Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752440AbcLEJOM (ORCPT ); Mon, 5 Dec 2016 04:14:12 -0500 Received: from mx2.suse.de ([195.135.220.15]:36318 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751736AbcLEJN5 (ORCPT ); Mon, 5 Dec 2016 04:13:57 -0500 Subject: Re: [PATCH 1/1 v2] xen: set error code on failures To: Pan Bian , David Vrabel , Boris Ostrovsky , xen-devel@lists.xenproject.org References: <1480926185-19926-1-git-send-email-bianpan2016@163.com> Cc: linux-kernel@vger.kernel.org From: Juergen Gross Message-ID: <5ef5e6ee-876b-ff02-6678-13e011fca4cd@suse.com> Date: Mon, 5 Dec 2016 09:58:50 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <1480926185-19926-1-git-send-email-bianpan2016@163.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1771 Lines: 56 On 05/12/16 09:23, Pan Bian wrote: > Variable rc is reset in the loop, and its value will be non-negative > during the second and after repeat of the loop. If it fails to allocate > memory then, it may return a non-negative integer, which indicates no > error. This patch fixes the bug, assigning "-ENOMEM" to rc when > kzalloc() or alloc_page() returns NULL, and removing the initialization > of rc outside of the loop. > > v1 is reviewed by: Juergen Gross Not being a real problem in this case I prefer spelling out explicit "Acked-by:" or "Reviewed-by:" tags myself. So for this version you can have: Reviewed-by: Juergen Gross Juergen > > Signed-off-by: Pan Bian > --- > drivers/xen/gntalloc.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c > index 7a47c4c..1bf55a3 100644 > --- a/drivers/xen/gntalloc.c > +++ b/drivers/xen/gntalloc.c > @@ -127,18 +127,21 @@ static int add_grefs(struct ioctl_gntalloc_alloc_gref *op, > struct gntalloc_gref *gref, *next; > > readonly = !(op->flags & GNTALLOC_FLAG_WRITABLE); > - rc = -ENOMEM; > for (i = 0; i < op->count; i++) { > gref = kzalloc(sizeof(*gref), GFP_KERNEL); > - if (!gref) > + if (!gref) { > + rc = -ENOMEM; > goto undo; > + } > list_add_tail(&gref->next_gref, &queue_gref); > list_add_tail(&gref->next_file, &queue_file); > gref->users = 1; > gref->file_index = op->index + i * PAGE_SIZE; > gref->page = alloc_page(GFP_KERNEL|__GFP_ZERO); > - if (!gref->page) > + if (!gref->page) { > + rc = -ENOMEM; > goto undo; > + } > > /* Grant foreign access to the page. */ > rc = gnttab_grant_foreign_access(op->domid, >