Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030220AbWJRMwL (ORCPT ); Wed, 18 Oct 2006 08:52:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030257AbWJRMwK (ORCPT ); Wed, 18 Oct 2006 08:52:10 -0400 Received: from emailer.gwdg.de ([134.76.10.24]:39085 "EHLO emailer.gwdg.de") by vger.kernel.org with ESMTP id S1030220AbWJRMwJ (ORCPT ); Wed, 18 Oct 2006 08:52:09 -0400 Date: Wed, 18 Oct 2006 14:47:20 +0200 (MEST) From: Jan Engelhardt To: Andreas Mohr cc: Ralf Baechle , "Randy.Dunlap" , Andrew Morton , Erik Frederiksen , linux-kernel@vger.kernel.org Subject: Re: IS_ERR Threshold Value In-Reply-To: <20061016193140.GA6422@rhlx01.fht-esslingen.de> Message-ID: References: <1151528227.3904.1110.camel@girvin.pmc-sierra.bc.ca> <20060628140825.692f31be.rdunlap@xenotime.net> <20060629181013.GA18777@linux-mips.org> <20061016193140.GA6422@rhlx01.fht-esslingen.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Report: Content analysis: 0.0 points, 6.0 required _SUMMARY_ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1165 Lines: 36 >Subject: Re: IS_ERR Threshold Value > >> > Peter Anvin mentioned just a few days ago that this threshold value >> > should be 4095 for all arches. I think we need to get that patch >> > done & submitted to Andrew for -mm. >> >> So here the patch is: >> >> o Raise the maximum error number in IS_ERR_VALUE to 4095. >> >> +#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO) There seems to be a slight problem with doing that. Running `ldd /bin/bash` prints out linux-gate.so.1 => (0xffffe000) and the topmost address a kernel function can return is 0xFFFFf000 when MAX_ERRNO=4095, but that is going to be tight with the vdso mapped at 0xffffE000. Or is ldd giving wrong output? Because actually, `cat /proc/$$/maps` ($$=bash) says it is mapped a lot less high: a7fbe000-a7fbf000 r-xp a7fbe000 00:00 0 [vdso] (CONFIG_COMPAT_VDSO=y, CONFIG_PAGE_OFFSET=0xB0000000, 2.6.18) -`J' -- - 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/