From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [10.3.1.93] (helo=sc8-sf-list1-new.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1Fi6VZ-0001HW-O9 for user-mode-linux-devel@lists.sourceforge.net; Mon, 22 May 2006 02:15:25 -0700 Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1Fi6VZ-00034L-JW for user-mode-linux-devel@lists.sourceforge.net; Mon, 22 May 2006 02:15:25 -0700 Received: from smtp004.mail.ukl.yahoo.com ([217.12.11.35]) by mail.sourceforge.net with smtp (Exim 4.44) id 1Fi6VW-00088j-RW for user-mode-linux-devel@lists.sourceforge.net; Mon, 22 May 2006 02:15:25 -0700 From: Blaisorblade Subject: Re: [uml-devel] [PATCH] RFC allow PTRACE_SYSCALL to selectively skip syscalls References: <200605211936.56902.blaisorblade@yahoo.it> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200605221115.10516.blaisorblade@yahoo.it> Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Mon, 22 May 2006 11:15:10 +0200 To: Steven James Cc: user-mode-linux-devel@lists.sourceforge.net, "Charles P. Wright" , Jeff Dike On Monday 22 May 2006 01:58, Steven James wrote: > On Sun, 21 May 2006, Blaisorblade wrote: > > On Friday 19 May 2006 16:09, Blaisorblade wrote: > > > That is more or less my idea, however I've not had the time to work on > > > it. Instead of changing the semantics we must add another option - I > > > thought to use a ptrace option (the ones you set with > > > PTRACE_SETOPTIONS), Charles Wright coded instead a PTRACE_CHECKEMU, but > > > this is the concept. > > > > > > So, I'm going to forward you the emails containing two patches: > > > *) PTRACE_CHECKEMU from Charles Wright > > > *) PTRACE_SYSCALL_MASK - to make the debugger be notified only of some > > > syscalls; the only check is via syscall number though. It's unrelated > > > to this but probably useful to you. > > > > > > And I'm attaching my original version of the PTRACE_CHECKEMU thing > > > > There's yet another implementation of this; look at the first 4 threads > > of this page - Renzo Davoli posted a set of 3-patches which include his > > PTRACE_SYSVM which has also this feature. > > > > http://marc.theaimsgroup.com/?a=106901060200003&r=1&w=2 > > I had hoped to test both of these today, but got caught up in a nasty bug > in 2.6.16.16 where syscall_trace_leave is sometimes getting called twice > for the same syscall. > > Unfortunatly, my program counts on only being called once on entry and onc > on exit from the syscall, so it gets hopelessly confused (not to mention > the extra wasted context switches). > > I haven't been keeping up quite as I should, has it bitten anyone else > and is there a fix? I have uml/64-bit (AMD64) not working on 2.6.16/64bit, while uml-32bit works fine on it, and the same uml/64-bit binaries work fine on 2.6.15. I haven't tracked it down fully, but could it be related? Possibly yes because I now seem to recall you run 64-bit host. So you likely found our bug! So, please, send a bug report to Roland McGrath , the ptrace maintainer (or so it seems), cc:ing uml-devel, Jeff and me at least. And note that neither UML works, though the UML crash hasn't been debugged down to verify it's this bug the cause. I've built all 2.6.16-rc kernels, I hope I can do binary search to insulate a bit where the bug was introduced. Now I know which bug it is, it'll be easier. Thanks a lot! -- Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!". Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894) http://www.user-mode-linux.org/~blaisorblade ___________________________________ Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB http://mail.yahoo.it ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel