From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161057AbWJDAyR (ORCPT ); Tue, 3 Oct 2006 20:54:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161056AbWJDAyR (ORCPT ); Tue, 3 Oct 2006 20:54:17 -0400 Received: from ozlabs.org ([203.10.76.45]:50066 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S1161057AbWJDAyQ (ORCPT ); Tue, 3 Oct 2006 20:54:16 -0400 Subject: Re: [PATCH 4/5] Generic BUG for powerpc From: Michael Ellerman Reply-To: michael@ellerman.id.au To: Jeremy Fitzhardinge Cc: Andrew Morton , linux-kernel@vger.kernel.org, Andi Kleen , Hugh Dickens , Paul Mackerras , Benjamin Herrenschmidt , Rusty Russell In-Reply-To: <20061003201812.313852083@goop.org>> References: <20061003201618.974094245@goop.org> > <20061003201812.313852083@goop.org>> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-uxJMfJcOOhC4dq6L/Y8e" Date: Wed, 04 Oct 2006 10:54:03 +1000 Message-Id: <1159923244.31312.21.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --=-uxJMfJcOOhC4dq6L/Y8e Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2006-10-03 at 13:16 -0700, Jeremy Fitzhardinge wrote: > plain text document attachment (mm) > This makes powerpc use the generic BUG machinery. The biggest > difference from the previous powerpc bug code is that it no longer > reports the function name, since it is redundant with kallsyms, and > not needed in general. >=20 > There is an overall reduction of code, since module_32/64 duplicated seve= ral > functions. >=20 > Unfortunately there's no way to tell gcc that BUG won't return, so the > BUG macro includes a goto loop. This will generate a real jmp > instruction, which is never used. I posted a patch a few weeks back to use __builtin_trap(), which gives GCC the hint that it's not going to return. (http://patchwork.ozlabs.org/linuxppc/patch?id=3D7047) Unfortunately this generated some negative feedback from some of our crackhead ... er wonderful colleagues who want to be able to step over BUGs in some circumstances. (http://ozlabs.org/pipermail/linuxppc-dev/2006-September/026161.html) I think they conceeded that it could be configurable, but I wasn't sure it was worth the trouble. cheers --=20 Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person --=-uxJMfJcOOhC4dq6L/Y8e Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQBFIwYrdSjSd0sB4dIRAkz3AJ0WAKX/hcLRHDne7E2SwegLZV72KQCdF7Du KMfJFr0ogeAIZ23cCXmj1Ko= =BG0n -----END PGP SIGNATURE----- --=-uxJMfJcOOhC4dq6L/Y8e--