Commit-ID: 98cd3c3f83fbba27a6bacd75ad12e8388a61a32a Gitweb: https://git.kernel.org/tip/98cd3c3f83fbba27a6bacd75ad12e8388a61a32a Author: Peter Collingbourne <[email protected]> AuthorDate: Fri, 21 Jun 2019 10:52:32 +0100 Committer: Thomas Gleixner <[email protected]> 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 <[email protected]> Signed-off-by: Vincenzo Frascino <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Shijith Thotton <[email protected]> Tested-by: Andre Przywara <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Russell King <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Paul Burton <[email protected]> Cc: Daniel Lezcano <[email protected]> Cc: Mark Salyzyn <[email protected]> Cc: Shuah Khan <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: Rasmus Villemoes <[email protected]> Cc: Huw Davies <[email protected]> Cc: Mark Salyzyn <[email protected]> Link: https://lkml.kernel.org/r/[email protected] --- 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
