On Wed, Aug 14, 2019 at 9:53 PM Knut Omang <knut.omang@xxxxxxxxxx> wrote: > > On Wed, 2019-08-14 at 07:52 +0200, Knut Omang wrote: > > On Wed, 2019-08-14 at 11:02 +0900, Masahiro Yamada wrote: > > > Hi Knut, > > > > > > On Wed, Aug 14, 2019 at 1:19 AM Knut Omang <knut.omang@xxxxxxxxxx> wrote: > > > > On Tue, 2019-08-13 at 23:01 +0900, Masahiro Yamada wrote: > > > > > On Tue, Aug 13, 2019 at 3:13 PM Knut Omang <knut.omang@xxxxxxxxxx> wrote: > > > > > > C++ libraries interfacing to C APIs might sometimes need some glue > > > > > > logic more easily written in C. > > > > > > Allow a C++ library to also contain 0 or more C objects. > > > > > > > > > > > > Also fix rules for both C and C++ shared libraries: > > > > > > - C++ shared libraries depended on .c instead of .cc files > > > > > > - Rules were referenced as -objs instead of the intended > > > > > > -cobjs and -cxxobjs following the pattern from hostprogs*. > > > > > > > > > > > > Signed-off-by: Knut Omang <knut.omang@xxxxxxxxxx> > > > > > > > > > > How is this patch related to the rest of this series? > > > > > > > > This is just my (likely naive) way I to get what I had working > > > > using autotools in the Github version of KTF) translated into something > > > > comparable using kbuild only. We need to build a shared library consisting > > > > of a few C++ files and a very simple C file, and a couple of simple binaries, > > > > and the rule in there does seem to take .c files and subject them to the > > > > C++ compiler, which makes this difficult to achieve? > > > > > > Looking at the diff stat of the cover-letter, > > > the rest of this patch series is touching only > > > Documentation/ and tools/testing/kselftests/. > > > > > > So, this one is unused by the rest of the changes, isn't it? > > > Am I missing something? > > > > > > > > > > > > > > This patch breaks GCC-plugins. > > > > > Did you really compile-test this patch before the submission? > > > > > > > > Sorry for my ignorance here: > > > > I ran through the kernel build and installed the resulting kernel > > > > on a VM that I used to test this, if that's what you are asking > > > > about? > > > > > > > > Do I need some unusual .config options or run a special make target > > > > to trigger the problem you see? > > > > > > > > I used a recent Fedora config with default values for new options, > > > > and ran the normal default make target (also with O=) and make selftests > > > > to test the patch itself. > > > > > > I just built allmodconfig for arm. > > > > > > (The 0-day bot tests allmodconfig for most of architectures, > > > so you may receive error reports anyway.) > > > > > > > > > With your patch, I got the following: > > > > > > > > > masahiro@grover:~/ref/linux$ make ARCH=arm > > > CROSS_COMPILE=- allmodconfig all > > > HOSTCC scripts/basic/fixdep > > > HOSTCC scripts/kconfig/conf.o > > > HOSTCC scripts/kconfig/confdata.o > > > HOSTCC scripts/kconfig/expr.o > > > LEX scripts/kconfig/lexer.lex.c > > > YACC scripts/kconfig/parser.tab.h > > > HOSTCC scripts/kconfig/lexer.lex.o > > > YACC scripts/kconfig/parser.tab.c > > > HOSTCC scripts/kconfig/parser.tab.o > > > HOSTCC scripts/kconfig/preprocess.o > > > HOSTCC scripts/kconfig/symbol.o > > > HOSTLD scripts/kconfig/conf > > > scripts/kconfig/conf --allmodconfig Kconfig > > > # > > > # configuration written to .config > > > # > > > SYSHDR arch/arm/include/generated/uapi/asm/unistd-common.h > > > SYSHDR arch/arm/include/generated/uapi/asm/unistd-oabi.h > > > SYSHDR arch/arm/include/generated/uapi/asm/unistd-eabi.h > > > HOSTCC scripts/dtc/dtc.o > > > HOSTCC scripts/dtc/flattree.o > > > HOSTCC scripts/dtc/fstree.o > > > HOSTCC scripts/dtc/data.o > > > HOSTCC scripts/dtc/livetree.o > > > HOSTCC scripts/dtc/treesource.o > > > HOSTCC scripts/dtc/srcpos.o > > > HOSTCC scripts/dtc/checks.o > > > HOSTCC scripts/dtc/util.o > > > LEX scripts/dtc/dtc-lexer.lex.c > > > YACC scripts/dtc/dtc-parser.tab.h > > > HOSTCC scripts/dtc/dtc-lexer.lex.o > > > YACC scripts/dtc/dtc-parser.tab.c > > > HOSTCC scripts/dtc/dtc-parser.tab.o > > > HOSTCC scripts/dtc/yamltree.o > > > HOSTLD scripts/dtc/dtc > > > CC scripts/gcc-plugins/latent_entropy_plugin.o > > > cc1: error: cannot load plugin ./scripts/gcc-plugins/arm_ssp_per_task_plugin.so > > > ./scripts/gcc-plugins/arm_ssp_per_task_plugin.so: cannot open > > > shared object file: No such file or directory > > > cc1: error: cannot load plugin ./scripts/gcc-plugins/structleak_plugin.so > > > ./scripts/gcc-plugins/structleak_plugin.so: cannot open shared > > > object file: No such file or directory > > > cc1: error: cannot load plugin ./scripts/gcc-plugins/latent_entropy_plugin.so > > > ./scripts/gcc-plugins/latent_entropy_plugin.so: cannot open shared > > > object file: No such file or directory > > > cc1: error: cannot load plugin ./scripts/gcc-plugins/randomize_layout_plugin.so > > > ./scripts/gcc-plugins/randomize_layout_plugin.so: cannot open > > > shared object file: No such file or directory > > > make[3]: *** [scripts/Makefile.build;281: > > > scripts/gcc-plugins/latent_entropy_plugin.o] Error 1 > > > make[2]: *** [scripts/Makefile.build;497: scripts/gcc-plugins] Error 2 > > > make[1]: *** [Makefile;1097: scripts] Error 2 > > > make: *** [Makefile;330: __build_one_by_one] Error 2 > > > > Ok, I see! > > > > I'll recall this target and look into it! > > Ok, so I have tried installing the arm-linux-gnueabihf cross compiler and compiled the kernel for arm, > but allmodconfig does not seem to enable any GCC plugins per default even on ARM and I haven't been able > to figure out how to enable any. Linaro toolchain supports gcc plugins. https://releases.linaro.org/components/toolchain/binaries/latest-7/arm-linux-gnueabihf/ kernel.org one supports it as well. https://mirrors.edge.kernel.org/pub/tools/crosstool/ > A plain allmodconfig generated config compiles perfectly for me both native x86 and w/arm cross compile, > but it doesn't seem to enable any gcc plugins. > > Anyway, maybe I am getting this wrong anyway: > Having played with cross compile, it starts to become clear to me that HOSTCC rules > might not be the right rules to use, as it will generate host user land binaries as opposed to > target user land binaries (in a cross compile world obviously these differ) > > Now, I started off with using the rules in the selftests makefiles for this, but they do not play that well with > kernel module building. My goal is to be able to do both user land and kernel module **target** compiles > from the same subtree. Any hints on how to accomplish this appreciated :-) tools/ is out of scope of kbuild because it adopted a different (more adhoc) build system. I have no idea. Please talk to the kselftest maintainer. > > Thanks, > Knut > -- Best Regards Masahiro Yamada
