Commit 7e16f581 authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
Browse files

ftrace: Separate out functionality from ftrace_location_range() 



Create a new function called lookup_rec() from the functionality of
ftrace_location_range(). The difference between lookup_rec() is that it
returns the record that it finds, where as ftrace_location_range() returns
only if it found a match or not.

The lookup_rec() is static, and can be used for new functionality where
ftrace needs to find a record of a specific address.

Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 714641c3

kernel/trace/ftrace.c

+23 −15
Original line number Diff line number Diff line
@@ -1541,6 +1541,26 @@ static int ftrace_cmp_recs(const void *a, const void *b) 
	return 0;

}



static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)

{

	struct ftrace_page *pg;

	struct dyn_ftrace *rec = NULL;

	struct dyn_ftrace key;



	key.ip = start;

	key.flags = end;	/* overload flags, as it is unsigned long */



	for (pg = ftrace_pages_start; pg; pg = pg->next) {

		if (end < pg->records[0].ip ||

		    start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))

			continue;

		rec = bsearch(&key, pg->records, pg->index,

			      sizeof(struct dyn_ftrace),

			      ftrace_cmp_recs);

	}

	return rec;

}



/**

 * ftrace_location_range - return the first address of a traced location

 *	if it touches the given ip range
@@ -1555,23 +1575,11 @@ static int ftrace_cmp_recs(const void *a, const void *b) 
 */

unsigned long ftrace_location_range(unsigned long start, unsigned long end)

{

	struct ftrace_page *pg;

	struct dyn_ftrace *rec;

	struct dyn_ftrace key;



	key.ip = start;

	key.flags = end;	/* overload flags, as it is unsigned long */



	for (pg = ftrace_pages_start; pg; pg = pg->next) {

		if (end < pg->records[0].ip ||

		    start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))

			continue;

		rec = bsearch(&key, pg->records, pg->index,

			      sizeof(struct dyn_ftrace),

			      ftrace_cmp_recs);

	rec = lookup_rec(start, end);

	if (rec)

		return rec->ip;

	}



	return 0;

}

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