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=-9.9 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,URIBL_BLOCKED, USER_AGENT_GIT 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 59748C433DF for ; Wed, 27 May 2020 01:26:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35BEB20B80 for ; Wed, 27 May 2020 01:26:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="A8UwiX4z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728414AbgE0B0b (ORCPT ); Tue, 26 May 2020 21:26:31 -0400 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:13588 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725294AbgE0B0a (ORCPT ); Tue, 26 May 2020 21:26:30 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Tue, 26 May 2020 18:25:07 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Tue, 26 May 2020 18:26:30 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Tue, 26 May 2020 18:26:30 -0700 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 27 May 2020 01:26:29 +0000 Received: from hqnvemgw03.nvidia.com (10.124.88.68) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Wed, 27 May 2020 01:26:29 +0000 Received: from sandstorm.nvidia.com (Not Verified[10.2.50.17]) by hqnvemgw03.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Tue, 26 May 2020 18:26:29 -0700 From: John Hubbard To: LKML CC: Souptick Joarder , John Hubbard , Derek Kiernan , Dragan Cvetic , Arnd Bergmann , Greg Kroah-Hartman , Michal Simek , Subject: [PATCH 1/3] misc: xilinx-sdfec: improve get_user_pages_fast() error handling Date: Tue, 26 May 2020 18:26:26 -0700 Message-ID: <20200527012628.1100649-2-jhubbard@nvidia.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200527012628.1100649-1-jhubbard@nvidia.com> References: <20200527012628.1100649-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public Content-Transfer-Encoding: quoted-printable Content-Type: text/plain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1590542707; bh=Z0H0NZ0azdDBw/pz6UaXScJeua7CgszsKUI21rNpIIc=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=A8UwiX4zwnd0jIKivrFW1WRvjUMNk0bhMGLDQydxVtXYlh9U/1D/h8QUT4RVJSryq BRY0WYKCu1Gcvx0n9z19TiS0jBZtZuVoHRyy+ZbyEQztjj66vY+dTPfRosbo2uSsgD ADGiYR4EScHloc8SrbdXxAfUgtaQLNAxZHmtgVtnKtxAJINkGsx7qlqC3Gb4YP4/UD aM+1SfGtF/Yy6j1DfnjNNcr+ASerSgFkpMfQsK/L6j4lztD5i8TOU4GShn8O8zWpab VAgP6OLlntY0JSi0Se/r9D9Q9r8lE1kyIantgllKdq77Np8d8b+qgAZJEUufvH8Sqh hRmQjiA9iUueg== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This fixes the case of get_user_pages_fast() returning a -errno. The result needs to be stored in a signed integer. And for safe signed/unsigned comparisons, it's best to keep everything signed. And get_user_pages_fast() also expects a signed value for number of pages to pin. Therefore, change most relevant variables, from u32 to int. Leave "n" unsigned, for convenience in checking for overflow. And provide a WARN_ON_ONCE() and early return, if overflow occurs. Also, as long as we're tidying up: rename the page array from page, to pages, in order to match the conventions used in most other call sites. Fixes: 20ec628e8007e ("misc: xilinx_sdfec: Add ability to configure LDPC") Cc: Derek Kiernan Cc: Dragan Cvetic Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Michal Simek Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: John Hubbard --- drivers/misc/xilinx_sdfec.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c index 71bbaa56bdb5..e2766aad9e14 100644 --- a/drivers/misc/xilinx_sdfec.c +++ b/drivers/misc/xilinx_sdfec.c @@ -602,10 +602,10 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdf= ec, u32 offset, const u32 depth) { u32 reg =3D 0; - u32 res; - u32 n, i; + int res, i, nr_pages; + u32 n; u32 *addr =3D NULL; - struct page *page[MAX_NUM_PAGES]; + struct page *pages[MAX_NUM_PAGES]; =20 /* * Writes that go beyond the length of @@ -622,15 +622,22 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdf= ec, u32 offset, if ((len * XSDFEC_REG_WIDTH_JUMP) % PAGE_SIZE) n +=3D 1; =20 - res =3D get_user_pages_fast((unsigned long)src_ptr, n, 0, page); - if (res < n) { - for (i =3D 0; i < res; i++) - put_page(page[i]); + if (WARN_ON_ONCE(n > INT_MAX)) + return -EINVAL; + + nr_pages =3D n; + + res =3D get_user_pages_fast((unsigned long)src_ptr, nr_pages, 0, pages); + if (res < nr_pages) { + if (res > 0) { + for (i =3D 0; i < res; i++) + put_page(pages[i]); + } return -EINVAL; } =20 - for (i =3D 0; i < n; i++) { - addr =3D kmap(page[i]); + for (i =3D 0; i < nr_pages; i++) { + addr =3D kmap(pages[i]); do { xsdfec_regwrite(xsdfec, base_addr + ((offset + reg) * @@ -639,7 +646,7 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdfec= , u32 offset, reg++; } while ((reg < len) && ((reg * XSDFEC_REG_WIDTH_JUMP) % PAGE_SIZE)); - put_page(page[i]); + put_page(pages[i]); } return reg; } --=20 2.26.2