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author | Ulf Magnusson <ulfalizer@gmail.com> | 2017-10-08 20:11:18 +0300 |
---|---|---|
committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-01-10 17:29:51 +0300 |
commit | 26e47a3c11a25cb3124facd3aae2737be6c568e4 (patch) | |
tree | 08638970d91f63777d703039c73bcd54acfc55c8 /scripts/kconfig | |
parent | 29c833061c1d8c2d1d23a62e7061561eadd76cdb (diff) | |
download | linux-26e47a3c11a25cb3124facd3aae2737be6c568e4.tar.xz |
kconfig: Don't leak symbol names during parsing
Prior to this fix, zconf.y did not free symbol names from zconf.l in
these contexts:
- After T_CONFIG ('config LEAKED')
- After T_MENUCONFIG ('menuconfig LEAKED')
- After T_SELECT ('select LEAKED')
- After T_IMPLY ('imply LEAKED')
- After T_DEFAULT in a choice ('default LEAKED')
All of these come in the form of T_WORD tokens, which always have their
associated string allocated on the heap in zconf.l and need to be freed.
Fix by introducing a new nonterminal 'nonconst_symbol' which takes a
T_WORD, fetches the symbol, and then frees the T_WORD string. The
already existing 'symbol' nonterminal works the same way but also
accepts T_WORD_QUOTE, corresponding to a constant symbol. T_WORD_QUOTE
should not be accepted in any of the contexts above, so the 'symbol'
nonterminal can't be reused here.
Fetching the symbol in 'nonconst_symbol' also removes a bunch of
sym_lookup() calls from actions.
Summary from Valgrind on 'menuconfig' (ARCH=x86) before the fix:
LEAK SUMMARY:
definitely lost: 711,571 bytes in 37,756 blocks
...
Summary after the fix:
LEAK SUMMARY:
definitely lost: 387,504 bytes in 15,545 blocks
...
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Diffstat (limited to 'scripts/kconfig')
-rw-r--r-- | scripts/kconfig/zconf.y | 36 |
1 files changed, 19 insertions, 17 deletions
diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y index 4b2cf4167415..616405b43e63 100644 --- a/scripts/kconfig/zconf.y +++ b/scripts/kconfig/zconf.y @@ -85,6 +85,7 @@ static struct menu *current_menu, *current_entry; %nonassoc T_NOT %type <string> prompt +%type <symbol> nonconst_symbol %type <symbol> symbol %type <expr> expr %type <expr> if_expr @@ -145,12 +146,11 @@ option_error: /* config/menuconfig entry */ -config_entry_start: T_CONFIG T_WORD T_EOL +config_entry_start: T_CONFIG nonconst_symbol T_EOL { - struct symbol *sym = sym_lookup($2, 0); - sym->flags |= SYMBOL_OPTIONAL; - menu_add_entry(sym); - printd(DEBUG_PARSE, "%s:%d:config %s\n", zconf_curname(), zconf_lineno(), $2); + $2->flags |= SYMBOL_OPTIONAL; + menu_add_entry($2); + printd(DEBUG_PARSE, "%s:%d:config %s\n", zconf_curname(), zconf_lineno(), $2->name); }; config_stmt: config_entry_start config_option_list @@ -159,12 +159,11 @@ config_stmt: config_entry_start config_option_list printd(DEBUG_PARSE, "%s:%d:endconfig\n", zconf_curname(), zconf_lineno()); }; -menuconfig_entry_start: T_MENUCONFIG T_WORD T_EOL +menuconfig_entry_start: T_MENUCONFIG nonconst_symbol T_EOL { - struct symbol *sym = sym_lookup($2, 0); - sym->flags |= SYMBOL_OPTIONAL; - menu_add_entry(sym); - printd(DEBUG_PARSE, "%s:%d:menuconfig %s\n", zconf_curname(), zconf_lineno(), $2); + $2->flags |= SYMBOL_OPTIONAL; + menu_add_entry($2); + printd(DEBUG_PARSE, "%s:%d:menuconfig %s\n", zconf_curname(), zconf_lineno(), $2->name); }; menuconfig_stmt: menuconfig_entry_start config_option_list @@ -211,15 +210,15 @@ config_option: T_DEFAULT expr if_expr T_EOL $1->stype); }; -config_option: T_SELECT T_WORD if_expr T_EOL +config_option: T_SELECT nonconst_symbol if_expr T_EOL { - menu_add_symbol(P_SELECT, sym_lookup($2, 0), $3); + menu_add_symbol(P_SELECT, $2, $3); printd(DEBUG_PARSE, "%s:%d:select\n", zconf_curname(), zconf_lineno()); }; -config_option: T_IMPLY T_WORD if_expr T_EOL +config_option: T_IMPLY nonconst_symbol if_expr T_EOL { - menu_add_symbol(P_IMPLY, sym_lookup($2, 0), $3); + menu_add_symbol(P_IMPLY, $2, $3); printd(DEBUG_PARSE, "%s:%d:imply\n", zconf_curname(), zconf_lineno()); }; @@ -308,10 +307,10 @@ choice_option: T_OPTIONAL T_EOL printd(DEBUG_PARSE, "%s:%d:optional\n", zconf_curname(), zconf_lineno()); }; -choice_option: T_DEFAULT T_WORD if_expr T_EOL +choice_option: T_DEFAULT nonconst_symbol if_expr T_EOL { if ($1->stype == S_UNKNOWN) { - menu_add_symbol(P_DEFAULT, sym_lookup($2, 0), $3); + menu_add_symbol(P_DEFAULT, $2, $3); printd(DEBUG_PARSE, "%s:%d:default\n", zconf_curname(), zconf_lineno()); } else @@ -491,7 +490,10 @@ expr: symbol { $$ = expr_alloc_symbol($1); } | expr T_AND expr { $$ = expr_alloc_two(E_AND, $1, $3); } ; -symbol: T_WORD { $$ = sym_lookup($1, 0); free($1); } +/* For symbol definitions, selects, etc., where quotes are not accepted */ +nonconst_symbol: T_WORD { $$ = sym_lookup($1, 0); free($1); }; + +symbol: nonconst_symbol | T_WORD_QUOTE { $$ = sym_lookup($1, SYMBOL_CONST); free($1); } ; |