ELF load command address/offset not page-aligned

1

Hi! I’m trying to get PyTorch’s libtorch to work. I downloaded its prebuilt binaries from Start Locally | PyTorch and got this weird message:

<command line>: libtorch_cuda.so: ELF load command address/offset not page-aligned

I checked the file with readelf and the 4th load command’s offset is indeed not aligned.

$ readelf -l /home/kenhkan/libtorch/lib/libtorch_cuda.so

Elf file type is DYN (Shared object file)
Entry point 0x1191370
There are 14 program headers, starting at offset 64

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
  LOAD           0x0000000000000000 0x0000000000000000 0x0000000000000000
                 0x000000000114e878 0x000000000114e878  R      0x1000
  GNU_STACK      0x0000000000000000 0x0000000000000000 0x0000000000000000
                 0x0000000000000000 0x0000000000000000  RW     0x10
  LOAD           0x000000000114f000 0x000000000114f000 0x000000000114f000
                 0x00000000036d5b41 0x00000000036d5b41  R E    0x1000
  LOAD           0x0000000004825000 0x0000000004825000 0x0000000004825000
                 0x000000004a567323 0x000000004a567323  R      0x1000
  GNU_EH_FRAME   0x000000004e64a808 0x000000004e64a808 0x000000004e64a808
                 0x00000000000cb63c 0x00000000000cb63c  R      0x4
  LOAD           0x000000004ed8ccd0 0x000000004ed8dcd0 0x000000004ed8dcd0
                 0x000000000dc74800 0x000000000ec468a8  RW     0x1000
... <redacted> ...

So NixOS is correctly reporting the issue, but I’ve used the same binary successfully for a long time on Ubuntu, and I assume that the same binary has been working for many people since it’s a popular library.

I assume that NixOS is just stricter in checking boundary misalignment even if it wouldn’t cause a problem when run. Is there a way to “relax” this check on NixOS?

Or if anyone has had experience with this or has some insights/alternatives, please chime in as well. Thank you!

2

I forgot to attach some contextual information:

$ nixos-version
24.05.1358.47b604b07d1e (Uakari)

$ uname -r
5.15.160

$ gcc --version
gcc (GCC) 13.2.0
Copyright (C) 2023 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


$ ldd --version
ldd (GNU libc) 2.39
Copyright (C) 2024 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by Roland McGrath and Ulrich Drepper.

$
3

Options:

Try torch from nixpkgs NixOS Search (maybe with devenv, devshell hand)

May be a case for patchelf GitHub - NixOS/patchelf: A small utility to modify the dynamic linker and RPATH of ELF executables (I not sure about this but the name is promising). Usually is required for executables not for libraries.

4

Thanks for the ideas Hugo! I’ve tried patchelf before for rpaths but I haven’t been able to adjust boundaries of .so files. As for python312Packages.torch. It seems to work for Python, but not is C++ distributable. There is some magic hidden in that package. Maybe I should reach out to them instead. Thanks for taking a look!