Commit 9cb37357 authored by Zhen Lei's avatar Zhen Lei Committed by Luis Chamberlain
Browse files

livepatch: Use kallsyms_on_each_match_symbol() to improve performance 



Based on the test results of kallsyms_on_each_match_symbol() and
kallsyms_on_each_symbol(), the average performance can be improved by
more than 1500 times.

Signed-off-by: default avatarZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
parent 4dc533e0

kernel/livepatch/core.c

+19 −1
Original line number Diff line number Diff line
@@ -153,6 +153,24 @@ static int klp_find_callback(void *data, const char *name, 
	return 0;

}



static int klp_match_callback(void *data, unsigned long addr)

{

	struct klp_find_arg *args = data;



	args->addr = addr;

	args->count++;



	/*

	 * Finish the search when the symbol is found for the desired position

	 * or the position is not defined for a non-unique symbol.

	 */

	if ((args->pos && (args->count == args->pos)) ||

	    (!args->pos && (args->count > 1)))

		return 1;



	return 0;

}



static int klp_find_object_symbol(const char *objname, const char *name,

				  unsigned long sympos, unsigned long *addr)

{
@@ -167,7 +185,7 @@ static int klp_find_object_symbol(const char *objname, const char *name, 
	if (objname)

		module_kallsyms_on_each_symbol(klp_find_callback, &args);

	else

		kallsyms_on_each_symbol(klp_find_callback, &args);

		kallsyms_on_each_match_symbol(klp_match_callback, name, &args);



	/*

	 * Ensure an address was found. If sympos is 0, ensure symbol is unique;