arm64: Switch to CROSS_COMPILE_COMPAT for vDSO32 compilation

Preparing for upstream commit 0fa97e9403c767a4af63cfb5a3badbbe69426085
("arm64: vdso32: Allow ld.lld to properly link the VDSO") and more.

Signed-off-by: Nauval Rizky <enuma.alrizky@gmail.com>
Signed-off-by: shygosh <mossynine@gmail.com>

arch/arm64/Kconfig

@@ -1471,21 +1471,21 @@ config COMPAT_VDSO
 	help
 	  Warning: a 32-bit toolchain is necessary to build the vDSO. You
 	  must explicitly define which toolchain should be used by setting
-	  CROSS_COMPILE_ARM32 to the prefix of the 32-bit toolchain (same format
-	  as CROSS_COMPILE). If CROSS_COMPILE_ARM32 is empty, a warning will be
+	  CROSS_COMPILE_COMPAT to the prefix of the 32-bit toolchain (same format
+	  as CROSS_COMPILE). If CROSS_COMPILE_COMPAT is empty, a warning will be
 	  printed and the kernel will be built as if COMPAT_VDSO had not been
-	  set. If CROSS_COMPILE_ARM32 is set to an invalid prefix, compilation
+	  set. If CROSS_COMPILE_COMPAT is set to an invalid prefix, compilation
 	  will be aborted.
 
 	  Provide a vDSO to 32-bit processes. It includes the symbols provided
 	  by the vDSO from the 32-bit kernel, so that a 32-bit libc can use
 	  the compat vDSO without modification. It also provides sigreturn
 	  trampolines, replacing the sigreturn page.
 
-config CROSS_COMPILE_ARM32
+config CROSS_COMPILE_COMPAT
 	string "32-bit toolchain prefix"
 	help
-	  Same as setting CROSS_COMPILE_ARM32 in the environment, but saved for
+	  Same as setting CROSS_COMPILE_COMPAT in the environment, but saved for
 	  future builds. The environment variable overrides this config option.
 
 endmenu

arch/arm64/Makefile

@@ -59,33 +59,33 @@ $(warning Detected assembler with broken .inst; disassembly will be unreliable)
 endif
 
 ifeq ($(CONFIG_COMPAT_VDSO), y)
-  CROSS_COMPILE_ARM32 ?= $(CONFIG_CROSS_COMPILE_ARM32:"%"=%)
+  CROSS_COMPILE_COMPAT ?= $(CONFIG_CROSS_COMPILE_COMPAT:"%"=%)
 
   # 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 $(cc-name) is actually the 32-bit ARM compiler to be used, the
-  # variable can be set to the dirname (e.g. CROSS_COMPILE_ARM32=/usr/bin/).
+  # variable can be set to the dirname (e.g. CROSS_COMPILE_COMPAT=/usr/bin/).
   # Note: this Makefile is read both before and after regenerating the config
   # (if needed). Any warning appearing before the config has been regenerated
   # should be ignored. If the error is triggered and you set
-  # CONFIG_CROSS_COMPILE_ARM32, set CROSS_COMPILE_ARM32 to an appropriate value
-  # when invoking make and fix CONFIG_CROSS_COMPILE_ARM32.
-  ifeq ($(CROSS_COMPILE_ARM32),)
-    $(error CROSS_COMPILE_ARM32 not defined or empty, the compat vDSO will not be built)
+  # CONFIG_CROSS_COMPILE_COMPAT, set CROSS_COMPILE_COMPAT to an appropriate value
+  # when invoking make and fix CONFIG_CROSS_COMPILE_COMPAT.
+  ifeq ($(CROSS_COMPILE_COMPAT),)
+    $(error CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built)
   else ifeq ($(cc-name),clang)
-    export CLANG_TRIPLE_ARM32 ?= $(CROSS_COMPILE_ARM32)
+    export CLANG_TRIPLE_ARM32 ?= $(CROSS_COMPILE_COMPAT)
     export CLANG_TARGET_ARM32 := --target=$(notdir $(CLANG_TRIPLE_ARM32:%-=%))
-    export GCC_TOOLCHAIN32_DIR := $(dir $(shell which $(CROSS_COMPILE_ARM32)ld))
+    export GCC_TOOLCHAIN32_DIR := $(dir $(shell which $(CROSS_COMPILE_COMPAT)ld))
     export GCC_TOOLCHAIN32 := $(realpath $(GCC_TOOLCHAIN32_DIR)/..)
-    export CLANG_PREFIX32 := --prefix=$(GCC_TOOLCHAIN32_DIR)$(notdir $(CROSS_COMPILE_ARM32))
+    export CLANG_PREFIX32 := --prefix=$(GCC_TOOLCHAIN32_DIR)$(notdir $(CROSS_COMPILE_COMPAT))
     export CLANG_GCC32_TC := --gcc-toolchain=$(GCC_TOOLCHAIN32)
     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 ifeq ($(shell which $(CROSS_COMPILE_COMPAT)$(cc-name) 2> /dev/null),)
+    $(error $(CROSS_COMPILE_COMPAT)$(cc-name) not found, check CROSS_COMPILE_COMPAT)
   else
-    export CROSS_COMPILE_ARM32
+    export CROSS_COMPILE_COMPAT
     export CONFIG_VDSO32 := y
     vdso32 := -DCONFIG_VDSO32=1
   endif

arch/arm64/kernel/vdso32/Makefile

@@ -7,7 +7,7 @@
 ifeq ($(cc-name),clang)
   CC_ARM32 := $(CC) $(CLANG_TARGET_ARM32) -no-integrated-as $(CLANG_GCC32_TC) $(CLANG_PREFIX32)
 else
-  CC_ARM32 := $(CROSS_COMPILE_ARM32)$(cc-name)
+  CC_ARM32 := $(CROSS_COMPILE_COMPAT)$(cc-name)
 endif
 
 # Same as cc-*option, but using CC_ARM32 instead of CC