Commit fb660794 authored Dec 03, 2018 by Alistair Strachan Committed by Greg Kroah-Hartman Dec 05, 2018

efi/libstub: arm: support building with clang



(commit 41f1c48420709470c51ee0e54b6fb28b956bb4e0 upstream)

When building with CONFIG_EFI and CONFIG_EFI_STUB on ARM, the libstub
Makefile would use -mno-single-pic-base without checking it was
supported by the compiler. As the ARM (32-bit) clang backend does not
support this flag, the build would fail.

This changes the Makefile to check the compiler's support for
-mno-single-pic-base before using it, similar to c1c386681bd7 ("ARM:
8767/1: add support for building ARM kernel with clang").

Signed-off-by: Alistair Strachan <astrachan@google.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[ND: adjusted due to missing commit ce279d374ff3 ("efi/libstub:
 Only disable stackleak plugin for arm64")]
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent c4c29e1b

drivers/firmware/efi/libstub/Makefile

+2 −1

Original line number	Diff line number	Diff line
		@@ -12,7 +12,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2 \

		cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie
		cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \
		-fno-builtin -fpic -mno-single-pic-base
		-fno-builtin -fpic \
		$(call cc-option,-mno-single-pic-base)

		cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt