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_PASS,URIBL_BLOCKED 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 50085C43387 for ; Thu, 3 Jan 2019 02:05:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15FB320836 for ; Thu, 3 Jan 2019 02:05:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727242AbfACCFv (ORCPT ); Wed, 2 Jan 2019 21:05:51 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:39479 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726071AbfACCFv (ORCPT ); Wed, 2 Jan 2019 21:05:51 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id C904E5351B4D9; Thu, 3 Jan 2019 10:05:46 +0800 (CST) Received: from [127.0.0.1] (10.177.31.96) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.408.0; Thu, 3 Jan 2019 10:05:48 +0800 Subject: Re: [PATCH -next] IB/qib: Add missing err handle for qib_user_sdma_rb_insert To: Jason Gunthorpe , Leon Romanovsky References: <20181221021938.13784-1-yuehaibing@huawei.com> <20190102171224.GA26765@ziepe.ca> <20190102184050.GI5424@mtr-leonro.mtl.com> <20190102190740.GH26211@ziepe.ca> CC: , , , , From: YueHaibing Message-ID: Date: Thu, 3 Jan 2019 10:05:25 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20190102190740.GH26211@ziepe.ca> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.31.96] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/1/3 3:07, Jason Gunthorpe wrote: > On Wed, Jan 02, 2019 at 08:40:50PM +0200, Leon Romanovsky wrote: >> On Wed, Jan 02, 2019 at 10:12:24AM -0700, Jason Gunthorpe wrote: >>> On Fri, Dec 21, 2018 at 10:19:38AM +0800, YueHaibing wrote: >>>> It should goto err handle if qib_user_sdma_rb_insert fails, >>>> other than success return. >>>> >>>> Fixes: 67810e8c3c01 ("RDMA/qib: Remove all occurrences of BUG_ON()") >>>> Signed-off-by: YueHaibing >>>> drivers/infiniband/hw/qib/qib_user_sdma.c | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c b/drivers/infiniband/hw/qib/qib_user_sdma.c >>>> index 31c523b..e87c0a7 100644 >>>> +++ b/drivers/infiniband/hw/qib/qib_user_sdma.c >>>> @@ -237,6 +237,8 @@ qib_user_sdma_queue_create(struct device *dev, int unit, int ctxt, int sctxt) >>>> >>>> ret = qib_user_sdma_rb_insert(&qib_user_sdma_rb_root, >>>> sdma_rb_node); >>>> + if (ret == 0) >>>> + goto err_rb; >>>> } >>> >>> This doesn't look right, what about undoing the kmalloc directly >>> above? >> >> Back then, I came to conclusion that qib_user_sdma_rb_insert() never >> returns 0. Otherwise, Dennis would see that BUG_ON() for a long time >> ago. > > It fails if the index is in the RB tree, which would indicate a > programming bug. > > The way to replace the BUG_ON is something like: > Oh, yes, I forget kfree this mem. > if (WARN_ON(ret == 0)) { > kfree() > goto err_rb; > } > > Jason > > . >