lkml.org 
[lkml]   [2013]   [Jan]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [BUG] Bug in netprio_cgroup and netcls_cgroup ?
On 23.01.2013 01:02, John Fastabend wrote:
> [...]
>
>>>
>>> OK, I guess we should do something similar in the netprio, netcls
>>> cgroups and
>>> yes document it as you noted in your last comment.
>>
>> Here is my attempt to add such a check. I really don't know if this is
>> the
>> correct way to do so. To test this I have written a test program, which
>> seems to test the right thing. Please have a look and let me know if
>> it is correct: http://www.monom.org/misc/scm_rights.c
>>
>> And here a dirty first version of the patch:
>>
>>
>> From 49a78d907eaf31c16673025e7e3b4844e419e416 Mon Sep 17 00:00:00 2001
>> From: Daniel Wagner <daniel.wagner@bmw-carit.de>
>> Date: Tue, 22 Jan 2013 11:08:22 +0100
>> Subject: [PATCH] net: net_prio: Block attach if a socket is shared
>>
>> ---
>> net/core/netprio_cgroup.c | 30 ++++++++++++++++++++++++++++++
>> 1 file changed, 30 insertions(+)
>>
>> diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
>> index 847c02b..de4e6c5 100644
>> --- a/net/core/netprio_cgroup.c
>> +++ b/net/core/netprio_cgroup.c
>> @@ -274,9 +274,39 @@ static struct cftype ss_files[] = {
>> { } /* terminate */
>> };
>>
>> +static int check_cnt(const void *v, struct file *file, unsigned n)
>> +{
>> + unsigned *flag = (unsigned *)v;
>> + int err;
>> +
>> + struct socket *sock = sock_from_file(file, &err);
>> + if (sock && file_count(file) > 1)
>> + *flag = 1;
>> +
>
> I think this check will catch a lot of cases that are not necessarily
> sharing a socket across tasks though. For example iscsid passes a file
> descriptor to the kernel which does a sockfd_lookup() incrementing
> f_count. Similarly look at dup/clone/etc.

Yep, I expected that this patch was too simple.

> In many of these cases I believe it should be OK to move the task
> around when the sockets are not shared between multiple tasks.

Do you know of a different way to identify the shared sockets?

thanks,
daniel



\
 
 \ /
  Last update: 2013-01-23 11:02    [W:0.089 / U:7.440 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site