From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: John Millikin <john@john-millikin.com>,
Nathan Chancellor <nathan@kernel.org>,
Borislav Petkov <bp@suse.de>, Ard Biesheuvel <ardb@kernel.org>,
Sedat Dilek <sedat.dilek@gmail.com>,
Sasha Levin <sashal@kernel.org>,
clang-built-linux@googlegroups.com
Subject: [PATCH AUTOSEL 4.14 08/16] x86/build: Propagate $(CLANG_FLAGS) to $(REALMODE_FLAGS)
Date: Sun, 2 May 2021 10:05:36 -0400 [thread overview]
Message-ID: <20210502140544.2720138-8-sashal@kernel.org> (raw)
In-Reply-To: <20210502140544.2720138-1-sashal@kernel.org>
From: John Millikin <john@john-millikin.com>
[ Upstream commit 8abe7fc26ad8f28bfdf78adbed56acd1fa93f82d ]
When cross-compiling with Clang, the `$(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>
---
arch/x86/Makefile | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 146aadeb7c8e..844d5a72d2ad 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -41,6 +41,7 @@ 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
--
2.30.2
next prev parent reply other threads:[~2021-05-02 14:07 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-02 14:05 [PATCH AUTOSEL 4.14 01/16] staging: wimax/i2400m: fix byte-order issue Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 02/16] crypto: api - check for ERR pointers in crypto_destroy_tfm() Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 03/16] usb: gadget: uvc: add bInterval checking for HS mode Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 04/16] usb: gadget: f_uac1: validate input parameters Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 05/16] usb: dwc3: gadget: Ignore EP queue requests during bus reset Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 06/16] usb: xhci: Fix port minor revision Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 07/16] PCI: PM: Do not read power state in pci_enable_device_flags() Sasha Levin
2021-05-02 14:05 ` Sasha Levin [this message]
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 09/16] tee: optee: do not check memref size on return from Secure World Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 10/16] perf/arm_pmu_platform: Fix error handling Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 11/16] spi: dln2: Fix reference leak to master Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 12/16] spi: omap-100k: " Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 13/16] platform/x86: thinkpad_acpi: Correct thermal sensor allocation Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 14/16] intel_th: Consistency and off-by-one fix Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 15/16] phy: phy-twl4030-usb: Fix possible use-after-free in twl4030_usb_remove() Sasha Levin
2021-05-02 14:05 ` [PATCH AUTOSEL 4.14 16/16] btrfs: convert logic BUG_ON()'s in replace_path to ASSERT()'s Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210502140544.2720138-8-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=ardb@kernel.org \
--cc=bp@suse.de \
--cc=clang-built-linux@googlegroups.com \
--cc=john@john-millikin.com \
--cc=linux-kernel@vger.kernel.org \
--cc=nathan@kernel.org \
--cc=sedat.dilek@gmail.com \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox