *pred;
 	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;
+	filter = kzalloc(sizeof(*filter), GFP_KERNEL);
+	if (!filter)
+		return ERR_PTR(-ENOMEM);
+
+	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;
 	}
 
-	events_for_each(call) {
-		if (!call->name || !call->regfunc)
+	return filter;
+
+oom:
+	__free_preds(filter);
+	return ERR_PTR(-ENOMEM);
+}
+
+static int init_preds(struct ftrace_event_call *call)
+{
+	if (call->filter)
+		return 0;
+
+	call->filter_active = 0;
+	call->filter = __alloc_preds();
+	if (IS_ERR(call->filter))
+		return PTR_ERR(call->filter);
+
+	return 0;
+}
+
+static int init_subsystem_preds(struct event_subsystem *system)
+{
+	struct ftrace_event_call *call;
+	int err;
+
+	list_for_each_entry(call, &ftrace_events, list) {
+		if (!call->define_fields)
 			continue;
 
-		if (!strcmp(call->system, system->name))
-			filter_free_preds(call);
+		if (strcmp(call->system, system->name) != 0)
+			continue;
+
+		err = init_preds(call);
+		if (err)
+			return err;
 	}
+
+	return 0;
 }
 
-static int __filter_add_pred(struct ftrace_event_call *call,
-			     struct filter_pred *pred)
+static void filter_free_subsystem_preds(struct event_subsystem *system)
 {
-	int i;
+	struct ftrace_event_call *call;
 
-	if (call->preds && !pred->compound)
-		filter_free_preds(call);
+	list_for_each_entry(call, &ftrace_events, list) {
+		if (!call->define_fields)
+			continue;
 
-	if (!call->preds) {
-		call->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
-				      GFP_KERNEL);
-		if (!call->preds)
-			return -ENOMEM;
+		if (strcmp(call->system, system->name) != 0)
+			continue;
+
+		filter_disable_preds(call);
+		remove_filter_string(call->filter);
 	}
+}
 
-	for (i = 0; i < MAX_FILTER_PRED; i++) {
-		if (!call->preds[i]) {
-			call->preds[i] = pred;
-			return 0;
-		}
+static int filter_add_pred_fn(struct filter_parse_state *ps,
+			      struct ftrace_event_call *call,
+			      struct event_filter *filter,
+			      struct filter_pred *pred,
+			      filter_pred_fn_t fn)
+{
+	int idx, err;
+
+	if (filter->n_preds == MAX_FILTER_PRED) {
+		parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
+		return -ENOSPC;
 	}
 
-	return -ENOMEM;
+	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++;
+
+	return 0;
 }
 
-static int is_string_field(const char *type)
+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 1;
+		return FILTER_STATIC_STRING;
 
-	return 0;
+	return FILTER_OTHER;
 }
 
-int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred)
+static bool is_string_field(struct ftrace_event_field *field)
 {
-	struct ftrace_event_field *field;
+	return field->filter_type == FILTER_DYN_STRING ||
+	       field->filter_type == FILTER_STATIC_STRING ||
+	       field->filter_type == FILTER_PTR_STRING;
+}
 
-	field = find_event_field(call, pred->field_name);
-	if (!field)
-		return -EINVAL;
+static int is_legal_op(struct ftrace_event_field *field, int op)
+{
+	if (is_string_field(field) &&
+	    (op != OP_EQ && op != OP_NE && op != OP_GLOB))
+		return 0;
+	if (!is_string_field(field) && op == OP_GLOB)
+		return 0;
 
-	pred->offset = field->offset;
+	return 1;
+}
 
-	if (is_string_field(field->type)) {
-		pred->fn = filter_pred_string;
-		pred->str_len = field->size;
-		return __filter_add_pred(call, pred);
-	}
+static filter_pred_fn_t select_comparison_fn(int op, int field_size,
+					     int field_is_signed)
+{
+	filter_pred_fn_t fn = NULL;
 
-	switch (field->size) {
+	switch (field_size) {
 	case 8:
-		pred->fn = filter_pred_64;
+		if (op == OP_EQ || op == OP_NE)
+			fn = filter_pred_64;
+		else if (field_is_signed)
+			fn = filter_pred_s64;
+		else
+			fn = filter_pred_u64;
 		break;
 	case 4:
-		pred->fn = filter_pred_32;
+		if (op == OP_EQ || op == OP_NE)
+			fn = filter_pred_32;
+		else if (field_is_signed)
+			fn = filter_pred_s32;
+		else
+			fn = filter_pred_u32;
 		break;
 	case 2:
-		pred->fn = filter_pred_16;
+		if (op == OP_EQ || op == OP_NE)
+			fn = filter_pred_16;
+		else if (field_is_signed)
+			fn = filter_pred_s16;
+		else
+			fn = filter_pred_u16;
 		break;
 	case 1:
-		pred->fn = filter_pred_8;
+		if (op == OP_EQ || op == OP_NE)
+			fn = filter_pred_8;
+		else if (field_is_signed)
+			fn = filter_pred_s8;
+		else
+			fn = filter_pred_u8;
 		break;
-	default:
-		return -EINVAL;
 	}
 
-	return __filter_add_pred(call, pred);
+	return fn;
 }
 
-static struct filter_pred *copy_pred(struct filter_pred *pred)
+static int filter_add_pred(struct filter_parse_state *ps,
+			   struct ftrace_event_call *call,
+			   struct event_filter *filter,
+			   struct filter_pred *pred,
+			   bool dry_run)
 {
-	struct filter_pred *new_pred = kmalloc(sizeof(*pred), GFP_KERNEL);
-	if (!new_pred)
-		return NULL;
+	struct ftrace_event_field *field;
+	filter_pred_fn_t fn;
+	unsigned long long val;
+	int ret;
+
+	pred->fn = filter_pred_none;
+
+	if (pred->op == OP_AND) {
+		pred->pop_n = 2;
+		fn = filter_pred_and;
+		goto add_pred_fn;
+	} else if (pred->op == OP_OR) {
+		pred->pop_n = 2;
+		fn = filter_pred_or;
+		goto add_pred_fn;
+	}
+
+	field = find_event_field(call, pred->field_name);
+	if (!field) {
+		parse_error(ps, FILT_ERR_FIELD_NOT_FOUND, 0);
+		return -EINVAL;
+	}
+
+	pred->offset = field->offset;
+
+	if (!is_legal_op(field, pred->op)) {
+		parse_error(ps, FILT_ERR_ILLEGAL_FIELD_OP, 0);
+		return -EINVAL;
+	}
 
-	memcpy(new_pred, pred, sizeof(*pred));
-	if (pred->str_val) {
-		new_pred->str_val = kstrdup(pred->str_val, GFP_KERNEL);
-		new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
-		if (!new_pred->str_val) {
-			kfree(new_pred);
-			return NULL;
+	if (is_string_field(field)) {
+		filter_build_regex(pred);
+
+		if (field->filter_type == FILTER_STATIC_STRING) {
+			fn = filter_pred_string;
+			pred->regex.field_len = field->size;
+		} else if (field->filter_type == FILTER_DYN_STRING)
+			fn = filter_pred_strloc;
+		else
+			fn = filter_pred_pchar;
+	} else {
+		if (field->is_signed)
+			ret = strict_strtoll(pred->regex.pattern, 0, &val);
+		else
+			ret = strict_strtoull(pred->regex.pattern, 0, &val);
+		if (ret) {
+			parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0);
+			return -EINVAL;
+		}
+		pred->val = val;
+
+		fn = select_comparison_fn(pred->op, field->size,
+					  field->is_signed);
+		if (!fn) {
+			parse_error(ps, FILT_ERR_INVALID_OP, 0);
+			return -EINVAL;
 		}
 	}
 
-	return new_pred;
+	if (pred->op == OP_NE)
+		pred->not = 1;
+
+add_pred_fn:
+	if (!dry_run)
+		return filter_add_pred_fn(ps, call, filter, pred, fn);
+	return 0;
 }
 
-int filter_add_subsystem_pred(struct event_subsystem *system,
-			      struct filter_pred *pred)
+static void parse_init(struct filter_parse_state *ps,
+		       struct filter_op *ops,
+		       char *infix_string)
+{
+	memset(ps, '\0', sizeof(*ps));
+
+	ps->infix.string = infix_string;
+	ps->infix.cnt = strlen(infix_string);
+	ps->ops = ops;
+
+	INIT_LIST_HEAD(&ps->opstack);
+	INIT_LIST_HEAD(&ps->postfix);
+}
+
+static char infix_next(struct filter_parse_state *ps)
+{
+	ps->infix.cnt--;
+
+	return ps->infix.string[ps->infix.tail++];
+}
+
+static char infix_peek(struct filter_parse_state *ps)
+{
+	if (ps->infix.tail == strlen(ps->infix.string))
+		return 0;
+
+	return ps->infix.string[ps->infix.tail];
+}
+
+static void infix_advance(struct filter_parse_state *ps)
+{
+	ps->infix.cnt--;
+	ps->infix.tail++;
+}
+
+static inline int is_precedence_lower(struct filter_parse_state *ps,
+				      int a, int b)
+{
+	return ps->ops[a].precedence < ps->ops[b].precedence;
+}
+
+static inline int is_op_char(struct filter_parse_state *ps, char c)
 {
-	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);
+	for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
+		if (ps->ops[i].string[0] == c)
+			return 1;
+	}
 
-	if (!system->preds) {
-		system->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
-					GFP_KERNEL);
-		if (!system->preds)
-			return -ENOMEM;
+	return 0;
+}
+
+static int infix_get_op(struct filter_parse_state *ps, char firstc)
+{
+	char nextc = infix_peek(ps);
+	char opstr[3];
+	int i;
+
+	opstr[0] = firstc;
+	opstr[1] = nextc;
+	opstr[2] = '\0';
+
+	for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
+		if (!strcmp(opstr, ps->ops[i].string)) {
+			infix_advance(ps);
+			return ps->ops[i].id;
+		}
 	}
 
-	for (i = 0; i < MAX_FILTER_PRED; i++) {
-		if (!system->preds[i]) {
-			system->preds[i] = pred;
-			break;
+	opstr[1] = '\0';
+
+	for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
+		if (!strcmp(opstr, ps->ops[i].string))
+			return ps->ops[i].id;
+	}
+
+	return OP_NONE;
+}
+
+static inline void clear_operand_string(struct filter_parse_state *ps)
+{
+	memset(ps->operand.string, '\0', MAX_FILTER_STR_VAL);
+	ps->operand.tail = 0;
+}
+
+static inline int append_operand_char(struct filter_parse_state *ps, char c)
+{
+	if (ps->operand.tail == MAX_FILTER_STR_VAL - 1)
+		return -EINVAL;
+
+	ps->operand.string[ps->operand.tail++] = c;
+
+	return 0;
+}
+
+static int filter_opstack_push(struct filter_parse_state *ps, int op)
+{
+	struct opstack_op *opstack_op;
+
+	opstack_op = kmalloc(sizeof(*opstack_op), GFP_KERNEL);
+	if (!opstack_op)
+		return -ENOMEM;
+
+	opstack_op->op = op;
+	list_add(&opstack_op->list, &ps->opstack);
+
+	return 0;
+}
+
+static int filter_opstack_empty(struct filter_parse_state *ps)
+{
+	return list_empty(&ps->opstack);
+}
+
+static int filter_opstack_top(struct filter_parse_state *ps)
+{
+	struct opstack_op *opstack_op;
+
+	if (filter_opstack_empty(ps))
+		return OP_NONE;
+
+	opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list);
+
+	return opstack_op->op;
+}
+
+static int filter_opstack_pop(struct filter_parse_state *ps)
+{
+	struct opstack_op *opstack_op;
+	int op;
+
+	if (filter_opstack_empty(ps))
+		return OP_NONE;
+
+	opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list);
+	op = opstack_op->op;
+	list_del(&opstack_op->list);
+
+	kfree(opstack_op);
+
+	return op;
+}
+
+static void filter_opstack_clear(struct filter_parse_state *ps)
+{
+	while (!filter_opstack_empty(ps))
+		filter_opstack_pop(ps);
+}
+
+static char *curr_operand(struct filter_parse_state *ps)
+{
+	return ps->operand.string;
+}
+
+static int postfix_append_operand(struct filter_parse_state *ps, char *operand)
+{
+	struct postfix_elt *elt;
+
+	elt = kmalloc(sizeof(*elt), GFP_KERNEL);
+	if (!elt)
+		return -ENOMEM;
+
+	elt->op = OP_NONE;
+	elt->operand = kstrdup(operand, GFP_KERNEL);
+	if (!elt->operand) {
+		kfree(elt);
+		return -ENOMEM;
+	}
+
+	list_add_tail(&elt->list, &ps->postfix);
+
+	return 0;
+}
+
+static int postfix_append_op(struct filter_parse_state *ps, int op)
+{
+	struct postfix_elt *elt;
+
+	elt = kmalloc(sizeof(*elt), GFP_KERNEL);
+	if (!elt)
+		return -ENOMEM;
+
+	elt->op = op;
+	elt->operand = NULL;
+
+	list_add_tail(&elt->list, &ps->postfix);
+
+	return 0;
+}
+
+static void postfix_clear(struct filter_parse_state *ps)
+{
+	struct postfix_elt *elt;
+
+	while (!list_empty(&ps->postfix)) {
+		elt = list_first_entry(&ps->postfix, struct postfix_elt, list);
+		list_del(&elt->list);
+		kfree(elt->operand);
+		kfree(elt);
+	}
+}
+
+static int filter_parse(struct filter_parse_state *ps)
+{
+	int in_string = 0;
+	int op, top_op;
+	char ch;
+
+	while ((ch = infix_next(ps))) {
+		if (ch == '"') {
+			in_string ^= 1;
+			continue;
 		}
-		if (i == MAX_FILTER_PRED - 1)
+
+		if (in_string)
+			goto parse_operand;
+
+		if (isspace(ch))
+			continue;
+
+		if (is_op_char(ps, ch)) {
+			op = infix_get_op(ps, ch);
+			if (op == OP_NONE) {
+				parse_error(ps, FILT_ERR_INVALID_OP, 0);
+				return -EINVAL;
+			}
+
+			if (strlen(curr_operand(ps))) {
+				postfix_append_operand(ps, curr_operand(ps));
+				clear_operand_string(ps);
+			}
+
+			while (!filter_opstack_empty(ps)) {
+				top_op = filter_opstack_top(ps);
+				if (!is_precedence_lower(ps, top_op, op)) {
+					top_op = filter_opstack_pop(ps);
+					postfix_append_op(ps, top_op);
+					continue;
+				}
+				break;
+			}
+
+			filter_opstack_push(ps, op);
+			continue;
+		}
+
+		if (ch == '(') {
+			filter_opstack_push(ps, OP_OPEN_PAREN);
+			continue;
+		}
+
+		if (ch == ')') {
+			if (strlen(curr_operand(ps))) {
+				postfix_append_operand(ps, curr_operand(ps));
+				clear_operand_string(ps);
+			}
+
+			top_op = filter_opstack_pop(ps);
+			while (top_op != OP_NONE) {
+				if (top_op == OP_OPEN_PAREN)
+					break;
+				postfix_append_op(ps, top_op);
+				top_op = filter_opstack_pop(ps);
+			}
+			if (top_op == OP_NONE) {
+				parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0);
+				return -EINVAL;
+			}
+			continue;
+		}
+parse_operand:
+		if (append_operand_char(ps, ch)) {
+			parse_error(ps, FILT_ERR_OPERAND_TOO_LONG, 0);
 			return -EINVAL;
+		}
 	}
 
-	events_for_each(call) {
-		if (!call->name || !call->regfunc)
-			continue;
+	if (strlen(curr_operand(ps)))
+		postfix_append_operand(ps, curr_operand(ps));
 
-		if (!strcmp(call->system, system->name)) {
-			event_pred = copy_pred(pred);
-			if (event_pred)
-				filter_add_pred(call, event_pred);
+	while (!filter_opstack_empty(ps)) {
+		top_op = filter_opstack_pop(ps);
+		if (top_op == OP_NONE)
+			break;
+		if (top_op == OP_OPEN_PAREN) {
+			parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0);
+			return -EINVAL;
 		}
+		postfix_append_op(ps, top_op);
 	}
 
 	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;
+static struct filter_pred *create_pred(int op, char *operand1, char *operand2)
+{
+	struct filter_pred *pred;
+
+	pred = kzalloc(sizeof(*pred), GFP_KERNEL);
+	if (!pred)
+		return NULL;
+
+	pred->field_name = kstrdup(operand1, GFP_KERNEL);
+	if (!pred->field_name) {
+		kfree(pred);
+		return NULL;
+	}
+
+	strcpy(pred->regex.pattern, operand2);
+	pred->regex.len = strlen(pred->regex.pattern);
+
+	pred->op = op;
+
+	return pred;
+}
+
+static struct filter_pred *create_logical_pred(int op)
+{
+	struct filter_pred *pred;
+
+	pred = kzalloc(sizeof(*pred), GFP_KERNEL);
+	if (!pred)
+		return NULL;
+
+	pred->op = op;
+
+	return pred;
+}
+
+static int check_preds(struct filter_parse_state *ps)
+{
+	int n_normal_preds = 0, n_logical_preds = 0;
+	struct postfix_elt *elt;
+
+	list_for_each_entry(elt, &ps->postfix, list) {
+		if (elt->op == OP_NONE)
+			continue;
+
+		if (elt->op == OP_AND || elt->op == OP_OR) {
+			n_logical_preds++;
 			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;
+		n_normal_preds++;
+	}
+
+	if (!n_normal_preds || n_logical_preds >= n_normal_preds) {
+		parse_error(ps, FILT_ERR_INVALID_FILTER, 0);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int replace_preds(struct ftrace_event_call *call,
+			 struct event_filter *filter,
+			 struct filter_parse_state *ps,
+			 char *filter_string,
+			 bool dry_run)
+{
+	char *operand1 = NULL, *operand2 = NULL;
+	struct filter_pred *pred;
+	struct postfix_elt *elt;
+	int err;
+	int n_preds = 0;
+
+	err = check_preds(ps);
+	if (err)
+		return err;
+
+	list_for_each_entry(elt, &ps->postfix, list) {
+		if (elt->op == OP_NONE) {
+			if (!operand1)
+				operand1 = elt->operand;
+			else if (!operand2)
+				operand2 = elt->operand;
 			else {
-				pred->field_name = NULL;
+				parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0);
 				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 (n_preds++ == MAX_FILTER_PRED) {
+			parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
+			return -ENOSPC;
 		}
-		if (tok_n == 3) {
-			val_str = tok;
-			break; /* done */
+
+		if (elt->op == OP_AND || elt->op == OP_OR) {
+			pred = create_logical_pred(elt->op);
+			goto add_pred;
 		}
-	}
 
-	pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
-	if (!pred->field_name)
-		return -ENOMEM;
+		if (!operand1 || !operand2) {
+			parse_error(ps, FILT_ERR_MISSING_FIELD, 0);
+			return -EINVAL;
+		}
 
-	pred->val = simple_strtoull(val_str, &tmp, 10);
-	if (tmp == val_str) {
-		pred->str_val = kstrdup(val_str, GFP_KERNEL);
-		if (!pred->str_val)
+		pred = create_pred(elt->op, operand1, operand2);
+add_pred:
+		if (!pred)
 			return -ENOMEM;
+		err = filter_add_pred(ps, call, filter, pred, dry_run);
+		filter_free_pred(pred);
+		if (err)
+			return err;
+
+		operand1 = operand2 = NULL;
 	}
 
 	return 0;
 }
 
+static int replace_system_preds(struct event_subsystem *system,
+				struct filter_parse_state *ps,
+				char *filter_string)
+{
+	struct ftrace_event_call *call;
+	bool fail = true;
+	int err;
+
+	list_for_each_entry(call, &ftrace_events, list) {
+		struct event_filter *filter = call->filter;
+
+		if (!call->define_fields)
+			continue;
+
+		if (strcmp(call->system, system->name) != 0)
+			continue;
+
+		/* try to see if the filter can be applied */
+		err = replace_preds(call, filter, ps, filter_string, true);
+		if (err)
+			continue;
+
+		/* really apply the filter */
+		filter_disable_preds(call);
+		err = replace_preds(call, filter, ps, filter_string, false);
+		if (err)
+			filter_disable_preds(call);
+		else {
+			call->filter_active = 1;
+			replace_filter_string(filter, filter_string);
+		}
+		fail = false;
+	}
+
+	if (fail) {
+		parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
+{
+	int err;
+	struct filter_parse_state *ps;
+
+	mutex_lock(&event_mutex);
+
+	err = init_preds(call);
+	if (err)
+		goto out_unlock;
+
+	if (!strcmp(strstrip(filter_string), "0")) {
+		filter_disable_preds(call);
+		remove_filter_string(call->filter);
+		goto out_unlock;
+	}
+
+	err = -ENOMEM;
+	ps = kzalloc(sizeof(*ps), GFP_KERNEL);
+	if (!ps)
+		goto out_unlock;
+
+	filter_disable_preds(call);
+	replace_filter_string(call->filter, filter_string);
+
+	parse_init(ps, filter_ops, filter_string);
+	err = filter_parse(ps);
+	if (err) {
+		append_filter_err(ps, call->filter);
+		goto out;
+	}
+
+	err = replace_preds(call, call->filter, ps, filter_string, false);
+	if (err)
+		append_filter_err(ps, call->filter);
+	else
+		call->filter_active = 1;
+out:
+	filter_opstack_clear(ps);
+	postfix_clear(ps);
+	kfree(ps);
+out_unlock:
+	mutex_unlock(&event_mutex);
+
+	return err;
+}
+
+int apply_subsystem_event_filter(struct event_subsystem *system,
+				 char *filter_string)
+{
+	int err;
+	struct filter_parse_state *ps;
+
+	mutex_lock(&event_mutex);
+
+	err = init_subsystem_preds(system);
+	if (err)
+		goto out_unlock;
+
+	if (!strcmp(strstrip(filter_string), "0")) {
+		filter_free_subsystem_preds(system);
+		remove_filter_string(system->filter);
+		goto out_unlock;
+	}
+
+	err = -ENOMEM;
+	ps = kzalloc(sizeof(*ps), GFP_KERNEL);
+	if (!ps)
+		goto out_unlock;
+
+	replace_filter_string(system->filter, filter_string);
+
+	parse_init(ps, filter_ops, filter_string);
+	err = filter_parse(ps);
+	if (err) {
+		append_filter_err(ps, system->filter);
+		goto out;
+	}
+
+	err = replace_system_preds(system, ps, filter_string);
+	if (err)
+		append_filter_err(ps, system->filter);
+
+out:
+	filter_opstack_clear(ps);
+	postfix_clear(ps);
+	kfree(ps);
+out_unlock:
+	mutex_unlock(&event_mutex);
+
+	return err;
+}
+
+#ifdef CONFIG_EVENT_PROFILE
+
+void ftrace_profile_free_filter(struct perf_event *event)
+{
+	struct event_filter *filter = event->filter;
+
+	event->filter = NULL;
+	__free_preds(filter);
+}
+
+int ftrace_profile_set_filter(struct perf_event *event, int event_id,
+			      char *filter_str)
+{
+	int err;
+	struct event_filter *filter;
+	struct filter_parse_state *ps;
+	struct ftrace_event_call *call = NULL;
+
+	mutex_lock(&event_mutex);
+
+	list_for_each_entry(call, &ftrace_events, list) {
+		if (call->id == event_id)
+			break;
+	}
+
+	err = -EINVAL;
+	if (!call)
+		goto out_unlock;
+
+	err = -EEXIST;
+	if (event->filter)
+		goto out_unlock;
+
+	filter = __alloc_preds();
+	if (IS_ERR(filter)) {
+		err = PTR_ERR(filter);
+		goto out_unlock;
+	}
+
+	err = -ENOMEM;
+	ps = kzalloc(sizeof(*ps), GFP_KERNEL);
+	if (!ps)
+		goto free_preds;
+
+	parse_init(ps, filter_ops, filter_str);
+	err = filter_parse(ps);
+	if (err)
+		goto free_ps;
+
+	err = replace_preds(call, filter, ps, filter_str, false);
+	if (!err)
+		event->filter = filter;
+
+free_ps:
+	filter_opstack_clear(ps);
+	postfix_clear(ps);
+	kfree(ps);
+
+free_preds:
+	if (err)
+		__free_preds(filter);
+
+out_unlock:
+	mutex_unlock(&event_mutex);
+
+	return err;
+}
+
+#endif /* CONFIG_EVENT_PROFILE */