ce6ed1c4c9
Linus reported a build error due to the GCC plugin incompatibility
when the compiler is upgraded. [1]
GCC plugins are tied to a particular GCC version. So, they must be
rebuilt when the compiler is upgraded.
This seems to be a long-standing flaw since the initial support of
GCC plugins.
Extend commit 8b59cd81dc ("kbuild: ensure full rebuild when the
compiler is updated"), so that GCC plugins are covered by the
compiler upgrade detection.
[1]: https://lore.kernel.org/lkml/CAHk-=wieoN5ttOy7SnsGwZv+Fni3R6m-Ut=oxih6bbZ28G+4dw@mail.gmail.com/
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
2.3 KiB
SPDX-License-Identifier: GPL-2.0
$(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
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)
GCC_PLUGINS_DIR = $(shell $(CC) -print-file-name=plugin)
plugin_cxxflags = -Wp,-MMD,$(depfile) $(KBUILD_HOSTCXXFLAGS) -fPIC
-include $(srctree)/include/linux/compiler-version.h
-I $(GCC_PLUGINS_DIR)/include -I $(obj) -std=gnu++11
-fno-rtti -fno-exceptions -fasynchronous-unwind-tables
-ggdb -Wno-narrowing -Wno-unused-variable
-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)