Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750810AbWI2JSr (ORCPT ); Fri, 29 Sep 2006 05:18:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750887AbWI2JSr (ORCPT ); Fri, 29 Sep 2006 05:18:47 -0400 Received: from smtp.osdl.org ([65.172.181.4]:13731 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1750810AbWI2JSp (ORCPT ); Fri, 29 Sep 2006 05:18:45 -0400 Date: Fri, 29 Sep 2006 02:18:33 -0700 From: Andrew Morton To: Andi Kleen Cc: Jeremy Fitzhardinge , linux-kernel@vger.kernel.org, Hugh Dickens , Michael Ellerman , Paul Mackerras Subject: Re: [PATCH RFC 1/4] Generic BUG handling. Message-Id: <20060929021833.147a17bd.akpm@osdl.org> In-Reply-To: <20060929091319.GB41098@muc.de> References: <20060928225444.439520197@goop.org> <20060928225452.229936605@goop.org> <20060929085745.GA41098@muc.de> <20060929021019.19058b98.akpm@osdl.org> <20060929091319.GB41098@muc.de> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1429 Lines: 43 On 29 Sep 2006 11:13:19 +0200 Andi Kleen wrote: > On Fri, Sep 29, 2006 at 02:10:19AM -0700, Andrew Morton wrote: > > On 29 Sep 2006 10:57:45 +0200 > > Andi Kleen wrote: > > > > > > Some architectures (powerpc) implement WARN using the same mechanism; > > > > if the illegal instruction was the result of a WARN, then report_bug() > > > > returns 1; otherwise it returns 0. > > > > > > In theory we could do that on x86 too (and skipping the instruction), > > > the only problem > > > is that the only guaranteed to fault opcode is ud2 :/. Ok maybe we could > > > reserve some int XXX vector. > > > > > > % gid WARN_ON | grep -v arch | wc -l > > > 299 > > > > powerpc sets a bit in the __LINE__ number to indicate that it was a > > WARN_ON. That'll work on all architectures. > > We still would need an architecture dependent way to skip the opcode > though (just returning would raise it again). On x86 > > regs->eip += 2 (rip on x86-64) > > should be enough > We have all that now. Do: if (report_bug(regs->eip) == BUG_TRAP_TYPE_WARN) regs>eip += 2; (The powerpc is_warning_bug() implementation needs to be hoisted into generic code) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/