From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.wrs.com (mail.windriver.com [147.11.1.11]) by ozlabs.org (Postfix) with ESMTP id 9112ADDE33 for ; Thu, 30 Aug 2007 12:13:05 +1000 (EST) Message-ID: <46D627B6.9060208@windriver.com> Date: Wed, 29 Aug 2007 21:13:10 -0500 From: Jason Wessel MIME-Version: 1.0 To: pete@bluelane.com Subject: Re: [Kgdb-bugreport] 2.6.23-rc3-mm1: kgdb build failure on powerpc References: <20070822020648.5ea3a612.akpm@linux-foundation.org> <200708222104.29432.m.kozlowski@tuxland.pl> <20070822124743.fc316963.akpm@linux-foundation.org> <46CCBC3C.7010307@windriver.com> <20070822165318.b82da13c.akpm@linux-foundation.org> <46CCFE2C.4050306@windriver.com> <46D604BF.7090905@bluelane.com> <46D61B21.1010703@bluelane.com> In-Reply-To: <46D61B21.1010703@bluelane.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: kgdb-bugreport@lists.sourceforge.net, amitkale@linsyssoft.com, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, Mariusz Kozlowski , Paul Mackerras , Andrew Morton List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Pete/Piet Delaney wrote: > We are getting a problem with VMware where kernel text is the schedler > is getting wacked with four null bytes into the code. Thought I'd use > the current linux-2.6-kgdb.git tree and possible the CONFIG_DEBUG_RODATA > patch to make kernel text readonly: > > https://www.x86-64.org/pipermail/patches/2007-March/003666.html > > I thought the kernel text was RO and gdb had to disable it to > insert a breakpoint. > > If you are going to make all the kernel text RO, then you are going to have to add some code to the kgdb write memory so as to unprotect a given page or all the breakpoint writes are going to fail. Alternatively you can use HW breakpoints. But, I have no idea if your VM Ware simulated HW emulate HW breakpoint registers or not. Jason.