linux-kernel - Re: [PATCH 0/4] - v2 - Object creation with a specified id

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 23 Apr 2008 16:23:51 +0200
From:	Pavel Machek <pavel@....cz>
To:	Nadia.Derbey@...l.net
Cc:	linux-kernel@...r.kernel.org,
	containers@...ts.linux-foundation.org, orenl@...columbia.edu,
	nick@...k-andrew.net
Subject: Re: [PATCH 0/4] - v2 -  Object creation with a specified id

Hi!

> When restarting a process that has been previously checkpointed, that process
> should keep on using some of its ids (such as its process id, or sysV ipc ids).
> 
> This patch provides a feature that can help ensuring this saved state reuse:
> it makes it possible to create an object with a pre-defined id.
> 
> A first implementation had been proposed 2 months ago. It consisted in
> changing an object's id after it had been created.
> 
> Here is a second implementation based on Oren Ladaan's idea: Oren's suggestion
> was to force an object's id during its creation, rather than 1. create it,
> 2. change its id.
> 
> A new file is created in procfs: /proc/self/task/<my_tid>/next_id.
> This makes it possible to avoid races between several threads belonging to
> the same process.

Ugly...

> When this file is filled with an id value, a structure pointed to by the
> calling task_struct is filled with that id.
> 
> Then, when an object supporting this feature is created, the id present in
> that new structure is used, instead of the default one.
> 
> The syntax is one of:
>    . echo "LONG XX" > /proc/self/task/<my_tid>/next_id
>      next object to be created will have an id set to XX
>    . echo "LONG<n> X0 ... X<n-1>" > /proc/self/task/<my_tid>/next_id
>      next object to be created will have its ids set to XX0, ... X<n-1>
>      This is particularly useful for processes that may have several ids if
>      they belong to nested namespaces.

So ugly it is not even funny.

Create fork_with_pid(int pid) and corresponding ipc primitives, if
you have to...
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/