From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH 3/3] add the clone64() and unshare64() syscalls Date: Wed, 09 Apr 2008 20:40:07 -0700 Message-ID: <47FD8C17.6040203@zytor.com> References: <20080409222611.GA28087@us.ibm.com> <20080409223459.GC28267@us.ibm.com> <20080409230733.GR20478@devserv.devel.redhat.com> <20080410021523.GB28477@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20080410021523.GB28477-r/Jw6+rmf7HQT0dZR+AlfA@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: sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org Cc: Jakub Jelinek , "David C. Hansen" , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, clg-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org, Containers , Pavel Emelyanov List-Id: containers.vger.kernel.org sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org wrote: > Jakub Jelinek [jakub-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org] wrote: > | On Wed, Apr 09, 2008 at 03:34:59PM -0700, sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org wrote: > | > From: Cedric Le Goater > | > Subject: [PATCH 3/3] add the clone64() and unshare64() syscalls > | > > | > This patch adds 2 new syscalls : > | > > | > long sys_clone64(unsigned long flags_high, unsigned long flags_low, > | > unsigned long newsp); > | > > | > long sys_unshare64(unsigned long flags_high, unsigned long flags_low); > | > | Can you explain why are you adding it for 64-bit arches too? unsigned long > | is there already 64-bit, and both sys_clone and sys_unshare have unsigned > | long flags, rather than unsigned int. > > Hmm, > > By simply resuing clone() on 64 bit and adding a new call for 32-bit won't > the semantics of clone() differ between the two ? > > i.e clone() on 64 bit supports say CLONE_NEWPTS clone() on 32bit does not ? > > Wouldn't it be simpler/cleaner if clone() and clone64() behaved the same > on both 32 and 64 bit systems ? > No, not really. The way this work on the libc side is pretty much "use clone64 if it exists, otherwise use clone". -hpa