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	The latest GCC 13 snapshot (13.0.1 20230129) gives the following: ``` cc1: error: cannot load plugin ./scripts/gcc-plugins/randomize_layout_plugin.so :./scripts/gcc-plugins/randomize_layout_plugin.so: undefined symbol: tree_code_type ``` This ends up being because of https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=b0241ce6e37031 upstream in GCC which changes the visibility of some types used by the kernel's plugin infrastructure like tree_code_type. After discussion with the GCC folks, we found that the kernel needs to be building plugins with the same flags used to build GCC - and GCC defaults to gnu++17 right now. The minimum GCC version needed to build the kernel is GCC 5.1 and GCC 5.1 already defaults to gnu++14 anyway, so just drop the flag, as all GCCs that could be used to build GCC already default to an acceptable version which was >= the version we forced via flags until now. Bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108634 Signed-off-by: Sam James <sam@gentoo.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230201230009.2252783-1-sam@gentoo.org
		
			
				
	
	
		
			68 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
			Makefile
		
	
	
	
	
	
			
		
		
	
	
			68 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
			Makefile
		
	
	
	
	
	
# SPDX-License-Identifier: GPL-2.0
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$(obj)/randomize_layout_plugin.so: $(obj)/randomize_layout_seed.h
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quiet_cmd_create_randomize_layout_seed = SEEDHDR $@
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cmd_create_randomize_layout_seed = \
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	SEED=$$(cat $(filter-out FORCE,$^) </dev/null); \
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	echo '/*' > $@; \
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	echo ' * This file is automatically generated. Keep it private.' >> $@; \
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	echo ' * Exposing this value will expose the layout of randomized structures.' >> $@; \
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	echo ' */' >> $@; \
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	echo "const char *randstruct_seed = \"$$SEED\";" >> $@
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$(obj)/randomize_layout_seed.h: $(objtree)/scripts/basic/randstruct.seed FORCE
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	$(call if_changed,create_randomize_layout_seed)
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targets += randomize_layout_seed.h
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# Build rules for plugins
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#
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# No extra code is needed for single-file plugins.
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# For multi-file plugins, use *-objs syntax to list the objects.
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#
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# If the plugin foo.so is compiled from foo.c and foo2.c, you can do:
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#
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# foo-objs := foo.o foo2.o
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always-y += $(GCC_PLUGIN)
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GCC_PLUGINS_DIR = $(shell $(CC) -print-file-name=plugin)
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plugin_cxxflags	= -Wp,-MMD,$(depfile) $(KBUILD_HOSTCXXFLAGS) -fPIC \
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		  -include $(srctree)/include/linux/compiler-version.h \
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		  -DPLUGIN_VERSION=$(call stringify,$(KERNELVERSION)) \
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		  -I $(GCC_PLUGINS_DIR)/include -I $(obj) \
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		  -fno-rtti -fno-exceptions -fasynchronous-unwind-tables \
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		  -ggdb -Wno-narrowing -Wno-unused-variable \
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		  -Wno-format-diag
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plugin_ldflags	= -shared
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plugin-single	:= $(foreach m, $(GCC_PLUGIN), $(if $($(m:%.so=%-objs)),,$(m)))
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plugin-multi	:= $(filter-out $(plugin-single), $(GCC_PLUGIN))
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plugin-objs	:= $(sort $(foreach m, $(plugin-multi), $($(m:%.so=%-objs))))
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targets += $(plugin-single) $(plugin-multi) $(plugin-objs)
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clean-files += *.so
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plugin-single	:= $(addprefix $(obj)/, $(plugin-single))
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plugin-multi	:= $(addprefix $(obj)/, $(plugin-multi))
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plugin-objs	:= $(addprefix $(obj)/, $(plugin-objs))
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quiet_cmd_plugin_cxx_so_c = HOSTCXX $@
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      cmd_plugin_cxx_so_c = $(HOSTCXX) $(plugin_cxxflags) $(plugin_ldflags) -o $@ $<
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$(plugin-single): $(obj)/%.so: $(src)/%.c FORCE
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	$(call if_changed_dep,plugin_cxx_so_c)
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quiet_cmd_plugin_ld_so_o = HOSTLD  $@
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      cmd_plugin_ld_so_o = $(HOSTCXX) $(plugin_ldflags) -o $@ \
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			   $(addprefix $(obj)/, $($(target-stem)-objs))
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$(plugin-multi): FORCE
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	$(call if_changed,plugin_ld_so_o)
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$(foreach m, $(notdir $(plugin-multi)), $(eval $(obj)/$m: $(addprefix $(obj)/, $($(m:%.so=%-objs)))))
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quiet_cmd_plugin_cxx_o_c = HOSTCXX $@
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      cmd_plugin_cxx_o_c = $(HOSTCXX) $(plugin_cxxflags) -c -o $@ $<
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$(plugin-objs): $(obj)/%.o: $(src)/%.c FORCE
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	$(call if_changed_dep,plugin_cxx_o_c)
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