ld.gold crashes or produces broken executables

[utsl42]

gold fails with pkgsMusl
As described in #49071, but the -pie workaround seems to no longer work.

To Reproduce
Steps to reproduce the behavior:

1. nix-build -E 'let pkgs = (import {}).pkgsMusl; in pkgs.hello.overrideDerivation(_: {CFLAGS="-fuse-ld=gold";})'
2. nix-build -E 'let pkgs = (import {}).pkgsMusl; in pkgs.llvm_9'
   All versions of llvm I tested failed tests, due to gold breaking.
3. nix-build -E 'let pkgs = (import {}).pkgsMusl; in pkgs.hello.overrideDerivation(_: {CFLAGS="-fuse-ld=gold -fPIE -pie";})'
   Suggested in ld.gold crashes or produces invalid executables when Musl is used as a libc #49071 also fails.

Expected behavior
gold should neither crash nor produce broken executables

Additional context
See also issues #49071, #94228, #96890, #84670

Notify maintainers

Metadata
Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

• system: "x86_64-linux"
• host os: Linux 5.4.39, NixOS, 20.09beta992.7badbf18c45 (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.7
• channels(root): "nixos-20.09beta992.7badbf18c45"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module:

[utsl42]

llvmPackages_9 and llvmPackages_10 build and work with pkgsMusl if gold is disabled

[utsl42]

I've reproduced the behavior described in #49071 (comment)

The -fPIE -pie fix works in a VM, but not on bare metal on the same machine.

I have also had it work with no issues on a Docker VM on a Macbook. (nix/nixos image)

I have tested with nixpkgs pinned to the same version across multiple machines. That's not causing it.

[utsl42]

Breaking this down further, I found that gold will link with musl with the exact arguments if I run the glibc build of gold. The musl linked version of gold fails with fatal error: hello: No error information.

[utsl42]

The reason for the difference between VM's and bare metal is that the bare metal machines are on ZFS, which doesn't support fallocate.

It appears that the fix in https://sourceware.org/bugzilla/show_bug.cgi?id=22540 is not working for some reason on Musl.

[utsl42]

fallocate returns -1 and sets errno, but the error handling code in output.cc added in that binutils bug doesn't check errno. This keeps it from ever getting to the ftruncate. Probably not helped by posix_fallocate and fallocate having different error return conventions. Worse, glibc appears to be handling this differently.

[utsl42]

https://www.openwall.com/lists/musl/2018/04/26/4 indicates that glibc has a hacky workaround in posix_fallocate. That's why this shows up on musl and not glibc.

[stale]

I marked this as stale due to inactivity. → More info