@@ -110,7 +110,7 @@ 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 && !COMPATCC_EMPTY)
select HANDLE_DOMAIN_IRQ
select HARDIRQS_SW_RESEND
select HAVE_PCI
@@ -313,6 +313,9 @@ config KASAN_SHADOW_OFFSET
default 0xeffffff900000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
default 0xffffffffffffffff
+config COMPATCC_EMPTY
+ def_bool $(success,test -z "${CROSS_COMPILE_COMPAT}")
+
source "arch/arm64/Kconfig.platforms"
menu "Kernel Features"
@@ -53,20 +53,12 @@ $(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) \
@@ -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))
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. The reason behind it comes from the fact that the master Makefile includes that architecture Makefile twice, once before the syncconfig and one after. Since the synchronization of the files happens only upon syncconfig, the architecture Makefile included before this event does not see the change in configuration. As a consequence of this it is not possible to handle the cross compiler definitions inside the architecture Makefile. Address the problem refactoring the arm64 main Makefile and removing the misleading warnings. As a consequence of this it is not possible anymore to set the compat cross compiler from menuconfig but it requires to be exported via command line. E.g.: $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- CROSS_COMPILE_COMPAT=arm-linux-gnueabihf- Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> --- arch/arm64/Kconfig | 5 ++++- arch/arm64/Makefile | 18 +++++------------- arch/arm64/kernel/vdso32/Makefile | 2 -- 3 files changed, 9 insertions(+), 16 deletions(-)