From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id CD1498D0039 for ; Thu, 27 Jan 2011 05:23:01 -0500 (EST) Subject: Re: [RFC] [PATCH 2.6.37-rc5-tip 5/20] 5: Uprobes: register/unregister probes. From: Peter Zijlstra In-Reply-To: <20110127100157.GS19725@linux.vnet.ibm.com> References: <20101216095714.23751.52601.sendpatchset@localhost6.localdomain6> <20101216095817.23751.76989.sendpatchset@localhost6.localdomain6> <1295957744.28776.722.camel@laptop> <20110126075558.GB19725@linux.vnet.ibm.com> <1296036708.28776.1138.camel@laptop> <20110126153036.GN19725@linux.vnet.ibm.com> <1296056756.28776.1247.camel@laptop> <20110126165645.GP19725@linux.vnet.ibm.com> <1296061949.28776.1343.camel@laptop> <20110127100157.GS19725@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Date: Thu, 27 Jan 2011 11:23:37 +0100 Message-ID: <1296123817.15234.57.camel@laptop> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org To: Srikar Dronamraju Cc: Ingo Molnar , Steven Rostedt , Linux-mm , Arnaldo Carvalho de Melo , Linus Torvalds , Ananth N Mavinakayanahalli , Christoph Hellwig , Masami Hiramatsu , Oleg Nesterov , Andrew Morton , SystemTap , Jim Keniston , Frederic Weisbecker , Andi Kleen , LKML , "Paul E. McKenney" List-ID: On Thu, 2011-01-27 at 15:31 +0530, Srikar Dronamraju wrote: > > > > - validate that the vma is indeed a map of the right inode > > >=20 > > > We can add a check in write_opcode( we need to pass the inode to > > > write_opcode). > >=20 > > sure.. > >=20 > > > > - validate that the offset of the probe corresponds with the store= d > > > > address > > >=20 > > > I am not clear on this. We would have derived the address from the > > > offset. So is that we check for > > > (vaddr =3D=3D vma->vm_start + uprobe->offset) > >=20 > > Sure, but the vma might have changed since you computed the offset -) >=20 > If the vma has changed then it would fail the 2nd validation i.e vma > corresponds to the uprobe inode right. If the vma was unmapped and > mapped back at the same place, then I guess we are okay to probe. It can be unmapped and mapped back slightly different. A map of the same file doesn't need to mean its in the exact same location or has the exact same pgoffset. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org