Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752231AbcL2CFQ (ORCPT ); Wed, 28 Dec 2016 21:05:16 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:6402 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752133AbcL2CFO (ORCPT ); Wed, 28 Dec 2016 21:05:14 -0500 Date: Thu, 29 Dec 2016 10:28:34 +0800 From: Kenneth Lee To: Mark Bloch CC: , , , , , , , , , , , , Subject: Re: [PATCH] ib umem: bug: put pid back before return from error path Message-ID: <20161229022834.GH46690@Turing-Arch-b> References: <1482390692-147946-1-git-send-email-liguozhu@hisilicon.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Originating-IP: [10.67.212.75] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2548 Lines: 69 Hi, Sorry for the delay (I'd got some problem in my procmailrc file, and miss this mail). The new patch, with title "[PATCH] ib umem: bugfix: mixed put_pid()s in ib_umem_get()", has been sent. On Thu, Dec 22, 2016 at 10:00:57AM +0200, Mark Bloch wrote: > Date: Thu, 22 Dec 2016 10:00:57 +0200 > From: Mark Bloch > To: Kenneth Lee , dledford@redhat.com, > sean.hefty@intel.com, hal.rosenstock@gmail.com > CC: robin.murphy@arm.com, jroedel@suse.de, egtvedt@samfundet.no, > vgupta@synopsys.com, dave.hansen@linux.intel.com, lstoakes@gmail.com, > krzk@kernel.org, sebott@linux.vnet.ibm.com, linux-rdma@vger.kernel.org, > linux-kernel@vger.kernel.org > Subject: Re: [PATCH] ib umem: bug: put pid back before return from error > path > User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 > Thunderbird/45.5.1 > Message-ID: > > Hi, > > You have two bugs here: > 1) When using ODP, ib_umem_release() checks for umem->odp_data != NULL > calls ib_umem_odp_release() and returns immediately without calling put_pid(). > This one isn't in the error path so the title doesn't fit. > > 2) In case the allocation failed, we return in -ENOMEM without calling put_pid(). > > Can you please resend this with proper fixes line and a better description of what is going on. > > On 22/12/2016 09:11, Kenneth Lee wrote: > > I catched this bug when reading the code. I'm sorry I have no hardware to test > > it. But it is abviously a bug. > > > > Signed-off-by: Kenneth Lee > > --- > > drivers/infiniband/core/umem.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c > > index 1e62a5f..4609b92 100644 > > --- a/drivers/infiniband/core/umem.c > > +++ b/drivers/infiniband/core/umem.c > > @@ -134,6 +134,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, > > IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND)); > > > > if (access & IB_ACCESS_ON_DEMAND) { > > + put_pid(umem->pid); > > ret = ib_umem_odp_get(context, umem); > > if (ret) { > > kfree(umem); > > @@ -149,6 +150,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, > > > > page_list = (struct page **) __get_free_page(GFP_KERNEL); > > if (!page_list) { > > + put_pid(umem->pid); > > kfree(umem); > > return ERR_PTR(-ENOMEM); > > } > > > > Mark. -- -Kenneth(Hisilicon)