From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4E01C04AB4 for ; Fri, 17 May 2019 10:00:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 74AED20873 for ; Fri, 17 May 2019 10:00:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728272AbfEQKAh (ORCPT ); Fri, 17 May 2019 06:00:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54104 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727309AbfEQKAh (ORCPT ); Fri, 17 May 2019 06:00:37 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2B4D630B46F1; Fri, 17 May 2019 10:00:32 +0000 (UTC) Received: from thuth.remote.csb (ovpn-117-142.ams2.redhat.com [10.36.117.142]) by smtp.corp.redhat.com (Postfix) with ESMTP id B242C101E661; Fri, 17 May 2019 10:00:24 +0000 (UTC) Subject: Re: [PATCH] KVM: selftests: Fix a condition in test_hv_cpuid() To: Dan Carpenter , Paolo Bonzini , Vitaly Kuznetsov Cc: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Shuah Khan , kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-janitors@vger.kernel.org, Peter Xu References: <20190514103451.GA1694@mwanda> From: Thomas Huth Openpgp: preference=signencrypt Autocrypt: addr=thuth@redhat.com; keydata= xsFNBFH7eUwBEACzyOXKU+5Pcs6wNpKzrlJwzRl3VGZt95VCdb+FgoU9g11m7FWcOafrVRwU yYkTm9+7zBUc0sW5AuPGR/dp3pSLX/yFWsA/UB4nJsHqgDvDU7BImSeiTrnpMOTXb7Arw2a2 4CflIyFqjCpfDM4MuTmzTjXq4Uov1giGE9X6viNo1pxyEpd7PanlKNnf4PqEQp06X4IgUacW tSGj6Gcns1bCuHV8OPWLkf4hkRnu8hdL6i60Yxz4E6TqlrpxsfYwLXgEeswPHOA6Mn4Cso9O 0lewVYfFfsmokfAVMKWzOl1Sr0KGI5T9CpmRfAiSHpthhHWnECcJFwl72NTi6kUcUzG4se81 O6n9d/kTj7pzTmBdfwuOZ0YUSqcqs0W+l1NcASSYZQaDoD3/SLk+nqVeCBB4OnYOGhgmIHNW 0CwMRO/GK+20alxzk//V9GmIM2ACElbfF8+Uug3pqiHkVnKqM7W9/S1NH2qmxB6zMiJUHlTH gnVeZX0dgH27mzstcF786uPcdEqS0KJuxh2kk5IvUSL3Qn3ZgmgdxBMyCPciD/1cb7/Ahazr 3ThHQXSHXkH/aDXdfLsKVuwDzHLVSkdSnZdt5HHh75/NFHxwaTlydgfHmFFwodK8y/TjyiGZ zg2Kje38xnz8zKn9iesFBCcONXS7txENTzX0z80WKBhK+XSFJwARAQABzRxUaG9tYXMgSHV0 aCA8dGguaHV0aEBnbXguZGU+wsF7BBMBAgAlAhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIX gAUCUfuWKwIZAQAKCRAu2dd0/nAttbe/EACb9hafyOb2FmhUqeAiBORSsUifFacQ7laVjcgR I4um8CSHvxijYftpkM2EdAtmXIKgbNDpQoXcWLXB9lu9mLgTO4DVT00TRR65ikn3FCWcyT74 ENTOzRKyKLsDCjhXKPblTPIQbYAUCOWElcyAPm0ERd62fA/rKNxgIiNo/l4UODOMoOJm2/Ox ZoTckW68Eqv7k9L7m7j+Hn3hoDTjAmcCBJt+j7pOhzWvCbqoNOIH8C8qvPaNlrba+R/K6jkO 6jZkTbYQpGIofEQJ/TNn38IsNGpI1ALTHWFtoMxp3j2Imz0REO6dRE2fHRN8sVlHgkoeGhmY NbDsDE1jFQOEObFnu0euk//7BXU7tGOHckVAZ8T1smiRPHfQU7UEH2a/grndxJ+PNeM5w7n2 l+FN3cf2KgPotCK2s9MjSdZA7C5e3rFYO8lqiqTJKvc62vqp3e7B0Kjyy5/QtzSOejBij2QL xkKSFNtxIz4MtuxN8e3IDQNxsKry3nF7R4MDvouXlMo6wP9KuyNWb+vFJt9GtbgfDMIFVamp ZfhEWzWRJH4VgksENA4K/BzjEHCcbTUb1TFsiB1VRnBPJ0SqlvifnfKk6HcpkDk6Pg8Q5FOJ gbNHrdgXsm+m/9GF2zUUr+rOlhVbK23TUqKqPfwnD7uxjpakVcJnsVCFqJpZi1F/ga9IN87B TQRR+3lMARAAtp831HniPHb9AuKq3wj83ujZK8lH5RLrfVsB4X1wi47bwo56BqhXpR/zxPTR eOFT0gnbw9UkphVc7uk/alnXMDEmgvnuxv89PwIQX6k3qLABeV7ykJQG/WT5HQ6+2DdGtVw3 2vjYAPiWQeETsgWRRQMDR0/hwp8s8tL/UodwYCScH6Vxx9pdy353L1fK4Bb9G73a+9FPjp9l x+WwKTsltVqSBuSjyZQ3c3EE8qbTidXZxB38JwARH8yN3TX+t65cbBqLl/zRUUUTapHQpUEd yoAsHIml32e4q+3xdLtTdlLi7FgPBItSazcqZPjEcYW73UAuLcmQmfJlQ5PkDiuqcitn+KzH /1pqsTU7QFZjbmSMJyXY0TDErOFuMOjf20b6arcpEqse1V3IKrb+nqqA2azboRm3pEANLAJw iVTwK3qwGRgK5ut6N/Znv20VEHkFUsRAZoOusrIRfR5HFDxlXguAdEz8M/hxXFYYXqOoaCYy 6pJxTjy0Y/tIfmS/g9Bnp8qg9wsrsnk0+XRnDVPak++G3Uq9tJPwpJbyO0vcqEI3vAXkAB7X VXLzvFwi66RrsPUoDkuzj+aCNumtOePDOCpXQGPpKl+l1aYRMN/+lNSk3+1sVuc2C07WnYyE gV/cbEVklPmKrNwu6DeUyD0qI/bVzKMWZAiB1r56hsGeyYcAEQEAAcLBXwQYAQIACQUCUft5 TAIbDAAKCRAu2dd0/nAttYTwEACLAS/THRqXRKb17PQmKwZHerUvZm2klo+lwQ3wNQBHUJAT p2R9ULexyXrJPqjUpy7+voz+FcKiuQBTKyieiIxO46oMxsbXGZ70o3gxjxdYdgimUD6U8PPd JH8tfAL4BR5FZNjspcnscN2jgbF4OrpDeOLyBaj6HPmElNPtECHWCaf1xbIFsZxSDGMA6cUh 0uX3Q8VI7JN1AR2cfiIRY7NrIlWYucJxyKjO3ivWm69nCtsHiJ0wcF8KlVo7F2eLaufo0K8A ynL8SHMF3VEyxsXOP2f1UR9T2Ur30MXcTBpjUxml1TX3RWY5uH89Js/jlIugBwuAmacJ7JYh lTg6sF/GNc4nPb4kk2yktNWTade+TzsllYlJPaorD2Qe8qX0iFUhFC6y9+O6mP4ZvWoYapp9 ezYNuebMgEr93ob1+4sFg3812wNP01WqsGtWCJHnPv/JoonFdMzD/bIkXGEJMk6ks2kxQQZq g6Ik/s/vxOfao/xCn8nHt7GwvVy41795hzK6tbSl+BuyCRp0vfPRP34OnK7+jR2nvQpJu/pU rCELuGwT9hsYkUPjVd4lfylN3mzEc6iAv/wwjsc0DRTSQCpXT3v2ymTAsRKrVaEZLibTXaf+ WslxWek3xNYRiqwwWAJuL652eAlxUgQ5ZS+fXBRTiQpJ+F26I/2lccScRd9G5w== Organization: Red Hat Message-ID: Date: Fri, 17 May 2019 12:00:23 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190514103451.GA1694@mwanda> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Fri, 17 May 2019 10:00:37 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 14/05/2019 12.34, Dan Carpenter wrote: > The code is trying to check that all the padding is zeroed out and it > does this: > > entry->padding[0] == entry->padding[1] == entry->padding[2] == 0 > > Assume everything is zeroed correctly, then the first comparison is > true, the next comparison is false and false is equal to zero so the > overall condition is true. This bug doesn't affect run time very > badly, but the code should instead just check that all three paddings > are zero individually. > > Also the error message was copy and pasted from an earlier error and it > wasn't correct. > > Fixes: 7edcb7343327 ("KVM: selftests: Add hyperv_cpuid test") > Signed-off-by: Dan Carpenter > --- > tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c > index 9a21e912097c..63b9fc3fdfbe 100644 > --- a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c > +++ b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c > @@ -58,9 +58,8 @@ static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries, > TEST_ASSERT(entry->flags == 0, > ".flags field should be zero"); > > - TEST_ASSERT(entry->padding[0] == entry->padding[1] > - == entry->padding[2] == 0, > - ".index field should be zero"); > + TEST_ASSERT(!entry->padding[0] && !entry->padding[1] && > + !entry->padding[2], "padding should be zero"); > > /* > * If needed for debug: > That was yet another good example that compiling with "-Wall" is a good idea... Reviewed-by: Thomas Huth