From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932550AbWF0L4U (ORCPT ); Tue, 27 Jun 2006 07:56:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932544AbWF0L4T (ORCPT ); Tue, 27 Jun 2006 07:56:19 -0400 Received: from mtagate4.de.ibm.com ([195.212.29.153]:48205 "EHLO mtagate4.de.ibm.com") by vger.kernel.org with ESMTP id S932512AbWF0L4S (ORCPT ); Tue, 27 Jun 2006 07:56:18 -0400 Subject: Re: [PATCH] kprobes for s390 architecture From: Martin Schwidefsky Reply-To: schwidefsky@de.ibm.com To: Mike Grundy Cc: jan.glauber@de.ibm.com, linux-kernel@vger.kernel.org, systemtap@sources.redhat.com In-Reply-To: <20060621171517.GA7421@localhost.localdomain> References: <20060612131552.GA6647@localhost.localdomain> <1150141217.5495.72.camel@localhost> <20060621042804.GA20300@localhost.localdomain> <1150907920.8295.10.camel@localhost> <20060621171517.GA7421@localhost.localdomain> Content-Type: text/plain Organization: IBM Corporation Date: Tue, 27 Jun 2006 13:56:11 +0200 Message-Id: <1151409371.5390.14.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.6.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2006-06-21 at 10:15 -0700, Mike Grundy wrote: > On Wed, Jun 21, 2006 at 06:38:40PM +0200, Martin Schwidefsky wrote: > > On Tue, 2006-06-20 at 21:28 -0700, Mike Grundy wrote: > > > Hi Martin - This patch implements the suggestions from your review. There were > > > a couple points I wanted to go over: > > > > There are some more instructions missing that need fixup: > > > > "brxh" 0x84??????, "brxle" 0x85??????, "brc" 0xa7?4????, > > > > "brct" 0xa7?6????, "brctg" 0xa7?7????, "bctgr" 0xb946????, > > > > "brxhg" 0xec????????44 and "brxlg" 0xec??????45. > > > Since all of these are relative branches, and they don't save the psw, the > > > standard clean up of adjusting the original psw by the offset from the out of > > > line address after single step. Unless I'm just being dense :-) > > > > All of these are conditional branches, if the branch is not taken you > > have to do a cleanup. > The reason I have a special cleanup for the other branches is the easy way to > tell if the branch wasn't taken is the pswa = orig pswa + instruction length. > The relative branches get cleaned up the same way if the branch was taken or > not, pswa = probe_addr + (out of line end psw - out of line start psw). These > are all relative branches and while they need cleanup, they don't get treated > differently based on the branch status. So you are always doing a sort of branch cleanup, even for non-branch instructions. Seems reasonable, since non-branch instructions don't branch and the standard cleanup logic can deal with. > > You misunderstood me here. I'm not talking about storing the same piece > > of data to memory on each processor. I'm talking about isolating all > > other cpus so that the initiating cpu can store the breakpoint to memory > Yep, I misunderstood that. The serialization is the point, not the replacement > of a word in memory. Exactly. -- blue skies, Martin. Martin Schwidefsky Linux for zSeries Development & Services IBM Deutschland Entwicklung GmbH "Reality continues to ruin my life." - Calvin.