[PATCH 0/2] selftests/nolibc: fix loongarch build with recent versions of clang

[PATCH 0/2] selftests/nolibc: fix loongarch build with recent versions of clang

[Thomas Weißschuh]

LLVM 21 switched to -mcmodel=medium for LoongArch64 compilations.
This code model uses R_LARCH_ECALL36 relocations which might not be
supported by GNU ld which the nolibc testsuite uses by default.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
Thomas Weißschuh (2):
      selftests/nolibc: use lld to link loongarch binaries
      selftests/nolibc: error out on linker warnings

 tools/testing/selftests/nolibc/Makefile.nolibc | 1 +
 tools/testing/selftests/nolibc/run-tests.sh    | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)
---
base-commit: 6059e06967aaac9bf736c6cec75b9bccaf5bbe18
change-id: 20251121-nolibc-lld-f32af4983cc0

Best regards,
-- 
Thomas Weißschuh <linux@weissschuh.net>

[PATCH 1/2] selftests/nolibc: use lld to link loongarch binaries

[Thomas Weißschuh]

LLVM 21 switched to -mcmodel=medium for LoongArch64 compilations.
This code model uses R_LARCH_ECALL36 relocations which might not be
supported by GNU ld which to nolibc testsuite uses by default.
ld will not resolve the relocation and all function calls will end up
as busy loops.

Use lld instead.

We can not switch to lld for all LLVM builds, as it does not support all
necessary architectures.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/Makefile.nolibc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/nolibc/Makefile.nolibc b/tools/testing/selftests/nolibc/Makefile.nolibc
index 330e000baeb1..9423f4a959b2 100644
--- a/tools/testing/selftests/nolibc/Makefile.nolibc
+++ b/tools/testing/selftests/nolibc/Makefile.nolibc
@@ -230,6 +230,7 @@ CFLAGS_mipsn32le = -EL -mabi=n32 -fPIC -march=mips64r2
 CFLAGS_mipsn32be = -EB -mabi=n32 -march=mips64r6
 CFLAGS_mips64le = -EL -mabi=64 -march=mips64r6
 CFLAGS_mips64be = -EB -mabi=64 -march=mips64r2
+CFLAGS_loongarch = $(if $(LLVM),-fuse-ld=lld)
 CFLAGS_sparc32 = $(call cc-option,-m32)
 CFLAGS_sh4 = -ml -m4
 ifeq ($(origin XARCH),command line)

-- 
2.52.0

[PATCH 2/2] selftests/nolibc: error out on linker warnings

[Thomas Weißschuh]

If the linker emits warnings these should abort the build.
Otherwise they will be swallowed by run-tests.sh and not shown.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/run-tests.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/run-tests.sh b/tools/testing/selftests/nolibc/run-tests.sh
index e8af1fb505cf..bbe8afbabd3a 100755
--- a/tools/testing/selftests/nolibc/run-tests.sh
+++ b/tools/testing/selftests/nolibc/run-tests.sh
@@ -169,7 +169,7 @@ test_arch() {
 	cross_compile=$(realpath "${download_location}gcc-${crosstool_version}-nolibc/${ct_arch}-${ct_abi}/bin/${ct_arch}-${ct_abi}-")
 	build_dir="${build_location}/${arch}"
 	if [ "$werror" -ne 0 ]; then
-		CFLAGS_EXTRA="$CFLAGS_EXTRA -Werror"
+		CFLAGS_EXTRA="$CFLAGS_EXTRA -Werror -Wl,--fatal-warnings"
 	fi
 	MAKE=(make -f Makefile.nolibc -j"${nproc}" XARCH="${arch}" CROSS_COMPILE="${cross_compile}" LLVM="${llvm}" O="${build_dir}")
 

-- 
2.52.0

Re: [PATCH 0/2] selftests/nolibc: fix loongarch build with recent versions of clang

[Willy Tarreau]

On Sat, Nov 22, 2025 at 12:01:56PM +0100, Thomas Weißschuh wrote:
> LLVM 21 switched to -mcmodel=medium for LoongArch64 compilations.
> This code model uses R_LARCH_ECALL36 relocations which might not be
> supported by GNU ld which the nolibc testsuite uses by default.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

Both patches make sense to me, thanks Thomas!

FWIW for the whole series: Acked-by: Willy Tarreau <w@1wt.eu>

Willy