From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Weimer Subject: Re: [PATCH v2 0/7] CLONE_FD: Task exit notification via file descriptor Date: Mon, 15 Jun 2015 12:06:00 +0200 Message-ID: <557EA388.5090902@redhat.com> References: <556818A7.3030804@redhat.com> <1775865.3maNSqUW4u@tjmaciei-mobl4> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1775865.3maNSqUW4u@tjmaciei-mobl4> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thiago Macieira Cc: Josh Triplett , Al Viro , Andrew Morton , Andy Lutomirski , Ingo Molnar , Kees Cook , Oleg Nesterov , "Paul E. McKenney" , "H. Peter Anvin" , Rik van Riel , Thomas Gleixner , Michael Kerrisk , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org List-Id: linux-api@vger.kernel.org On 05/29/2015 10:27 PM, Thiago Macieira wrote: >> It has been suggested (e.g., >> ) that you can >> use the existing clone(2) without specifying SIGCHLD to create a new >> process. The resulting child process is not supposed to show up in >> wait(2), only in a waitpid(2) (or similar) explicitly specifying the >> PID. Is this not the case? > > Hi Florian > > That sounds orthogonal to what we're looking for. Our objective is to get > notification of when the child exited without resorting to SIGCHLD. If we use > the regular clone(2) without SIGCHLD and without CLONE_FD, we get no > notification. The only way to know of the child's termination is by a blocking > waitpid(2), like you indicated, which is counter productive to our needs. > > We need something we can select(2)/poll(2) on. Thanks for the clarification. I agree that this is a separate and quite sensible use case. -- Florian Weimer / Red Hat Product Security