From: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> [ Upstream commit e0de01aafc3dd7b73308106b056ead2d48391905 ] The .config file and the generated include/config/auto.conf can end up out of sync after a set of commands since CONFIG_CROSS_COMPILE_COMPAT_VDSO is not updated correctly. The sequence can be reproduced as follows: $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig [...] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig [set CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-"] $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Which results in: arch/arm64/Makefile:62: CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built even though the compat vDSO has been built: $ file arch/arm64/kernel/vdso32/vdso.so arch/arm64/kernel/vdso32/vdso.so: ELF 32-bit LSB pie executable, ARM, EABI5 version 1 (SYSV), dynamically linked, BuildID[sha1]=c67f6c786f2d2d6f86c71f708595594aa25247f6, stripped A similar case that involves changing the configuration parameter multiple times can be reconducted to the same family of problems. Remove the use of CONFIG_CROSS_COMPILE_COMPAT_VDSO altogether and instead rely on the cross-compiler prefix coming from the environment via CROSS_COMPILE_COMPAT, much like we do for the rest of the kernel. Cc: Will Deacon <will@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Reported-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/arm64/Kconfig | 2 +- arch/arm64/Makefile | 18 +++++------------- arch/arm64/kernel/vdso32/Makefile | 2 -- 3 files changed, 6 insertions(+), 16 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e8cf562838716..f63b824cdc2d3 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -111,7 +111,7 @@ config ARM64 select GENERIC_STRNLEN_USER select GENERIC_TIME_VSYSCALL select GENERIC_GETTIMEOFDAY - select GENERIC_COMPAT_VDSO if (!CPU_BIG_ENDIAN && COMPAT) + select GENERIC_COMPAT_VDSO if (!CPU_BIG_ENDIAN && COMPAT && "$(CROSS_COMPILE_COMPAT)" != "") select HANDLE_DOMAIN_IRQ select HARDIRQS_SW_RESEND select HAVE_PCI diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 61de992bbea3f..9743b50bdee7d 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -47,20 +47,12 @@ $(warning Detected assembler with broken .inst; disassembly will be unreliable) endif endif +COMPATCC ?= $(CROSS_COMPILE_COMPAT)gcc +export COMPATCC + ifeq ($(CONFIG_GENERIC_COMPAT_VDSO), y) - CROSS_COMPILE_COMPAT ?= $(CONFIG_CROSS_COMPILE_COMPAT_VDSO:"%"=%) - - ifeq ($(CONFIG_CC_IS_CLANG), y) - $(warning CROSS_COMPILE_COMPAT is clang, the compat vDSO will not be built) - else ifeq ($(strip $(CROSS_COMPILE_COMPAT)),) - $(warning CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built) - else ifeq ($(shell which $(CROSS_COMPILE_COMPAT)gcc 2> /dev/null),) - $(error $(CROSS_COMPILE_COMPAT)gcc not found, check CROSS_COMPILE_COMPAT) - else - export CROSS_COMPILE_COMPAT - export CONFIG_COMPAT_VDSO := y - compat_vdso := -DCONFIG_COMPAT_VDSO=1 - endif + export CONFIG_COMPAT_VDSO := y + compat_vdso := -DCONFIG_COMPAT_VDSO=1 endif KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst) $(compat_vdso) diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index 1fba0776ed40e..19e0d3115ffe0 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -8,8 +8,6 @@ ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32 include $(srctree)/lib/vdso/Makefile -COMPATCC := $(CROSS_COMPILE_COMPAT)gcc - # Same as cc-*option, but using COMPATCC instead of CC cc32-option = $(call try-run,\ $(COMPATCC) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) -- 2.20.1