LLD-linked binary segfaults at runtime on alpine linux

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#1

Alpine linux is a distribution that uses musl libc instead glibc. Here are my steps to reproduce:

On Alpine linux, download LLVM, Clang, LLD 6.0.0 from releases.llvm.org, and build them from source.

$ clang -c hello_world.c
$ ld.lld --gc-sections -m elf_x86_64 -o hello_world /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/…/…/…/…/lib/Scrt1.o /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/…/…/…/…/lib/crti.o /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/crtbegin.o -L /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/…/…/…/…/lib -L /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0 -dynamic-linker /lib/…/lib/ld-musl-x86_64.so.1 hello_world.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lm -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/crtend.o /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/…/…/…/…/lib/crtn.o

$ ./hello_world
Segmentation fault (core dumped)

Now try with binutils:
$ ld --gc-sections -m elf_x86_64 -o hello_world /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/…/…/…/…/lib/Scrt1.o /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/…/…/…/…/lib/crti.o /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/crtbegin.o -L /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/…/…/…/…/lib -L /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0 -dynamic-linker /lib/…/lib/ld-musl-x86_64.so.1 hello_world.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lm -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/crtend.o /usr/lib/gcc/x86_64-alpine-linux-musl/6.4.0/…/…/…/…/lib/crtn.o

$ ./hello_world

Hello, World!

Does the linker line look ok? Should I file a bug?

#2

Can you add --reproduce=repro to lld command line? That generates repro.tar in your current directory which contains all input files. And then please compress and upload it somewhere so that we can take a look.

#3

https://superjoe.s3.amazonaws.com/temp/repro.tar.xz

#4

I created https://bugs.llvm.org/show_bug.cgi?id=36991