[arm32] R_ARM_PREL31 relocation at offset 0x18 against symbol `__gxx_personality_v0'

[lancethepants]

For a project of mine I compile a bunch of packages for arm32.
The majority link with mold, but of that ones that do not this is the most prevalent issue.

R_ARM_PREL31 relocation at offset 0x18 against symbol `__gxx_personality_v0' can not be used; recompile with -fPIC

[lancethepants]

I did try adding -fPIC but still got the same error.

[rui314]

It is hard to fix it without the object file causing this error. If your project is open-source, please share its URL so that I can try to built it on my machine.

[jpalus]

Just tried mold 1.3.0 on armv7 to check if #442 improved and got the same error specifically when compiling pulseaudio.

Object file: webrtc.cc.o.zip

Compiled with:

armv7hnl-pld-linux-gnueabi-g++ -Isrc/modules/echo-cancel/libwebrtc-util.so.p -Isrc/modules/echo-cancel -I../src/modules/echo-cancel -I. -I.. -Isrc -I../src -I/usr/include/webrtc_aud
io_processing -fdiagnostics-color=always -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wnon-virtual-dtor -std=c++11 -O2 -fwrapv -pipe -Wformat -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -f
stack-protector-strong --param=ssp-buffer-size=4 -Werror=trampolines -fomit-frame-pointer -mfpu=neon-vfpv3 -march=armv7-a -mfloat-abi=hard -mthumb -fPIC -DWEBRTC_AUDIO_PROCESSING_ONLY_BUILD -
DWEBRTC_POSIX -DHAVE_CONFIG_H -D_GNU_SOURCE -D__INCLUDED_FROM_PULSE_AUDIO -MD -MQ src/modules/echo-cancel/libwebrtc-util.so.p/webrtc.cc.o -MF src/modules/echo-cancel/libwebrtc-util.so.p/webrt
c.cc.o.d -o src/modules/echo-cancel/libwebrtc-util.so.p/webrtc.cc.o -c ../src/modules/echo-cancel/webrtc.cc  

Linker invocation with error:

armv7hnl-pld-linux-gnueabi-g++  -o src/modules/echo-cancel/libwebrtc-util.so src/modules/echo-cancel/libwebrtc-util.so.p/webrtc.cc.o -Wl,--as-needed -Wl,--no-undefined -shared -fPIC -Wl,--sta
rt-group -Wl,-soname,libwebrtc-util.so -Wl,--as-needed -Wl,--no-copy-dt-needed-entries -Wl,-z,relro -Wl,-z,combreloc -Wl,-fuse-ld=mold -O2 -fwrapv -pipe -Wformat -Werror=format-security -Wp,-
D_FORTIFY_SOURCE=2 -fstack-protector-strong --param=ssp-buffer-size=4 -Werror=trampolines -fomit-frame-pointer -mfpu=neon-vfpv3 -march=armv7-a -mfloat-abi=hard -mthumb '-Wl,-rpath,$ORIGIN/../
../pulse:$ORIGIN/../..:$ORIGIN/../../pulsecore' -Wl,-rpath-link,/home/users/builder/rpm/BUILD/pulseaudio-16.0/build/src/pulse -Wl,-rpath-link,/home/users/builder/rpm/BUILD/pulseaudio-16.0/bui
ld/src -Wl,-rpath-link,/home/users/builder/rpm/BUILD/pulseaudio-16.0/build/src/pulsecore src/pulse/libpulse.so.0.24.2 src/libpulsecommon-16.0.so src/pulsecore/libpulsecore-16.0.so -Wl,-z,node
lete -Wl,--unresolved-symbols=ignore-in-object-files /usr/lib/libwebrtc_audio_processing.so -Wl,--end-group
mold: error: src/modules/echo-cancel/libwebrtc-util.so.p/webrtc.cc.o:(.ARM.extab): R_ARM_PREL31 relocation at offset 0x24 against symbol `__gxx_personality_v0' can not be used; recompile with
 -fPIC   

[jpalus]

Same issue, same reproducer with armv6 in ARM mode (armv7 used Thumb).

[rui314]

Can you try again with the above commit?

[turkerali]

Hi there,
I tried the above commit, but this time I get SIGSEGV errors while building my rust project:

error: failed to run custom build command for libc v0.2.126

Caused by:
process didn't exit successfully: /srv/emmc/aet_rust/project1/target/debug/build/libc-038fb7a43663205c/build-script-build (signal: 11, SIGSEGV: invalid memory reference)
warning: build failed, waiting for other jobs to finish...
error: failed to run custom build command for proc-macro2 v1.0.39

Caused by:
process didn't exit successfully: /srv/emmc/aet_rust/project1/target/debug/build/proc-macro2-475e27ce17eff2b4/build-script-build (signal: 11, SIGSEGV: invalid memory reference)
error: failed to run custom build command for libc v0.2.126

Caused by:
process didn't exit successfully: /srv/emmc/aet_rust/project1/target/debug/build/libc-ceba8fa7b5020822/build-script-build (signal: 11, SIGSEGV: invalid memory reference)
error: failed to run custom build command for syn v1.0.98

Caused by:
process didn't exit successfully: /srv/emmc/aet_rust/project1/target/debug/build/syn-5bb2bb3ff346bd4b/build-script-build (signal: 11, SIGSEGV: invalid memory reference)

[jpalus]

@rui314 with your commit pulseaudio links and works fine on both armv6 and armv7. Thanks!

I suppose above segfault is unrelated issue and if needed new ticket should be opened. Feel free to close this one.

[rui314]

OK, let me close this bug.

@turkerali Can you reopen a bug with a link to a repository which I can build on my machine, so that I can reproduce your issue locally?

[lancethepants]

The patch does fix my issue as well. Thanks a bunch! Linkers must be black magic looking at that patch.

I've also had issues linking rust on armv7, but that'll be a different issue. I suspect the firefox issue might be related.