From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Ledford Subject: Re: [PATCH] IB/hfi1: Fix a wrapping test (make it less strict) Date: Mon, 23 Oct 2017 11:05:16 -0400 Message-ID: <1508771116.3325.0.camel@redhat.com> References: <20171013105559.tqzh6jhcnvmqhdwy@mwanda> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171013105559.tqzh6jhcnvmqhdwy@mwanda> Sender: kernel-janitors-owner@vger.kernel.org To: Dan Carpenter , Mike Marciniszyn Cc: Dennis Dalessandro , Sean Hefty , Hal Rosenstock , linux-rdma@vger.kernel.org, kernel-janitors@vger.kernel.org List-Id: linux-rdma@vger.kernel.org On Fri, 2017-10-13 at 13:56 +0300, Dan Carpenter wrote: > The "2 * UINT_MAX" overflows so the test is essentially doing this: > > if ((u64)(ts - cce->timestamp) > UINT_MAX - 1) { > > I've changed it to a 64bit type. > > Signed-off-by: Dan Carpenter > --- > Not tested. > > diff --git a/drivers/infiniband/hw/hfi1/mad.c > b/drivers/infiniband/hw/hfi1/mad.c > index f4c0ffc040cc..3aeea8afd44f 100644 > --- a/drivers/infiniband/hw/hfi1/mad.c > +++ b/drivers/infiniband/hw/hfi1/mad.c > @@ -3781,7 +3781,7 @@ static int __subn_get_opa_hfi1_cong_log(struct > opa_smp *smp, u32 am, > * required to wrap the counter are supposed to > * be zeroed (CA10-49 IBTA, release 1.2.1, V1). > */ > - if ((u64)(ts - cce->timestamp) > (2 * UINT_MAX)) > + if ((u64)(ts - cce->timestamp) > (2ULL * UINT_MAX)) > continue; > memcpy(cong_log->events[i].local_qp_cn_entry, &cce- > >lqpn, 3); > memcpy(cong_log- > >events[i].remote_qp_number_cn_entry, Denny, I'm looking for feedback from you on this patch. This fixes a bug, my only concern is that the code used to work with the bug, could this make the code not work? -- Doug Ledford GPG KeyID: B826A3330E572FDD Key fingerprint = AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57 2FDD