linux-kernel - Re: [PATCH 09/10] ptrace: add JOBCTL_BLOCK

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]

Message-ID: <20110519164402.GO627@htj.dyndns.org>
Date:	Thu, 19 May 2011 18:44:02 +0200
From:	Tejun Heo <tj@...nel.org>
To:	Oleg Nesterov <oleg@...hat.com>
Cc:	jan.kratochvil@...hat.com, vda.linux@...glemail.com,
	linux-kernel@...r.kernel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, indan@....nu, bdonlan@...il.com
Subject: Re: [PATCH 09/10] ptrace: add JOBCTL_BLOCK_NOTIFY

Hello,

On Thu, May 19, 2011 at 06:32:33PM +0200, Oleg Nesterov wrote:
> > +	/*
> > +	 * Make sure @chlid is still ptraced by us and clear BLOCK_NOTIFY.
> > +	 */
> > +	if (likely((child->ptrace & PT_PTRACED) && child->parent == current))
> 
> This looks a bit confusing... It is either traced or not. If it is traced,
> nobody else can trace it. In fact even PT_PTRACED is not strictly needed
> but I agree this check makes the code cleaner.

Hmmm... I suppose we can make the error paths finer grained so that
attach failure doesn't end up calling ptrace_put_task_struct() but I
think it would be better to keep the two tests there so that the
function can be called regardless of what happened.

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/