lkml.org 
[lkml]   [2011]   [Oct]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: A Plumber’s Wish List for Linux
Lennart Poettering <mzxreary@0pointer.de> writes:

> On Fri, 07.10.11 00:49, Matt Helsley (matthltc@us.ibm.com) wrote:
>
>>
>> On Fri, Oct 07, 2011 at 01:17:02AM +0200, Kay Sievers wrote:
>>
>> <snip>
>>
>> > * simple, reliable and future-proof way to detect whether a specific pid
>> > is running in a CLONE_NEWPID container, i.e. not in the root PID
>> > namespace. Currently, there are available a few ugly hacks to detect
>>
>> Is that precisely what's needed or would it be sufficient to know
>> that the pid is running in a child pid namespace of the current pid
>> namespace? If so, I think this could eventually be done by comparing
>> the inode numbers assigned to /proc/<pid>/ns/pid to those of
>> /proc/1/ns/pid.
>
> I think the most interesting test would be to figure out for a process
> if itself is running in a PID namespace. And for that comparing inodes
> wouldn't work since the namespace process would never get access to the
> inode of the outside init.

Strictly correct answer. All processes are running in a pid namespace.
I think we can implement that in a libc header.

static inline bool in_pid_namespace(void)
{
return true;
}
Why does it matter if you are running in something other than the
initial pid namespace? I expect what you are really after is something
else entirely, and you are asking the wrong question.

Eric


\
 
 \ /
  Last update: 2011-10-08 06:27    [from the cache]
©2003-2011 Jasper Spaans