FROMLIST: BACKPORT: [PATCH 6/6] arm64: Wire up and expose the new compat vDSO

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / arch / arm64 / Makefile

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 67074e612db230cd2a3e1e836097601ce5dd8a85..4239853dd16c32cdf54e44f939c5988a07da2e43 100644 (file)
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -10,13 +10,17 @@
 #
 # Copyright (C) 1995-2001 by Russell King
 
+ifeq ($(CONFIG_RELOCATABLE_KERNEL), y)
+LDFLAGS_vmlinux        :=-p --no-undefined -X -pie -Bsymbolic
+else
 LDFLAGS_vmlinux        :=-p --no-undefined -X
+endif
 CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)
 OBJCOPYFLAGS   :=-O binary -R .note -R .note.gnu.build-id -R .comment -S
 GZFLAGS                :=-9
 
 ifneq ($(CONFIG_RELOCATABLE),)
-LDFLAGS_vmlinux                += -pie
+LDFLAGS_vmlinux                += -pie -Bsymbolic
 endif
 
 KBUILD_DEFCONFIG := defconfig
@@ -30,11 +34,48 @@ $(warning LSE atomics not supported by binutils)
   endif
 endif
 
-KBUILD_CFLAGS  += -mgeneral-regs-only $(lseinstr)
+ifeq ($(CONFIG_COMPAT_VDSO), y)
+  CROSS_COMPILE_ARM32 ?= $(CONFIG_CROSS_COMPILE_ARM32:"%"=%)
+
+  # Check that the user has provided a valid prefix for the 32-bit toolchain.
+  # To prevent selecting the system $(cc-name) by default, the prefix is not
+  # allowed to be empty, unlike CROSS_COMPILE. In the unlikely event that the
+  # system $(cc-name) is actually the 32-bit ARM compiler to be used, the
+  # variable can be set to the dirname (e.g. CROSS_COMPILE_ARM32=/usr/bin/).
+  # Note: this Makefile is read both before and after regenerating the config
+  # (if needed). Any warning appearing before the config has been regenerated
+  # should be ignored. If the error is triggered and you set
+  # CONFIG_CROSS_COMPILE_ARM32, set CROSS_COMPILE_ARM32 to an appropriate value
+  # when invoking make and fix CONFIG_CROSS_COMPILE_ARM32.
+  ifeq ($(CROSS_COMPILE_ARM32),)
+    $(warning CROSS_COMPILE_ARM32 not defined or empty, the compat vDSO will not be built)
+  else ifeq ($(cc-name),clang)
+    export CLANG_TRIPLE_ARM32 ?= $(CROSS_COMPILE_ARM32)
+    export CLANG_TARGET_ARM32 := --target=$(notdir $(CLANG_TRIPLE_ARM32:%-=%))
+    export CONFIG_VDSO32 := y
+    vdso32 := -DCONFIG_VDSO32=1
+  else ifeq ($(shell which $(CROSS_COMPILE_ARM32)$(cc-name) 2> /dev/null),)
+    $(error $(CROSS_COMPILE_ARM32)$(cc-name) not found, check CROSS_COMPILE_ARM32)
+  else
+    export CROSS_COMPILE_ARM32
+    export CONFIG_VDSO32 := y
+    vdso32 := -DCONFIG_VDSO32=1
+  endif
+endif
+
+ifeq ($(cc-name),clang)
+# This is a workaround for https://bugs.llvm.org/show_bug.cgi?id=30792.
+# TODO: revert when this is fixed in LLVM.
+KBUILD_CFLAGS  += -mno-implicit-float
+else
+KBUILD_CFLAGS  += -mgeneral-regs-only
+endif
+KBUILD_CFLAGS  += $(lseinstr) $(vdso32)
 KBUILD_CFLAGS  += -fno-pic
 KBUILD_CFLAGS  += -fno-asynchronous-unwind-tables
 KBUILD_CFLAGS  += $(call cc-option, -mpc-relative-literal-loads)
-KBUILD_AFLAGS  += $(lseinstr)
+KBUILD_CFLAGS  += -fno-pic
+KBUILD_AFLAGS  += $(lseinstr) $(vdso32)
 
 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
 KBUILD_CPPFLAGS        += -mbig-endian
@@ -66,6 +107,10 @@ else
 TEXT_OFFSET := 0x00080000
 endif
 
+ifeq ($(cc-name),clang)
+KBUILD_CFLAGS += $(call cc-disable-warning, asm-operand-widths)
+endif
+
 # KASAN_SHADOW_OFFSET = VA_START + (1 << (VA_BITS - 3)) - (1 << 61)
 # in 32-bit arithmetic
 KASAN_SHADOW_OFFSET := $(shell printf "0x%08x00000000\n" $$(( \
@@ -85,7 +130,7 @@ core-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
 
 # Default target when executing plain make
 ifeq ($(CONFIG_BUILD_ARM64_APPENDED_DTB_IMAGE),y)
-KBUILD_IMAGE   := Image.gz-dtb
+KBUILD_IMAGE   := $(subst $\",,$(CONFIG_BUILD_ARM64_APPENDED_KERNEL_IMAGE_NAME))
 else
 KBUILD_IMAGE   := Image.gz
 endif
@@ -128,6 +173,18 @@ archclean:
        $(Q)$(MAKE) $(clean)=$(boot)
        $(Q)$(MAKE) $(clean)=$(boot)/dts
 
+# We need to generate vdso-offsets.h before compiling certain files in kernel/.
+# In order to do that, we should use the archprepare target, but we can't since
+# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
+# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
+# Therefore we need to generate the header after prepare0 has been made, hence
+# this hack.
+prepare: vdso_prepare
+vdso_prepare: prepare0
+       $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
+       $(if $(CONFIG_VDSO32),$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 \
+                                         include/generated/vdso32-offsets.h)
+
 define archhelp
   echo  '* Image.gz      - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
   echo  '  Image         - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'