Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753901AbaFLFZg (ORCPT ); Thu, 12 Jun 2014 01:25:36 -0400 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:34409 "EHLO lgemrelse6q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751427AbaFLFZe (ORCPT ); Thu, 12 Jun 2014 01:25:34 -0400 X-Original-SENDERIP: 10.177.220.169 X-Original-MAILFROM: minchan@kernel.org Date: Thu, 12 Jun 2014 14:25:43 +0900 From: Minchan Kim To: Joonsoo Kim Cc: Andrew Morton , "Aneesh Kumar K.V" , Marek Szyprowski , Michal Nazarewicz , Russell King - ARM Linux , kvm@vger.kernel.org, linux-mm@kvack.org, Gleb Natapov , Greg Kroah-Hartman , Alexander Graf , kvm-ppc@vger.kernel.org, linux-kernel@vger.kernel.org, Paul Mackerras , Benjamin Herrenschmidt , Paolo Bonzini , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 02/10] DMA, CMA: fix possible memory leak Message-ID: <20140612052543.GE12415@bbox> References: <1402543307-29800-1-git-send-email-iamjoonsoo.kim@lge.com> <1402543307-29800-3-git-send-email-iamjoonsoo.kim@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1402543307-29800-3-git-send-email-iamjoonsoo.kim@lge.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 12, 2014 at 12:21:39PM +0900, Joonsoo Kim wrote: > We should free memory for bitmap when we find zone mis-match, > otherwise this memory will leak. Then, -stable stuff? > > Additionally, I copy code comment from ppc kvm's cma code to notify > why we need to check zone mis-match. > > Signed-off-by: Joonsoo Kim > > diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c > index bd0bb81..fb0cdce 100644 > --- a/drivers/base/dma-contiguous.c > +++ b/drivers/base/dma-contiguous.c > @@ -177,14 +177,24 @@ static int __init cma_activate_area(struct cma *cma) > base_pfn = pfn; > for (j = pageblock_nr_pages; j; --j, pfn++) { > WARN_ON_ONCE(!pfn_valid(pfn)); > + /* > + * alloc_contig_range requires the pfn range > + * specified to be in the same zone. Make this > + * simple by forcing the entire CMA resv range > + * to be in the same zone. > + */ > if (page_zone(pfn_to_page(pfn)) != zone) > - return -EINVAL; > + goto err; At a first glance, I thought it would be better to handle such error before activating. So when I see the registration code(ie, dma_contiguous_revere_area), I realized it is impossible because we didn't set up zone yet. :( If so, when we detect to fail here, it would be better to report more meaningful error message like what was successful zone and what is new zone and failed pfn number? > } > init_cma_reserved_pageblock(pfn_to_page(base_pfn)); > } while (--i); > > mutex_init(&cma->lock); > return 0; > + > +err: > + kfree(cma->bitmap); > + return -EINVAL; > } > > static struct cma cma_areas[MAX_CMA_AREAS]; > -- > 1.7.9.5 -- Kind regards, Minchan Kim -- 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/