From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14633 invoked by alias); 8 Feb 2007 21:14:58 -0000 Received: (qmail 14588 invoked by uid 22791); 8 Feb 2007 21:14:57 -0000 X-Spam-Check-By: sourceware.org Received: from sibelius.xs4all.nl (HELO brahms.sibelius.xs4all.nl) (82.92.89.47) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 08 Feb 2007 21:14:52 +0000 Received: from brahms.sibelius.xs4all.nl (kettenis@localhost.sibelius.xs4all.nl [127.0.0.1]) by brahms.sibelius.xs4all.nl (8.14.0/8.14.0) with ESMTP id l18LEeCT014543; Thu, 8 Feb 2007 22:14:40 +0100 (CET) Received: (from kettenis@localhost) by brahms.sibelius.xs4all.nl (8.14.0/8.14.0/Submit) id l18LEbGk029498; Thu, 8 Feb 2007 22:14:37 +0100 (CET) Date: Thu, 08 Feb 2007 21:14:00 -0000 Message-Id: <200702082114.l18LEbGk029498@brahms.sibelius.xs4all.nl> From: Mark Kettenis To: drow@false.org CC: brobecker@adacore.com, Wiljan.Derks@zonnet.nl, gdb@sourceware.org In-reply-to: <20070207221644.GA26833@nevyn.them.org> (message from Daniel Jacobowitz on Wed, 7 Feb 2007 17:16:44 -0500) Subject: Re: How to tell gdb about dlls using remote protocol References: <003f01c7457c$0f2d8090$9600000a@kamer> <20070131223113.GA15122@nevyn.them.org> <20070201175311.GG17864@adacore.com> <200702072214.l17MER45023107@brahms.sibelius.xs4all.nl> <20070207221644.GA26833@nevyn.them.org> 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 X-SW-Source: 2007-02/txt/msg00047.txt.bz2 > Date: Wed, 7 Feb 2007 17:16:44 -0500 > From: Daniel Jacobowitz > > On Wed, Feb 07, 2007 at 11:14:27PM +0100, Mark Kettenis wrote: > > I think this diff makes sense. However, I'm pretty sure there are > > Linux systems out there where this will make things worse :(. In > > particular, on kernels with a vsyscall page buit without the stub > > shared library for that page, this change will systematically skip a > > frame. And that frame is quite crucial since it is the frame for the > > libc system call stub, so it will be hard for a user to find out in > > what system call the program is blocked on. > > > > I have no idea though how many people are still runing those kernels. > > That number might be very low enough for us not to care. > > For what it's worth, I think it is. And, if it isn't, it would be > straightforward to add a custom frame sniffer to i386-linux-tdep.c > to recognize that case. I don't know what the affected versions > are, though. Me neither. However, Joel's diff has a problem: it makes the signull.exp tests fail. They explicitly test calling a null pointer, and that case is now caught by Joel's check. Skipping a frame in that case is not acceptable to me. I'm currently testing chaning Joel's original: else if (cache->pc == 0) into: else if (cache->pc == 0 && frame_pc_unwind (next_frame) != 0) What do you think of that? Mark