From: Pavel Machek <pavel@ucw.cz>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: printk: Add kernel parameter to disable writes to /dev/kmsg
Date: Tue, 26 Apr 2016 20:44:58 +0200 [thread overview]
Message-ID: <20160426184458.GB8162@amd> (raw)
In-Reply-To: <20160425130629.188a901c@gandalf.local.home>
On Mon 2016-04-25 13:06:29, Steven Rostedt wrote:
> Over the weekend my server was acting funny. The display wasn't working
> well, and I assumed that a driver was going bad. I went to look at the
> kernel dmesg, but the buffer only had the following over and over:
>
> [226062.401405] systemd-logind[3511]: Removed session 4168.
> [226063.381051] systemd-logind[3511]: Removed session 4169.
systemd has root. I'm not sure additional parameter to fight it is
good idea. What's next? systemd evolves a way to override kernel
parameters? :-)
> I simply propose a way to let us kernel developers keep user space from
> interfering, by adding a new kernel command line parameter that will
> disable writing to /dev/kmsg. Any attempt to open the file in write
> mode will return a -EPERM error.
chmod 400 /dev/kmsg? With udev, it should be possible to make it persistent...
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2016-04-26 18:45 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-25 17:06 printk: Add kernel parameter to disable writes to /dev/kmsg Steven Rostedt
2016-04-25 17:08 ` [PATCH] " Steven Rostedt
2016-04-25 18:32 ` Borislav Petkov
2016-04-25 18:40 ` Steven Rostedt
2016-04-25 18:50 ` Peter Zijlstra
2016-04-26 18:44 ` Pavel Machek [this message]
2016-04-26 19:47 ` Steven Rostedt
2016-04-27 11:25 ` Austin S. Hemmelgarn
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160426184458.GB8162@amd \
--to=pavel@ucw.cz \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox