From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: [RFC][v7][PATCH 8/9]: Define clone2() syscall Date: Wed, 30 Sep 2009 09:27:56 -0700 (PDT) Message-ID: References: <20090924165548.GA16586@us.ibm.com> <4AC287F2.8060603@zytor.com> <200909301815.45211.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200909301815.45211.arnd-r2nGTMty4D4@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: Arnd Bergmann Cc: Pavel Emelyanov , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Containers , Nathan Lynch , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Eric W. Biederman" , kosaki.motohiro-+CUm20s59erQFUHtdCDX3A@public.gmane.org, "H. Peter Anvin" , mingo-X9Un+BFzKDI@public.gmane.org, Sukadev Bhattiprolu , Alexey Dobriyan , Roland McGrath , Arjan van de Ven List-Id: linux-api@vger.kernel.org On Wed, 30 Sep 2009, Arnd Bergmann wrote: > > One more argument for this is that the new code is architecture independent > using user_stack_pointer(), while the original sys_clone is highly > architecture specific, which is a source for bugs when trying to > extend it. Umm. I don't think that is possible. You need architecture-specific code to even get access to all registers to copy and get a signal-handler-compatible stack frame. See for example arch/alpha/kernel/entry.S with the switch-stack thing etc. I don't think there is any way to make that even remotely architecture-neutral. Linus