Re: [PATCH 1/2] kbuild: move shared library build rules to scripts/gcc-plugins/Makefile
On Thu, Jul 30, 2020 at 6:18 AM Kees Cook wrote: > > On Wed, Jul 29, 2020 at 12:15:36PM +0900, Masahiro Yamada wrote: > > The shared library build rules are currently implemented in > > scripts/Makefile.host, but actually GCC-plugin is the only user of > > them. Hence, they do not need to be treewide available. > > Are none of the VDSOs intending to use these rules? Right. GCC plugin .so files are compiled for the _host_ architecture. vDSO .so files are compiled for the _target_ architecture. They are built in completely different ways. > > Move all the relevant build rules to scripts/gcc-plugins/Makefile. > > > > I also optimized the build steps so *.so is directly built from .c > > because every upstream plugin is compiled from a single source file. > > > > I am still keeping the infrastructure to build a plugin from multiple > > files because Kees suggested to do so in my previous attempt. > > (https://lkml.org/lkml/2019/1/11/1107) > > > > If the plugin, foo.so, is compiled from two files foo.c and foo2.c, > > then you can do like follows: > > > > foo-objs := foo.o foo2.o > > > > Single-file plugins do not need the *-objs notation. > > > > Signed-off-by: Masahiro Yamada > > But, yeah, sure! > > Acked-by: Kees Cook > > Unrelated, but I do note that objtool maybe has the wrong indentation, > path name reporting, and tool names (HOSTLD vs CC)? Right. Many people know it. objtool opts out the Kbuild instructure. I wrote a patch to make objtool join the Kbuild: https://patchwork.kernel.org/patch/10839051/ The objtool maintainers refused to do this. > ... > HOSTCC scripts/asn1_compiler > HOSTCC scripts/extract-cert > HOSTCC scripts/genksyms/genksyms.o > YACCscripts/genksyms/parse.tab.[ch] > LEX scripts/genksyms/lex.lex.c > DESCEND objtool > HOSTCXX scripts/gcc-plugins/cyc_complexity_plugin.so > HOSTCXX scripts/gcc-plugins/latent_entropy_plugin.so > HOSTCXX scripts/gcc-plugins/structleak_plugin.so > GENSEED scripts/gcc-plugins/randomize_layout_seed.h > HOSTCXX scripts/gcc-plugins/stackleak_plugin.so > HOSTCC scripts/genksyms/parse.tab.o > HOSTCC scripts/genksyms/lex.lex.o > HOSTCC /home/kees/src/linux-build/plugins/tools/objtool/fixdep.o > HOSTLD arch/x86/tools/relocs > HOSTLD /home/kees/src/linux-build/plugins/tools/objtool/fixdep-in.o > LINK /home/kees/src/linux-build/plugins/tools/objtool/fixdep > CC /home/kees/src/linux-build/plugins/tools/objtool/exec-cmd.o > CC /home/kees/src/linux-build/plugins/tools/objtool/help.o > CC /home/kees/src/linux-build/plugins/tools/objtool/weak.o > ... > > -- > Kees Cook -- Best Regards Masahiro Yamada
Re: [PATCH 1/2] kbuild: move shared library build rules to scripts/gcc-plugins/Makefile
On Wed, Jul 29, 2020 at 12:15:36PM +0900, Masahiro Yamada wrote: > The shared library build rules are currently implemented in > scripts/Makefile.host, but actually GCC-plugin is the only user of > them. Hence, they do not need to be treewide available. Are none of the VDSOs intending to use these rules? > Move all the relevant build rules to scripts/gcc-plugins/Makefile. > > I also optimized the build steps so *.so is directly built from .c > because every upstream plugin is compiled from a single source file. > > I am still keeping the infrastructure to build a plugin from multiple > files because Kees suggested to do so in my previous attempt. > (https://lkml.org/lkml/2019/1/11/1107) > > If the plugin, foo.so, is compiled from two files foo.c and foo2.c, > then you can do like follows: > > foo-objs := foo.o foo2.o > > Single-file plugins do not need the *-objs notation. > > Signed-off-by: Masahiro Yamada But, yeah, sure! Acked-by: Kees Cook Unrelated, but I do note that objtool maybe has the wrong indentation, path name reporting, and tool names (HOSTLD vs CC)? ... HOSTCC scripts/asn1_compiler HOSTCC scripts/extract-cert HOSTCC scripts/genksyms/genksyms.o YACCscripts/genksyms/parse.tab.[ch] LEX scripts/genksyms/lex.lex.c DESCEND objtool HOSTCXX scripts/gcc-plugins/cyc_complexity_plugin.so HOSTCXX scripts/gcc-plugins/latent_entropy_plugin.so HOSTCXX scripts/gcc-plugins/structleak_plugin.so GENSEED scripts/gcc-plugins/randomize_layout_seed.h HOSTCXX scripts/gcc-plugins/stackleak_plugin.so HOSTCC scripts/genksyms/parse.tab.o HOSTCC scripts/genksyms/lex.lex.o HOSTCC /home/kees/src/linux-build/plugins/tools/objtool/fixdep.o HOSTLD arch/x86/tools/relocs HOSTLD /home/kees/src/linux-build/plugins/tools/objtool/fixdep-in.o LINK /home/kees/src/linux-build/plugins/tools/objtool/fixdep CC /home/kees/src/linux-build/plugins/tools/objtool/exec-cmd.o CC /home/kees/src/linux-build/plugins/tools/objtool/help.o CC /home/kees/src/linux-build/plugins/tools/objtool/weak.o ... -- Kees Cook
[PATCH 1/2] kbuild: move shared library build rules to scripts/gcc-plugins/Makefile
The shared library build rules are currently implemented in scripts/Makefile.host, but actually GCC-plugin is the only user of them. Hence, they do not need to be treewide available. Move all the relevant build rules to scripts/gcc-plugins/Makefile. I also optimized the build steps so *.so is directly built from .c because every upstream plugin is compiled from a single source file. I am still keeping the infrastructure to build a plugin from multiple files because Kees suggested to do so in my previous attempt. (https://lkml.org/lkml/2019/1/11/1107) If the plugin, foo.so, is compiled from two files foo.c and foo2.c, then you can do like follows: foo-objs := foo.o foo2.o Single-file plugins do not need the *-objs notation. Signed-off-by: Masahiro Yamada --- scripts/Makefile.build | 4 +-- scripts/Makefile.clean | 3 +- scripts/Makefile.host| 30 ++ scripts/gcc-plugins/Makefile | 61 +--- 4 files changed, 55 insertions(+), 43 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 2e8810b7e5ed..d41c1cd453b9 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -45,8 +45,8 @@ include $(kbuild-file) include scripts/Makefile.lib -# Do not include host rules unless needed -ifneq ($(hostprogs)$(hostcxxlibs-y)$(hostcxxlibs-m),) +# Do not include hostprogs rules unless needed +ifneq ($(hostprogs),) include scripts/Makefile.host endif diff --git a/scripts/Makefile.clean b/scripts/Makefile.clean index e2c76122319d..3cdf31218198 100644 --- a/scripts/Makefile.clean +++ b/scripts/Makefile.clean @@ -29,8 +29,7 @@ subdir-ymn:= $(addprefix $(obj)/,$(subdir-ymn)) __clean-files := $(extra-y) $(extra-m) $(extra-) \ $(always) $(always-y) $(always-m) $(always-) $(targets) $(clean-files) \ - $(hostprogs) $(hostprogs-y) $(hostprogs-m) $(hostprogs-) $(userprogs) \ - $(hostcxxlibs-y) $(hostcxxlibs-m) + $(hostprogs) $(hostprogs-y) $(hostprogs-m) $(hostprogs-) $(userprogs) __clean-files := $(filter-out $(no-clean-files), $(__clean-files)) diff --git a/scripts/Makefile.host b/scripts/Makefile.host index c8a4a033dc3e..687ca3f309e9 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -39,7 +39,6 @@ $(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE # They are linked as C++ code to the executable qconf __hostprogs := $(sort $(hostprogs)) -host-cxxshlib := $(sort $(hostcxxlibs-y) $(hostcxxlibs-m)) # C code # Executables compiled from a single .c file @@ -61,16 +60,11 @@ host-cxxmulti := $(foreach m,$(__hostprogs),$(if $($(m)-cxxobjs),$(m))) # C++ Object (.o) files compiled from .cc files host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs))) -# Object (.o) files used by the shared libaries -host-cxxshobjs := $(sort $(foreach m,$(host-cxxshlib),$($(m:.so=-objs - host-csingle := $(addprefix $(obj)/,$(host-csingle)) host-cmulti:= $(addprefix $(obj)/,$(host-cmulti)) host-cobjs := $(addprefix $(obj)/,$(host-cobjs)) host-cxxmulti := $(addprefix $(obj)/,$(host-cxxmulti)) host-cxxobjs := $(addprefix $(obj)/,$(host-cxxobjs)) -host-cxxshlib := $(addprefix $(obj)/,$(host-cxxshlib)) -host-cxxshobjs := $(addprefix $(obj)/,$(host-cxxshobjs)) # # Handle options to gcc. Support building with separate output directory @@ -136,25 +130,5 @@ quiet_cmd_host-cxxobjs = HOSTCXX $@ $(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE $(call if_changed_dep,host-cxxobjs) -# Compile .c file, create position independent .o file -# Note that plugin capable gcc versions can be either C or C++ based -# therefore plugin source files have to be compilable in both C and C++ mode. -# This is why a C++ compiler is invoked on a .c file. -# host-cxxshobjs -> .o -quiet_cmd_host-cxxshobjs = HOSTCXX -fPIC $@ - cmd_host-cxxshobjs = $(HOSTCXX) $(hostcxx_flags) -fPIC -c -o $@ $< -$(host-cxxshobjs): $(obj)/%.o: $(src)/%.c FORCE - $(call if_changed_dep,host-cxxshobjs) - -# Link a shared library, based on position independent .o files -# *.o -> .so shared library (host-cxxshlib) -quiet_cmd_host-cxxshlib= HOSTLLD -shared $@ - cmd_host-cxxshlib= $(HOSTCXX) $(KBUILD_HOSTLDFLAGS) -shared -o $@ \ - $(addprefix $(obj)/, $($(target-stem)-objs)) \ - $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem).so) -$(host-cxxshlib): FORCE - $(call if_changed,host-cxxshlib) -$(call multi_depend, $(host-cxxshlib), .so, -objs) - -targets += $(host-csingle) $(host-cmulti) $(host-cobjs)\ - $(host-cxxmulti) $(host-cxxobjs) $(host-cxxshlib) $(host-cxxshobjs) +targets += $(host-csingle) $(host-cmulti) $(host-cobjs) \ + $(host-cxxmulti) $(host-cxxobjs) diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile index 4014ba7e2fbd..d66949bfeba4 100644 ---
