kernel/scripts/kconfig/confdata.c, branch linux-5.1.y

kconfig: fix missing choice values in auto.conf

2019-07-26T07:13:02Z

commit 8e2442a5f86e1f77b86401fce274a7f622740bc4 upstream. Since commit 00c864f8903d ("kconfig: allow all config targets to write auto.conf if missing"), Kconfig creates include/config/auto.conf in the defconfig stage when it is missing. Joonas Kylmälä reported incorrect auto.conf generation under some circumstances. To reproduce it, apply the following diff: | --- a/arch/arm/configs/imx_v6_v7_defconfig | +++ b/arch/arm/configs/imx_v6_v7_defconfig | @@ -345,14 +345,7 @@ CONFIG_USB_CONFIGFS_F_MIDI=y | CONFIG_USB_CONFIGFS_F_HID=y | CONFIG_USB_CONFIGFS_F_UVC=y | CONFIG_USB_CONFIGFS_F_PRINTER=y | -CONFIG_USB_ZERO=m | -CONFIG_USB_AUDIO=m | -CONFIG_USB_ETH=m | -CONFIG_USB_G_NCM=m | -CONFIG_USB_GADGETFS=m | -CONFIG_USB_FUNCTIONFS=m | -CONFIG_USB_MASS_STORAGE=m | -CONFIG_USB_G_SERIAL=m | +CONFIG_USB_FUNCTIONFS=y | CONFIG_MMC=y | CONFIG_MMC_SDHCI=y | CONFIG_MMC_SDHCI_PLTFM=y And then, run: $ make ARCH=arm mrproper imx_v6_v7_defconfig You will see CONFIG_USB_FUNCTIONFS=y is correctly contained in the .config, but not in the auto.conf. Please note drivers/usb/gadget/legacy/Kconfig is included from a choice block in drivers/usb/gadget/Kconfig. So USB_FUNCTIONFS is a choice value. This is probably a similar situation described in commit beaaddb62540 ("kconfig: tests: test defconfig when two choices interact"). When sym_calc_choice() is called, the choice symbol forgets the SYMBOL_DEF_USER unless all of its choice values are explicitly set by the user. The choice symbol is given just one chance to recall it because set_all_choice_values() is called if SYMBOL_NEED_SET_CHOICE_VALUES is set. When sym_calc_choice() is called again, the choice symbol forgets it forever, since SYMBOL_NEED_SET_CHOICE_VALUES is a one-time aid. Hence, we cannot call sym_clear_all_valid() again and again. It is crazy to repeat set and unset of internal flags. However, we cannot simply get rid of "sym->flags &= flags | ~SYMBOL_DEF_USER;" Doing so would re-introduce the problem solved by commit 5d09598d488f ("kconfig: fix new choices being skipped upon config update"). To work around the issue, conf_write_autoconf() stopped calling sym_clear_all_valid(). conf_write() must be changed accordingly. Currently, it clears SYMBOL_WRITE after the symbol is written into the .config file. This is needed to prevent it from writing the same symbol multiple times in case the symbol is declared in two or more locations. I added the new flag SYMBOL_WRITTEN, to track the symbols that have been written. Anyway, this is a cheesy workaround in order to suppress the issue as far as defconfig is concerned. Handling of choices is totally broken. sym_clear_all_valid() is called every time a user touches a symbol from the GUI interface. To reproduce it, just add a new symbol drivers/usb/gadget/legacy/Kconfig, then touch around unrelated symbols from menuconfig. USB_FUNCTIONFS will disappear from the .config file. I added the Fixes tag since it is more fatal than before. But, this has been broken since long long time before, and still it is. We should take a closer look to fix this correctly somehow. Fixes: 00c864f8903d ("kconfig: allow all config targets to write auto.conf if missing") Cc: linux-stable # 4.19+ Reported-by: Joonas Kylmälä Signed-off-by: Masahiro Yamada Tested-by: Joonas Kylmälä Signed-off-by: Greg Kroah-Hartman

kconfig: split some C files out of zconf.y

2018-12-28T13:22:38Z

I want to compile each C file independently instead of including all of them from zconf.y. Split out confdata.c, expr.c, symbol.c, and preprocess.c . These are low-hanging fruits. Signed-off-by: Masahiro Yamada

kconfig: convert to SPDX License Identifier

2018-12-28T13:22:28Z

All files in lxdialog/ are licensed under GPL-2.0+, and the rest are under GPL-2.0. I added GPL-2.0 tags to test scripts in tests/. Documentation/process/license-rules.rst does not suggest anything about the flex/bison files. Because flex does not accept the C++ comment style at the very top of a file, I used the C style for zconf.l, and so for zconf.y for consistency. Signed-off-by: Masahiro Yamada

kconfig: remove S_OTHER symbol type and correct dependency tracking

2018-12-08T01:42:41Z

The S_OTHER type could be set only when conf_read_simple() is reading include/config/auto.conf file. For example, CONFIG_FOO=y exists in include/config/auto.conf but it is missing from the currently parsed Kconfig files, sym_lookup() allocates a new symbol, and sets its type to S_OTHER. Strangely, it will be set to S_STRING by conf_set_sym_val() a few lines below while it is obviously bool or tristate type. On the other hand, when CONFIG_BAR="bar" is being dropped from include/config/auto.conf, its type remains S_OTHER. Because for_all_symbols() omits S_OTHER symbols, conf_touch_deps() misses to touch include/config/bar.h This behavior has been a pretty mystery for me, and digging the git histroy did not help. At least, touching depfiles is broken for string type symbols. I removed S_OTHER entirely, and reimplemented it more simply. If CONFIG_FOO was visible in the previous syncconfig, but is missing now, what we want to do is quite simple; just call conf_touch_dep() to touch include/config/foo.h instead of allocating a new symbol data. Signed-off-by: Masahiro Yamada

kconfig: split out code touching a file to conf_touch_dep()

2018-12-08T01:42:30Z

conf_touch_deps() iterates over symbols, touching corresponding include/config/*.h files as needed. Split the part that touches a single file into a new helper so it can be reused. The new helper, conf_touch_dep(), takes a symbol name as a parameter, and touches the corresponding include/config/*.h file. Signed-off-by: Masahiro Yamada

kconfig: rename conf_split_config() to conf_touch_deps()

2018-12-08T01:40:52Z

According to commit 2e3646e51b2d ("kconfig: integrate split config into silentoldconfig"), this function was named after split-include tool, which used to exist in old versions of Linux. Setting aside the historical reason, rename it into a more intuitive name. This function touches timestamp files under include/config/ in order to interact with the fixdep tool. Signed-off-by: Masahiro Yamada

kconfig: remove unneeded setsym label in conf_read_simple()

2018-12-08T01:40:52Z

The two 'goto setsym' statements are reachable only when sym == NULL. The code below the 'setsym:' label does nothing when sym == NULL since there is just one if-block guarded by 'if (sym && ...)'. Hence, 'goto setsym' can be replaced with 'continue'. Signed-off-by: Masahiro Yamada

kconfig: allow all config targets to write auto.conf if missing

2018-07-25T14:25:30Z

Currently, only syncconfig creates or updates include/config/auto.conf and some other files. Other config targets create or update only the .config file. When you configure and build the kernel from a pristine source tree, any config target is followed by syncconfig in the build stage since include/config/auto.conf is missing. We are moving compiler tests from Makefile to Kconfig. It means that parsing Kconfig files will be more costly since Kconfig invokes the compiler commands internally. Thus, we want to avoid invoking Kconfig twice (one for *config to create the .config, and one for syncconfig to synchronize the auto.conf). If auto.conf does not exist, we can generate all configuration files in the first configuration stage, which will save the syncconfig in the build stage. Please note this should be done only when auto.conf is missing. If *config blindly did this, time stamp files under include/config/ would be unnecessarily touched, triggering unneeded rebuild of objects. I assume a scenario like this: 1. You have a source tree that has already been built with CONFIG_FOO disabled 2. Run "make menuconfig" to enable CONFIG_FOO 3. CONFIG_FOO turns out to be unnecessary. Run "make menuconfig" again to disable CONFIG_FOO 4. Run "make" In this case, include/config/foo.h should not be touched since there is no change in CONFIG_FOO. The sync process should be delayed until the user really attempts to build the kernel. This commit has another motivation; I want to suppress the 'No such file or directory' warning from the 'include' directive. The top-level Makefile includes auto.conf with '-include' directive, like this: ifeq ($(dot-config),1) -include include/config/auto.conf endif This looks strange because auto.conf is mandatory when dot-config is 1. I guess only the reason of using '-include' is to suppress the warning 'include/config/auto.conf: No such file or directory' when building from a clean tree. However, this has a side-effect; Make considers the files included by '-include' are optional. Hence, Make continues to build even if it fails to generate include/config/auto.conf. I will change this in the next commit, but the warning message is annoying. (At least, kbuild test robot reports it as a regression.) With this commit, Kconfig will generate all configuration files together with the .config and I guess it is a solution good enough to suppress the warning. Note: GNU Make 4.2 or later does not display the warning from the 'include' directive if include files are successfully generated. See GNU Make commit 87a5f98d248f ("[SV 102] Don't show unnecessary include file errors.") However, older GNU Make versions are still widely used. Signed-off-by: Masahiro Yamada

kconfig: create directories needed for syncconfig by itself

2018-07-25T14:25:30Z

'make syncconfig' creates some files such as include/config/auto.conf, include/generate/autoconf.h, etc. but the necessary directory creation relies on scripts/kconfig/Makefile. To make Kconfig self-contained, create directories as needed in conf_write_autoconf(). This change allows scripts/kconfig/Makefile cleanups; syncconfig can be merged into simple-targets. Signed-off-by: Masahiro Yamada

kconfig: split out useful helpers in confdata.c

2018-07-25T14:25:29Z

Split out helpers: is_present() - check if the given path exists is_dir() - check if the given path exists and it is a directory make_parent_dir() - create the parent directories of the given path These helpers will be reused in later commits. Signed-off-by: Masahiro Yamada