From mboxrd@z Thu Jan 1 00:00:00 1970 From: sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org Subject: Re: [PATCH 0/4] Devices accessibility control group (v2) Date: Mon, 14 Jan 2008 09:42:20 -0800 Message-ID: <20080114174220.GA17825@us.ibm.com> References: <47833C3A.8090106@openvz.org> <20080112212014.GA12085@us.ibm.com> <478B14DB.4000106@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <478B14DB.4000106-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Pavel Emelyanov Cc: Linux Containers , Paul Menage List-Id: containers.vger.kernel.org | > I started playing with this and noticed that even if I try to | > enable read access to device [c, 1:3] it also grants access | > to device [c, 1:5]. | | Hm... I can't reproduce this: | | # /bin/echo 'c 1:3 r-' > /cnt/dev/0/devices.permissions | # /bin/echo -n $$ > /cnt/dev/0/tasks | # cat /cnt/dev/0/devices.permissions | c 1:3 r- | # hexdump /dev/null | # hexdump /dev/zero | hexdump: /dev/zero: No such device or address | hexdump: /dev/zero: Bad file descriptor | | Maybe you have played with devs cgroups before getting this? | Can you show what's the contents of the devices.permissions file | in your case? Here is the repro again. I even tried after a reboot. Basically, granting access to /dev/null is also granting access to /dev/zero. # cat devices.permissions # hexdump /dev/zero hexdump: /dev/zero: No such device or address hexdump: /dev/zero: Bad file descriptor # hexdump /dev/null hexdump: /dev/null: No such device or address hexdump: /dev/null: Bad file descriptor # echo 'c 1:3 r-' > devices.permissions # hexdump /dev/null # hexdump /dev/zero 0000000 0000 0000 0000 0000 0000 0000 0000 0000 * ^C # cat tasks 3279 22266 # ps PID TTY TIME CMD 3279 pts/0 00:00:00 bash 22267 pts/0 00:00:00 ps