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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 ED6B0C54E4B for ; Mon, 11 May 2020 19:49:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ADAB1206DB for ; Mon, 11 May 2020 19:49:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="ASQBGY0g" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ADAB1206DB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4317390007E; Mon, 11 May 2020 15:49:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3E16F900036; Mon, 11 May 2020 15:49:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 31DBA90007E; Mon, 11 May 2020 15:49:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0001.hostedemail.com [216.40.44.1]) by kanga.kvack.org (Postfix) with ESMTP id 1C476900036 for ; Mon, 11 May 2020 15:49:40 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id B0FC08248047 for ; Mon, 11 May 2020 19:49:39 +0000 (UTC) X-FDA: 76805478078.25.loss65_54331e10aed42 X-HE-Tag: loss65_54331e10aed42 X-Filterd-Recvd-Size: 6044 Received: from hqnvemgate24.nvidia.com (hqnvemgate24.nvidia.com [216.228.121.143]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Mon, 11 May 2020 19:49:38 +0000 (UTC) Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 May 2020 12:47:22 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 May 2020 12:49:37 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 May 2020 12:49:37 -0700 Received: from rcampbell-dev.nvidia.com (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 11 May 2020 19:49:36 +0000 Subject: Re: [PATCH] mm/hmm/test: Fix some copy_to_user() error handling To: Dan Carpenter , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= CC: Jason Gunthorpe , , References: <20200511183704.GA225608@mwanda> From: Ralph Campbell X-Nvconfidentiality: public Message-ID: <45d2a836-67d1-ad07-7a1d-0031865f6742@nvidia.com> Date: Mon, 11 May 2020 12:49:36 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200511183704.GA225608@mwanda> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL101.nvidia.com (172.20.187.10) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589226442; bh=PBC+0STwLzeZBP0HEvdFrTGn0AxD5O/UYz1nIZQS02o=; h=X-PGP-Universal:Subject:To:CC:References:From:X-Nvconfidentiality: Message-ID:Date:User-Agent:MIME-Version:In-Reply-To: X-Originating-IP:X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=ASQBGY0g2vzTx088oZmTchA4HHL5cP00ci4We3aT4tW4T3Mrl8rtFEqjvjCUT01LQ 29EnYHyDnHNJNez1+LdvQQjja1Cuy2XpZK/H7AbeiRGv49YoDMiY/pHStX5GsDSUlO oOan2nQGcvYULMvYgfcoGI5sExwhxe6XXzjaJ9iNUfg+jZmxRbXLGzkQtachwertMu HQ/pFo+gt+6/Ov/YK3wBRhp/ZvsppyiryODmkMax20NwNZsFj1MVu9pPP12Jl7Ns8f /izTA2UzQeuoD3RIfbK9Ph5vdJ6gQ7FzGfqYUqvZupoMc3Zu3W5KKPLKxRT2+ip8Gk 34+4STB22bbnA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 5/11/20 11:37 AM, Dan Carpenter wrote: > The copy_to_user() function returns the number of bytes which weren't > copied but we want to return negative error codes. Also in dmirror_write() > if the copy_from_user() fails then there is some cleanup needed before > we can return so I fixed that as well. > > Fixes: 5d5e54be8a1e3 ("mm/hmm/test: add selftest driver for HMM") > Signed-off-by: Dan Carpenter Thanks for fixing this. Reviewed-by: Ralph Campbell > --- > lib/test_hmm.c | 41 +++++++++++++++++++++++++---------------- > 1 file changed, 25 insertions(+), 16 deletions(-) > > diff --git a/lib/test_hmm.c b/lib/test_hmm.c > index 00bca6116f930..fd4889f7b3d90 100644 > --- a/lib/test_hmm.c > +++ b/lib/test_hmm.c > @@ -360,9 +360,11 @@ static int dmirror_read(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd) > cmd->faults++; > } > > - if (ret == 0) > - ret = copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr, > - bounce.size); > + if (ret == 0) { > + if (copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr, > + bounce.size)) > + ret = -EFAULT; > + } > cmd->cpages = bounce.cpages; > dmirror_bounce_fini(&bounce); > return ret; > @@ -412,10 +414,11 @@ static int dmirror_write(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd) > ret = dmirror_bounce_init(&bounce, start, size); > if (ret) > return ret; > - ret = copy_from_user(bounce.ptr, u64_to_user_ptr(cmd->ptr), > - bounce.size); > - if (ret) > - return ret; > + if (copy_from_user(bounce.ptr, u64_to_user_ptr(cmd->ptr), > + bounce.size)) { > + ret = -EFAULT; > + goto fini; > + } > > while (1) { > mutex_lock(&dmirror->mutex); > @@ -431,6 +434,7 @@ static int dmirror_write(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd) > cmd->faults++; > } > > +fini: > cmd->cpages = bounce.cpages; > dmirror_bounce_fini(&bounce); > return ret; > @@ -715,9 +719,11 @@ static int dmirror_migrate(struct dmirror *dmirror, > mutex_lock(&dmirror->mutex); > ret = dmirror_do_read(dmirror, start, end, &bounce); > mutex_unlock(&dmirror->mutex); > - if (ret == 0) > - ret = copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr, > - bounce.size); > + if (ret == 0) { > + if (copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr, > + bounce.size)) > + ret = -EFAULT; > + } > cmd->cpages = bounce.cpages; > dmirror_bounce_fini(&bounce); > return ret; > @@ -886,9 +892,10 @@ static int dmirror_snapshot(struct dmirror *dmirror, > break; > > n = (range.end - range.start) >> PAGE_SHIFT; > - ret = copy_to_user(uptr, perm, n); > - if (ret) > + if (copy_to_user(uptr, perm, n)) { > + ret = -EFAULT; > break; > + } > > cmd->cpages += n; > uptr += n; > @@ -911,9 +918,8 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp, > if (!dmirror) > return -EINVAL; > > - ret = copy_from_user(&cmd, uarg, sizeof(cmd)); > - if (ret) > - return ret; > + if (copy_from_user(&cmd, uarg, sizeof(cmd))) > + return -EFAULT; > > if (cmd.addr & ~PAGE_MASK) > return -EINVAL; > @@ -946,7 +952,10 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp, > if (ret) > return ret; > > - return copy_to_user(uarg, &cmd, sizeof(cmd)); > + if (copy_to_user(uarg, &cmd, sizeof(cmd))) > + return -EFAULT; > + > + return 0; > } > > static const struct file_operations dmirror_fops = { >