This is a note to let you know that I've just added the patch titled
efi/libstub: Add $(CLANG_FLAGS) to x86 flags
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
efi-libstub-add-clang_flags-to-x86-flags.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 50ce99634d2ec57a412feb25aa8c54f5d3404e44
Author: Nathan Chancellor <nathan@xxxxxxxxxx>
Date: Thu Mar 25 17:04:35 2021 -0700
efi/libstub: Add $(CLANG_FLAGS) to x86 flags
[ Upstream commit 58d746c119dfa28e72fc35aacaf3d2a3ac625cd0 ]
When cross compiling x86 on an ARM machine with clang, there are several
errors along the lines of:
arch/x86/include/asm/page_64.h:52:7: error: invalid output constraint '=D' in asm
This happens because the x86 flags in the EFI stub are not derived from
KBUILD_CFLAGS like the other architectures are and the clang flags that
set the target architecture ('--target=') and the path to the GNU cross
tools ('--prefix=') are not present, meaning that the host architecture
is targeted.
These flags are available as $(CLANG_FLAGS) from the main Makefile so
add them to the cflags for x86 so that cross compiling works as expected.
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20210326000435.4785-4-nathan@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 8a94388e38b3..a2ae9c3b9579 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -13,7 +13,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \
-Wno-pointer-sign \
$(call cc-disable-warning, address-of-packed-member) \
$(call cc-disable-warning, gnu) \
- -fno-asynchronous-unwind-tables
+ -fno-asynchronous-unwind-tables \
+ $(CLANG_FLAGS)
# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly
# disable the stackleak plugin
