From: Masahiro Yamada yamada.masahiro@socionext.com
commit d2f8ae0e4c5c754f1b2a7b8388d19a1a977e698a upstream.
syncconfig is responsible for keeping auto.conf up-to-date, so if it fails for any reason, the build must be terminated immediately.
However, since commit 9390dff66a52 ("kbuild: invoke syncconfig if include/config/auto.conf.cmd is missing"), Kbuild continues running even after syncconfig fails.
You can confirm this by intentionally making syncconfig error out:
# diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c # index 08ba146..307b9de 100644 # --- a/scripts/kconfig/confdata.c # +++ b/scripts/kconfig/confdata.c # @@ -1023,6 +1023,9 @@ int conf_write_autoconf(int overwrite) # FILE *out, *tristate, *out_h; # int i; # # + if (overwrite) # + return 1; # + # if (!overwrite && is_present(autoconf_name)) # return 0;
Then, syncconfig fails, but Make would not stop:
$ make -s mrproper allyesconfig defconfig $ make scripts/kconfig/conf --syncconfig Kconfig
*** Error during sync of the configuration.
make[2]: *** [scripts/kconfig/Makefile;69: syncconfig] Error 1 make[1]: *** [Makefile;557: syncconfig] Error 2 make: *** [include/config/auto.conf.cmd] Deleting file 'include/config/tristate.conf' make: Failed to remake makefile 'include/config/auto.conf'. SYSTBL arch/x86/include/generated/asm/syscalls_32.h SYSHDR arch/x86/include/generated/asm/unistd_32_ia32.h SYSHDR arch/x86/include/generated/asm/unistd_64_x32.h SYSTBL arch/x86/include/generated/asm/syscalls_64.h [ continue running ... ]
The reason is in the behavior of a pattern rule with multi-targets.
%/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG) $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
GNU Make knows this rule is responsible for making all the three files simultaneously. As far as examined, auto.conf.cmd is the target in question when this rule is invoked. It is probably because auto.conf.cmd is included below the inclusion of auto.conf.
The inclusion of auto.conf is mandatory, while that of auto.conf.cmd is optional. GNU Make does not care about the failure in the process of updating optional include files.
I filed this issue (https://savannah.gnu.org/bugs/?56301) in case this behavior could be improved somehow in future releases of GNU Make. Anyway, it is quite easy to fix our Makefile.
Given that auto.conf is already a mandatory include file, there is no reason to stick auto.conf.cmd optional. Make it mandatory as well.
Cc: linux-stable stable@vger.kernel.org # 5.0+ Fixes: 9390dff66a52 ("kbuild: invoke syncconfig if include/config/auto.conf.cmd is missing") Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com [commented out diff above to keep patch happy - gregkh] Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/Makefile +++ b/Makefile @@ -642,7 +642,7 @@ ifeq ($(may-sync-config),1) # Read in dependencies to all Kconfig* files, make sure to run syncconfig if # changes are detected. This should be included after arch/$(SRCARCH)/Makefile # because some architectures define CROSS_COMPILE there. --include include/config/auto.conf.cmd +include include/config/auto.conf.cmd
# To avoid any implicit rule to kick in, define an empty command $(KCONFIG_CONFIG): ;