diff options
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 105 |
1 files changed, 64 insertions, 41 deletions
@@ -191,10 +191,9 @@ endif ifneq ($(abs_srctree),$(abs_objtree)) # Look for make include files relative to root of kernel src # -# This does not become effective immediately because MAKEFLAGS is re-parsed -# once after the Makefile is read. We need to invoke sub-make. +# --included-dir is added for backward compatibility, but you should not rely on +# it. Please add $(srctree)/ prefix to include Makefiles in the source tree. MAKEFLAGS += --include-dir=$(abs_srctree) -need-sub-make := 1 endif ifneq ($(filter 3.%,$(MAKE_VERSION)),) @@ -404,6 +403,11 @@ ifeq ($(ARCH),sparc64) SRCARCH := sparc endif +# Additional ARCH settings for parisc +ifeq ($(ARCH),parisc64) + SRCARCH := parisc +endif + export cross_compiling := ifneq ($(SRCARCH),$(SUBARCH)) cross_compiling := 1 @@ -582,23 +586,10 @@ endif # 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 = $(subst $(pound),,$(shell $(CC) --version 2>/dev/null | head -n 1)) +CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1)) ifneq ($(findstring clang,$(CC_VERSION_TEXT)),) -ifneq ($(CROSS_COMPILE),) -CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%)) -endif -ifeq ($(LLVM_IAS),1) -CLANG_FLAGS += -integrated-as -else -CLANG_FLAGS += -no-integrated-as -GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit)) -CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE)) -endif -CLANG_FLAGS += -Werror=unknown-warning-option -KBUILD_CFLAGS += $(CLANG_FLAGS) -KBUILD_AFLAGS += $(CLANG_FLAGS) -export CLANG_FLAGS +include $(srctree)/scripts/Makefile.clang endif # Include this also for config targets because some architectures need @@ -683,9 +674,10 @@ endif # KBUILD_EXTMOD # 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,) +CFLAGS_GCOV := -fprofile-arcs -ftest-coverage +ifdef CONFIG_CC_IS_GCC +CFLAGS_GCOV += -fno-tree-loop-im +endif export CFLAGS_GCOV # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later. @@ -693,12 +685,14 @@ ifdef CONFIG_FUNCTION_TRACER CC_FLAGS_FTRACE := -pg endif -RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register -RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register -RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk -RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline -RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG))) -RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG))) +ifdef CONFIG_CC_IS_GCC +RETPOLINE_CFLAGS := $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register) +RETPOLINE_VDSO_CFLAGS := $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register) +endif +ifdef CONFIG_CC_IS_CLANG +RETPOLINE_CFLAGS := -mretpoline-external-thunk +RETPOLINE_VDSO_CFLAGS := -mretpoline +endif export RETPOLINE_CFLAGS export RETPOLINE_VDSO_CFLAGS @@ -751,7 +745,7 @@ include/config/auto.conf: endif # may-sync-config endif # need-config -KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) +KBUILD_CFLAGS += -fno-delete-null-pointer-checks KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,) KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation) KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow) @@ -766,17 +760,19 @@ KBUILD_CFLAGS += -Os endif # Tell gcc to never replace conditional load with a non-conditional one +ifdef CONFIG_CC_IS_GCC +# gcc-10 renamed --param=allow-store-data-races=0 to +# -fno-allow-store-data-races. KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0) KBUILD_CFLAGS += $(call cc-option,-fno-allow-store-data-races) +endif ifdef CONFIG_READABLE_ASM # Disable optimizations that make assembler listings hard to read. # reorder blocks reorders the control in the function # ipa clone creates specialized cloned functions # partial inlining inlines only parts of functions -KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \ - $(call cc-option,-fno-ipa-cp-clone,) \ - $(call cc-option,-fno-partial-inlining) +KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining endif ifneq ($(CONFIG_FRAME_WARN),0) @@ -789,9 +785,12 @@ stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong KBUILD_CFLAGS += $(stackp-flags-y) +KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror +KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) + ifdef CONFIG_CC_IS_CLANG KBUILD_CPPFLAGS += -Qunused-arguments -KBUILD_CFLAGS += -Wno-format-invalid-specifier +# The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable. KBUILD_CFLAGS += -Wno-gnu # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the # source of a reference will be _MergedGlobals and not on of the whitelisted names. @@ -803,13 +802,15 @@ else # Disabled for clang while comment to attribute conversion happens and # https://github.com/ClangBuiltLinux/linux/issues/636 is discussed. KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=5,) +# gcc inanely warns about local variables called 'main' +KBUILD_CFLAGS += -Wno-main endif # These warnings generated too much noise in a regular build. # Use make W=1 to enable them (see scripts/Makefile.extrawarn) KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) - KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable) + ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls else @@ -841,6 +842,11 @@ endif # for the randomize_kstack_offset feature. Disable it for all compilers. KBUILD_CFLAGS += $(call cc-option, -fno-stack-clash-protection) +# Clear used registers at func exit (to reduce data lifetime and ROP gadgets). +ifdef CONFIG_ZERO_CALL_USED_REGS +KBUILD_CFLAGS += -fzero-call-used-regs=used-gpr +endif + DEBUG_CFLAGS := # Workaround for GCC versions < 5.0 @@ -857,7 +863,7 @@ else DEBUG_CFLAGS += -g endif -ifneq ($(LLVM_IAS),1) +ifndef CONFIG_AS_IS_LLVM KBUILD_AFLAGS += -Wa,-gdwarf-2 endif @@ -868,8 +874,10 @@ DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) endif ifdef CONFIG_DEBUG_INFO_REDUCED -DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \ - $(call cc-option,-fno-var-tracking) +DEBUG_CFLAGS += -fno-var-tracking +ifdef CONFIG_CC_IS_GCC +DEBUG_CFLAGS += -femit-struct-debug-baseonly +endif endif ifdef CONFIG_DEBUG_INFO_COMPRESSED @@ -903,6 +911,7 @@ ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT endif endif ifdef CONFIG_HAVE_FENTRY + # s390-linux-gnu-gcc did not support -mfentry until gcc-9. ifeq ($(call cc-option-yn, -mfentry),y) CC_FLAGS_FTRACE += -mfentry CC_FLAGS_USING += -DCC_USING_FENTRY @@ -915,7 +924,7 @@ endif # We trigger additional mismatches with less inlining ifdef CONFIG_DEBUG_SECTION_MISMATCH -KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once) +KBUILD_CFLAGS += -fno-inline-functions-called-once endif ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION @@ -994,14 +1003,16 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) # We'll want to enable this eventually, but it's not going away for 5.7 at least KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds) -KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds) +KBUILD_CFLAGS += -Wno-array-bounds KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) # Another good warning that we'll want to enable eventually KBUILD_CFLAGS += $(call cc-disable-warning, restrict) # Enabled with W=2, disabled by default as noisy -KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized) +ifdef CONFIG_CC_IS_GCC +KBUILD_CFLAGS += -Wno-maybe-uninitialized +endif # disable invalid "can't wrap" optimizations for signed / pointers KBUILD_CFLAGS += -fno-strict-overflow @@ -1010,7 +1021,9 @@ KBUILD_CFLAGS += -fno-strict-overflow KBUILD_CFLAGS += -fno-stack-check # conserve stack if available -KBUILD_CFLAGS += $(call cc-option,-fconserve-stack) +ifdef CONFIG_CC_IS_GCC +KBUILD_CFLAGS += -fconserve-stack +endif # Prohibit date/time macros, which would make the build non-deterministic KBUILD_CFLAGS += -Werror=date-time @@ -1740,6 +1753,16 @@ clean-dirs := $(KBUILD_EXTMOD) clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \ $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache +PHONY += prepare +# now expand this into a simple variable to reduce the cost of shell evaluations +prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT) +prepare: + @if [ "$(CC_VERSION_TEXT)" != $(CONFIG_CC_VERSION_TEXT) ]; then \ + echo >&2 "warning: the compiler differs from the one used to build the kernel"; \ + echo >&2 " The kernel was built by: "$(CONFIG_CC_VERSION_TEXT); \ + echo >&2 " You are using: $(CC_VERSION_TEXT)"; \ + fi + PHONY += help help: @echo ' Building external modules.' @@ -1751,7 +1774,7 @@ help: @echo '' # no-op for external module builds -PHONY += prepare modules_prepare +PHONY += modules_prepare endif # KBUILD_EXTMOD |