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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,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 A50ABC54FCB for ; Fri, 24 Apr 2020 15:39:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C83E20706 for ; Fri, 24 Apr 2020 15:39:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b="JRszSWBI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729098AbgDXPjs (ORCPT ); Fri, 24 Apr 2020 11:39:48 -0400 Received: from gateway30.websitewelcome.com ([50.116.125.1]:44663 "EHLO gateway30.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728519AbgDXPg0 (ORCPT ); Fri, 24 Apr 2020 11:36:26 -0400 X-Greylist: delayed 1364 seconds by postgrey-1.27 at vger.kernel.org; Fri, 24 Apr 2020 11:36:26 EDT Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway30.websitewelcome.com (Postfix) with ESMTP id 0BDCFD585FB for ; Fri, 24 Apr 2020 10:13:41 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id S01Njl5JBAGTXS01Nj4UaG; Fri, 24 Apr 2020 10:13:41 -0500 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:Subject:From:References:Cc:To:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=GtcnpGsolmgR53+FPf7YoLxFdbs5TBp3BgCqahnxZ6Y=; b=JRszSWBIDiIx+kiBBosfMlCQy/ 5lkVx+FrQnZhEsZDP7hcLs8TUpKxd5R4ikmH4H7wr5hWKSH3Aa37dzKwxMk+69js4HoXHJFA121tc 5jGtWkmST36gJCkuz1JOnzRCBxUVuKB1dT+2IOBVPDrMPAauZMxO9ZRqbqmFep9f868Blke6RJrIj HMhCzc0bvBkB5iEtGFtNgCuNdph6Ci1nOsh6qtNNBVFSQw9LcChAeNqKX2D4v871u/dVpCYmItlHg rMuGyhR70WOUq8OxcudWFahcPngjRb/W6bszhreOe1f9H0pqJ1rq/UMnoOp+drY0xJdwqP0/inbd3 MtJW9T8g==; Received: from [201.162.177.68] (port=57568 helo=[192.168.43.132]) by gator4166.hostgator.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.92) (envelope-from ) id 1jS01M-000a3c-JL; Fri, 24 Apr 2020 10:13:40 -0500 To: Nathan Chancellor Cc: Linus Torvalds , Kees Cook , Greg KH , Linux Kernel Mailing List , linux-rdma@vger.kernel.org, clang-built-linux@googlegroups.com References: <6342c465-e34b-3e18-cc31-1d989926aebd@embeddedor.com> <20200424034704.GA12320@ubuntu-s3-xlarge-x86> From: "Gustavo A. R. Silva" Autocrypt: addr=gustavo@embeddedor.com; keydata= xsFNBFssHAwBEADIy3ZoPq3z5UpsUknd2v+IQud4TMJnJLTeXgTf4biSDSrXn73JQgsISBwG 2Pm4wnOyEgYUyJd5tRWcIbsURAgei918mck3tugT7AQiTUN3/5aAzqe/4ApDUC+uWNkpNnSV tjOx1hBpla0ifywy4bvFobwSh5/I3qohxDx+c1obd8Bp/B/iaOtnq0inli/8rlvKO9hp6Z4e DXL3PlD0QsLSc27AkwzLEc/D3ZaqBq7ItvT9Pyg0z3Q+2dtLF00f9+663HVC2EUgP25J3xDd 496SIeYDTkEgbJ7WYR0HYm9uirSET3lDqOVh1xPqoy+U9zTtuA9NQHVGk+hPcoazSqEtLGBk YE2mm2wzX5q2uoyptseSNceJ+HE9L+z1KlWW63HhddgtRGhbP8pj42bKaUSrrfDUsicfeJf6 m1iJRu0SXYVlMruGUB1PvZQ3O7TsVfAGCv85pFipdgk8KQnlRFkYhUjLft0u7CL1rDGZWDDr NaNj54q2CX9zuSxBn9XDXvGKyzKEZ4NY1Jfw+TAMPCp4buawuOsjONi2X0DfivFY+ZsjAIcx qQMglPtKk/wBs7q2lvJ+pHpgvLhLZyGqzAvKM1sVtRJ5j+ARKA0w4pYs5a5ufqcfT7dN6TBk LXZeD9xlVic93Ju08JSUx2ozlcfxq+BVNyA+dtv7elXUZ2DrYwARAQABzSxHdXN0YXZvIEEu IFIuIFNpbHZhIDxndXN0YXZvQGVtYmVkZGVkb3IuY29tPsLBfQQTAQgAJwUCWywcDAIbIwUJ CWYBgAULCQgHAgYVCAkKCwIEFgIDAQIeAQIXgAAKCRBHBbTLRwbbMZ6tEACk0hmmZ2FWL1Xi l/bPqDGFhzzexrdkXSfTTZjBV3a+4hIOe+jl6Rci/CvRicNW4H9yJHKBrqwwWm9fvKqOBAg9 obq753jydVmLwlXO7xjcfyfcMWyx9QdYLERTeQfDAfRqxir3xMeOiZwgQ6dzX3JjOXs6jHBP cgry90aWbaMpQRRhaAKeAS14EEe9TSIly5JepaHoVdASuxklvOC0VB0OwNblVSR2S5i5hSsh ewbOJtwSlonsYEj4EW1noQNSxnN/vKuvUNegMe+LTtnbbocFQ7dGMsT3kbYNIyIsp42B5eCu JXnyKLih7rSGBtPgJ540CjoPBkw2mCfhj2p5fElRJn1tcX2McsjzLFY5jK9RYFDavez5w3lx JFgFkla6sQHcrxH62gTkb9sUtNfXKucAfjjCMJ0iuQIHRbMYCa9v2YEymc0k0RvYr43GkA3N PJYd/vf9vU7VtZXaY4a/dz1d9dwIpyQARFQpSyvt++R74S78eY/+lX8wEznQdmRQ27kq7BJS R20KI/8knhUNUJR3epJu2YFT/JwHbRYC4BoIqWl+uNvDf+lUlI/D1wP+lCBSGr2LTkQRoU8U 64iK28BmjJh2K3WHmInC1hbUucWT7Swz/+6+FCuHzap/cjuzRN04Z3Fdj084oeUNpP6+b9yW e5YnLxF8ctRAp7K4yVlvA87BTQRbLBwMARAAsHCE31Ffrm6uig1BQplxMV8WnRBiZqbbsVJB H1AAh8tq2ULl7udfQo1bsPLGGQboJSVN9rckQQNahvHAIK8ZGfU4Qj8+CER+fYPp/MDZj+t0 DbnWSOrG7z9HIZo6PR9z4JZza3Hn/35jFggaqBtuydHwwBANZ7A6DVY+W0COEU4of7CAahQo 5NwYiwS0lGisLTqks5R0Vh+QpvDVfuaF6I8LUgQR/cSgLkR//V1uCEQYzhsoiJ3zc1HSRyOP otJTApqGBq80X0aCVj1LOiOF4rrdvQnj6iIlXQssdb+WhSYHeuJj1wD0ZlC7ds5zovXh+FfF l5qH5RFY/qVn3mNIVxeO987WSF0jh+T5ZlvUNdhedGndRmwFTxq2Li6GNMaolgnpO/CPcFpD jKxY/HBUSmaE9rNdAa1fCd4RsKLlhXda+IWpJZMHlmIKY8dlUybP+2qDzP2lY7kdFgPZRU+e zS/pzC/YTzAvCWM3tDgwoSl17vnZCr8wn2/1rKkcLvTDgiJLPCevqpTb6KFtZosQ02EGMuHQ I6Zk91jbx96nrdsSdBLGH3hbvLvjZm3C+fNlVb9uvWbdznObqcJxSH3SGOZ7kCHuVmXUcqoz ol6ioMHMb+InrHPP16aVDTBTPEGwgxXI38f7SUEn+NpbizWdLNz2hc907DvoPm6HEGCanpcA EQEAAcLBZQQYAQgADwUCWywcDAIbDAUJCWYBgAAKCRBHBbTLRwbbMdsZEACUjmsJx2CAY+QS UMebQRFjKavwXB/xE7fTt2ahuhHT8qQ/lWuRQedg4baInw9nhoPE+VenOzhGeGlsJ0Ys52sd XvUjUocKgUQq6ekOHbcw919nO5L9J2ejMf/VC/quN3r3xijgRtmuuwZjmmi8ct24TpGeoBK4 WrZGh/1hAYw4ieARvKvgjXRstcEqM5thUNkOOIheud/VpY+48QcccPKbngy//zNJWKbRbeVn imua0OpqRXhCrEVm/xomeOvl1WK1BVO7z8DjSdEBGzbV76sPDJb/fw+y+VWrkEiddD/9CSfg fBNOb1p1jVnT2mFgGneIWbU0zdDGhleI9UoQTr0e0b/7TU+Jo6TqwosP9nbk5hXw6uR5k5PF 8ieyHVq3qatJ9K1jPkBr8YWtI5uNwJJjTKIA1jHlj8McROroxMdI6qZ/wZ1ImuylpJuJwCDC ORYf5kW61fcrHEDlIvGc371OOvw6ejF8ksX5+L2zwh43l/pKkSVGFpxtMV6d6J3eqwTafL86 YJWH93PN+ZUh6i6Rd2U/i8jH5WvzR57UeWxE4P8bQc0hNGrUsHQH6bpHV2lbuhDdqo+cM9eh GZEO3+gCDFmKrjspZjkJbB5Gadzvts5fcWGOXEvuT8uQSvl+vEL0g6vczsyPBtqoBLa9SNrS VtSixD1uOgytAP7RWS474w== Subject: Re: remaining flexible-array conversions Message-ID: Date: Fri, 24 Apr 2020 10:17:51 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200424034704.GA12320@ubuntu-s3-xlarge-x86> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 201.162.177.68 X-Source-L: No X-Exim-ID: 1jS01M-000a3c-JL X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: ([192.168.43.132]) [201.162.177.68]:57568 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 5 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Nathan, On 4/23/20 22:47, Nathan Chancellor wrote: > Hi Gustavo, > > That patch in -next appears to introduce some warnings with clang when > CONFIG_UAPI_HEADER_TEST is enabled (allyesconfig/allmodconfig exposed it > for us with KernelCI [1]): > Thanks a lot for reporting this. > ./usr/include/rdma/ib_user_verbs.h:436:34: warning: field 'base' with > variable sized type 'struct ib_uverbs_create_cq_resp' not at the end of > a struct or class is a GNU extension > [-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_cq_resp base; > ^ > ./usr/include/rdma/ib_user_verbs.h:647:34: warning: field 'base' with > variable sized type 'struct ib_uverbs_create_qp_resp' not at the end of > a struct or class is a GNU extension > [-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_qp_resp base; > ^ > ./usr/include/rdma/ib_user_verbs.h:743:29: warning: field 'base' with > variable sized type 'struct ib_uverbs_modify_qp' not at the end of a > struct or class is a GNU extension > [-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_modify_qp base; > ^ > 3 warnings generated. > > I presume this is part of the point of the conversion since you mention > a compiler warning when the flexible member is not at the end of a > struct. How should they be fixed? That should probably happen before the > patch gets merged. > For all the cases above, the solution seems to be to move the declaration of the "base" member to the end of the corresponding structure, as below: diff --git a/include/uapi/rdma/ib_user_verbs.h b/include/uapi/rdma/ib_user_verbs.h index a390a667b3f3..e05538be8b30 100644 --- a/include/uapi/rdma/ib_user_verbs.h +++ b/include/uapi/rdma/ib_user_verbs.h @@ -644,9 +644,9 @@ struct ib_uverbs_create_qp_resp { }; struct ib_uverbs_ex_create_qp_resp { - struct ib_uverbs_create_qp_resp base; __u32 comp_mask; __u32 response_length; + struct ib_uverbs_create_qp_resp base; }; /* but I guess this will change the ABI? Also, notice that: "A structure containing a flexible array member, or a union containing such a structure (possibly recursively), may not be a member of a structure or an element of an array. (However, these uses are permitted by GCC as extensions.)"[1] [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Thanks -- Gustavo