From patchwork Tue Dec 17 09:58:52 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Yann Droneaud X-Patchwork-Id: 3360341 Return-Path: X-Original-To: patchwork-linux-rdma@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id C47299F314 for ; Tue, 17 Dec 2013 09:59:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7E9C9203AA for ; Tue, 17 Dec 2013 09:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D735203A8 for ; Tue, 17 Dec 2013 09:59:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753153Ab3LQJ7o (ORCPT ); Tue, 17 Dec 2013 04:59:44 -0500 Received: from smtp5-g21.free.fr ([212.27.42.5]:51085 "EHLO smtp5-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751430Ab3LQJ7o (ORCPT ); Tue, 17 Dec 2013 04:59:44 -0500 Received: from localhost.localdomain (unknown [37.163.161.54]) by smtp5-g21.free.fr (Postfix) with ESMTP id 977A3D48047; Tue, 17 Dec 2013 10:59:35 +0100 (CET) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by localhost.localdomain (8.14.7/8.14.7) with ESMTP id rBH9xWZ2002061; Tue, 17 Dec 2013 10:59:32 +0100 Received: (from ydroneaud@localhost) by localhost.localdomain (8.14.7/8.14.7/Submit) id rBH9xWWR002060; Tue, 17 Dec 2013 10:59:32 +0100 From: Yann Droneaud To: Roland Dreier , Roland Dreier Cc: linux-rdma@vger.kernel.org, Yann Droneaud Subject: [PATCHv4 for-3.13 03/10] IB/uverbs: remove implicit cast in INIT_UDATA() Date: Tue, 17 Dec 2013 10:58:52 +0100 Message-Id: X-Mailer: git-send-email 1.8.4.2 In-Reply-To: References: In-Reply-To: References: MIME-Version: 1.0 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently, INIT_UDATA() does an implicit cast to a pointer, so that 'response' address, eg. output buffer, can be used as is to initialize a struct ib_udata: do { \ (udata)->inbuf = (void __user *) (ibuf); \ (udata)->outbuf = (void __user *) (obuf); \ (udata)->inlen = (ilen); \ (udata)->outlen = (olen); \ } while (0) ... INIT_UDATA(&udata, buf + sizeof cmd, (unsigned long) cmd.response + sizeof resp, in_len - sizeof cmd, out_len - sizeof resp); ... Unfortunately, sparse reports an error if literal 0 is used to initialize inbuf or outbuf, for example in: INIT_UDATA(&ucore, (hdr.in_words) ? buf : 0, (unsigned long)ex_hdr.response, hdr.in_words * 8, hdr.out_words * 8); It was reported by kbuild test robot in message[1]: From: kbuild test robot Subject: "drivers/infiniband/core/uverbs_main.c:683:17: sparse: Using plain integer as NULL pointer", Message-Id: <528b3984.SVGs20ZWpcuR/Jls%fengguang.wu@intel.com> Replacing 0 by NULL in ib_uverbs_write() might turn off sparse warning, but it trigger a GCC warning: drivers/infiniband/core/uverbs_main.c: In function 'ib_uverbs_write': drivers/infiniband/core/uverbs_main.c:685:200: warning: pointer/integer type mismatch in conditional expression [enabled by default] So fixing the sparse warning require broad changes in uverbs. By removing the implicit cast INIT_UDATA(), this patch fixes the warnings reported by sparse and allows the compiler to report a warning in case a plain integer get used to initialize an udata pointer. This patch requires - calls to INIT_UDATA() to be modified to pass a pointer instead of an unsigned long, - struct ib_udata to be modified to have a const void __user *inbuf field[2], otherwise compiler will report warnings regarding const to non const conversion: drivers/infiniband/core/uverbs_main.c: In function ‘ib_uverbs_write’: drivers/infiniband/core/uverbs_main.c:682:24: attention : assignment discards ‘const’ qualifier from pointer target type [enabled by default] drivers/infiniband/core/uverbs_main.c:688:22: attention : assignment discards ‘const’ qualifier from pointer target type [enabled by default] drivers/infiniband/core/uverbs_cmd.c: In function ‘ib_uverbs_get_context’: drivers/infiniband/core/uverbs_cmd.c:307:23: attention : assignment discards ‘const’ qualifier from pointer target type [enabled by default] drivers/infiniband/core/uverbs_cmd.c: In function ‘ib_uverbs_alloc_pd’: drivers/infiniband/core/uverbs_cmd.c:516:23: attention : assignment discards ‘const’ qualifier from pointer target type [enabled by default] ... [1] https://lists.01.org/pipermail/kbuild-all/2013-November/002120.html [2] https://patchwork.kernel.org/patch/2846202/ http://marc.info/?i=3050a98379b4342ea59d59aeaf1ce162171df928.1376847403.git.ydroneaud@opteya.com Link: http://marc.info/?i=cover.1387273677.git.ydroneaud@opteya.com Signed-off-by: Yann Droneaud --- drivers/infiniband/core/uverbs.h | 12 ++++++------ drivers/infiniband/core/uverbs_main.c | 13 ++++++++----- 2 files changed, 14 insertions(+), 11 deletions(-) diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h index 9879568aed8c..0dca1975d59d 100644 --- a/drivers/infiniband/core/uverbs.h +++ b/drivers/infiniband/core/uverbs.h @@ -47,12 +47,12 @@ #include #include -#define INIT_UDATA(udata, ibuf, obuf, ilen, olen) \ - do { \ - (udata)->inbuf = (const void __user *) (ibuf); \ - (udata)->outbuf = (void __user *) (obuf); \ - (udata)->inlen = (ilen); \ - (udata)->outlen = (olen); \ +#define INIT_UDATA(udata, ibuf, obuf, ilen, olen) \ + do { \ + (udata)->inbuf = (ibuf); \ + (udata)->outbuf = (obuf); \ + (udata)->inlen = (ilen); \ + (udata)->outlen = (olen); \ } while (0) /* diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index 34386943ebcf..14d864371050 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -635,6 +635,7 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf, __u32 command; struct ib_uverbs_ex_cmd_hdr ex_hdr; + char __user *response; struct ib_udata ucore; struct ib_udata uhw; int err; @@ -668,7 +669,9 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf, if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count) return -EINVAL; - if (ex_hdr.response) { + response = (char __user *)(unsigned long)ex_hdr.response; + + if (response) { if (!hdr.out_words && !ex_hdr.provider_out_words) return -EINVAL; } else { @@ -677,14 +680,14 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf, } INIT_UDATA(&ucore, - (hdr.in_words) ? buf : 0, - (unsigned long)ex_hdr.response, + (hdr.in_words) ? buf : NULL, + response, hdr.in_words * 8, hdr.out_words * 8); INIT_UDATA(&uhw, - (ex_hdr.provider_in_words) ? buf + ucore.inlen : 0, - (ex_hdr.provider_out_words) ? (unsigned long)ex_hdr.response + ucore.outlen : 0, + (ex_hdr.provider_in_words) ? buf + ucore.inlen : NULL, + (ex_hdr.provider_out_words) ? response + ucore.outlen : NULL, ex_hdr.provider_in_words * 8, ex_hdr.provider_out_words * 8);