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

[Greg KH]

On Thu, Apr 29, 2021 at 09:40:08AM -0400, Phillip Susi wrote:
> 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
> 

Spaming kernel logs with things that userspace can trigger is generally
a bad idea.  But I understand the pain here, sorry to hear it.

Was the offending drivers ever fixed?

thanks,

greg k-h