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Commit 9f4801e3 authored by Steven Rostedt's avatar Steven Rostedt
Browse files

ftrace: break up ftrace_match_records into smaller components 



Impact: clean up

ftrace_match_records does a lot of things that other features
can use. This patch breaks up ftrace_match_records and pulls
out ftrace_setup_glob and ftrace_match_record.

ftrace_setup_glob prepares a simple glob expression for use with
ftrace_match_record. ftrace_match_record compares a single record
with a glob type.

Breaking this up will allow for more features to run on individual
records.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
parent 7f24b31b

kernel/trace/ftrace.c

+75 −40
Original line number Diff line number Diff line
@@ -1053,79 +1053,114 @@ enum { 
	MATCH_END_ONLY,

};



static void

ftrace_match_records(unsigned char *buff, int len, int enable)

/*

 * (static function - no need for kernel doc)

 *

 * Pass in a buffer containing a glob 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.

 */

static int

ftrace_setup_glob(unsigned char *buff, int len, char **search, int *not)

{

	char str[KSYM_SYMBOL_LEN];

	char *search = NULL;

	struct ftrace_page *pg;

	struct dyn_ftrace *rec;

	int type = MATCH_FULL;

	unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;

	unsigned i, match = 0, search_len = 0;

	int not = 0;

	int i;



	if (buff[0] == '!') {

		not = 1;

		*not = 1;

		buff++;

		len--;

	}

	} else

		*not = 0;



	*search = buff;



	for (i = 0; i < len; i++) {

		if (buff[i] == '*') {

			if (!i) {

				search = buff + i + 1;

				*search = buff + 1;

				type = MATCH_END_ONLY;

				search_len = len - (i + 1);

			} else {

				if (type == MATCH_END_ONLY) {

				if (type == MATCH_END_ONLY)

					type = MATCH_MIDDLE_ONLY;

				} else {

					match = i;

				else

					type = MATCH_FRONT_ONLY;

				}

				buff[i] = 0;

				break;

			}

		}

	}



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);

	if (enable)

		ftrace_filtered = 1;

	do_for_each_ftrace_rec(pg, rec) {

	return type;

}



static int

ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type)

{

	char str[KSYM_SYMBOL_LEN];

	int matched = 0;

	char *ptr;



		if (rec->flags & FTRACE_FL_FAILED)

			continue;

	kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);

	switch (type) {

	case MATCH_FULL:

			if (strcmp(str, buff) == 0)

		if (strcmp(str, regex) == 0)

			matched = 1;

		break;

	case MATCH_FRONT_ONLY:

			if (memcmp(str, buff, match) == 0)

		if (strncmp(str, regex, len) == 0)

			matched = 1;

		break;

	case MATCH_MIDDLE_ONLY:

			if (strstr(str, search))

		if (strstr(str, regex))

			matched = 1;

		break;

	case MATCH_END_ONLY:

			ptr = strstr(str, search);

			if (ptr && (ptr[search_len] == 0))

		ptr = strstr(str, regex);

		if (ptr && (ptr[len] == 0))

			matched = 1;

		break;

	}

		if (matched) {



	return matched;

}



static void ftrace_match_records(char *buff, int len, int enable)

{

	char *search;

	struct ftrace_page *pg;

	struct dyn_ftrace *rec;

	int type;

	unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;

	unsigned search_len;

	int not;



	type = ftrace_setup_glob(buff, len, &search, &not);



	search_len = strlen(search);



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);

	if (enable)

		ftrace_filtered = 1;

	do_for_each_ftrace_rec(pg, rec) {



		if (rec->flags & FTRACE_FL_FAILED)

			continue;



		if (ftrace_match_record(rec, search, search_len, type)) {

			if (not)

				rec->flags &= ~flag;

			else

				rec->flags |= flag;

		}



	} while_for_each_ftrace_rec();

	spin_unlock(&ftrace_lock);

}