diff options
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 147 |
1 files changed, 36 insertions, 111 deletions
@@ -442,8 +442,6 @@ export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL export KBUILD_ARFLAGS -export CC_VERSION_TEXT := $(shell $(CC) --version | head -n 1) - # When compiling out-of-tree modules, put MODVERDIR in the module # tree rather than in the kernel tree. The kernel tree might # even be read-only. @@ -514,6 +512,12 @@ ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/cc-can-link.sh $(CC)), y) export CC_CAN_LINK endif +# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included. +# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile. +# CC_VERSION_TEXT is referenced from Kconfig (so it needs export), +# and from include/config/auto.conf.cmd to detect the compiler upgrade. +CC_VERSION_TEXT = $(shell $(CC) --version | head -n 1) + ifeq ($(config-targets),1) # =========================================================================== # *config targets only - make sure prerequisites are updated, and descend @@ -523,7 +527,7 @@ ifeq ($(config-targets),1) # KBUILD_DEFCONFIG may point out an alternative default configuration # used for 'make defconfig' include arch/$(SRCARCH)/Makefile -export KBUILD_DEFCONFIG KBUILD_KCONFIG +export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT config: scripts_basic outputmakefile FORCE $(Q)$(MAKE) $(build)=scripts/kconfig $@ @@ -585,12 +589,32 @@ virt-y := virt/ endif # KBUILD_EXTMOD ifeq ($(dot-config),1) -# Read in config -include include/config/auto.conf +endif + +# The all: target is the default when no target is given on the +# command line. +# This allow a user to issue only 'make' to build a kernel including modules +# Defaults to vmlinux, but the arch makefile usually adds further targets +all: vmlinux + +CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \ + $(call cc-option,-fno-tree-loop-im) \ + $(call cc-disable-warning,maybe-uninitialized,) +export CFLAGS_GCOV +# The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default +# values of the respective KBUILD_* variables +ARCH_CPPFLAGS := +ARCH_AFLAGS := +ARCH_CFLAGS := +include arch/$(SRCARCH)/Makefile + +ifeq ($(dot-config),1) ifeq ($(KBUILD_EXTMOD),) -# Read in dependencies to all Kconfig* files, make sure to run -# oldconfig if changes are detected. +# Read in dependencies to all Kconfig* files, make sure to run syncconfig if +# changes are detected. This should be included after arch/$(SRCARCH)/Makefile +# because some architectures define CROSS_COMPILE there. -include include/config/auto.conf.cmd # To avoid any implicit rule to kick in, define an empty command @@ -622,24 +646,6 @@ else include/config/auto.conf: ; endif # $(dot-config) -# The all: target is the default when no target is given on the -# command line. -# This allow a user to issue only 'make' to build a kernel including modules -# Defaults to vmlinux, but the arch makefile usually adds further targets -all: vmlinux - -CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \ - $(call cc-option,-fno-tree-loop-im) \ - $(call cc-disable-warning,maybe-uninitialized,) -export CFLAGS_GCOV CFLAGS_KCOV - -# The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default -# values of the respective KBUILD_* variables -ARCH_CPPFLAGS := -ARCH_AFLAGS := -ARCH_CFLAGS := -include arch/$(SRCARCH)/Makefile - KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,) KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation) @@ -680,55 +686,11 @@ ifneq ($(CONFIG_FRAME_WARN),0) KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN}) endif -# 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_AUTO - stackp-flag := $(call cc-option,-fstack-protector-strong,$(call cc-option,-fstack-protector)) - stackp-name := AUTO -else -ifdef CONFIG_CC_STACKPROTECTOR_REGULAR - stackp-flag := -fstack-protector - stackp-name := REGULAR -else -ifdef CONFIG_CC_STACKPROTECTOR_STRONG - stackp-flag := -fstack-protector-strong - stackp-name := STRONG -else - # If either there is no stack protector for this architecture or - # CONFIG_CC_STACKPROTECTOR_NONE is selected, we're done, and $(stackp-name) - # is empty, skipping all remaining stack protector tests. - # - # Force off for distro compilers that enable stack protector by default. - KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector) -endif -endif -endif -# Find arch-specific stack protector compiler sanity-checking script. -ifdef stackp-name -ifneq ($(stackp-flag),) - stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh - stackp-check := $(wildcard $(stackp-path)) - # If the wildcard test matches a test script, run it to check functionality. - ifdef stackp-check - ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y) - stackp-broken := y - endif - endif - ifndef stackp-broken - # If the stack protector is functional, enable code that depends on it. - KBUILD_CPPFLAGS += -DCONFIG_CC_STACKPROTECTOR - # Either we've already detected the flag (for AUTO) or we'll fail the - # build in the prepare-compiler-check rule (for specific flag). - KBUILD_CFLAGS += $(stackp-flag) - else - # We have to make sure stack protector is unconditionally disabled if - # the compiler is broken (in case we're going to continue the build in - # AUTO mode). - KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector) - endif -endif -endif +stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector +stackp-flags-$(CONFIG_CC_STACKPROTECTOR) := -fstack-protector +stackp-flags-$(CONFIG_CC_STACKPROTECTOR_STRONG) := -fstack-protector-strong + +KBUILD_CFLAGS += $(stackp-flags-y) ifeq ($(cc-name),clang) KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,) @@ -1112,7 +1074,7 @@ endif # 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 +prepare2: prepare3 outputmakefile asm-generic prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h \ include/config/auto.conf @@ -1138,43 +1100,6 @@ uapi-asm-generic: PHONY += prepare-objtool prepare-objtool: $(objtool_target) -# Check for CONFIG flags that require compiler support. Abort the build -# after .config has been processed, but before the kernel build starts. -# -# For security-sensitive CONFIG options, we don't want to fallback and/or -# silently change which compiler flags will be used, since that leads to -# producing kernels with different security feature characteristics -# depending on the compiler used. (For example, "But I selected -# CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!") -PHONY += prepare-compiler-check -prepare-compiler-check: FORCE -# Make sure compiler supports requested stack protector flag. -ifdef stackp-name - # Warn about CONFIG_CC_STACKPROTECTOR_AUTO having found no option. - ifeq ($(stackp-flag),) - @echo CONFIG_CC_STACKPROTECTOR_$(stackp-name): \ - Compiler does not support any known stack-protector >&2 - else - # Fail if specifically requested stack protector is missing. - ifeq ($(call cc-option, $(stackp-flag)),) - @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \ - $(stackp-flag) not supported by compiler >&2 && exit 1 - endif - endif -endif -# Make sure compiler does not have buggy stack-protector support. If a -# specific stack-protector was requested, fail the build, otherwise warn. -ifdef stackp-broken - ifeq ($(stackp-name),AUTO) - @echo CONFIG_CC_STACKPROTECTOR_$(stackp-name): \ - $(stackp-flag) available but compiler is broken: disabling >&2 - else - @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \ - $(stackp-flag) available but compiler is broken >&2 && exit 1 - endif -endif - @: - # Generate some files # --------------------------------------------------------------------------- |