Subject: clang nightly builds failing on PowerPc

From: Dan Carpenter <[email-masked]>
Date: Fri, 19 Sep 2025 14:17:41 +0300

Hi the Clang nightly builds are failing on PowerPC with the
ppc64e_defconfig.  They started failing on Sept 11.  Clang is failing on
PowerPC in both linux-next and stable so it seems like something changed
in Clang and not the kernel.

Unfortunately I don't have ready access to the /tmp/vgetrandom-fef220.c
file that was generated, but hopefully these logs are enough to reproduce
the issue.

regards,
dan carpenter

tuxmake --target-arch=powerpc --kconfig=ppc64e_defconfig --toolchain=clang-nightly --wrapper=none --environment=KBUILD_BUILD_TIMESTAMP=@1758237451 --environment=KBUILD_BUILD_USER=tuxmake --environment=KBUILD_BUILD_HOST=tuxmake --environment=KCFLAGS=-ffile-prefix-map=/home/tuxbuild/.cache/tuxmake/builds/1/build/= --runtime=podman --image=855116176053.dkr.ecr.us-east-1.amazonaws.com/tuxmake/powerpc_clang-nightly LLVM=1 LLVM_IAS=0 LD=powerpc64le-linux-gnu-ld config default kernel xipkernel modules dtbs dtbs-legacy debugkernel headers
make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/build ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- HOSTCC=clang CC=clang LLVM=1 LLVM_IAS=0 LD=powerpc64le-linux-gnu-ld ppc64e_defconfig
make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/build ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- HOSTCC=clang CC=clang LLVM=1 LLVM_IAS=0 LD=powerpc64le-linux-gnu-ld
fatal error: error in backend: Cannot select: 0x60f13bcf8910: ch,glue = PPCISD::CALL_NOP 0x60f13bcf5e70, TargetGlobalAddress:i32<ptr @__arch_chacha20_blocks_nostack> 0, Register:i64 $x3, Register:i64 $x4, Register:i64 $x5, Register:i64 $x6, Register:i64 $x2, RegisterMask:Untyped, 0x60f13bcf5e70:1
  0x60f13bcf5e70: ch,glue = CopyToReg 0x60f13bcf8750, Register:i64 $x6, 0x60f13bcf5cb0, 0x60f13bcf8750:1
    0x60f13bcf5cb0: i64 = zero_extend 0x60f13bcf8600
      0x60f13bcf8600: i32 = srl 0x60f13bcf8280, Constant:i32<6>
        0x60f13bcf8280: i32,ch = CopyFromReg 0x60f13bc01ec0, Register:i32 %43
    0x60f13bcf8750: ch,glue = CopyToReg 0x60f13bcf6490, Register:i64 $x5, 0x60f13bcf8440, 0x60f13bcf6490:1
      0x60f13bcf8440: i64 = zero_extend FrameIndex:i32<0>
      0x60f13bcf6490: ch,glue = CopyToReg 0x60f13bcf8590, Register:i64 $x4, 0x60f13bcf69d0, 0x60f13bcf8590:1
        0x60f13bcf69d0: i64 = zero_extend 0x60f13bcf5bd0
          0x60f13bcf5bd0: i32,ch = CopyFromReg 0x60f13bc01ec0, Register:i32 %3
        0x60f13bcf8590: ch,glue = CopyToReg 0x60f13bcf6960, Register:i64 $x3, 0x60f13bcf68f0
          0x60f13bcf68f0: i64 = zero_extend 0x60f13bcf8520
            0x60f13bcf8520: i32,ch = CopyFromReg 0x60f13bc01ec0, Register:i32 %44
In function: __c_kernel_getrandom
clang: error: clang frontend command failed with exit code 70 (use -v to see invocation)
Debian clang version 22.0.0 (++20250917082822+6c8fcd6089b9-1~exp1~20250917203011.86)
Target: powerpc-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm-22/bin
clang: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/vgetrandom-fef220.c
clang: note: diagnostic msg: /tmp/vgetrandom-fef220.sh
clang: note: diagnostic msg: 

********************
fatal error: error in backend: Don't know how to emit this value.
make[3]: *** [/builds/linux/arch/powerpc/kernel/vdso/Makefile:91: arch/powerpc/kernel/vdso/vgetrandom-32.o] Error 1
clang: error: clang frontend command failed with exit code 70 (use -v to see invocation)
Debian clang version 22.0.0 (++20250917082822+6c8fcd6089b9-1~exp1~20250917203011.86)
Target: powerpc-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm-22/bin
clang: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/vgettimeofday-43498a.c
clang: note: diagnostic msg: /tmp/vgettimeofday-43498a.sh
clang: note: diagnostic msg: 

********************
make[3]: *** [/builds/linux/arch/powerpc/kernel/vdso/Makefile:89: arch/powerpc/kernel/vdso/vgettimeofday-32.o] Error 1
make[3]: Target 'include/generated/vdso32-offsets.h' not remade because of errors.
make[2]: *** [/builds/linux/arch/powerpc/Makefile:388: vdso_prepare] Error 2
make[2]: Target '__all' not remade because of errors.
make[1]: *** [/builds/linux/Makefile:248: __sub-make] Error 2
make[1]: Target '__all' not remade because of errors.
make: *** [Makefile:248: __sub-make] Error 2
make: Target '__all' not remade because of errors.
rm -rf /home/tuxbuild/.cache/tuxmake/builds/1/build/modinstall
make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/build INSTALL_MOD_STRIP=1 INSTALL_MOD_PATH=/home/tuxbuild/.cache/tuxmake/builds/1/build/modinstall ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- HOSTCC=clang CC=clang LLVM=1 LLVM_IAS=0 LD=powerpc64le-linux-gnu-ld modules_install
make[3]: *** No rule to make target 'modules.order', needed by '/home/tuxbuild/.cache/tuxmake/builds/1/build/modinstall/lib/modules/6.17.0-rc6/modules.order'.
make[3]: *** No rule to make target 'modules.builtin', needed by '/home/tuxbuild/.cache/tuxmake/builds/1/build/modinstall/lib/modules/6.17.0-rc6/modules.builtin'.
make[3]: *** No rule to make target 'modules.builtin.modinfo', needed by '/home/tuxbuild/.cache/tuxmake/builds/1/build/modinstall/lib/modules/6.17.0-rc6/modules.builtin.modinfo'.
make[3]: Target '__modinst' not remade because of errors.
make[2]: *** [/builds/linux/Makefile:1917: modules_install] Error 2
make[1]: *** [/builds/linux/Makefile:248: __sub-make] Error 2
make[1]: Target 'modules_install' not remade because of errors.
make: *** [Makefile:248: __sub-make] Error 2
make: Target 'modules_install' not remade because of errors.
make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/build INSTALL_DTBS_PATH=/home/tuxbuild/.cache/tuxmake/builds/1/build/dtbsinstall/dtbs ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- HOSTCC=clang CC=clang LLVM=1 LLVM_IAS=0 LD=powerpc64le-linux-gnu-ld dtbs
rm -rf /home/tuxbuild/.cache/tuxmake/builds/1/build/dtbsinstall
mkdir -p /home/tuxbuild/.cache/tuxmake/builds/1/build/dtbsinstall/dtbs
make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/build INSTALL_DTBS_PATH=/home/tuxbuild/.cache/tuxmake/builds/1/build/dtbsinstall/dtbs ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- HOSTCC=clang CC=clang LLVM=1 LLVM_IAS=0 LD=powerpc64le-linux-gnu-ld dtbs_install
tar --sort=name --owner=tuxmake:1000 --group=tuxmake:1000 --mtime=@1758237451 --clamp-mtime -caf /home/tuxbuild/.cache/tuxmake/builds/1/build/dtbs.tar.xz -C /home/tuxbuild/.cache/tuxmake/builds/1/build/dtbsinstall dtbs
rm -rf /home/tuxbuild/.cache/tuxmake/builds/1/build/install_hdr
make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/build INSTALL_HDR_PATH=/home/tuxbuild/.cache/tuxmake/builds/1/build/install_hdr/ ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- HOSTCC=clang CC=clang LLVM=1 LLVM_IAS=0 LD=powerpc64le-linux-gnu-ld headers_install
tar --sort=name --owner=tuxmake:1000 --group=tuxmake:1000 --mtime=@1758237451 --clamp-mtime -caf /home/tuxbuild/.cache/tuxmake/builds/1/build/headers.tar.xz -C /home/tuxbuild/.cache/tuxmake/builds/1/build/install_hdr .