From 8bf116b258c286137635542a752ec68ffebd809b Mon Sep 17 00:00:00 2001 From: Ulf Magnusson Date: Sun, 8 Oct 2017 19:11:21 +0200 Subject: [PATCH] kconfig: Don't leak main menus during parsing [ Upstream commit 0724a7c32a54e3e50d28e19e30c59014f61d4e2c ] 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 Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- scripts/kconfig/zconf.y | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y index c8f396c3b190..20d9caa4be99 100644 --- a/scripts/kconfig/zconf.y +++ b/scripts/kconfig/zconf.y @@ -108,7 +108,27 @@ 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 */ @@ -351,13 +371,6 @@ 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 @@ -502,6 +515,7 @@ word_opt: /* empty */ { $$ = NULL; } void conf_parse(const char *name) { + const char *tmp; struct symbol *sym; int i; @@ -509,7 +523,6 @@ 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; @@ -519,8 +532,10 @@ 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) { -- 2.20.1