From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3972 invoked by alias); 20 Nov 2008 23:52:36 -0000 Received: (qmail 3893 invoked by uid 22791); 20 Nov 2008 23:52:35 -0000 X-Spam-Check-By: sourceware.org Received: from NaN.false.org (HELO nan.false.org) (208.75.86.248) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 20 Nov 2008 23:51:55 +0000 Received: from nan.false.org (localhost [127.0.0.1]) by nan.false.org (Postfix) with ESMTP id 0711910C2E; Thu, 20 Nov 2008 23:51:53 +0000 (GMT) Received: from caradoc.them.org (209.195.188.212.nauticom.net [209.195.188.212]) by nan.false.org (Postfix) with ESMTP id B8D4C10C2C; Thu, 20 Nov 2008 23:51:52 +0000 (GMT) Received: from drow by caradoc.them.org with local (Exim 4.69) (envelope-from ) id 1L3JJP-0003Et-1i; Thu, 20 Nov 2008 18:51:51 -0500 Date: Fri, 21 Nov 2008 15:16:00 -0000 From: Daniel Jacobowitz To: Ulrich Weigand Cc: gdb-patches@sourceware.org Subject: Re: [rfc] Handle broken CFI for signal trampolines in libc on amd64-linux Message-ID: <20081120235151.GA12123@caradoc.them.org> Mail-Followup-To: Ulrich Weigand , gdb-patches@sourceware.org References: <200811202338.mAKNcBlR016418@d12av02.megacenter.de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200811202338.mAKNcBlR016418@d12av02.megacenter.de.ibm.com> User-Agent: Mutt/1.5.17 (2008-05-11) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2008-11/txt/msg00569.txt.bz2 On Fri, Nov 21, 2008 at 12:38:11AM +0100, Ulrich Weigand wrote: > Unfortunately even if I use the dwarf_signal_frame_p hook to have the > DWARF-2 sniffer recognize a SIGTRAMP_FRAME, it still doesn't work as > the __restore_rt CFI (at least in my glibc) only describes the unwind > effects as if it were a regular function, without taking into account > the restoring of registers by the sigreturn system call. What version of glibc is this? It was fixed two years ago this month: 2006-12-01 Jan Kratochvil * sysdeps/unix/sysv/linux/x86_64/sigaction.c: Fix compatibility with libgcc not supporting `rflags' unwinding (register # >= 17). 2006-11-29 Daniel Jacobowitz Jakub Jelinek Jan Kratochvil * sysdeps/unix/sysv/linux/x86_64/sigaction.c (restore_rt): Add correct unwind information. * sysdeps/unix/sysv/linux/x86_64/Makefile: Provide symbols for 'restore_rt' even in the 'signal' directory. * sysdeps/unix/sysv/linux/x86_64/ucontext_i.sym: Extend the regs list. -- Daniel Jacobowitz CodeSourcery