From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-2.mimecast.com ([205.139.110.61]:32914 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728154AbgDCNJb (ORCPT ); Fri, 3 Apr 2020 09:09:31 -0400 Subject: Re: [PATCH v1 5/5] KVM: s390: vsie: gmap_table_walk() simplifications References: <20200402184819.34215-1-david@redhat.com> <20200402184819.34215-6-david@redhat.com> <99c824d1-88ca-c98d-c4e9-75a97c2a8a7b@linux.ibm.com> From: David Hildenbrand Message-ID: <867be74b-0ff2-23e1-3d02-3803c478e205@redhat.com> Date: Fri, 3 Apr 2020 15:09:22 +0200 MIME-Version: 1.0 In-Reply-To: <99c824d1-88ca-c98d-c4e9-75a97c2a8a7b@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Janosch Frank , kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Vasily Gorbik , Heiko Carstens , Cornelia Huck , Christian Borntraeger On 03.04.20 15:03, Janosch Frank wrote: > On 4/2/20 8:48 PM, David Hildenbrand wrote: >> Let's use asce_type where applicable. Also, simplify our sanity check for >> valid table levels and convert it into a WARN_ON_ONCE(). Check if we even >> have a valid gmap shadow as the very first step. >> >> Signed-off-by: David Hildenbrand >> --- >> arch/s390/mm/gmap.c | 7 ++++--- >> 1 file changed, 4 insertions(+), 3 deletions(-) >> >> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c >> index fd32ab566f57..3c801dae7988 100644 >> --- a/arch/s390/mm/gmap.c >> +++ b/arch/s390/mm/gmap.c >> @@ -790,17 +790,18 @@ static inline unsigned long *gmap_table_walk(struct gmap *gmap, >> const int asce_type = gmap->asce & _ASCE_TYPE_MASK; >> unsigned long *table; >> >> - if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4)) >> - return NULL; >> if (gmap_is_shadow(gmap) && gmap->removed) >> return NULL; >> >> + if (WARN_ON_ONCE(level > (asce_type >> 2) + 1)) >> + return NULL; >> + >> if (WARN_ON_ONCE(asce_type != _ASCE_TYPE_REGION1) && >> gaddr & (-1UL << (31 + (asce_type >> 2) * 11))) >> return NULL; >> >> table = gmap->table; > > We could also initialize this variable at the top, no? very right, add that. -- Thanks, David / dhildenb