linux-kernel - Re: [PATCH 03/10] ptrace: implement PTRACE

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, 18 May 2011 13:14:24 +0200
From:	Tejun Heo <tj@...nel.org>
To:	Denys Vlasenko <vda.linux@...glemail.com>
Cc:	oleg@...hat.com, jan.kratochvil@...hat.com,
	linux-kernel@...r.kernel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, indan@....nu, bdonlan@...il.com
Subject: Re: [PATCH 03/10] ptrace: implement PTRACE_SEIZE

Hello, Denys.

On Wed, May 18, 2011 at 12:44:58PM +0200, Denys Vlasenko wrote:
> > But as SEIZE introduces behavior differences throughout ptrace
> > operation,
> >
> > Similar issue with PTRACE_O_TRACESTOP.  It won't only enable TRACESTOP
> > it will change other behaviors too
> 
> All these differences revolve around making handling of stops
> and SIGCONT better. It seems fitting to the option name.
>
> PTRACE_SEIZE sets a flag somewhere "please convert
> group-stops into PTRACE_EVENT_STOPs".

I don't know.  It seems a bit too subtle.  The new behaviors are a lot
more pervasive than any controlled by PTRACE_O_ flags and there's the
problem of allowing its clearing.

> Since we have this API, why not use it for the very similar
> concept of modifying group-stops too?

Different scope.  Conflicting semantics (clearing).  API compatibility
as you pointed out.

> > I think it's actually beneficial to use a distinctively new
> > request.  It's not like it costs anything or we're short on request
> > number space.
> 
> "Entities must not be multiplied beyond necessity"?

Sure, but whether to have a flag or a request is trivial.  When one of
them has issues like above, I see a new request number go above the
necessity threshold.

Thanks.

-- 
tejun
--
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/