From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755024AbaEOXEv (ORCPT ); Thu, 15 May 2014 19:04:51 -0400 Received: from smtprelay0154.hostedemail.com ([216.40.44.154]:40451 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751654AbaEOXEu (ORCPT ); Thu, 15 May 2014 19:04:50 -0400 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1261:1277:1311:1313:1314:1345:1359:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2197:2199:2393:2553:2559:2562:2828:2897:3138:3139:3140:3141:3142:3352:3622:3653:3865:3867:3868:3872:3874:4250:4321:5007:6119:7652:7903:8957:10004:10400:10848:10967:11026:11232:11473:11658:11914:12043:12049:12517:12519:12740:13069:13161:13229:13311:13357,0,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: event94_ccecec531f2c X-Filterd-Recvd-Size: 2042 Message-ID: <1400195086.5058.26.camel@joe-AO725> Subject: Re: [PATCH] checkpatch: Add --strict test for kmalloc/kzalloc with multiply From: Joe Perches To: Andrew Morton Cc: Andy Whitcroft , LKML Date: Thu, 15 May 2014 16:04:46 -0700 In-Reply-To: <20140515155844.041ee0bc17aae5f3b8eacd70@linux-foundation.org> References: <1400024929.24350.76.camel@joe-AO725> <20140515155844.041ee0bc17aae5f3b8eacd70@linux-foundation.org> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.10.4-0ubuntu1 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 Thu, 2014-05-15 at 15:58 -0700, Andrew Morton wrote: > On Tue, 13 May 2014 16:48:49 -0700 Joe Perches wrote: > > Protect against sizeof overflows by preferring > > kmalloc_array and kcalloc to kmalloc/kzalloc > > with a sizeof multiply. [] > > +# check for k[mz]alloc with multiplies that could be kmalloc_array/kcalloc > > + if ($^V && $^V ge 5.10.0 && > > + $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*(k[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/) { > > + my $oldfunc = $3; > > + my $a1 = $4; > > + my $a2 = $10; > > + my $newfunc = "kmalloc_array"; > > + $newfunc = "kcalloc" if ($oldfunc eq "kzalloc"); > > + if ($a1 =~ /^sizeof\s*\S/ || $a2 =~ /^sizeof\s*\S/) { > > + CHK("ALLOC_WITH_MULTIPLY", > > + "Prefer $newfunc over $oldfunc with multiply\n" . $herecurr); > > + } > > + } > > + > > Why hide this behind --strict? Non-obvious CHK/--strict tests are less controversial. The block above it "prefer foo = alloc(sizeof(*foo)) over foo = alloc(sizeof(struct bar))" used CHK so I copied it. I've no objection to making it WARN instead,