kernel/linux.git/scripts/kconfig/confdata.c, branch v5.2.19

kconfig: Clear "written" flag to avoid data loss

2019-08-06T17:08:14+00:00

commit 0c5b6c28ed68becb692b43eae5e44d5aa7e160ce upstream. Prior to this commit, starting nconfig, xconfig or gconfig, and saving the .config file more than once caused data loss, where a .config file that contained only comments would be written to disk starting from the second save operation. This bug manifests itself because the SYMBOL_WRITTEN flag is never cleared after the first call to conf_write, and subsequent calls to conf_write then skip all of the configuration symbols due to the SYMBOL_WRITTEN flag being set. This commit resolves this issue by clearing the SYMBOL_WRITTEN flag from all symbols before conf_write returns. Fixes: 8e2442a5f86e ("kconfig: fix missing choice values in auto.conf") Cc: linux-stable # 4.19+ Signed-off-by: M. Vefa Bicakci Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

kconfig: fix missing choice values in auto.conf

2019-07-26T07:10:56+00:00

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: Terminate menu blocks with a comment in the generated config

2019-05-18T06:31:24+00:00

Currently menu blocks start with a pretty header but end with nothing in the generated config. So next config options stick together with the options from the menu block. Let's terminate menu blocks in the generated config with a comment and a newline if needed. Example: ... CONFIG_BPF_STREAM_PARSER=y CONFIG_NET_FLOW_LIMIT=y # # Network testing # CONFIG_NET_PKTGEN=y CONFIG_NET_DROP_MONITOR=y # end of Network testing # end of Networking options CONFIG_HAMRADIO=y ... Signed-off-by: Alexander Popov Reviewed-by: Kees Cook Signed-off-by: Masahiro Yamada

kconfig: make conf_get_autoconfig_name() static

2019-05-14T14:23:25+00:00

This is only used in confdata.c Signed-off-by: Masahiro Yamada

kconfig: use snprintf for formatting pathnames

2019-05-14T14:23:25+00:00

Valid pathnames will never exceed PATH_MAX, but these file names are unsanitized and can cause buffer overflow if set incorrectly. Use snprintf to avoid this. This was flagged during a Coverity scan of the coreboot project, which also uses kconfig for its build system. Signed-off-by: Jacob Garber Signed-off-by: Masahiro Yamada

kconfig: remove useless NULL pointer check in conf_write_dep()

2019-05-14T14:23:16+00:00

conf_write_dep() has just one caller: conf_write_dep("include/config/auto.conf.cmd"); "name" always points to a valid string. Signed-off-by: Masahiro Yamada

kconfig: make parent directories for the saved .config as needed

2019-05-10T17:16:21+00:00

With menuconfig / nconfig, users can input any file path from the "Save" menu, but it fails if the parent directory does not exist. Why not create the parent directory automatically. I think this is a user-friendly behavior. I changed the error messages in menuconfig / nconfig. "Nonexistent directory" is no longer the most likely reason of the failure. Perhaps, the user specified the existing directory, or attempted to write to the location without write permission. Signed-off-by: Masahiro Yamada

kconfig: do not write .config if the content is the same

2019-05-10T17:15:49+00:00

Kconfig updates the .config when it exits even if its content is exactly the same as before. Since its timestamp becomes newer than that of other build artifacts, additional processing is invoked, which is annoying. - syncconfig is invoked to update include/config/auto.conf, etc. - kernel/configs.o is recompiled if CONFIG_IKCONFIG is enabled, then vmlinux is relinked as well. If the .config is not changed at all, we do not have to even touch it. Just bail out showing "No change to .config". $ make allmodconfig scripts/kconfig/conf --allmodconfig Kconfig # # configuration written to .config # $ make allmodconfig scripts/kconfig/conf --allmodconfig Kconfig # # No change to .config # Reported-by: Linus Torvalds Signed-off-by: Masahiro Yamada Reviewed-by: Greg Kroah-Hartman

kconfig: do not accept a directory for configuration output

2019-05-10T17:14:27+00:00

Currently, conf_write() can be called with a directory name instead of a file name. As far as I see, this can happen for menuconfig, nconfig, gconfig. If it is given with a directory path, conf_write() kindly appends getenv("KCONFIG_CONFIG"), but this ends up with hacky dir/basename handling, and screwed up in corner-cases like "what if KCONFIG_CONFIG is an absolute path?" as discussed before: https://patchwork.kernel.org/patch/9910037/ Since conf_write() is already messed up, I'd say "do not do it". Please pass a file path all the time. If a directory path is specified for the configuration output, conf_write() will simply error out. Now that the tmp file is created in the same directory as the .config, the previously reported "what if KCONFIG_CONFIG points to a different file system?" has been solved. Signed-off-by: Masahiro Yamada Cc: Nicolas Porcel

kconfig: split some C files out of zconf.y

2018-12-28T13:22:38+00:00

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