sched_ext: module init failure

[LeonardoTemperanza]

The init procedure for the sched_ext module fails with the following errors:

BPF:    type_id=70136 offset=224704 size=960
BPF:
BPF: Invalid offset
BPF:
sched_ext: Failed to register kfunc sets (-22)

This only happens on some distros/toolchain configurations. I can confirm this happens on Debian 12.8.0, but not on Ubuntu 24.10.

To Reproduce

After a clean installation of Debian 12.8.0, run the following commands:

• sudo apt install git build-essential libncurses5-dev wget bzip2 libssl-dev libelf-dev flex bison dwarves
• git clone https://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git/
• cd sched_ext
• ./scripts/kconfig/streamline_config.pl > .config
• make menuconfig
  <Add the required features listed here: https://github.com/sched-ext/scx/blob/main/.github/workflows/sched-ext.config >
• make
• make modules
• sudo make modules_install
• sudo make install

[arighi]

Probably not related... but can you try to install the modules using make modules_install INSTALL_MOD_STRIP=1?

I think I've seen something similar happening and the reason was that the initramfs was too large (due to unstripped modules) and some modules were not included in the initramfs.

[hodgesds]

What happens if you try to generate a vmlinux directly? What is the output of:

sudo bpftool btf dump file /sys/kernel/btf/vmlinux format c

[LeonardoTemperanza]

The issue persists even with stripped modules.
As for the btf dump, here it is:
output.txt