From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20836 invoked by alias); 21 Jul 2004 21:16:35 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 20824 invoked from network); 21 Jul 2004 21:16:33 -0000 Received: from unknown (HELO sccrmhc11.comcast.net) (204.127.202.55) by sourceware.org with SMTP; 21 Jul 2004 21:16:33 -0000 Received: from lucon.org ([24.6.43.109]) by comcast.net (sccrmhc11) with ESMTP id <2004072121163201100dvkome>; Wed, 21 Jul 2004 21:16:33 +0000 Received: by lucon.org (Postfix, from userid 1000) id 6E8A064298; Wed, 21 Jul 2004 14:16:32 -0700 (PDT) Date: Wed, 21 Jul 2004 22:05:00 -0000 From: "H. J. Lu" To: Mark Kettenis Cc: eliz@gnu.org, cagney@gnu.org, gdb@sources.redhat.com Subject: Re: [6.2] PROBLEMS file Message-ID: <20040721211632.GA26232@lucon.org> References: <40FB3F1F.3040900@gnu.org> <1659-Mon19Jul2004215127+0300-eliz@gnu.org> <200407212059.i6LKxgQ9019045@copland.kettenis.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200407212059.i6LKxgQ9019045@copland.kettenis.dyndns.org> User-Agent: Mutt/1.4.1i X-SW-Source: 2004-07/txt/msg00272.txt.bz2 On Wed, Jul 21, 2004 at 10:59:42PM +0200, Mark Kettenis wrote: > Date: Mon, 19 Jul 2004 21:51:27 +0200 > From: "Eli Zaretskii" > > > Date: Sun, 18 Jul 2004 23:25:19 -0400 > > From: Andrew Cagney > > > > gdb/1505: [regression] gdb prints a bad backtrace for a thread > > > > When backtracing a thread, gdb does not stop when it reaches the > > outermost frame, instead continuing until it hits garbage. This is > > sensitive to the operating system and thread library. > > In most cases there is no way for GDB to tell what the outermost frame > is. Some people think that %ebp == 0 or %eip == 0 serves as a marker, > but they're mistaken. The usage as %ebp as a frame pointer is a > software comvention which isn't mandated by the ABI. More and more FYI, the i386 psABI, which is also used by the x86-64 psABI, says: %ebp The content of this register is unspecified at process initialization time, but the user code should mark the deepest stack frame by setting the frame pointer to zero. No other frame's %ebp should have a zero value. H.J.