From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vk1-xa2c.google.com (mail-vk1-xa2c.google.com [IPv6:2607:f8b0:4864:20::a2c]) by sourceware.org (Postfix) with ESMTPS id 5713E3858C5E for ; Wed, 5 Jul 2023 13:46:26 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 5713E3858C5E Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=rodriguez.im Authentication-Results: sourceware.org; spf=none smtp.mailfrom=cristianrodriguez.net Received: by mail-vk1-xa2c.google.com with SMTP id 71dfb90a1353d-47db84f6d3cso613839e0c.0 for ; Wed, 05 Jul 2023 06:46:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rodriguez.im; s=google; t=1688564785; x=1691156785; h=to:subject:message-id:date:from:mime-version:from:to:cc:subject :date:message-id:reply-to; bh=2smjtfFUvHlooZr38G5CTxVKHD9i1MmrFZZENLXo/iA=; b=jcfh56Gx8wGaNhMwnsTKAZZg5yBZfXrPDxJnYXrJkBmKBOxxEs7Xo/VfXkzrx3E8aP WBTkbP83SeHW7nCEH4Qa8ZlcfaawfSxn+/Ei+E/HLTI2291QJ7sk74i1MRN+Vdi+5RQY 1E925Zo8+wM2Afhj8lOF8+RaEuYUuHuPUFRkY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688564785; x=1691156785; h=to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=2smjtfFUvHlooZr38G5CTxVKHD9i1MmrFZZENLXo/iA=; b=XJrgl+yVRnrv5jjwppbb3B69fSbipdrykcq7BQ3jWueXcP/vWpzj9ys3X1DFOd78Q+ f5sETquZGuT6HJs6UBDSDIMibZFL2hR6ASN5Q2Mmw4qdLpVwqQJheAa8HT8iBDACbM8e TZHGZIeAA/B/2FXNa5SiVHNlvK6spf5TKZh1bSW4dzcvHxPgbvFvkhHv4ty+F/Lf0iqU CsmUffiE0MyvUw+OdmGlkMW5WD4PZ3sSxG5nTwm0TGZCx9M8jdt4NZ8lH01ja2XUb2+Q jGh4Zb96Kqn1Al0VOFQ/A0aJ1gqEgEq8m/XCYGx3sIhzhpGFdCSBddCE10eCFoPCwtIi Sx3Q== X-Gm-Message-State: ABy/qLajJmIuRxcw43Dbuie9dVvkvNGNaLN/NU6SK/v4a8TanLIJmAEo wa5EvZJ9Ok33Bio9kOiH4qnb1df1FtQqDCUqEhFCkwEgAyzrmUBdUx8= X-Google-Smtp-Source: APBJJlH+j7jjEHKCok2riPHzyPbDuxUaLH5XAEZvBlfIguZyqXJFJuubM7LqfpZFVNsj00cA4NFT/Wkkpejw9G3Ro5M= X-Received: by 2002:a05:6102:3e03:b0:443:58e3:80e8 with SMTP id j3-20020a0561023e0300b0044358e380e8mr6379376vsv.2.1688564785525; Wed, 05 Jul 2023 06:46:25 -0700 (PDT) MIME-Version: 1.0 From: =?UTF-8?Q?Cristian_Rodr=C3=ADguez?= Date: Wed, 5 Jul 2023 09:46:14 -0400 Message-ID: Subject: gcc-14 Wflex-array-member-not-at-end may-be-ub in struct pthread To: Adhemerval Zanella via Libc-alpha Content-Type: multipart/alternative; boundary="00000000000038e49805ffbda030" X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: --00000000000038e49805ffbda030 Content-Type: text/plain; charset="UTF-8" gcc-14 says that struct pthread { ... struct rseq rseq_area; /* This member must be last. */ char end_padding[]; --> This is incorrect, since struct rseq contains a flexible array it must be the last member.. } The current docs say: "A structure containing a C99 flexible array member, or a union containing such a structure, is not the last field of another structure, for example: struct flex { int length; char data[]; }; struct mid_flex { int m; struct flex flex_data; int n; }; In the above, accessing a member of the array mid_flex.flex_data.data[] might have undefined behavior. Compilers do not handle such a case consistently. Any code relying on this case should be modified to ensure that flexible array members only end up at the ends of structures." Who is right.. ? is this intentional? --00000000000038e49805ffbda030--