[PATCH 5.4 0/6] Fix build due to clang -Qunused-arguments change

[PATCH 5.4 0/6] Fix build due to clang -Qunused-arguments change

[Nathan Chancellor]

This is an updated version of [1], just for 5.4, which was waiting on
commit 87c4e1459e80 ("ARM: 9448/1: Use an absolute path to unified.h in
KBUILD_AFLAGS") to avoid regressing the build [2].

These changes are needed there due to an upstream LLVM change [3] that
changes the behavior of -Qunused-arguments with unknown target options,
which is only used in 6.1 and older since I removed it in commit
8d9acfce3332 ("kbuild: Stop using '-Qunused-arguments' with clang") in
6.3.

Please let me know if there are any issues.

[1]: https://lore.kernel.org/20250604233141.GA2374479@ax162/
[2]: https://lore.kernel.org/CACo-S-1qbCX4WAVFA63dWfHtrRHZBTyyr2js8Lx=Az03XHTTHg@mail.gmail.com/
[3]: https://github.com/llvm/llvm-project/commit/a4b2f4a72aa9b4655ecc723838830e0a7f29c9ca

Masahiro Yamada (1):
  kbuild: add $(CLANG_FLAGS) to KBUILD_CPPFLAGS

Nathan Chancellor (4):
  ARM: 9448/1: Use an absolute path to unified.h in KBUILD_AFLAGS
  mips: Include KBUILD_CPPFLAGS in CHECKFLAGS invocation
  kbuild: Add CLANG_FLAGS to as-instr
  kbuild: Add KBUILD_CPPFLAGS to as-option invocation

Nick Desaulniers (1):
  kbuild: Update assembler calls to use proper flags and language target

 Makefile               | 3 +--
 arch/arm/Makefile      | 2 +-
 arch/mips/Makefile     | 2 +-
 scripts/Kbuild.include | 8 ++++----
 4 files changed, 7 insertions(+), 8 deletions(-)


base-commit: 04b7726c3cdd2fb4da040c2b898bcf405ed607bd
-- 
2.50.1

[PATCH 5.4 1/6] ARM: 9448/1: Use an absolute path to unified.h in KBUILD_AFLAGS

[Nathan Chancellor]

commit 87c4e1459e80bf65066f864c762ef4dc932fad4b upstream.

After commit d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper
flags and language target"), which updated as-instr to use the
'assembler-with-cpp' language option, the Kbuild version of as-instr
always fails internally for arch/arm with

  <command-line>: fatal error: asm/unified.h: No such file or directory
  compilation terminated.

because '-include' flags are now taken into account by the compiler
driver and as-instr does not have '$(LINUXINCLUDE)', so unified.h is not
found.

This went unnoticed at the time of the Kbuild change because the last
use of as-instr in Kbuild that arch/arm could reach was removed in 5.7
by commit 541ad0150ca4 ("arm: Remove 32bit KVM host support") but a
stable backport of the Kbuild change to before that point exposed this
potential issue if one were to be reintroduced.

Follow the general pattern of '-include' paths throughout the tree and
make unified.h absolute using '$(srctree)' to ensure KBUILD_AFLAGS can
be used independently.

Closes: https://lore.kernel.org/CACo-S-1qbCX4WAVFA63dWfHtrRHZBTyyr2js8Lx=Az03XHTTHg@mail.gmail.com/

Cc: stable@vger.kernel.org
Fixes: d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper flags and language target")
Reported-by: KernelCI bot <bot@kernelci.org>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
[nathan: Fix conflicts]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 arch/arm/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 4f098edfbf20..cb33ed8de5f8 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -136,7 +136,7 @@ endif
 
 # Need -Uarm for gcc < 3.x
 KBUILD_CFLAGS	+=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
-KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
+KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include $(srctree)/arch/arm/include/asm/unified.h -msoft-float
 
 CHECKFLAGS	+= -D__arm__
 
-- 
2.50.1

[PATCH 5.4 2/6] kbuild: Update assembler calls to use proper flags and language target

[Nathan Chancellor]

From: Nick Desaulniers <ndesaulniers@google.com>

commit d5c8d6e0fa61401a729e9eb6a9c7077b2d3aebb0 upstream.

as-instr uses KBUILD_AFLAGS, but as-option uses KBUILD_CFLAGS. This can
cause as-option to fail unexpectedly when CONFIG_WERROR is set, because
clang will emit -Werror,-Wunused-command-line-argument for various -m
and -f flags in KBUILD_CFLAGS for assembler sources.

Callers of as-option and as-instr should be adding flags to
KBUILD_AFLAGS / aflags-y, not KBUILD_CFLAGS / cflags-y. Use
KBUILD_AFLAGS in all macros to clear up the initial problem.

Unfortunately, -Wunused-command-line-argument can still be triggered
with clang by the presence of warning flags or macro definitions because
'-x assembler' is used, instead of '-x assembler-with-cpp', which will
consume these flags. Switch to '-x assembler-with-cpp' in places where
'-x assembler' is used, as the compiler is always used as the driver for
out of line assembler sources in the kernel.

Finally, add -Werror to these macros so that they behave consistently
whether or not CONFIG_WERROR is set.

[nathan: Reworded and expanded on problems in commit message
         Use '-x assembler-with-cpp' in a couple more places]

Link: https://github.com/ClangBuiltLinux/linux/issues/1699
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 scripts/Kbuild.include | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 82eb69f07b35..11f905b95e65 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -99,16 +99,16 @@ try-run = $(shell set -e;		\
 	fi)
 
 # as-option
-# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
+# Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
 
 as-option = $(call try-run,\
-	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) -Werror $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2))
 
 # as-instr
-# Usage: cflags-y += $(call as-instr,instr,option1,option2)
+# Usage: aflags-y += $(call as-instr,instr,option1,option2)
 
 as-instr = $(call try-run,\
-	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
+	printf "%b\n" "$(1)" | $(CC) -Werror $(KBUILD_AFLAGS) -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3))
 
 # __cc-option
 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
-- 
2.50.1

[PATCH 5.4 3/6] mips: Include KBUILD_CPPFLAGS in CHECKFLAGS invocation

[Nathan Chancellor]

commit 08f6554ff90ef189e6b8f0303e57005bddfdd6a7 upstream.

A future change will move CLANG_FLAGS from KBUILD_{A,C}FLAGS to
KBUILD_CPPFLAGS so that '--target' is available while preprocessing.
When that occurs, the following error appears when building ARCH=mips
with clang (tip of tree error shown):

  clang: error: unsupported option '-mabi=' for target 'x86_64-pc-linux-gnu'

Add KBUILD_CPPFLAGS in the CHECKFLAGS invocation to keep everything
working after the move.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 arch/mips/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 4542258027a7..cc6f8265f28c 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -319,7 +319,7 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 KBUILD_LDFLAGS		+= -m $(ld-emul)
 
 ifdef CONFIG_MIPS
-CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
+CHECKFLAGS += $(shell $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
 	egrep -vw '__GNUC_(MINOR_|PATCHLEVEL_)?_' | \
 	sed -e "s/^\#define /-D'/" -e "s/ /'='/" -e "s/$$/'/" -e 's/\$$/&&/g')
 endif
-- 
2.50.1

[PATCH 5.4 4/6] kbuild: Add CLANG_FLAGS to as-instr

[Nathan Chancellor]

commit cff6e7f50bd315e5b39c4e46c704ac587ceb965f upstream.

A future change will move CLANG_FLAGS from KBUILD_{A,C}FLAGS to
KBUILD_CPPFLAGS so that '--target' is available while preprocessing.
When that occurs, the following errors appear multiple times when
building ARCH=powerpc powernv_defconfig:

  ld.lld: error: vmlinux.a(arch/powerpc/kernel/head_64.o):(.text+0x12d4): relocation R_PPC64_ADDR16_HI out of range: -4611686018409717520 is not in [-2147483648, 2147483647]; references '__start___soft_mask_table'
  ld.lld: error: vmlinux.a(arch/powerpc/kernel/head_64.o):(.text+0x12e8): relocation R_PPC64_ADDR16_HI out of range: -4611686018409717392 is not in [-2147483648, 2147483647]; references '__stop___soft_mask_table'

Diffing the .o.cmd files reveals that -DHAVE_AS_ATHIGH=1 is not present
anymore, because as-instr only uses KBUILD_AFLAGS, which will no longer
contain '--target'.

Mirror Kconfig's as-instr and add CLANG_FLAGS explicitly to the
invocation to ensure the target information is always present.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 scripts/Kbuild.include | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 11f905b95e65..b01d3108596b 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -108,7 +108,7 @@ as-option = $(call try-run,\
 # Usage: aflags-y += $(call as-instr,instr,option1,option2)
 
 as-instr = $(call try-run,\
-	printf "%b\n" "$(1)" | $(CC) -Werror $(KBUILD_AFLAGS) -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3))
+	printf "%b\n" "$(1)" | $(CC) -Werror $(CLANG_FLAGS) $(KBUILD_AFLAGS) -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3))
 
 # __cc-option
 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
-- 
2.50.1

[PATCH 5.4 5/6] kbuild: add $(CLANG_FLAGS) to KBUILD_CPPFLAGS

[Nathan Chancellor]

From: Masahiro Yamada <masahiroy@kernel.org>

commit feb843a469fb0ab00d2d23cfb9bcc379791011bb upstream.

When preprocessing arch/*/kernel/vmlinux.lds.S, the target triple is
not passed to $(CPP) because we add it only to KBUILD_{C,A}FLAGS.

As a result, the linker script is preprocessed with predefined macros
for the build host instead of the target.

Assuming you use an x86 build machine, compare the following:

 $ clang -dM -E -x c /dev/null
 $ clang -dM -E -x c /dev/null -target aarch64-linux-gnu

There is no actual problem presumably because our linker scripts do not
rely on such predefined macros, but it is better to define correct ones.

Move $(CLANG_FLAGS) to KBUILD_CPPFLAGS, so that all *.c, *.S, *.lds.S
will be processed with the proper target triple.

[Note]
After the patch submission, we got an actual problem that needs this
commit. (CBL issue 1859)

Link: https://github.com/ClangBuiltLinux/linux/issues/1859
Reported-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index f65e282f4a3f..16a23aaaa547 100644
--- a/Makefile
+++ b/Makefile
@@ -568,8 +568,7 @@ ifneq ($(LLVM_IAS),1)
 CLANG_FLAGS	+= -no-integrated-as
 endif
 CLANG_FLAGS	+= -Werror=unknown-warning-option
-KBUILD_CFLAGS	+= $(CLANG_FLAGS)
-KBUILD_AFLAGS	+= $(CLANG_FLAGS)
+KBUILD_CPPFLAGS	+= $(CLANG_FLAGS)
 export CLANG_FLAGS
 endif
 
-- 
2.50.1

[PATCH 5.4 6/6] kbuild: Add KBUILD_CPPFLAGS to as-option invocation

[Nathan Chancellor]

commit 43fc0a99906e04792786edf8534d8d58d1e9de0c upstream.

After commit feb843a469fb ("kbuild: add $(CLANG_FLAGS) to
KBUILD_CPPFLAGS"), there is an error while building certain PowerPC
assembly files with clang:

  arch/powerpc/lib/copypage_power7.S: Assembler messages:
  arch/powerpc/lib/copypage_power7.S:34: Error: junk at end of line: `0b01000'
  arch/powerpc/lib/copypage_power7.S:35: Error: junk at end of line: `0b01010'
  arch/powerpc/lib/copypage_power7.S:37: Error: junk at end of line: `0b01000'
  arch/powerpc/lib/copypage_power7.S:38: Error: junk at end of line: `0b01010'
  arch/powerpc/lib/copypage_power7.S:40: Error: junk at end of line: `0b01010'
  clang: error: assembler command failed with exit code 1 (use -v to see invocation)

as-option only uses KBUILD_AFLAGS, so after removing CLANG_FLAGS from
KBUILD_AFLAGS, there is no more '--target=' or '--prefix=' flags. As a
result of those missing flags, the host target
will be tested during as-option calls and likely fail, meaning necessary
flags may not get added when building assembly files, resulting in
errors like seen above.

Add KBUILD_CPPFLAGS to as-option invocations to clear up the errors.
This should have been done in commit d5c8d6e0fa61 ("kbuild: Update
assembler calls to use proper flags and language target"), which
switched from using the assembler target to the assembler-with-cpp
target, so flags that affect preprocessing are passed along in all
relevant tests. as-option now mirrors cc-option.

Fixes: feb843a469fb ("kbuild: add $(CLANG_FLAGS) to KBUILD_CPPFLAGS")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/CA+G9fYs=koW9WardsTtora+nMgLR3raHz-LSLr58tgX4T5Mxag@mail.gmail.com/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 scripts/Kbuild.include | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index b01d3108596b..4d2b8e659747 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -102,7 +102,7 @@ try-run = $(shell set -e;		\
 # Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
 
 as-option = $(call try-run,\
-	$(CC) -Werror $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2))
 
 # as-instr
 # Usage: aflags-y += $(call as-instr,instr,option1,option2)
-- 
2.50.1

Patch "ARM: 9448/1: Use an absolute path to unified.h in KBUILD_AFLAGS" has been added to the 5.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ARM: 9448/1: Use an absolute path to unified.h in KBUILD_AFLAGS

to the 5.4-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:
     arm-9448-1-use-an-absolute-path-to-unified.h-in-kbuild_aflags.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From stable+bounces-167082-greg=kroah.com@vger.kernel.org Tue Aug 12 01:52:48 2025
From: Nathan Chancellor <nathan@kernel.org>
Date: Mon, 11 Aug 2025 16:51:46 -0700
Subject: ARM: 9448/1: Use an absolute path to unified.h in KBUILD_AFLAGS
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Sasha Levin <sashal@kernel.org>
Cc: stable@vger.kernel.org, llvm@lists.linux.dev
Message-ID: <20250811235151.1108688-2-nathan@kernel.org>

From: Nathan Chancellor <nathan@kernel.org>

commit 87c4e1459e80bf65066f864c762ef4dc932fad4b upstream.

After commit d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper
flags and language target"), which updated as-instr to use the
'assembler-with-cpp' language option, the Kbuild version of as-instr
always fails internally for arch/arm with

  <command-line>: fatal error: asm/unified.h: No such file or directory
  compilation terminated.

because '-include' flags are now taken into account by the compiler
driver and as-instr does not have '$(LINUXINCLUDE)', so unified.h is not
found.

This went unnoticed at the time of the Kbuild change because the last
use of as-instr in Kbuild that arch/arm could reach was removed in 5.7
by commit 541ad0150ca4 ("arm: Remove 32bit KVM host support") but a
stable backport of the Kbuild change to before that point exposed this
potential issue if one were to be reintroduced.

Follow the general pattern of '-include' paths throughout the tree and
make unified.h absolute using '$(srctree)' to ensure KBUILD_AFLAGS can
be used independently.

Closes: https://lore.kernel.org/CACo-S-1qbCX4WAVFA63dWfHtrRHZBTyyr2js8Lx=Az03XHTTHg@mail.gmail.com/

Cc: stable@vger.kernel.org
Fixes: d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper flags and language target")
Reported-by: KernelCI bot <bot@kernelci.org>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
[nathan: Fix conflicts]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm/Makefile |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -136,7 +136,7 @@ endif
 
 # Need -Uarm for gcc < 3.x
 KBUILD_CFLAGS	+=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
-KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
+KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include $(srctree)/arch/arm/include/asm/unified.h -msoft-float
 
 CHECKFLAGS	+= -D__arm__
 


Patches currently in stable-queue which might be from nathan@kernel.org are

queue-5.4/kbuild-add-clang_flags-to-as-instr.patch
queue-5.4/wifi-brcmsmac-remove-const-from-tbl_ptr-parameter-in-wlc_lcnphy_common_read_table.patch
queue-5.4/mips-include-kbuild_cppflags-in-checkflags-invocation.patch
queue-5.4/kbuild-add-clang_flags-to-kbuild_cppflags.patch
queue-5.4/ftrace-also-allocate-and-copy-hash-for-reading-of-filter-files.patch
queue-5.4/memstick-core-zero-initialize-id_reg-in-h_memstick_read_dev_id.patch
queue-5.4/kbuild-update-assembler-calls-to-use-proper-flags-and-language-target.patch
queue-5.4/phonet-pep-move-call-to-pn_skb_get_dst_sockaddr-earlier-in-pep_sock_accept.patch
queue-5.4/arm-9448-1-use-an-absolute-path-to-unified.h-in-kbuild_aflags.patch
queue-5.4/kbuild-add-kbuild_cppflags-to-as-option-invocation.patch
queue-5.4/usb-atm-cxacru-merge-cxacru_upload_firmware-into-cxacru_heavy_init.patch

Patch "kbuild: Add CLANG_FLAGS to as-instr" has been added to the 5.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    kbuild: Add CLANG_FLAGS to as-instr

to the 5.4-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:
     kbuild-add-clang_flags-to-as-instr.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From stable+bounces-167085-greg=kroah.com@vger.kernel.org Tue Aug 12 01:52:35 2025
From: Nathan Chancellor <nathan@kernel.org>
Date: Mon, 11 Aug 2025 16:51:49 -0700
Subject: kbuild: Add CLANG_FLAGS to as-instr
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Sasha Levin <sashal@kernel.org>
Cc: stable@vger.kernel.org, llvm@lists.linux.dev
Message-ID: <20250811235151.1108688-5-nathan@kernel.org>

From: Nathan Chancellor <nathan@kernel.org>

commit cff6e7f50bd315e5b39c4e46c704ac587ceb965f upstream.

A future change will move CLANG_FLAGS from KBUILD_{A,C}FLAGS to
KBUILD_CPPFLAGS so that '--target' is available while preprocessing.
When that occurs, the following errors appear multiple times when
building ARCH=powerpc powernv_defconfig:

  ld.lld: error: vmlinux.a(arch/powerpc/kernel/head_64.o):(.text+0x12d4): relocation R_PPC64_ADDR16_HI out of range: -4611686018409717520 is not in [-2147483648, 2147483647]; references '__start___soft_mask_table'
  ld.lld: error: vmlinux.a(arch/powerpc/kernel/head_64.o):(.text+0x12e8): relocation R_PPC64_ADDR16_HI out of range: -4611686018409717392 is not in [-2147483648, 2147483647]; references '__stop___soft_mask_table'

Diffing the .o.cmd files reveals that -DHAVE_AS_ATHIGH=1 is not present
anymore, because as-instr only uses KBUILD_AFLAGS, which will no longer
contain '--target'.

Mirror Kconfig's as-instr and add CLANG_FLAGS explicitly to the
invocation to ensure the target information is always present.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 scripts/Kbuild.include |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -108,7 +108,7 @@ as-option = $(call try-run,\
 # Usage: aflags-y += $(call as-instr,instr,option1,option2)
 
 as-instr = $(call try-run,\
-	printf "%b\n" "$(1)" | $(CC) -Werror $(KBUILD_AFLAGS) -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3))
+	printf "%b\n" "$(1)" | $(CC) -Werror $(CLANG_FLAGS) $(KBUILD_AFLAGS) -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3))
 
 # __cc-option
 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)


Patches currently in stable-queue which might be from nathan@kernel.org are

queue-5.4/kbuild-add-clang_flags-to-as-instr.patch
queue-5.4/wifi-brcmsmac-remove-const-from-tbl_ptr-parameter-in-wlc_lcnphy_common_read_table.patch
queue-5.4/mips-include-kbuild_cppflags-in-checkflags-invocation.patch
queue-5.4/kbuild-add-clang_flags-to-kbuild_cppflags.patch
queue-5.4/ftrace-also-allocate-and-copy-hash-for-reading-of-filter-files.patch
queue-5.4/memstick-core-zero-initialize-id_reg-in-h_memstick_read_dev_id.patch
queue-5.4/kbuild-update-assembler-calls-to-use-proper-flags-and-language-target.patch
queue-5.4/phonet-pep-move-call-to-pn_skb_get_dst_sockaddr-earlier-in-pep_sock_accept.patch
queue-5.4/arm-9448-1-use-an-absolute-path-to-unified.h-in-kbuild_aflags.patch
queue-5.4/kbuild-add-kbuild_cppflags-to-as-option-invocation.patch
queue-5.4/usb-atm-cxacru-merge-cxacru_upload_firmware-into-cxacru_heavy_init.patch

Patch "kbuild: add $(CLANG_FLAGS) to KBUILD_CPPFLAGS" has been added to the 5.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    kbuild: add $(CLANG_FLAGS) to KBUILD_CPPFLAGS

to the 5.4-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:
     kbuild-add-clang_flags-to-kbuild_cppflags.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From stable+bounces-167086-greg=kroah.com@vger.kernel.org Tue Aug 12 01:53:32 2025
From: Nathan Chancellor <nathan@kernel.org>
Date: Mon, 11 Aug 2025 16:51:50 -0700
Subject: kbuild: add $(CLANG_FLAGS) to KBUILD_CPPFLAGS
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Sasha Levin <sashal@kernel.org>
Cc: stable@vger.kernel.org, llvm@lists.linux.dev
Message-ID: <20250811235151.1108688-6-nathan@kernel.org>

From: Masahiro Yamada <masahiroy@kernel.org>

commit feb843a469fb0ab00d2d23cfb9bcc379791011bb upstream.

When preprocessing arch/*/kernel/vmlinux.lds.S, the target triple is
not passed to $(CPP) because we add it only to KBUILD_{C,A}FLAGS.

As a result, the linker script is preprocessed with predefined macros
for the build host instead of the target.

Assuming you use an x86 build machine, compare the following:

 $ clang -dM -E -x c /dev/null
 $ clang -dM -E -x c /dev/null -target aarch64-linux-gnu

There is no actual problem presumably because our linker scripts do not
rely on such predefined macros, but it is better to define correct ones.

Move $(CLANG_FLAGS) to KBUILD_CPPFLAGS, so that all *.c, *.S, *.lds.S
will be processed with the proper target triple.

[Note]
After the patch submission, we got an actual problem that needs this
commit. (CBL issue 1859)

Link: https://github.com/ClangBuiltLinux/linux/issues/1859
Reported-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 Makefile |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/Makefile
+++ b/Makefile
@@ -568,8 +568,7 @@ ifneq ($(LLVM_IAS),1)
 CLANG_FLAGS	+= -no-integrated-as
 endif
 CLANG_FLAGS	+= -Werror=unknown-warning-option
-KBUILD_CFLAGS	+= $(CLANG_FLAGS)
-KBUILD_AFLAGS	+= $(CLANG_FLAGS)
+KBUILD_CPPFLAGS	+= $(CLANG_FLAGS)
 export CLANG_FLAGS
 endif
 


Patches currently in stable-queue which might be from nathan@kernel.org are

queue-5.4/kbuild-add-clang_flags-to-as-instr.patch
queue-5.4/wifi-brcmsmac-remove-const-from-tbl_ptr-parameter-in-wlc_lcnphy_common_read_table.patch
queue-5.4/mips-include-kbuild_cppflags-in-checkflags-invocation.patch
queue-5.4/kbuild-add-clang_flags-to-kbuild_cppflags.patch
queue-5.4/ftrace-also-allocate-and-copy-hash-for-reading-of-filter-files.patch
queue-5.4/memstick-core-zero-initialize-id_reg-in-h_memstick_read_dev_id.patch
queue-5.4/kbuild-update-assembler-calls-to-use-proper-flags-and-language-target.patch
queue-5.4/phonet-pep-move-call-to-pn_skb_get_dst_sockaddr-earlier-in-pep_sock_accept.patch
queue-5.4/arm-9448-1-use-an-absolute-path-to-unified.h-in-kbuild_aflags.patch
queue-5.4/kbuild-add-kbuild_cppflags-to-as-option-invocation.patch
queue-5.4/usb-atm-cxacru-merge-cxacru_upload_firmware-into-cxacru_heavy_init.patch

Patch "kbuild: Add KBUILD_CPPFLAGS to as-option invocation" has been added to the 5.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    kbuild: Add KBUILD_CPPFLAGS to as-option invocation

to the 5.4-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:
     kbuild-add-kbuild_cppflags-to-as-option-invocation.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From stable+bounces-167087-greg=kroah.com@vger.kernel.org Tue Aug 12 01:53:34 2025
From: Nathan Chancellor <nathan@kernel.org>
Date: Mon, 11 Aug 2025 16:51:51 -0700
Subject: kbuild: Add KBUILD_CPPFLAGS to as-option invocation
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Sasha Levin <sashal@kernel.org>
Cc: stable@vger.kernel.org, llvm@lists.linux.dev
Message-ID: <20250811235151.1108688-7-nathan@kernel.org>

From: Nathan Chancellor <nathan@kernel.org>

commit 43fc0a99906e04792786edf8534d8d58d1e9de0c upstream.

After commit feb843a469fb ("kbuild: add $(CLANG_FLAGS) to
KBUILD_CPPFLAGS"), there is an error while building certain PowerPC
assembly files with clang:

  arch/powerpc/lib/copypage_power7.S: Assembler messages:
  arch/powerpc/lib/copypage_power7.S:34: Error: junk at end of line: `0b01000'
  arch/powerpc/lib/copypage_power7.S:35: Error: junk at end of line: `0b01010'
  arch/powerpc/lib/copypage_power7.S:37: Error: junk at end of line: `0b01000'
  arch/powerpc/lib/copypage_power7.S:38: Error: junk at end of line: `0b01010'
  arch/powerpc/lib/copypage_power7.S:40: Error: junk at end of line: `0b01010'
  clang: error: assembler command failed with exit code 1 (use -v to see invocation)

as-option only uses KBUILD_AFLAGS, so after removing CLANG_FLAGS from
KBUILD_AFLAGS, there is no more '--target=' or '--prefix=' flags. As a
result of those missing flags, the host target
will be tested during as-option calls and likely fail, meaning necessary
flags may not get added when building assembly files, resulting in
errors like seen above.

Add KBUILD_CPPFLAGS to as-option invocations to clear up the errors.
This should have been done in commit d5c8d6e0fa61 ("kbuild: Update
assembler calls to use proper flags and language target"), which
switched from using the assembler target to the assembler-with-cpp
target, so flags that affect preprocessing are passed along in all
relevant tests. as-option now mirrors cc-option.

Fixes: feb843a469fb ("kbuild: add $(CLANG_FLAGS) to KBUILD_CPPFLAGS")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/CA+G9fYs=koW9WardsTtora+nMgLR3raHz-LSLr58tgX4T5Mxag@mail.gmail.com/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 scripts/Kbuild.include |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -102,7 +102,7 @@ try-run = $(shell set -e;		\
 # Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
 
 as-option = $(call try-run,\
-	$(CC) -Werror $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2))
 
 # as-instr
 # Usage: aflags-y += $(call as-instr,instr,option1,option2)


Patches currently in stable-queue which might be from nathan@kernel.org are

queue-5.4/kbuild-add-clang_flags-to-as-instr.patch
queue-5.4/wifi-brcmsmac-remove-const-from-tbl_ptr-parameter-in-wlc_lcnphy_common_read_table.patch
queue-5.4/mips-include-kbuild_cppflags-in-checkflags-invocation.patch
queue-5.4/kbuild-add-clang_flags-to-kbuild_cppflags.patch
queue-5.4/ftrace-also-allocate-and-copy-hash-for-reading-of-filter-files.patch
queue-5.4/memstick-core-zero-initialize-id_reg-in-h_memstick_read_dev_id.patch
queue-5.4/kbuild-update-assembler-calls-to-use-proper-flags-and-language-target.patch
queue-5.4/phonet-pep-move-call-to-pn_skb_get_dst_sockaddr-earlier-in-pep_sock_accept.patch
queue-5.4/arm-9448-1-use-an-absolute-path-to-unified.h-in-kbuild_aflags.patch
queue-5.4/kbuild-add-kbuild_cppflags-to-as-option-invocation.patch
queue-5.4/usb-atm-cxacru-merge-cxacru_upload_firmware-into-cxacru_heavy_init.patch

Patch "mips: Include KBUILD_CPPFLAGS in CHECKFLAGS invocation" has been added to the 5.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mips: Include KBUILD_CPPFLAGS in CHECKFLAGS invocation

to the 5.4-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:
     mips-include-kbuild_cppflags-in-checkflags-invocation.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From stable+bounces-167084-greg=kroah.com@vger.kernel.org Tue Aug 12 01:52:33 2025
From: Nathan Chancellor <nathan@kernel.org>
Date: Mon, 11 Aug 2025 16:51:48 -0700
Subject: mips: Include KBUILD_CPPFLAGS in CHECKFLAGS invocation
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Sasha Levin <sashal@kernel.org>
Cc: stable@vger.kernel.org, llvm@lists.linux.dev
Message-ID: <20250811235151.1108688-4-nathan@kernel.org>

From: Nathan Chancellor <nathan@kernel.org>

commit 08f6554ff90ef189e6b8f0303e57005bddfdd6a7 upstream.

A future change will move CLANG_FLAGS from KBUILD_{A,C}FLAGS to
KBUILD_CPPFLAGS so that '--target' is available while preprocessing.
When that occurs, the following error appears when building ARCH=mips
with clang (tip of tree error shown):

  clang: error: unsupported option '-mabi=' for target 'x86_64-pc-linux-gnu'

Add KBUILD_CPPFLAGS in the CHECKFLAGS invocation to keep everything
working after the move.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/mips/Makefile |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -319,7 +319,7 @@ KBUILD_CFLAGS += -fno-asynchronous-unwin
 KBUILD_LDFLAGS		+= -m $(ld-emul)
 
 ifdef CONFIG_MIPS
-CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
+CHECKFLAGS += $(shell $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
 	egrep -vw '__GNUC_(MINOR_|PATCHLEVEL_)?_' | \
 	sed -e "s/^\#define /-D'/" -e "s/ /'='/" -e "s/$$/'/" -e 's/\$$/&&/g')
 endif


Patches currently in stable-queue which might be from nathan@kernel.org are

queue-5.4/kbuild-add-clang_flags-to-as-instr.patch
queue-5.4/wifi-brcmsmac-remove-const-from-tbl_ptr-parameter-in-wlc_lcnphy_common_read_table.patch
queue-5.4/mips-include-kbuild_cppflags-in-checkflags-invocation.patch
queue-5.4/kbuild-add-clang_flags-to-kbuild_cppflags.patch
queue-5.4/ftrace-also-allocate-and-copy-hash-for-reading-of-filter-files.patch
queue-5.4/memstick-core-zero-initialize-id_reg-in-h_memstick_read_dev_id.patch
queue-5.4/kbuild-update-assembler-calls-to-use-proper-flags-and-language-target.patch
queue-5.4/phonet-pep-move-call-to-pn_skb_get_dst_sockaddr-earlier-in-pep_sock_accept.patch
queue-5.4/arm-9448-1-use-an-absolute-path-to-unified.h-in-kbuild_aflags.patch
queue-5.4/kbuild-add-kbuild_cppflags-to-as-option-invocation.patch
queue-5.4/usb-atm-cxacru-merge-cxacru_upload_firmware-into-cxacru_heavy_init.patch

Patch "kbuild: Update assembler calls to use proper flags and language target" has been added to the 5.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    kbuild: Update assembler calls to use proper flags and language target

to the 5.4-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:
     kbuild-update-assembler-calls-to-use-proper-flags-and-language-target.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From stable+bounces-167083-greg=kroah.com@vger.kernel.org Tue Aug 12 01:52:49 2025
From: Nathan Chancellor <nathan@kernel.org>
Date: Mon, 11 Aug 2025 16:51:47 -0700
Subject: kbuild: Update assembler calls to use proper flags and language target
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Sasha Levin <sashal@kernel.org>
Cc: stable@vger.kernel.org, llvm@lists.linux.dev
Message-ID: <20250811235151.1108688-3-nathan@kernel.org>

From: Nick Desaulniers <ndesaulniers@google.com>

commit d5c8d6e0fa61401a729e9eb6a9c7077b2d3aebb0 upstream.

as-instr uses KBUILD_AFLAGS, but as-option uses KBUILD_CFLAGS. This can
cause as-option to fail unexpectedly when CONFIG_WERROR is set, because
clang will emit -Werror,-Wunused-command-line-argument for various -m
and -f flags in KBUILD_CFLAGS for assembler sources.

Callers of as-option and as-instr should be adding flags to
KBUILD_AFLAGS / aflags-y, not KBUILD_CFLAGS / cflags-y. Use
KBUILD_AFLAGS in all macros to clear up the initial problem.

Unfortunately, -Wunused-command-line-argument can still be triggered
with clang by the presence of warning flags or macro definitions because
'-x assembler' is used, instead of '-x assembler-with-cpp', which will
consume these flags. Switch to '-x assembler-with-cpp' in places where
'-x assembler' is used, as the compiler is always used as the driver for
out of line assembler sources in the kernel.

Finally, add -Werror to these macros so that they behave consistently
whether or not CONFIG_WERROR is set.

[nathan: Reworded and expanded on problems in commit message
         Use '-x assembler-with-cpp' in a couple more places]

Link: https://github.com/ClangBuiltLinux/linux/issues/1699
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 scripts/Kbuild.include |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -99,16 +99,16 @@ try-run = $(shell set -e;		\
 	fi)
 
 # as-option
-# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
+# Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
 
 as-option = $(call try-run,\
-	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) -Werror $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2))
 
 # as-instr
-# Usage: cflags-y += $(call as-instr,instr,option1,option2)
+# Usage: aflags-y += $(call as-instr,instr,option1,option2)
 
 as-instr = $(call try-run,\
-	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
+	printf "%b\n" "$(1)" | $(CC) -Werror $(KBUILD_AFLAGS) -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3))
 
 # __cc-option
 # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)


Patches currently in stable-queue which might be from nathan@kernel.org are

queue-5.4/kbuild-add-clang_flags-to-as-instr.patch
queue-5.4/wifi-brcmsmac-remove-const-from-tbl_ptr-parameter-in-wlc_lcnphy_common_read_table.patch
queue-5.4/mips-include-kbuild_cppflags-in-checkflags-invocation.patch
queue-5.4/kbuild-add-clang_flags-to-kbuild_cppflags.patch
queue-5.4/ftrace-also-allocate-and-copy-hash-for-reading-of-filter-files.patch
queue-5.4/memstick-core-zero-initialize-id_reg-in-h_memstick_read_dev_id.patch
queue-5.4/kbuild-update-assembler-calls-to-use-proper-flags-and-language-target.patch
queue-5.4/phonet-pep-move-call-to-pn_skb_get_dst_sockaddr-earlier-in-pep_sock_accept.patch
queue-5.4/arm-9448-1-use-an-absolute-path-to-unified.h-in-kbuild_aflags.patch
queue-5.4/kbuild-add-kbuild_cppflags-to-as-option-invocation.patch
queue-5.4/usb-atm-cxacru-merge-cxacru_upload_firmware-into-cxacru_heavy_init.patch