From mboxrd@z Thu Jan 1 00:00:00 1970 From: sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org Subject: Re: [PATCH 11/15] Signal semantics Date: Fri, 27 Jul 2007 13:23:37 -0700 Message-ID: <20070727202337.GC1072@us.ibm.com> References: <46A8B37B.6050108@openvz.org> <46A8B5C7.9040407@openvz.org> <20070727123153.GA92@tv-sign.ru> <46A9F54B.5050000@openvz.org> <20070727184604.GB1072@us.ibm.com> <20070727195943.GA25878@sergelap.austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20070727195943.GA25878-6s5zFf/epYLPQpwDFJZrxKsjOiXwFzmk@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: "Serge E. Hallyn" Cc: Linux Containers , Oleg Nesterov , Pavel Emelyanov List-Id: containers.vger.kernel.org Serge E. Hallyn [serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org] wrote: | Quoting sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org (sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org): | > Pavel Emelianov [xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org] wrote: | > | Oleg Nesterov wrote: | > | >(What about ptrace_attach() btw? If it is possible to send a signal to init | > | > from the "parent" namespace, perhaps it makes sense to allow ptracing as | > | > well). | > | | > | ptracing of tasks fro different namespaces is not possible at all, since | > | strace utility determines the fork()-ed child pid from the parent's eax | > | register, which would contain the pid value as this parent sees his child. | > | But if the strace is in different namespace - it won't be able to find | > | this child with the pid value from parent's eax. | > | | > | Maybe it's worth disabling cross-namespaces ptracing... | > | > I think so too. Its probably not a serious limitation ? | | Several people think we will implement 'namespace entering' through a | ptrace hack, where maybe the admin ptraces the init in a child pidns, | makes it fork, and makes the child execute what it wants (i.e. ps -ef). | | You're talking about killing that functionality? No. I was only thinking in terms of debugging container init and missed the namespace entering part. Pavel, I am not sure I understand your comment about being unable to ptrace() a child ns. BTW, I am able to gdb a process (incl container-init) from parent ns now. | | -serge