From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24642 invoked by alias); 19 Jul 2010 09:20:29 -0000 Received: (qmail 24625 invoked by uid 22791); 19 Jul 2010 09:20:27 -0000 X-SWARE-Spam-Status: No, hits=-5.9 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 19 Jul 2010 09:20:23 +0000 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o6J9K0BD012376 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 19 Jul 2010 05:20:00 -0400 Received: from host1.dyn.jankratochvil.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o6J9JvrM025665 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 19 Jul 2010 05:19:59 -0400 Received: from host1.dyn.jankratochvil.net (localhost [127.0.0.1]) by host1.dyn.jankratochvil.net (8.14.4/8.14.4) with ESMTP id o6J9JvXu026587; Mon, 19 Jul 2010 11:19:57 +0200 Received: (from jkratoch@localhost) by host1.dyn.jankratochvil.net (8.14.4/8.14.4/Submit) id o6J9JuOi026581; Mon, 19 Jul 2010 11:19:56 +0200 Date: Mon, 19 Jul 2010 09:20:00 -0000 From: Jan Kratochvil To: Tristan Gingold Cc: gdb-patches@sourceware.org Subject: Re: [patch] Fix linux-ia64 on SIGILL for deleted breakpoint Message-ID: <20100719091956.GA25899@host1.dyn.jankratochvil.net> References: <20100719085817.GA24395@host1.dyn.jankratochvil.net> <00CE116D-04D6-477D-9D71-0EBAD7017283@adacore.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <00CE116D-04D6-477D-9D71-0EBAD7017283@adacore.com> User-Agent: Mutt/1.5.20 (2009-12-10) 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: 2010-07/txt/msg00277.txt.bz2 On Mon, 19 Jul 2010 11:04:26 +0200, Tristan Gingold wrote: > On Jul 19, 2010, at 10:58 AM, Jan Kratochvil wrote: > > in some cases ia64 can generate SIGILL instead of SIGTRAP. Guessing it is > > a CPU bug instead of Linux kernel bug (but I may be wrong). > > https://bugzilla.redhat.com/show_bug.cgi?id=615538 > > http://sources.redhat.com/cgi-bin/cvsweb.cgi/~checkout~/tests/ptrace-tests/tests/ia64-sigill.c?cvsroot=systemtap > > This is not a bug but a feature: the immediate of break.b is ignored by the processor. You are right, Intel IA64 manual says: For the b_unit_form, imm21 is ignored and the value zero is placed in the Interruption Immediate control register (IIM). And kernel/arch/ia64/kernel/traps.c ia64_bad_break(): case 0: /* unknown error (used by GCC for __builtin_abort()) */ [...] sig = SIGILL; code = ILL_ILLOPC; And it really reports SIGILL even for example for: ...0: 10 00 00 00 01 00 [MIB] nop.m 0x0 ...6: 00 00 00 00 00 00 break.i 0x0 ...c: 00 00 00 20 nop.b 0x0 Thanks for the explanation (embarassingly I did read the IA64 manual first). (The GDB patch part meaning has not changed by this mail.) Jan