From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754138AbaB0AsO (ORCPT ); Wed, 26 Feb 2014 19:48:14 -0500 Received: from smtprelay0225.hostedemail.com ([216.40.44.225]:53287 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751929AbaB0AsN (ORCPT ); Wed, 26 Feb 2014 19:48:13 -0500 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::,RULES_HIT:41:355:379:541:560:599:960:973:982:988:989:1260:1261:1277:1311:1313:1314:1345:1359:1373:1431:1437:1515:1516:1518:1534:1542:1593:1594:1711:1730:1747:1777:1792:2393:2559:2562:2687:2828:2892:2894:2895:3138:3139:3140:3141:3142:3355:3622:3834:3865:3866:3867:3868:3870:3871:3872:3874:4321:4605:5007:6119:7652:8784:10004:10400:10848:11026:11232:11473:11658:11914:12043:12296:12438:12517:12519:12555:12663:12740,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: peace74_d4d7a87f2047 X-Filterd-Recvd-Size: 3731 Message-ID: <1393462087.24588.50.camel@joe-AO722> Subject: Re: The sheer number of sparse warnings in the kernel From: Joe Perches To: "H. Peter Anvin" Cc: Linux Kernel Mailing List Date: Wed, 26 Feb 2014 16:48:07 -0800 In-Reply-To: <530E6F76.1070605@zytor.com> References: <530E6F76.1070605@zytor.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.8.4-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2014-02-26 at 14:49 -0800, H. Peter Anvin wrote: > The number of sparse errors in the current kernel is staggering, and it > makes sparse a lot less valuable of a tool that it otherwise could be. > On a build of x86-64 allyesconfig I'm getting 20,676 sparse messages. > Out of those, 12,358 come from linux/err.h. Given that the latter > basically spams *everything*, I can only conclude that almost noone uses > sparse unless they have a filter script. > > So a lot of these are certainly nuisance problems, like the > stuff which has to do with the handling of error values, > but some of these look like real bugs. > > What do we need to do to actually make our tools be able to do work for > us? Newbie projects to clean up? Trying to get the larger Linux > companies to put resources on it? gcc 4.8 does annoyingly warn on all unsigned/signed mismatches/implicit conversions too. err.h could also return bool instead of long for the IS_ERR and IS_ERR_OR_NULL tests. Maybe something like this could be useful. Shut up the unsigned<->signed pointer conversions and implicit conversions in the Makefile. Use bool not long for IS_ERR and IS_ERR_OR_NULL Update the dentry description of kernel pointers left over from 2002's move to err.h unsigned... --- Makefile | 1 + include/linux/err.h | 7 ++++--- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index fce2ba7..a9c11c4 100644 --- a/Makefile +++ b/Makefile @@ -381,6 +381,7 @@ KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common \ -Werror-implicit-function-declaration \ + -Wno-sign-conversion -Wno-pointer-sign \ -Wno-format-security \ -fno-delete-null-pointer-checks KBUILD_AFLAGS_KERNEL := diff --git a/include/linux/err.h b/include/linux/err.h index 15f92e0..a729120 100644 --- a/include/linux/err.h +++ b/include/linux/err.h @@ -2,12 +2,13 @@ #define _LINUX_ERR_H #include +#include #include /* * Kernel pointers have redundant information, so we can use a - * scheme where we can return either an error code or a dentry + * scheme where we can return either an error code or a normal * pointer with the same return value. * * This should be a per-architecture thing, to allow different @@ -29,12 +30,12 @@ static inline long __must_check PTR_ERR(__force const void *ptr) return (long) ptr; } -static inline long __must_check IS_ERR(__force const void *ptr) +static inline bool __must_check IS_ERR(__force const void *ptr) { return IS_ERR_VALUE((unsigned long)ptr); } -static inline long __must_check IS_ERR_OR_NULL(__force const void *ptr) +static inline bool __must_check IS_ERR_OR_NULL(__force const void *ptr) { return !ptr || IS_ERR_VALUE((unsigned long)ptr); }