--- /dev/null
+From 8e2442a5f86e1f77b86401fce274a7f622740bc4 Mon Sep 17 00:00:00 2001
+From: Masahiro Yamada <yamada.masahiro@socionext.com>
+Date: Fri, 12 Jul 2019 15:07:09 +0900
+Subject: kconfig: fix missing choice values in auto.conf
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Masahiro Yamada <yamada.masahiro@socionext.com>
+
+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 <stable@vger.kernel.org> # 4.19+
+Reported-by: Joonas Kylmälä <joonas.kylmala@iki.fi>
+Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
+Tested-by: Joonas Kylmälä <joonas.kylmala@iki.fi>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ scripts/kconfig/confdata.c | 7 +++----
+ scripts/kconfig/expr.h | 1 +
+ 2 files changed, 4 insertions(+), 4 deletions(-)
+
+--- a/scripts/kconfig/confdata.c
++++ b/scripts/kconfig/confdata.c
+@@ -871,11 +871,12 @@ int conf_write(const char *name)
+ "#\n"
+ "# %s\n"
+ "#\n", str);
+- } else if (!(sym->flags & SYMBOL_CHOICE)) {
++ } else if (!(sym->flags & SYMBOL_CHOICE) &&
++ !(sym->flags & SYMBOL_WRITTEN)) {
+ sym_calc_value(sym);
+ if (!(sym->flags & SYMBOL_WRITE))
+ goto next;
+- sym->flags &= ~SYMBOL_WRITE;
++ sym->flags |= SYMBOL_WRITTEN;
+
+ conf_write_symbol(out, sym, &kconfig_printer_cb, NULL);
+ }
+@@ -1026,8 +1027,6 @@ int conf_write_autoconf(int overwrite)
+ if (!overwrite && is_present(autoconf_name))
+ return 0;
+
+- sym_clear_all_valid();
+-
+ conf_write_dep("include/config/auto.conf.cmd");
+
+ if (conf_touch_deps())
+--- a/scripts/kconfig/expr.h
++++ b/scripts/kconfig/expr.h
+@@ -141,6 +141,7 @@ struct symbol {
+ #define SYMBOL_OPTIONAL 0x0100 /* choice is optional - values can be 'n' */
+ #define SYMBOL_WRITE 0x0200 /* write symbol to file (KCONFIG_CONFIG) */
+ #define SYMBOL_CHANGED 0x0400 /* ? */
++#define SYMBOL_WRITTEN 0x0800 /* track info to avoid double-write to .config */
+ #define SYMBOL_NO_WRITE 0x1000 /* Symbol for internal use only; it will not be written */
+ #define SYMBOL_CHECKED 0x2000 /* used during dependency checking */
+ #define SYMBOL_WARNED 0x8000 /* warning has been issued */
projects / thirdparty / kernel / stable-queue.git / commitdiff
