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kconfig: Don't leak main menus during parsing

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If a 'mainmenu' entry appeared in the Kconfig files, two things would
leak:

	- The 'struct property' allocated for the default "Linux Kernel
	  Configuration" prompt.

	- The string for the T_WORD/T_WORD_QUOTE prompt after the
	  T_MAINMENU token, allocated on the heap in zconf.l.

To fix it, introduce a new 'no_mainmenu_stmt' nonterminal that matches
if there's no 'mainmenu' and adds the default prompt. That means the
prompt only gets allocated once regardless of whether there's a
'mainmenu' statement or not, and managing it becomes simple.

Summary from Valgrind on 'menuconfig' (ARCH=x86) before the fix:

	LEAK SUMMARY:
	   definitely lost: 344,568 bytes in 14,352 blocks
	   ...

Summary after the fix:

	LEAK SUMMARY:
	   definitely lost: 344,440 bytes in 14,350 blocks
	   ...

Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit is contained in:
Ulf Magnusson 2017-10-08 19:11:21 +02:00 committed by Masahiro Yamada
parent bc28fe1d5e
commit 0724a7c32a
1 changed files with 24 additions and 9 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

33
scripts/kconfig/zconf.y
View file

@ -109,7 +109,27 @@ static struct menu *current_menu, *current_entry;
%%
input: nl start | start;
start: mainmenu_stmt stmt_list | stmt_list;
start: mainmenu_stmt stmt_list | no_mainmenu_stmt stmt_list;
/* mainmenu entry */
mainmenu_stmt: T_MAINMENU prompt nl
{
menu_add_prompt(P_MENU, $2, NULL);
};
/* Default main menu, if there's no mainmenu entry */
no_mainmenu_stmt: /* empty */
{
/*
* Hack: Keep the main menu title on the heap so we can safely free it
* later regardless of whether it comes from the 'prompt' in
* mainmenu_stmt or here
*/
menu_add_prompt(P_MENU, strdup("Linux Kernel Configuration"), NULL);
};
stmt_list:
/* empty */
@ -352,13 +372,6 @@ if_block:
| if_block choice_stmt
;
/* mainmenu entry */
mainmenu_stmt: T_MAINMENU prompt nl
{
menu_add_prompt(P_MENU, $2, NULL);
};
/* menu entry */
menu: T_MENU prompt T_EOL
@ -507,6 +520,7 @@ word_opt: /* empty */ { $$ = NULL; }
void conf_parse(const char *name)
{
const char *tmp;
struct symbol *sym;
int i;
@ -514,7 +528,6 @@ void conf_parse(const char *name)
sym_init();
_menu_init();
rootmenu.prompt = menu_add_prompt(P_MENU, "Linux Kernel Configuration", NULL);
if (getenv("ZCONF_DEBUG"))
zconfdebug = 1;
@ -524,8 +537,10 @@ void conf_parse(const char *name)
if (!modules_sym)
modules_sym = sym_find( "n" );
tmp = rootmenu.prompt->text;
rootmenu.prompt->text = _(rootmenu.prompt->text);
rootmenu.prompt->text = sym_expand_string_value(rootmenu.prompt->text);
free((char*)tmp);
menu_finalize(&rootmenu);
for_all_symbols(i, sym) {