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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.