From mint-bounce@lists.fishpool.fi Sun Nov 6 12:12:08 2005 X-Original-To: fnaumann@mail.boerde.de Delivered-To: fnaumann@mail.boerde.de Message-ID: <436DE43C.2010900@obta.uw.edu.pl> Date: Sun, 06 Nov 2005 12:08:44 +0100 From: Konrad Kokoszkiewicz User-Agent: Mozilla Thunderbird 1.0.7 (X11/20051003) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Miro Kropacek Cc: Mint List Subject: Re: [MiNT] strange memory violation References: <436DD2D2.6090103@hysteria.sk> In-Reply-To: <436DD2D2.6090103@hysteria.sk> Content-Type: text/plain; charset=ISO-8859-2; format=flowed Content-Transfer-Encoding: 7bit X-ecartis-version: Ecartis v1.0.0 Sender: mint-bounce@lists.fishpool.fi Errors-To: mint-bounce@lists.fishpool.fi X-original-sender: draco@obta.uw.edu.pl Precedence: bulk List-help: List-unsubscribe: List-Id: X-List-ID: X-Virus-Scanned: by amavisd-new at relay.boerde.de X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on relay.boerde.de X-Spam-Status: No, hits=-0.8 tagged_above=-50.5 required=7.0 tests=AWL, BAYES_00 X-Spam-Level: > after this, Toswin was still active (just desktop.prg was killed, so > I've tried it from this) > memory violation, type: private, PC: 1112c3c, Addr: 1a9a2be, test killed > > after restart, I've tried it from gdb: > memory violation, type: private, PC: 1c922be, Addr: 1c922be, gdb(!) killed > memory violation, type: free, PC: 1112c3c, Addr: 18da2be, test killed > (yeah, two memory violations at once) > > Could me someone tell, what I'm doing wrong? You are doing wrong one thing: everything. You're grabbing an interrupt vector and it points to your program. This is a timer interrupt and it occurs asynchronously to task switches, so it occurs even when your program does not run (it is waiting for its turn to run). The memory that belong to your program is NOT ACCESSIBLE AT THAT TIME. But the timer interrupt code tries to access it. So the current process gets bus errors, naturally. First of all, you should never ever make an interrupt vector point to your user application. This is unsafe. When the application somehow crashes and exits behind your control, its memory becomes invalid, and the next interrupt you had grabbed will instantly bring the system down. Second, you must mark your program Supervisor-protected to avoid bus errors. Third, MiNT systems will never be stable if such style of programming doesn't become exstinct once for good. KMK