Bug 779856

Summary:	udev issues (system stops responding after boot)
Product:	Gentoo Linux	Reporter:	sliwa
Component:	Current packages	Assignee:	Gentoo Linux bug wranglers <bug-wranglers>
Status:	RESOLVED NEEDINFO
Severity:	normal	CC:	jstein, sliwa
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---

Description sliwa 2021-04-03 08:36:50 UTC

I am tracking down system stopping to respond soon after boot. I believe it is related to udev and a cd drive, as the behavior depends on how I connect the drive.

The issue occurs when the drive is connected to an Asmedia SATA controller.

1. I have inspected /lib/udev/rules.d/60-persistent-storage.rule and can see three rules running /lib/udev/ata_id and I am not sure if the rules are mutually exclusive. If they are not, could that hurt (cause the system to stop respond)?

2. I have run "/lib/udev/ata_id --export /dev/sr0" from a user account with no cdrom permissions. It has output the drive information and returned a succes exit code. I believe this should not happen, as there are no special permissions on the binary either. I checked what is going on with strace: the device is opened asynchronously (with a success!), a few following syscalls fail (invalid parameter or permission denied), then HDIO_GET_IDENTITY ioctl succeds. A kernel bug?

Comment 1 Jonas Stein gentoo-dev

2021-04-05 14:01:27 UTC

It is sad to read that you have problems with the udev. 
The situation seems to be a bit more complicate and requires some analysis.
We can not help you efficiently via bug tracker. The bug tracker aims rather on specific problems in .ebuilds and less on individual systems. 

I have had very good experience on the gentoo IRC [1] with questions like this. Of course there are also forums and mailing lists [2,3].
I hope you understand, that I will close the bug here therefore and wish you good luck on one of the mentioned channels [4].
Please reopen the ticket in order to provide an indication for an specific error in an ebuild or any gentoo related product.

[1] https://www.gentoo.org/get-involved/irc-channels/
[2] https://forums.gentoo.org/
[3] https://www.gentoo.org/get-involved/mailing-lists/all-lists.html
[4] https://www.gentoo.org/support/

Comment 2 sliwa 2021-04-05 18:32:39 UTC

I understand the issues I have reported affect only a fraction of users. Please understand, however, this is still a bug report ([1] a hard lockup making Gentoo unusable in some configurations and [2] a security or privacy threat).

Comment 3 sliwa 2021-04-08 21:10:21 UTC

ad 1. The kernel message is "AHCI controller unavailable". This happens even with no udev running when the drive is accessed (e.g. ata_id, cdrom_id or eject). So, probably flaky hardware (pci id 1b21:0612) or kernel driver issues.

ad 2. Probably behavior related to uaccess.