diff options
Diffstat (limited to 'Makefile')
-rw-r--r-- | Makefile | 115 |
1 files changed, 66 insertions, 49 deletions
@@ -370,27 +370,28 @@ LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL = LDFLAGS_vmlinux = -CFLAGS_GCOV = -fprofile-arcs -ftest-coverage -fno-tree-loop-im -Wno-maybe-uninitialized -CFLAGS_KCOV = -fsanitize-coverage=trace-pc +CFLAGS_GCOV = -fprofile-arcs -ftest-coverage -fno-tree-loop-im +CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) # Use USERINCLUDE when you must reference the UAPI directories only. USERINCLUDE := \ -I$(srctree)/arch/$(hdr-arch)/include/uapi \ - -Iarch/$(hdr-arch)/include/generated/uapi \ + -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \ -I$(srctree)/include/uapi \ - -Iinclude/generated/uapi \ + -I$(objtree)/include/generated/uapi \ -include $(srctree)/include/linux/kconfig.h # Use LINUXINCLUDE when you must reference the include/ directory. # Needed to be compatible with the O= option LINUXINCLUDE := \ -I$(srctree)/arch/$(hdr-arch)/include \ - -Iarch/$(hdr-arch)/include/generated/uapi \ - -Iarch/$(hdr-arch)/include/generated \ + -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \ + -I$(objtree)/arch/$(hdr-arch)/include/generated \ $(if $(KBUILD_SRC), -I$(srctree)/include) \ - -Iinclude \ - $(USERINCLUDE) + -I$(objtree)/include + +LINUXINCLUDE += $(filter-out $(LINUXINCLUDE),$(USERINCLUDE)) KBUILD_CPPFLAGS := -D__KERNEL__ @@ -554,7 +555,7 @@ ifeq ($(KBUILD_EXTMOD),) # in parallel PHONY += scripts scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \ - asm-generic + asm-generic gcc-plugins $(Q)$(MAKE) $(build)=$(@) # Objects we will link into vmlinux / subdirs we need to visit @@ -619,12 +620,13 @@ ARCH_CFLAGS := include arch/$(SRCARCH)/Makefile KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) +KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,) ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE -KBUILD_CFLAGS += -Os $(call cc-disable-warning,maybe-uninitialized,) +KBUILD_CFLAGS += -Os else ifdef CONFIG_PROFILE_ALL_BRANCHES -KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,) +KBUILD_CFLAGS += -O2 else KBUILD_CFLAGS += -O2 endif @@ -633,6 +635,15 @@ endif # Tell gcc to never replace conditional load with a non-conditional one KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0) +PHONY += gcc-plugins +gcc-plugins: scripts_basic +ifdef CONFIG_GCC_PLUGINS + $(Q)$(MAKE) $(build)=scripts/gcc-plugins +endif + @: + +include scripts/Makefile.gcc-plugins + ifdef CONFIG_READABLE_ASM # Disable optimizations that make assembler listings hard to read. # reorder blocks reorders the control in the function @@ -647,50 +658,27 @@ ifneq ($(CONFIG_FRAME_WARN),0) KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN}) endif -# Handle stack protector mode. -# -# Since kbuild can potentially perform two passes (first with the old -# .config values and then with updated .config values), we cannot error out -# if a desired compiler option is unsupported. If we were to error, kbuild -# could never get to the second pass and actually notice that we changed -# the option to something that was supported. -# -# Additionally, we don't want to fallback and/or silently change which compiler -# flags will be used, since that leads to producing kernels with different -# security feature characteristics depending on the compiler used. ("But I -# selected CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!") -# -# The middle ground is to warn here so that the failed option is obvious, but -# to let the build fail with bad compiler flags so that we can't produce a -# kernel when there is a CONFIG and compiler mismatch. -# +# This selects the stack protector compiler flag. Testing it is delayed +# until after .config has been reprocessed, in the prepare-compiler-check +# target. ifdef CONFIG_CC_STACKPROTECTOR_REGULAR stackp-flag := -fstack-protector - ifeq ($(call cc-option, $(stackp-flag)),) - $(warning Cannot use CONFIG_CC_STACKPROTECTOR_REGULAR: \ - -fstack-protector not supported by compiler) - endif + stackp-name := REGULAR else ifdef CONFIG_CC_STACKPROTECTOR_STRONG stackp-flag := -fstack-protector-strong - ifeq ($(call cc-option, $(stackp-flag)),) - $(warning Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: \ - -fstack-protector-strong not supported by compiler) - endif + stackp-name := STRONG else # Force off for distro compilers that enable stack protector by default. stackp-flag := $(call cc-option, -fno-stack-protector) endif endif -KBUILD_CFLAGS += $(stackp-flag) - -ifdef CONFIG_KCOV - ifeq ($(call cc-option, $(CFLAGS_KCOV)),) - $(warning Cannot use CONFIG_KCOV: \ - -fsanitize-coverage=trace-pc is not supported by compiler) - CFLAGS_KCOV = - endif +# Find arch-specific stack protector compiler sanity-checking script. +ifdef CONFIG_CC_STACKPROTECTOR + stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh + stackp-check := $(wildcard $(stackp-path)) endif +KBUILD_CFLAGS += $(stackp-flag) ifeq ($(cc-name),clang) KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,) @@ -1017,8 +1005,10 @@ ifneq ($(KBUILD_SRC),) fi; endif -# prepare2 creates a makefile if using a separate output directory -prepare2: prepare3 outputmakefile asm-generic +# prepare2 creates a makefile if using a separate output directory. +# From this point forward, .config has been reprocessed, so any rules +# that need to depend on updated CONFIG_* values can be checked here. +prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic prepare1: prepare2 $(version_h) include/generated/utsrelease.h \ include/config/auto.conf @@ -1028,7 +1018,7 @@ prepare1: prepare2 $(version_h) include/generated/utsrelease.h \ archprepare: archheaders archscripts prepare1 scripts_basic -prepare0: archprepare +prepare0: archprepare gcc-plugins $(Q)$(MAKE) $(build)=. # All the preparing.. @@ -1049,6 +1039,32 @@ endif PHONY += prepare-objtool prepare-objtool: $(objtool_target) +# Check for CONFIG flags that require compiler support. Abort the build +# after .config has been processed, but before the kernel build starts. +# +# For security-sensitive CONFIG options, we don't want to fallback and/or +# silently change which compiler flags will be used, since that leads to +# producing kernels with different security feature characteristics +# depending on the compiler used. (For example, "But I selected +# CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!") +PHONY += prepare-compiler-check +prepare-compiler-check: FORCE +# Make sure compiler supports requested stack protector flag. +ifdef stackp-name + ifeq ($(call cc-option, $(stackp-flag)),) + @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \ + $(stackp-flag) not supported by compiler >&2 && exit 1 + endif +endif +# Make sure compiler does not have buggy stack-protector support. +ifdef stackp-check + ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y) + @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \ + $(stackp-flag) available but compiler is broken >&2 && exit 1 + endif +endif + @: + # Generate some files # --------------------------------------------------------------------------- @@ -1416,7 +1432,7 @@ $(help-board-dirs): help-%: # Documentation targets # --------------------------------------------------------------------------- -DOC_TARGETS := xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs epubdocs cleandocs cleanmediadocs +DOC_TARGETS := xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs epubdocs cleandocs PHONY += $(DOC_TARGETS) $(DOC_TARGETS): scripts_basic FORCE $(Q)$(MAKE) $(build)=scripts build_docproc build_check-lc_ctype @@ -1514,6 +1530,7 @@ clean: $(clean-dirs) -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ -o -name '*.symtypes' -o -name 'modules.order' \ -o -name modules.builtin -o -name '.tmp_*.o.*' \ + -o -name '*.c.[012]*.*' \ -o -name '*.gcno' \) -type f -print | xargs rm -f # Generate tags for editors @@ -1624,7 +1641,7 @@ endif $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \ $(build)=$(build-dir) # Make sure the latest headers are built for Documentation -Documentation/: headers_install +Documentation/ samples/: headers_install %/: prepare scripts FORCE $(cmd_crmodverdir) $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \ |