Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934275AbbEMMv4 (ORCPT ); Wed, 13 May 2015 08:51:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36418 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754608AbbEMMvy (ORCPT ); Wed, 13 May 2015 08:51:54 -0400 Date: Wed, 13 May 2015 14:51:36 +0200 From: Thomas Huth To: Alexey Kardashevskiy Cc: Gavin Shan , Wei Yang , linux-kernel@vger.kernel.org, Alex Williamson , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, David Gibson Subject: Re: [PATCH kernel v10 05/34] powerpc/iommu: Always release iommu_table in iommu_free_table() Message-ID: <20150513145136.1a85f536@thh440s> In-Reply-To: <5552EF78.6020301@ozlabs.ru> References: <1431358763-24371-1-git-send-email-aik@ozlabs.ru> <1431358763-24371-6-git-send-email-aik@ozlabs.ru> <20150513053337.GA479@gwshan> <5552EF78.6020301@ozlabs.ru> Organization: Red Hat MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1935 Lines: 49 On Wed, 13 May 2015 16:30:16 +1000 Alexey Kardashevskiy wrote: > On 05/13/2015 03:33 PM, Gavin Shan wrote: > > On Tue, May 12, 2015 at 01:38:54AM +1000, Alexey Kardashevskiy wrote: > >> At the moment iommu_free_table() only releases memory if > >> the table was initialized for the platform code use, i.e. it had > >> it_map initialized (which purpose is to track DMA memory space use). > >> > >> With dynamic DMA windows, we will need to be able to release > >> iommu_table even if it was used for VFIO in which case it_map is NULL > >> so does the patch. > >> > >> Signed-off-by: Alexey Kardashevskiy > > > > Reviewed-by: Gavin Shan > > > >> --- > >> arch/powerpc/kernel/iommu.c | 3 +-- > >> 1 file changed, 1 insertion(+), 2 deletions(-) > >> > >> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c > >> index 3d47eb3..2c02d4c 100644 > >> --- a/arch/powerpc/kernel/iommu.c > >> +++ b/arch/powerpc/kernel/iommu.c > >> @@ -714,8 +714,7 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name) > >> unsigned int order; > >> > >> if (!tbl || !tbl->it_map) { > >> - printk(KERN_ERR "%s: expected TCE map for %s\n", __func__, > >> - node_name); > >> + kfree(tbl); > > > > I'm not sure if the "tbl" needs to be checked against NULL as kfree() already > > has the check. But it looks a bit strange to free NULL "tbl" from the code > > itself. > > Yeah, looks a bit weird, agree, I'll change but in general kfree/vfree/... > - they all check the passed pointer for NULL. But if tbl is NULL, the tbl->it_map check will fail, won't it? So in this case, I think you have to keep it. Thomas -- 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/