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| author | John Millikin <john@john-millikin.com> | 2021-03-25 17:04:33 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-22 10:38:17 +0200 |
| commit | 95f98ee1b46d470554abdee020c0740bcfff44a1 (patch) | |
| tree | 6d67b407ef891c949663b5a40fcfc72c52fa6d9d | |
| parent | 8e22771a3b142da0aac674671a55d7587aa0117f (diff) | |
x86/build: Propagate $(CLANG_FLAGS) to $(REALMODE_FLAGS)
[ Upstream commit 8abe7fc26ad8f28bfdf78adbed56acd1fa93f82d ]
When cross-compiling with Clang, the `$(CLANG_FLAGS)' variable
contains additional flags needed to build C and assembly sources
for the target platform. Normally this variable is automatically
included in `$(KBUILD_CFLAGS)' via the top-level Makefile.
The x86 real-mode makefile builds `$(REALMODE_CFLAGS)' from a
plain assignment and therefore drops the Clang flags. This causes
Clang to not recognize x86-specific assembler directives:
arch/x86/realmode/rm/header.S:36:1: error: unknown directive
.type real_mode_header STT_OBJECT ; .size real_mode_header, .-real_mode_header
^
Explicit propagation of `$(CLANG_FLAGS)' to `$(REALMODE_CFLAGS)',
which is inherited by real-mode make rules, fixes cross-compilation
with Clang for x86 targets.
Relevant flags:
* `--target' sets the target architecture when cross-compiling. This
flag must be set for both compilation and assembly (`KBUILD_AFLAGS')
to support architecture-specific assembler directives.
* `-no-integrated-as' tells clang to assemble with GNU Assembler
instead of its built-in LLVM assembler. This flag is set by default
unless `LLVM_IAS=1' is set, because the LLVM assembler can't yet
parse certain GNU extensions.
Signed-off-by: John Millikin <john@john-millikin.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Link: https://lkml.kernel.org/r/20210326000435.4785-2-nathan@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/x86/Makefile | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 2b3adb3008c3..c0045e3ad0f5 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -40,6 +40,7 @@ REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector) REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member) REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4)) +REALMODE_CFLAGS += $(CLANG_FLAGS) export REALMODE_CFLAGS # BITS is used as extension for files which are available in a 32 bit |