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| author | Christoph Muellner <christoph.muellner@theobroma-systems.com> | 2018-03-20 11:16:02 +0100 |
|---|---|---|
| committer | Christoph Muellner <christoph.muellner@theobroma-systems.com> | 2018-04-27 08:28:29 +0200 |
| commit | 685aaecf4e90f0c1148222e95629ca562e8093db (patch) | |
| tree | 0da2df49a7973f54a7cd0e1fb8fe48e725ce1621 /arch/arm64/Makefile | |
| parent | 5a0f312409eab96928a95598d440cf54b5cf7153 (diff) | |
arm64: Introduce retpoline for aarch64/arm64.linux-4.16.5-amp
This patch adds retpoline support for aarch64.
This includes:
* Kconfig flag CONFIG_RETPOLINE to enable it
* testing for required compiler support
* generation of external retpoline thunk functions
* patches for the arm64 specific assembly code
* Enable /sys/devices/system/cpu/vulnerabilities
* arm64: retpoline: Use kernel's EXPORT_SYMBOL macro.
* arm64: retpoline: Add thunks for x29 and x30.
* arm64: retpoline: Add function signature for symbol versioning.
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Diffstat (limited to 'arch/arm64/Makefile')
| -rw-r--r-- | arch/arm64/Makefile | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index a8f6aa92a144..8df25a60dbb9 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -88,6 +88,17 @@ ifeq ($(CONFIG_ARM64_MODULE_PLTS),y) KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/arm64/kernel/module.lds endif +RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern +RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC)) +export RETPOLINE_CFLAGS + +# Avoid indirect branches in kernel to deal with Spectre +ifdef CONFIG_RETPOLINE +ifneq ($(RETPOLINE_CFLAGS),) + KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE +endif +endif + # Default value head-y := arch/arm64/kernel/head.o |