Segmentation Fault using GCC 8.3 + LTO in kernel 4.14

[rhilderm]

Hi,
We have been using kernel 4.14 with your 4.15.8 patches ported back and additional patches changes we've made for arm. Building using Yocto sumo so picked up GNU toolchain 6.x. Everything was working with wonderful memory savings! We recently updated to Yocto Warrior and our tool chain updated to GCC 8.3. Since then we've had issues with Segmentation faults during the final link stage. Here is one such error:

| + arm-picoos-linux-musleabi-gcc-ar rcsTPD built-in.o arch/arm/kernel/head.o init/built-in.o usr/built-in.o arch/arm/vfp/built-in.o arch/arm/vdso/built-in.o arch/arm/kernel/built-in.o arch/arm/mm/built-in.o arch/arm/common/built-in.o arch/arm/probes/built-in.o arch/arm/net/built-in.o arch/arm/crypto/built-in.o arch/arm/firmware/built-in.o arch/arm/mach-serena/built-in.o kernel/built-in.o certs/built-in.o mm/built-in.o fs/built-in.o ipc/built-in.o security/built-in.o crypto/built-in.o block/built-in.o arch/arm/lib/built-in.o lib/built-in.o drivers/built-in.o sound/built-in.o firmware/built-in.o net/built-in.o virt/built-in.o
| + info LD vmlinux.o
| + '[' '' '!=' silent_ ']'
| + printf ' %-7s %s\n' LD vmlinux.o
| LD vmlinux.o
| + modpost_link vmlinux.o
| + local objects
| + '[' -n y ']'
| + objects='--whole-archive built-in.o --no-whole-archive --start-group arch/arm/lib/lib.a lib/lib.a --end-group'
| + /bin/sh /localdisk/h3/broadband-build/sources/linux-stable/scripts/gcc-ld -fuse-linker-plugin -g -flto=jobserver -flto -fno-fat-lto-objects -Wno-attribute-alias -fwhole-program -r -o vmlinux.o --whole-archive built-in.o --no-whole-archive --start-group arch/arm/lib/lib.a lib/lib.a --end-group
| during IPA pass: icf
| In function 'select_task_rq_idle':
| lto1: internal compiler error: Segmentation fault
| Please submit a full bug report,
| with preprocessed source if appropriate.
| See https://gcc.gnu.org/bugs/ for instructions.
| lto-wrapper: fatal error: arm-picoos-linux-musleabi-gcc returned 1 exit status
| compilation terminated.
| /localdisk/h3/broadband-build/build/tmp/work/wl5e_mcs1-picoos-linux-musleabi/linux-skynet/4.14.48-ciena-r0/recipe-sysroot-native/usr/bin/arm-picoos-linux-musleabi/../../libexec/arm-picoos-linux-musleabi/gcc/arm-picoos-linux-musleabi/8.3.0/ld.bfd: error: lto-wrapper failed

I have tried to adding DISABLE_LTO for the C file in question, but then get a segmentation fault again on the next C file.

Andi, do you have any idea on how to debug this issue, or is this a known issue with the newer gcc 8.3 tool chain?

Thanks, Randy

[ytrezq]

This is a gcc bug not a Keernel bug.