classic snaps do not work on ARM64 kernel configured to use 64k pages

patchelf (in the version bundled with snapcraft) creates segments that overlap when aligned to a page size greater than 4k, e.g. from readelf -h on the python3.8 interpreter in the current subiquity snap:

  LOAD 0x000000 0x00000000003ff000 0x00000000003ff000 0x001000 0x001000 RW 0x1000
  LOAD 0x001000 0x0000000000400000 0x0000000000400000 0x4bab44 0x4bab44 R E 0x1000

This makes the kernel very unhappy indeed and it refuses to load such a binary (execve returns EINVAL). Upstream patchelf fixed this in https://github.com/NixOS/patchelf/pull/216. I don't know if cherry picking that fix or just updating the version of patchelf bundled by snapcraft to the latest release is more appropriate.

[Problem Description]

Subiquity fails to execute when running on ARM64 with -64k Kernel. It exits with the "Segmentation fault" message

[Additional Info]

The problem seems to be with python3.8 binary in the snap. The same problem occurs with wget binary in the same snap, but ubuntu-distro-info works fine. Both python3.8 and wget are statically compiled, while ubuntu-distro-info is not.

root@jammy-arm:~# file /snap/subiquity/4236/usr/bin/python3.8
/snap/subiquity/4236/usr/bin/python3.8: ELF 64-bit LSB executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /snap/core20/current/lib/ld-linux-aarch64.so.1, for GNU/Linux 3.7.0, BuildID[sha1]=bad3f5d001ec1e2ec539f16d8f6729a06cdd68df, stripped
root@jammy-arm:~# /snap/subiquity/4236/usr/bin/python3.8
Segmentation fault
root@jammy-arm:~# ldd /snap/subiquity/4236/usr/bin/python3.8
 not a dynamic executable

root@jammy-arm:~# file /snap/subiquity/4236/usr/bin/wget
/snap/subiquity/4236/usr/bin/wget: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /snap/core20/current/lib/ld-linux-aarch64.so.1, for GNU/Linux 3.7.0, BuildID[sha1]=0f2234825d67c22b6b320139445759f6662aa01e, stripped
root@jammy-arm:~# /snap/subiquity/4236/usr/bin/wget
Segmentation fault
root@jammy-arm:~# ldd /snap/subiquity/4236/usr/bin/wget
 not a dynamic executable

root@jammy-arm:~# file /snap/subiquity/4236/usr/bin/ubuntu-distro-info
/snap/subiquity/4236/usr/bin/ubuntu-distro-info: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /snap/core20/current/lib/ld-linux-aarch64.so.1, for GNU/Linux 3.7.0, BuildID[sha1]=5d8c4c52d7ce614024eba1ba9069e48ad4192508, stripped
root@jammy-arm:~# /snap/subiquity/4236/usr/bin/ubuntu-distro-info
ubuntu-distro-info: You have to select exactly one of --all, --devel, --latest, --lts, --stable, --supported, --supported-esm, --series, --unsupported.
root@jammy-arm:~# ldd /snap/subiquity/4236/usr/bin/ubuntu-distro-info
 linux-vdso.so.1 (0x0000fffe72270000)
 libc.so.6 => /snap/core20/current/lib/aarch64-linux-gnu/libc.so.6 (0x0000fffe720b0000)
 /snap/core20/current/lib/ld-linux-aarch64.so.1 => /lib/ld-linux-aarch64.so.1 (0x0000fffe72280000)

The same VM, using the non -64k kernel works:

# uname -a
Linux jammy-arm 5.15.0-27-generic #28-Ubuntu SMP Thu Apr 14 12:56:31 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux
# /snap/subiquity/4236/usr/bin/python3.8 -c "print('Works')"
Works

Tried other kernels (5.17, 5.19) with the same error.

[Reproducer]

1. Run a VM in ARM64 architecture:
virt-install --arch aarch64 --boot uefi --osinfo detect=on,require=off --name jammy-arm --memory 8096 --vcpus 4 --disk=jammy-server-cloudimg-arm64.img,bus=virtio --disk=jammy-arm-seed.qcow2,bus=virtio --network network=default,model=virtio --boot hd --noautoconsole

2. Connect to the VM and install a -64k kernel
https://launchpad.net/~canonical-kernel-team/+archive/ubuntu/bootstrap/+build/23546569

3. Reboot in the kernel (I disabled secure boot)
# uname -a
Linux jammy-arm 5.15.0-27-generic-64k #28-Ubuntu SMP Thu Apr 14 19:01:31 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux

4. Install subiquity
sudo snap install subiquity

5. Try to run it
# /snap/bin/subiquity
Segmentation fault
---
ProblemType: Bug
AlsaDevices:
 total 0
 crw-rw---- 1 root audio 116, 1 Jan 10 18:24 seq
 crw-rw---- 1 root audio 116, 33 Jan 10 18:24 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.20.11-0ubuntu82.3
Architecture: arm64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CRDA: N/A
CasperMD5CheckResult: unknown
DistroRelease: Ubuntu 22.04
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Lsusb-t:
 /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/15p, 5000M
 /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/15p, 480M
MachineType: QEMU QEMU Virtual Machine
Package: linux (not installed)
PciMultimedia:

ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=C.UTF-8
 SHELL=/bin/bash
ProcFB:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.15.0-27-generic-64k root=UUID=a6c92eea-e1ae-4ec4-9fbc-69e3ab11d0f7 ro console=tty1 console=ttyS0
ProcVersionSignature: Ubuntu 5.15.0-27.28-generic-64k 5.15.30
RelatedPackageVersions:
 linux-restricted-modules-5.15.0-27-generic-64k N/A
 linux-backports-modules-5.15.0-27-generic-64k N/A
 linux-firmware N/A
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
Tags: jammy uec-images
Uname: Linux 5.15.0-27-generic-64k aarch64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: N/A
_MarkForUpload: True
dmi.bios.date: 02/06/2015
dmi.bios.release: 0.0
dmi.bios.vendor: EFI Development Kit II / OVMF
dmi.bios.version: 0.0.0
dmi.chassis.type: 1
dmi.chassis.vendor: QEMU
dmi.chassis.version: virt-6.2
dmi.modalias: dmi:bvnEFIDevelopmentKitII/OVMF:bvr0.0.0:bd02/06/2015:br0.0:svnQEMU:pnQEMUVirtualMachine:pvrvirt-6.2:cvnQEMU:ct1:cvrvirt-6.2:sku:
dmi.product.name: QEMU Virtual Machine
dmi.product.version: virt-6.2
dmi.sys.vendor: QEMU