From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Subject: Re: [PATCH] fs/proc: report eip/esp in /prod/PID/stat for
 coredumping
Date: Thu, 14 Sep 2017 17:37:20 +0200 (CEST)
Message-ID: <alpine.DEB.2.20.1709141735420.1916@nanos>
References: <87poatfwg6.fsf@linutronix.de>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Return-path: <linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
In-Reply-To: <87poatfwg6.fsf-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
To: John Ogness <john.ogness-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Cc: Andy Lutomirski <luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org>, Brian Gerst <brgerst-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>, Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>, Tetsuo Handa <penguin-kernel-1yMVhJb1mP/7nzcFbJAaVXf5DAMn2ifp@public.gmane.org>, Tycho Andersen <tycho.andersen-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>, Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
List-Id: linux-api@vger.kernel.org

On Thu, 14 Sep 2017, John Ogness wrote:

> Commit 0a1eb2d474ed ("fs/proc: Stop reporting eip and esp in
> /proc/PID/stat") stopped reporting eip/esp because it is
> racey and dangerous for executing tasks. The comment adds:
> 
>     As far as I know, there are no use programs that make any
>     material use of these fields, so just get rid of them.
> 
> However, existing userspace core-dump-handler applications (for
> example, minicoredumper) are using these fields since they
> provide an excellent cross-platform interface to these valuable
> pointers. So that commit introduced a user space visible
> regression.
> 
> Partially revert the change and make the readout possible for
> tasks with the proper permissions and only if the target task
> has the PF_DUMPCORE flag set.

Duh, I completely forgot about mini core dumper when I acked that commit.

Reviewed-by: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>