arm64: vdso: Enable vDSO compat support
Add vDSO compat support to the arm64 build system.
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shijith Thotton <sthotton@marvell.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Huw Davies <huw@codeweavers.com>
Link: https://lkml.kernel.org/r/20190621095252.32307-16-vincenzo.frascino@arm.com
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index e9d2e57..e3d3fd0 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -49,10 +49,26 @@
endif
endif
-KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst)
+ifeq ($(CONFIG_GENERIC_COMPAT_VDSO), y)
+ CROSS_COMPILE_COMPAT ?= $(CONFIG_CROSS_COMPILE_COMPAT_VDSO:"%"=%)
+
+ ifeq ($(CONFIG_CC_IS_CLANG), y)
+ $(warning CROSS_COMPILE_COMPAT is clang, the compat vDSO will not be built)
+ else ifeq ($(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
+endif
+
+KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst) $(compat_vdso)
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
-KBUILD_AFLAGS += $(lseinstr) $(brokengasinst)
+KBUILD_AFLAGS += $(lseinstr) $(brokengasinst) $(compat_vdso)
KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)
@@ -164,6 +180,9 @@
prepare: vdso_prepare
vdso_prepare: prepare0
$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
+ $(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \
+ $(build)=arch/arm64/kernel/vdso32 \
+ include/generated/vdso32-offsets.h)
endif
define archhelp