selftests/nolibc: add x32 test configuration

Nolibc supports the x32 ABI on x86.
Add a testcase to make sure the support stays functional.

QEMU user does not have support for x32, so skip the test there.

Signed-off-by: Thomas Weißschuh <[email protected]>
Acked-by: Willy Tarreau <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: t-8ch

tools/testing/selftests/nolibc/Makefile.nolibc

@@ -47,6 +47,7 @@ XARCH_riscv      = riscv64
 XARCH            = $(or $(XARCH_$(ARCH)),$(ARCH))
 
 # map from user input variants to their kernel supported architectures
+ARCH_x32         = x86
 ARCH_armthumb    = arm
 ARCH_ppc         = powerpc
 ARCH_ppc64       = powerpc
@@ -68,6 +69,7 @@ ARCH            := $(or $(ARCH_$(XARCH)),$(XARCH))
 # kernel image names by architecture
 IMAGE_i386       = arch/x86/boot/bzImage
 IMAGE_x86_64     = arch/x86/boot/bzImage
+IMAGE_x32        = arch/x86/boot/bzImage
 IMAGE_x86        = arch/x86/boot/bzImage
 IMAGE_arm64      = arch/arm64/boot/Image
 IMAGE_arm        = arch/arm/boot/zImage
@@ -97,6 +99,7 @@ IMAGE_NAME       = $(notdir $(IMAGE))
 # default kernel configurations that appear to be usable
 DEFCONFIG_i386       = defconfig
 DEFCONFIG_x86_64     = defconfig
+DEFCONFIG_x32        = defconfig
 DEFCONFIG_x86        = defconfig
 DEFCONFIG_arm64      = defconfig
 DEFCONFIG_arm        = multi_v7_defconfig
@@ -122,6 +125,7 @@ DEFCONFIG_m68k       = virt_defconfig
 DEFCONFIG_sh4        = rts7751r2dplus_defconfig
 DEFCONFIG            = $(DEFCONFIG_$(XARCH))
 
+EXTRACONFIG_x32       = -e CONFIG_X86_X32_ABI
 EXTRACONFIG_arm       = -e CONFIG_NAMESPACES
 EXTRACONFIG_armthumb  = -e CONFIG_NAMESPACES
 EXTRACONFIG_m68k      = -e CONFIG_BLK_DEV_INITRD
@@ -134,6 +138,7 @@ TEST =
 # QEMU_ARCH: arch names used by qemu
 QEMU_ARCH_i386       = i386
 QEMU_ARCH_x86_64     = x86_64
+QEMU_ARCH_x32        = x86_64
 QEMU_ARCH_x86        = x86_64
 QEMU_ARCH_arm64      = aarch64
 QEMU_ARCH_arm        = arm
@@ -174,6 +179,7 @@ endif
 # QEMU_ARGS : some arch-specific args to pass to qemu
 QEMU_ARGS_i386       = -M pc -append "console=ttyS0,9600 i8042.noaux panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_x86_64     = -M pc -append "console=ttyS0,9600 i8042.noaux panic=-1 $(TEST:%=NOLIBC_TEST=%)"
+QEMU_ARGS_x32        = -M pc -append "console=ttyS0,9600 i8042.noaux panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_x86        = -M pc -append "console=ttyS0,9600 i8042.noaux panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_arm64      = -M virt -cpu cortex-a53 -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_arm        = -M virt -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
@@ -210,6 +216,7 @@ Q=@
 endif
 
 CFLAGS_i386 = $(call cc-option,-m32)
+CFLAGS_x32 = -mx32
 CFLAGS_arm = -marm
 CFLAGS_armthumb = -mthumb -march=armv6t2
 CFLAGS_ppc = -m32 -mbig-endian -mno-vsx $(call cc-option,-mmultiple)
@@ -236,6 +243,11 @@ LDFLAGS :=
 
 LIBGCC := -lgcc
 
+ifeq ($(ARCH),x86)
+# Not needed on x86, probably not present for x32
+LIBGCC :=
+endif
+
 ifneq ($(LLVM),)
 # Not needed for clang
 LIBGCC :=

tools/testing/selftests/nolibc/run-tests.sh

@@ -18,7 +18,7 @@ test_mode=system
 werror=1
 llvm=
 all_archs=(
-	i386 x86_64
+	i386 x86_64 x32
 	arm64 arm armthumb
 	mips32le mips32be mipsn32le mipsn32be mips64le mips64be
 	ppc ppc64 ppc64le
@@ -115,6 +115,7 @@ crosstool_arch() {
 	mips*) echo mips;;
 	s390*) echo s390;;
 	sparc*) echo sparc64;;
+	x32*) echo x86_64;;
 	*) echo "$1";;
 	esac
 }
@@ -192,6 +193,10 @@ test_arch() {
 		echo "Unsupported configuration"
 		return
 	fi
+	if [ "$arch" = "x32" ] && [ "$test_mode" = "user" ]; then
+		echo "Unsupported configuration"
+		return
+	fi
 
 	mkdir -p "$build_dir"
 	swallow_output "${MAKE[@]}" defconfig