From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 106422 invoked by alias); 17 Aug 2016 00:02:12 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 106411 invoked by uid 89); 17 Aug 2016 00:02:11 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_PASS autolearn=ham version=3.3.2 spammy=Whatever, grab, Hx-languages-length:1128, grabbing X-HELO: mail2.candelatech.com Received: from mail2.candelatech.com (HELO mail2.candelatech.com) (208.74.158.173) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 17 Aug 2016 00:02:00 +0000 Received: from [192.168.100.149] (firewall.candelatech.com [50.251.239.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail2.candelatech.com (Postfix) with ESMTPSA id 6B8B840A626 for ; Tue, 16 Aug 2016 17:01:59 -0700 (PDT) To: gdb@sourceware.org From: Ben Greear Subject: Need some help with xtensa processor Message-ID: <268c3c75-f5b8-4eac-3999-bbf29d0ec10d@candelatech.com> Date: Wed, 17 Aug 2016 00:02:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2016-08/txt/msg00031.txt.bz2 Hello! I'm working on a closed source (not my decision) project that uses an xtensa cpu. I have no jtag access to this board, but I can pass messages, including grabbing 'logs' and stack traces on crash, and so forth. Currently, I have narrowed down a bug to a wild write on a structure of method pointers. Next time code tries to execute one of these methods, it crashes spectacularly. So, I wanted to tell the processor to set a watchpoint on this address, and then assert or otherwise give me an ability to grab the program counter, stack, etc, when something writes on the memory. I think I know how to set the BREAKA, BREAKC registers, but I must be missing something related perhaps to setting up a proper exception vector handler for this? Whatever the cause, I can scribble on memory after setting the watchpoint and nothing useful happens. So, I'd appreciate pointers if someone has some ideas. And, if someone wants to work on this for pay, please contact me off-list. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com