From patchwork Mon Oct 26 16:15:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 11857721 X-Patchwork-Delegate: jgg@ziepe.ca Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F3A65139F for ; Mon, 26 Oct 2020 16:15:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D90BA2465B for ; Mon, 26 Oct 2020 16:15:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603728957; bh=WqkBUcS83VtOQSnX/TD6ZEtEOPKFuqQjQUXMWk3f5bU=; h=From:To:Cc:Subject:Date:List-ID:From; b=1Jxn7s8uDqGKFEGxSfg13mB2o0n+9/oe99HX7s7xjRrA1H983dV5f8zibmtk0lZXi 2cJMwURqOZuHMekx319VNykKzytjmvXLEelqcKB8nN8QWmqYU/FRYxaKsF0EtZXKna fw1v5Ddryl/VOkZEqQOmdiLFl7uNWVV3YkcWrvYY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1775315AbgJZQP5 (ORCPT ); Mon, 26 Oct 2020 12:15:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:59950 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1775124AbgJZQP4 (ORCPT ); Mon, 26 Oct 2020 12:15:56 -0400 Received: from localhost.localdomain (unknown [192.30.34.233]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 37F0B22400; Mon, 26 Oct 2020 16:15:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603728956; bh=WqkBUcS83VtOQSnX/TD6ZEtEOPKFuqQjQUXMWk3f5bU=; h=From:To:Cc:Subject:Date:From; b=btA7bA6RH7NP/KOcg8Btw2N2xshmuPwDmBfZZXGhze+A27KNxVyNcVjxyPGc9tg5l TwSLVhPRi3KAKaUJaJ08MEzLnqwOzUozATOkS02BZLL3PBKtpDtW/cAmxmvb6xMsLt h/vMwj43CECO+sC82PnK0UhZReXE8oW/6Z5cN0c0= From: Arnd Bergmann To: Doug Ledford , Jason Gunthorpe , Shamir Rabinovitch Cc: Arnd Bergmann , Jason Gunthorpe , Leon Romanovsky , Yishai Hadas , Michael Guralnik , "Gustavo A. R. Silva" , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] IB/verbs: avoid nested container_of() Date: Mon, 26 Oct 2020 17:15:39 +0100 Message-Id: <20201026161549.3709175-1-arnd@kernel.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Arnd Bergmann Nested container_of() calls work correctly but cause a warning when building with W=2. Invoking it from an inline function like in drivers/infiniband/hw/mlx5/mlx5_ib.h means we get hundreds of warnings like: include/linux/kernel.h:852:8: warning: declaration of '__mptr' shadows a previous local [-Wshadow] 852 | void *__mptr = (void *)(ptr); \ | ^~~~~~ include/rdma/uverbs_ioctl.h:651:11: note: in expansion of macro 'container_of' 651 | (udata ? container_of(container_of(udata, struct uverbs_attr_bundle, \ | ^~~~~~~~~~~~ include/rdma/uverbs_ioctl.h:651:24: note: in expansion of macro 'container_of' 651 | (udata ? container_of(container_of(udata, struct uverbs_attr_bundle, \ | ^~~~~~~~~~~~ drivers/infiniband/hw/mthca/mthca_qp.c:564:35: note: in expansion of macro 'rdma_udata_to_drv_context' 564 | struct mthca_ucontext *context = rdma_udata_to_drv_context( | ^~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/kernel.h:852:8: note: shadowed declaration is here 852 | void *__mptr = (void *)(ptr); \ | ^~~~~~ include/rdma/uverbs_ioctl.h:651:11: note: in expansion of macro 'container_of' 651 | (udata ? container_of(container_of(udata, struct uverbs_attr_bundle, \ | ^~~~~~~~~~~~ drivers/infiniband/hw/mthca/mthca_qp.c:564:35: note: in expansion of macro 'rdma_udata_to_drv_context' 564 | struct mthca_ucontext *context = rdma_udata_to_drv_context( | ^~~~~~~~~~~~~~~~~~~~~~~~~ In file included from : include/linux/kernel.h:852:8: warning: declaration of '__mptr' shadows a previous local [-Wshadow] 852 | void *__mptr = (void *)(ptr); \ | ^~~~~~ Rewrite the macro to use an inline function internally, which makes it more readable and reduces the amount of useless output from make W=2. Fixes: 730623f4a56f ("IB/verbs: Add helper function rdma_udata_to_drv_context") Signed-off-by: Arnd Bergmann --- include/rdma/uverbs_ioctl.h | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/include/rdma/uverbs_ioctl.h b/include/rdma/uverbs_ioctl.h index b00270c72740..bf167ef6c688 100644 --- a/include/rdma/uverbs_ioctl.h +++ b/include/rdma/uverbs_ioctl.h @@ -647,12 +647,15 @@ static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_b * 'ucontext'. * */ -#define rdma_udata_to_drv_context(udata, drv_dev_struct, member) \ - (udata ? container_of(container_of(udata, struct uverbs_attr_bundle, \ - driver_udata) \ - ->context, \ - drv_dev_struct, member) : \ - (drv_dev_struct *)NULL) +static inline struct uverbs_attr_bundle * +rdma_udata_to_uverbs_attr_bundle(struct ib_udata *udata) +{ + return container_of(udata, struct uverbs_attr_bundle, driver_udata); +} + +#define rdma_udata_to_drv_context(udata, drv_dev_struct, member) \ + (udata ? container_of(rdma_udata_to_uverbs_attr_bundle(udata)->context, \ + drv_dev_struct, member) : (drv_dev_struct *)NULL) #define IS_UVERBS_COPY_ERR(_ret) ((_ret) && (_ret) != -ENOENT)