# git rev-parse -q --verify aa9581108f498991e309c4a90b1af0805d2e41b5^{commit}
aa9581108f498991e309c4a90b1af0805d2e41b5
already have revision, skipping fetch
# git checkout -q -f -B kisskb aa9581108f498991e309c4a90b1af0805d2e41b5
# git clean -qxdf
# < git log -1
# commit aa9581108f498991e309c4a90b1af0805d2e41b5
# Author: Masahiro Yamada <yamada.masahiro@socionext.com>
# Date:   Wed Nov 6 20:23:57 2019 +0900
# 
#     modpost: add an option to suppress 'exported twice' warnings
#     
#     Since commit "modpost: do not set ->preloaded for symbols from
#     Module.symvers", the modpost always warns about symbols exported
#     multiple times.
#     
#     Generally, I believe it is a good thing to show a warning when the
#     same symbol name is exported twice. This avoids the accidental symbol
#     conflict.
#     
#     However, in some cases, we build an external module to provide a
#     different version/variant of the in-kernel module, overriding the
#     same set of exported symbols.
#     
#     At least, there is one use-case in the upstream code;
#     tools/testing/nvdimm/libnvdimm.ko replaces drivers/nvdimm/libnvdimm.ko
#     in order to link it against mocked version of core kernel symbols.
#     
#     Now, this emits a lots of 'exported twice' warnings:
#     
#       https://lkml.org/lkml/2019/10/31/627
#     
#     To suppress those, add a new option KBUILD_MULTI_EXPORT_NO_WARN.
#     
#     If you intentionally override the existing symbols, you can pass it
#     from the command line:
#     
#       make M=tools/testing/nvdimm KBUILD_MULTI_EXPORT_NO_WARN=1
#     
#     Or, more conveniently, you can add it to the module Makefile, so
#     you can still do:
#     
#       make M=tools/testing/nvdimm
#     
#     without sprinkling the warnings.
#     
#     Reported-by: Jeff Moyer <jmoyer@redhat.com>
#     Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
#     Tested-by: Jeff Moyer <jmoyer@redhat.com>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-gcc --version
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-ld --version
# < git log --format=%s --max-count=1 aa9581108f498991e309c4a90b1af0805d2e41b5
# < make -s -j 48 ARCH=s390 O=/kisskb/build/kbuild_s390-defconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-  defconfig
# make -s -j 48 ARCH=s390 O=/kisskb/build/kbuild_s390-defconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-  
cc1: error: unrecognized command line option '-mtune=zEC12'
cc1: error: unrecognized command line option '-mtune=zEC12'
make[2]: *** [/kisskb/src/scripts/Makefile.build:99: scripts/mod/devicetable-offsets.s] Error 1
make[2]: *** Waiting for unfinished jobs....
make[2]: *** [/kisskb/src/scripts/Makefile.build:266: scripts/mod/empty.o] Error 1
make[1]: *** [/kisskb/src/Makefile:1109: prepare0] Error 2
make: *** [Makefile:179: sub-make] Error 2
Command 'make -s -j 48 ARCH=s390 O=/kisskb/build/kbuild_s390-defconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-  ' returned non-zero exit status 2
# rm -rf /kisskb/build/kbuild_s390-defconfig_s390x
# Build took: 0:00:03.260442