Re: v6.1-rc1: Regression in notification of sethostname changes

From: Petr Vorel
Date: Wed Oct 19 2022 - 06:55:39 EST


Hi Torsten,

> Hello Petr,

> your commit

> commit bfca3dd3d0680fc2fc7f659a152234afbac26e4d
> Author: Petr Vorel <pvorel@xxxxxxx>
> Date: Thu Sep 1 21:44:03 2022 +0200

> kernel/utsname_sysctl.c: print kernel arch

> Print the machine hardware name (UTS_MACHINE) in /proc/sys/kernel/arch.

> This helps people who debug kernel with initramfs with minimal environment
> (i.e. without coreutils or even busybox) or allow to open sysfs file
> instead of run 'uname -m' in high level languages.

> broke the notification mechanism between the sethostname syscall and the pollers of /proc/sys/kernel/hostname.

> The table uts_kern_table is addressed within uts_proc_notify by the enum value, however no new enum value was added in "enum uts_proc".

> I noticed the problem when journald-systemd failed to detect hostname changes made with the sethostname syscall (as used by the hostname tool).
> When setting the hostname through /proc/sys/kernel/hostname the poll notification was working.

Thanks a lot for your report, working on a fix!
Andrew, Greg, sorry for a regression.

Kind regards,
Petr

> Torsten