linux-stable/scripts/kconfig
Ulf Magnusson f77850d3fe kconfig: Clean up modules handling and fix crash
Kconfig currently doesn't handle 'm' appearing in a Kconfig file before
the modules symbol is defined (the symbol with 'option modules'). The
problem is the following code, which runs during parsing:

	/* change 'm' into 'm' && MODULES */
	if (e->left.sym == &symbol_mod)
		return expr_alloc_and(e, expr_alloc_symbol(modules_sym));

If the modules symbol has not yet been defined, modules_sym is NULL,
giving an invalid expression.

Here is a test file where both BEFORE_1 and BEFORE_2 trigger a segfault.
If the modules symbol is removed, all symbols trigger segfaults.

	config BEFORE_1
		def_tristate y if m

	if m
	config BEFORE_2
		def_tristate y
	endif

	config MODULES
		def_bool y
		option modules

	config AFTER_1
		def_tristate y if m

	if m
	config AFTER_2
		def_tristate y
	endif

Fix the issue by rewriting 'm' in menu_finalize() instead. This function
runs after parsing and is the proper place to do it. The following
existing code in conf_parse() in zconf.y ensures that the modules symbol
exists at that point:

	if (!modules_sym)
		modules_sym = sym_find( "n" );

	...

	menu_finalize(&rootmenu);

The following tests were done to ensure no functional changes for
configurations that don't reference 'm' before the modules symbol:

	- zconfdump(stdout) was run with ARCH=x86 and ARCH=arm before
	  and after the change and verified to produce identical output.
	  This function prints all symbols, choices, and menus together
	  with their properties and their dependency expressions. A
	  rewritten 'm' appears as 'm && MODULES'.

	  A small annoyance is that the assert(len != 0) in xfwrite()
	  needs to be disabled in order to use zconfdump(), because it
	  chokes on e.g. 'default ""'.

	- The Kconfiglib test suite was run to indirectly verify that
	  alldefconfig, allyesconfig, allnoconfig, and all defconfigs in
	  the kernel still generate the same final .config.

	- Valgrind was used to check for memory errors and (new) memory
	  leaks.

Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-12-15 08:21:37 +09:00
..
lxdialog License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
.gitignore Remove gperf usage from toolchain 2017-08-19 11:02:53 -07:00
check.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
conf.c kconfig: allow kconfig to handle longer path names 2015-12-10 11:06:10 +01:00
confdata.c kconfig: add unexpected data itself to warning 2016-05-10 17:20:19 +02:00
expr.c kconfig: Fix copy&paste error 2015-10-20 19:13:14 +02:00
expr.h kconfig: Document the 'symbol' struct 2017-12-07 23:46:57 +09:00
gconf.c gconfig: remove misleading parentheses around a condition 2017-03-22 02:56:33 +09:00
gconf.glade scripts/kconfig/gconf.glade Update broken web addresses. 2010-09-17 16:54:42 +02:00
images.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
kconf_id.c Remove gperf usage from toolchain 2017-08-19 11:02:53 -07:00
kxgettext.c kconfig: nuke LKC_DIRECT_LINK cruft 2011-06-06 15:32:20 -04:00
list.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
lkc.h Remove gperf usage from toolchain 2017-08-19 11:02:53 -07:00
lkc_proto.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mconf.c kconfig: Do not print status messages in make -s mode 2015-04-09 17:44:34 +02:00
menu.c kconfig: Clean up modules handling and fix crash 2017-12-15 08:21:37 +09:00
merge_config.sh kconfig/merge_config.sh: Accept a single file 2015-10-14 16:19:37 +02:00
nconf.c kconfig: fix sparse warnings in nconfig 2017-06-23 06:00:52 +09:00
nconf.gui.c kconfig: fix sparse warnings in nconfig 2017-06-23 06:00:52 +09:00
nconf.h scripts/kconfig/nconf: dynamically alloc dialog_input_result 2011-09-09 14:40:08 +02:00
POTFILES.in kconfig: gettext support for lxdialog 2008-01-28 23:14:39 +01:00
qconf.cc xconfig: fix missing suboption and help panels on first run 2016-12-11 21:40:54 +01:00
qconf.h Port xconfig to Qt5 - Source format. 2015-10-14 14:59:03 +02:00
streamline_config.pl scripts: Switch to more portable Perl shebang 2017-05-14 11:20:44 +09:00
symbol.c kconfig/symbol.c: use correct pointer type argument for sizeof 2017-11-23 23:12:02 +09:00
util.c kconfig: Remove dead code 2015-02-25 15:00:16 +01:00
zconf.l kconfig: warn of unhandled characters in Kconfig commands 2015-08-19 17:05:39 +02:00
zconf.lex.c_shipped kconfig: Regenerate shipped zconf.{hash,lex}.c files 2015-08-19 17:05:39 +02:00
zconf.tab.c_shipped Remove gperf usage from toolchain 2017-08-19 11:02:53 -07:00
zconf.y kconfig: Sync zconf.y with zconf.tab.c_shipped 2017-12-12 23:56:45 +09:00