[REGRESSION] module BTF validation failure (Error -22) on next

[Laura Nao <laura.nao@collabora.com>]

Hello,

KernelCI has detected a module loading regression affecting all AMD and 
Intel Chromebooks in the Collabora LAVA lab, occurring between 
next-20241024 and next-20241025.

The logs indicate a failure in BTF module validation, preventing all 
modules from loading correctly (with CONFIG_MODULE_ALLOW_BTF_MISMATCH 
unset). The example below is from an AMD Chromebook (HP 14b na0052xx), 
with similar errors observed on other AMD and Intel devices:

[    5.284373] failed to validate module [cros_kbd_led_backlight] BTF: -22
[    5.291392] failed to validate module [i2c_hid] BTF: -22
[    5.293958] failed to validate module [chromeos_pstore] BTF: -22
[    5.302832] failed to validate module [coreboot_table] BTF: -22
[    5.309175] failed to validate module [raydium_i2c_ts] BTF: -22
[    5.309264] failed to validate module [i2c_cros_ec_tunnel] BTF: -22
[    5.322158] failed to validate module [typec] BTF: -22
[    5.327554] failed to validate module [snd_timer] BTF: -22
[    5.327573] failed to validate module [cros_usbpd_notify] BTF: -22
[    5.339272] failed to validate module [elan_i2c] BTF: -22
[    5.345821] failed to validate module [industrialio] BTF: -22
[    5.423113] failed to validate module [cfg80211] BTF: -22
[    5.443074] failed to validate module [cros_ec_dev] BTF: -22
[    5.448857] failed to validate module [snd_pci_acp3x] BTF: -22
[    5.454736] failed to validate module [cros_kbd_led_backlight] BTF: -22
[    5.461458] failed to validate module [regmap_i2c] BTF: -22
[    5.470228] failed to validate module [i2c_piix4] BTF: -22
[    5.491123] failed to validate module [i2c_hid] BTF: -22
[    5.491226] failed to validate module [chromeos_pstore] BTF: -22
[    5.496519] failed to validate module [coreboot_table] BTF: -22
[    5.502632] failed to validate module [snd_timer] BTF: -22
[    5.538916] failed to validate module [gsmi] BTF: -22
[    5.604971] failed to validate module [mii] BTF: -22
[    5.604971] failed to validate module [videobuf2_common] BTF: -22
[    5.604972] failed to validate module [sp5100_tco] BTF: -22
[    5.616068] failed to validate module [snd_soc_acpi] BTF: -22
[    5.680553] failed to validate module [bluetooth] BTF: -22
[    5.749320] failed to validate module [chromeos_pstore] BTF: -22
[    5.755440] failed to validate module [mii] BTF: -22
[    5.760522] failed to validate module [snd_timer] BTF: -22
[    5.783549] failed to validate module [bluetooth] BTF: -22
[    5.841561] failed to validate module [mii] BTF: -22
[    5.846699] failed to validate module [snd_timer] BTF: -22
[    5.892444] failed to validate module [mii] BTF: -22
[    5.897708] failed to validate module [snd_timer] BTF: -22
[    5.945507] failed to validate module [snd_timer] BTF: -22

The full kernel log is available on [1]. The config used is available on
[2] and the kernel/modules have been built using gcc-12.

The issue is still present on next-20241105.

I'm sending this report to track the regression while a fix is
identified. The culprit commit hasn't been pinpointed yet, I'll report
back once it's identified.

Any feedback or suggestion for additional debugging steps would be greatly 
appreciated.

Best,

Laura

[1] https://pastebin.com/raw/dtvzBkxh
[2] https://pastebin.com/raw/a1MGi3wH

#regzbot introduced: next-20241024..next-20241025