Commit a650e02a authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

ftrace: Consolidate ftrace_location() and ftrace_text_reserved() 



Both ftrace_location() and ftrace_text_reserved() do basically the same thing.
They search to see if an address is in the ftace table (contains an address
that may change from nop to call ftrace_caller). The difference is
that ftrace_location() searches a single address, but ftrace_text_reserved()
searches a range.

This also makes the ftrace_text_reserved() faster as it now uses a bsearch()
instead of linearly searching all the addresses within a page.

Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 9644302e

kernel/trace/ftrace.c

+40 −40
Original line number Diff line number Diff line
@@ -1383,35 +1383,28 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) 


static int ftrace_cmp_recs(const void *a, const void *b)

{

	const struct dyn_ftrace *reca = a;

	const struct dyn_ftrace *recb = b;

	const struct dyn_ftrace *key = a;

	const struct dyn_ftrace *rec = b;



	if (reca->ip > recb->ip)

		return 1;

	if (reca->ip < recb->ip)

	if (key->flags < rec->ip)

		return -1;

	if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)

		return 1;

	return 0;

}



/**

 * ftrace_location - return true if the ip giving is a traced location

 * @ip: the instruction pointer to check

 *

 * Returns 1 if @ip given is a pointer to a ftrace location.

 * That is, the instruction that is either a NOP or call to

 * the function tracer. It checks the ftrace internal tables to

 * determine if the address belongs or not.

 */

int ftrace_location(unsigned long ip)

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

{

	struct ftrace_page *pg;

	struct dyn_ftrace *rec;

	struct dyn_ftrace key;



	key.ip = ip;

	key.ip = start;

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



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

		if (ip < pg->records[0].ip || ip > pg->records[pg->index - 1].ip)

		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),
@@ -1423,6 +1416,36 @@ int ftrace_location(unsigned long ip) 
	return 0;

}



/**

 * ftrace_location - return true if the ip giving is a traced location

 * @ip: the instruction pointer to check

 *

 * Returns 1 if @ip given is a pointer to a ftrace location.

 * That is, the instruction that is either a NOP or call to

 * the function tracer. It checks the ftrace internal tables to

 * determine if the address belongs or not.

 */

int ftrace_location(unsigned long ip)

{

	return ftrace_location_range(ip, ip);

}



/**

 * ftrace_text_reserved - return true if range contains an ftrace location

 * @start: start of range to search

 * @end: end of range to search (inclusive). @end points to the last byte to check.

 *

 * Returns 1 if @start and @end contains a ftrace location.

 * That is, the instruction that is either a NOP or call to

 * the function tracer. It checks the ftrace internal tables to

 * determine if the address belongs or not.

 */

int ftrace_text_reserved(void *start, void *end)

{

	return ftrace_location_range((unsigned long)start,

				     (unsigned long)end);

}



static void __ftrace_hash_rec_update(struct ftrace_ops *ops,

				     int filter_hash,

				     bool inc)
@@ -1571,29 +1594,6 @@ void ftrace_bug(int failed, unsigned long ip) 
	}

}





/* Return 1 if the address range is reserved for ftrace */

int ftrace_text_reserved(void *s, void *e)

{

	struct dyn_ftrace *rec;

	struct ftrace_page *pg;

	unsigned long start = (unsigned long)s;

	unsigned long end = (unsigned long)e;

	int i;



	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;

		for (i = 0; i < pg->index; i++) {

			rec = &pg->records[i];

			if (rec->ip <= end && rec->ip + MCOUNT_INSN_SIZE > start)

				return 1;

		}

	}

	return 0;

}



static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)

{

	unsigned long flag = 0UL;

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