Commit-ID: 98cd3c3f83fbba27a6bacd75ad12e8388a61a32a Gitweb: https://git.kernel.org/tip/98cd3c3f83fbba27a6bacd75ad12e8388a61a32a Author: Peter Collingbourne <pcc@xxxxxxxxxx> AuthorDate: Fri, 21 Jun 2019 10:52:32 +0100 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Sat, 22 Jun 2019 21:21:06 +0200 arm64: vdso: Build vDSO with -ffixed-x18 The vDSO needs to be built with x18 reserved in order to accommodate userspace platform ABIs built on top of Linux that use the register to carry inter-procedural state, as provided for by the AAPCS. An example of such a platform ABI is the one that will be used by an upcoming version of Android. Although this change is currently a no-op due to the fact that the vDSO is currently implemented in pure assembly on arm64, it is necessary in order to prepare for using the generic C implementation of the vDSO. [ tglx: Massaged changelog ] Signed-off-by: Peter Collingbourne <pcc@xxxxxxxxxx> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Tested-by: Shijith Thotton <sthotton@xxxxxxxxxxx> Tested-by: Andre Przywara <andre.przywara@xxxxxxx> Cc: linux-arch@xxxxxxxxxxxxxxx Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: linux-mips@xxxxxxxxxxxxxxx Cc: linux-kselftest@xxxxxxxxxxxxxxx Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: Paul Burton <paul.burton@xxxxxxxx> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> Cc: Mark Salyzyn <salyzyn@xxxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Dmitry Safonov <0x7f454c46@xxxxxxxxx> Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Cc: Huw Davies <huw@xxxxxxxxxxxxxxx> Cc: Mark Salyzyn <salyzyn@xxxxxxxxxx> Link: https://lkml.kernel.org/r/20190621095252.32307-6-vincenzo.frascino@xxxxxxx --- arch/arm64/kernel/vdso/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index 3acfc813e966..ec81d28aeb5d 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -20,7 +20,7 @@ obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \ --build-id -n -T -ccflags-y := -fno-common -fno-builtin -fno-stack-protector +ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18 ccflags-y += -DDISABLE_BRANCH_PROFILING VDSO_LDFLAGS := -Bsymbolic
|