4.9-stable review patch. If anyone has any objections, please let me know.
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From: Alistair Strachan astrachan@google.com
(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 --- drivers/firmware/efi/libstub/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -12,7 +12,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__K
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