Re: [PATCH 1/2] kobject: return error code if writing /sys/.../uevent fails

From: Phillip Susi
Date: Thu Apr 29 2021 - 09:59:37 EST


Just an FYI, I've been tracking down a bug that was causing the debian
bullseye installer to immediately crash and reboot the xen domU and
bisected it to this commit. It appears that the Xen Virtual Keyboard
driver ( and at least one other, probably more ) were always broken and
failed to trigger the udev event, but this was never noticed. When this
patch returned the error code, it caused the d-i init scripts triggering
coldplug events to fail, which caused init to bail out, causing a kernel
panic.

In the future, when fixing error returns like this, could you please add
a big fat printk so that hopefully things that always should have failed
but didn't and now do can get noticed and fixed more quickly.

https://bugzilla.kernel.org/show_bug.cgi?id=207695
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=983357