Program headers not in the first page when trying to run on FreeBSD

[probonopd]

Program headers not in the first page error message when trying to run the contents of extracted AppImages on FreeBSD.

AppImage/AppImageKit#98 (comment)

Same issue with the GCompris AppImage.

Interestingly, this error does not happen e.g., with the Akira AppImage that was made with go-appimage's appimagetool -s deploy: akiraux/Akira#3 (comment)

I don't have any idea yet what may be causing this. Probably something related to the way the ingredients are compiled, or something about the systems/tools they are compiled on?

(May be useful for testing: https://www.nomadbsd.org/)

[probonopd]

freebsd/freebsd-src@1cfd0bd seems to have some information on this:

@DarkHelmet433 wrote there in 1998:

Update the ELF image activator to use some of the exec resources rather
than rolling it's own. This means that it now uses the "safe"
exec_map_first_page() to get the ld.so headers rather than risking a panic
on a page fault failure (eg: NFS server goes down).
Since all the ELF tools go to a lot of trouble to make sure everything
lives in the first page for executables, this is a win. I have not seen
any ELF executable on any system where all the headers didn't fit in the
first page with lots of room to spare.
I have been running variations of this code for some time on my pure ELF
systems.

And @emaste added the Program headers not in the first page message in 2015:
freebsd/freebsd-src@41e1b13#diff-d67c2311eb3db76bf6d25a9bde8a531aR758

[probonopd]

Possibly caused by
NixOS/patchelf#153

Underlying issue
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=229708

[azubieta]

I'm testing using LIEF tool to change the PT_INTERP segment in ELF files. But now I'm getting an Invalid PT_INTERP error.

Edit

It seems that the ld-linux binary that comes in ubuntu is not compatible with FreeBSD. When executed manually it complains with this message:

ELF type "0" not known
Exec format error

[azubieta]

The Akira AppImage seems to be built on Centos or Fedora. Maybe their ld-linux version is "better" that the one shipped in Ubuntu

Edit

With patchelf 0.12, brandelf -t linux squashfs-root/usr/lib64/ld-linux-x86-64.so.2 and sysctl compat.linux.osrelease=4.0.00 I was able to make a kcalc AppDir that runs on FuryBSD 🥳

[azubieta]

I guess that I can close this issue, as it's related to patchelf. Please feel free to reopen it if required.

The solution: use patchelf >= 0.12

[probonopd]

This is excellent news @azubieta - but don't the new patchelf versions cripple our binaries?

[azubieta]

The binaries ran well on FuryBSD after being patched, also they ran on all the docker containers.

Do you remember in which systems this used to happen?

[probonopd]

I remember that it crippled Qt libs.

[azubieta]

I'm only patching the executable (not the libraries), maybe that's why it doesn't produce any issues.