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Subject: Re: [patch 2/2] c/r: prctl: Add ability to get clear_tid_address
From: Kees Cook <keescook@chromium.org>
To: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Oleg Nesterov <oleg@redhat.com>,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Pavel Emelyanov <xemul@parallels.com>, Tejun Heo <tj@kernel.org>,
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On Fri, Mar 16, 2012 at 1:55 PM, Cyrill Gorcunov <gorcunov@openvz.org> wrote:
> Zero is written at clear_tid_address, when
> the process exits. This functionality is used
> by pthread_join().
>
> We already have sys_set_tid_address() to change this
> address for current task but there is no way to obtain
> it from a user space.

Is it worth introducing a syscall for this just for symmetry? I
suspect not, in which case:

Acked-by: Kees Cook <keescook@chromium.org>

-Kees

-- 
Kees Cook
ChromeOS Security