From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [PATCH] utimensat() non-conformances and fixes [v3] Date: Tue, 3 Jun 2008 13:10:15 +0100 Message-ID: <20080603121015.GC28905@shareable.org> References: <48401E7E.9090304@gmail.com> <20080603112221.GW28946@ZenIV.linux.org.uk> <20080603113018.GA27955@shareable.org> <20080603114921.GX28946@ZenIV.linux.org.uk> <20080603120135.GA28905@shareable.org> <20080603120850.GZ28946@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Michael Kerrisk , Miklos Szeredi , drepper-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Al Viro Return-path: Content-Disposition: inline In-Reply-To: <20080603120850.GZ28946-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org> Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org Al Viro wrote: > On Tue, Jun 03, 2008 at 01:01:35PM +0100, Jamie Lokier wrote: > > > with a lot of things, starting with "why utimes(2) has weaker requirements > > > with NULL argument", but we are far too late to fix that. > > > > To be fair, having a writable file descriptor only lets you change the > > mtime to "now", and having a readable file descriptor only lets you > > change the atime to "now". > > > > Changing the times _in general_ can be seen as over-reaching those > > capabilities and arguably justifies more strict checks. > > Which is what all questions about writability apply only to NULL case > anyway... Oh! So if I have the file descriptor, I can just as well change the mtime by read a byte and write it back. Or even do a zero-length write, on some OSes. -- Jamie -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html