From 42640b134bf44e3bac34808e8c39660c7ae42855 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 29 Jul 2020 12:15:36 +0900 Subject: kbuild: move host .so build rules to scripts/gcc-plugins/Makefile The host shared library rules are currently implemented in scripts/Makefile.host, but actually GCC-plugin is the only user of them. (The VDSO .so files are built for the target by different build rules) 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 multi-file plugin support, which Kees Cook mentioned might be needed by out-of-tree plugins. (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 Acked-by: Kees Cook --- 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 246426fa1282..d54adf0dcf39 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 --- a/scripts/gcc-plugins/Makefile +++ b/scripts/gcc-plugins/Makefile @@ -1,22 +1,61 @@ # SPDX-License-Identifier: GPL-2.0 -GCC_PLUGINS_DIR := $(shell $(CC) -print-file-name=plugin) -HOST_EXTRACXXFLAGS += -I$(GCC_PLUGINS_DIR)/include -I$(src) -std=gnu++98 -fno-rtti -HOST_EXTRACXXFLAGS += -fno-exceptions -fasynchronous-unwind-tables -ggdb -HOST_EXTRACXXFLAGS += -Wno-narrowing -Wno-unused-variable -Wno-c++11-compat -HOST_EXTRACXXFLAGS += -Wno-format-diag - -$(obj)/randomize_layout_plugin.o: $(objtree)/$(obj)/randomize_layout_seed.h +$(obj)/randomize_layout_plugin.so: $(objtree)/$(obj)/randomize_layout_seed.h quiet_cmd_create_randomize_layout_seed = GENSEED $@ cmd_create_randomize_layout_seed = \ $(CONFIG_SHELL) $(srctree)/$(src)/gen-random-seed.sh $@ $(objtree)/include/generated/randomize_layout_hash.h $(objtree)/$(obj)/randomize_layout_seed.h: FORCE $(call if_changed,create_randomize_layout_seed) -targets = randomize_layout_seed.h randomize_layout_hash.h +targets += randomize_layout_seed.h randomize_layout_hash.h + +# Build rules for plugins +# +# No extra code is needed for single-file plugins. +# For multi-file plugins, use *-objs syntax to list the objects. +# +# If the plugin foo.so is compiled from foo.c and foo2.c, you can do: +# +# foo-objs := foo.o foo2.o + +always-y += $(GCC_PLUGIN) -hostcxxlibs-y := $(GCC_PLUGIN) -always-y := $(hostcxxlibs-y) +GCC_PLUGINS_DIR = $(shell $(CC) -print-file-name=plugin) -$(foreach p,$(hostcxxlibs-y:%.so=%),$(eval $(p)-objs := $(p).o)) +plugin_cxxflags = -Wp,-MMD,$(depfile) $(KBUILD_HOSTCXXFLAGS) -fPIC \ + -I $(GCC_PLUGINS_DIR)/include -I $(obj) -std=gnu++98 \ + -fno-rtti -fno-exceptions -fasynchronous-unwind-tables \ + -ggdb -Wno-narrowing -Wno-unused-variable -Wno-c++11-compat \ + -Wno-format-diag +plugin_ldflags = -shared + +plugin-single := $(foreach m, $(GCC_PLUGIN), $(if $($(m:%.so=%-objs)),,$(m))) +plugin-multi := $(filter-out $(plugin-single), $(GCC_PLUGIN)) +plugin-objs := $(sort $(foreach m, $(plugin-multi), $($(m:%.so=%-objs)))) + +targets += $(plugin-single) $(plugin-multi) $(plugin-objs) clean-files += *.so + +plugin-single := $(addprefix $(obj)/, $(plugin-single)) +plugin-multi := $(addprefix $(obj)/, $(plugin-multi)) +plugin-objs := $(addprefix $(obj)/, $(plugin-objs)) + +quiet_cmd_plugin_cxx_so_c = HOSTCXX $@ + cmd_plugin_cxx_so_c = $(HOSTCXX) $(plugin_cxxflags) $(plugin_ldflags) -o $@ $< + +$(plugin-single): $(obj)/%.so: $(src)/%.c FORCE + $(call if_changed_dep,plugin_cxx_so_c) + +quiet_cmd_plugin_ld_so_o = HOSTLD $@ + cmd_plugin_ld_so_o = $(HOSTCXX) $(plugin_ldflags) -o $@ \ + $(addprefix $(obj)/, $($(target-stem)-objs)) + +$(plugin-multi): FORCE + $(call if_changed,plugin_ld_so_o) +$(foreach m, $(notdir $(plugin-multi)), $(eval $(obj)/$m: $(addprefix $(obj)/, $($(m:%.so=%-objs))))) + +quiet_cmd_plugin_cxx_o_c = HOSTCXX $@ + cmd_plugin_cxx_o_c = $(HOSTCXX) $(plugin_cxxflags) -c -o $@ $< + +$(plugin-objs): $(obj)/%.o: $(src)/%.c FORCE + $(call if_changed_dep,plugin_cxx_o_c) -- cgit v1.2.3