From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 6BB064611F; Fri, 24 Jan 2025 19:37:53 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 29556402AB; Fri, 24 Jan 2025 19:37:53 +0100 (CET) Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) by mails.dpdk.org (Postfix) with ESMTP id CA31C40279 for ; Fri, 24 Jan 2025 19:37:51 +0100 (CET) Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-2162c0f6a39so67118765ad.0 for ; Fri, 24 Jan 2025 10:37:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1737743871; x=1738348671; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=YbQMh6W6bDRYJp/hob9UTJrke9/s9KHDuENT9+oVBXQ=; b=g1I39J0TzXiuK8MmqukH+Il3v8IsQ3E76DpmAYyrlpuj8P/HR4MgWYoDJMV3N/QfQ0 bJvJZZj7veIKosmfta8HjnuBKZ2f+atMwnpXmqQXWfLSKz6W6LdQ/2it+Ron63BHPN0N HAOqmIxMtDiZROAELRh+KyOl+XDEIsolsO0EfjSrxDT14p4mFrnhn3Faf1shDqCs7v6J 8PqF097YPmkZU2ASiAKJOZ0QDGtY8DhT81r9ezDbNve2aqs3K/f+XLeeamLsz0PdPU// i2NtOOVgL6MjBmfr5kfP2YooNEFpCjY+ufrNDtGaxRAHcmbsT3esVMCpChVKddIlJEpP jaoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1737743871; x=1738348671; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=YbQMh6W6bDRYJp/hob9UTJrke9/s9KHDuENT9+oVBXQ=; b=ZZO3E6QtRDkrMIq/H2tAODEA9RfeZra9X3KZASZHmV5YQBKm22pHqL7CwLZDvx79Lp 4AJJJNMQJnNZIZgkT0bcnxREitJ7hKMeajlinPxuYadLyaVUuoRXfwpzja6QR2sTG7II pisPwmUNv9fWtwnErna9pZCQ61hIyr8KaWrYJJ84ZQ9hTlZ8VbZegvwNz4IChBgOhGHv RQ52LFJIdMJYbvyMPaqVwi3qbmkCejBCn1/2ZrXvp4wINt+Csp8IGCRxJH6b4adEgx1M THa6gOEd0ww1FUlMxoTjDBeqJA7VIIpxTQzF72gP6VVA+u3m8N2HbGZPgGVJRGkdmfMX slzw== X-Forwarded-Encrypted: i=1; AJvYcCVY+vs4oVfoZdmfLuewednz31GzfG3Afs7hfIZZie6mBoxPfNdZPtKinCqXqXjBxc0VTcc=@dpdk.org X-Gm-Message-State: AOJu0YwngB4GMCWIE91rt8soEDE0PTiibH/vMAfcmWB9qzavwS7ffq0E yOzyp82061ODShIOY1KcXY5EaQ1bvrzfVpOYjNIwKzrT8/XG0k4gwcW8Ybw7Q9Q= X-Gm-Gg: ASbGnctRQzsRjCnJzI00shzqELpJQ28c5cgCKQXVzu6xFLhaKkTODv4hb/050TGb16J QuIGrzZnQvhARVdU/8PxejA/NxSNS65FoMI7eefTn4+VFHQEmGuCCsL+nzyr8X9fniu/ABYRCHW AEiYhmCvLloKG7JNpXUg++5gZpA77OYcmDDNIeAsUV/5L4Fc/oWctkuYL+4edZYGoY1MMLHY5J6 ohIJG4HsNCQ2QIailwai/aPYjUk64mP5rrU8M5oAbhhumleQwlpL9dlT6J3Tjkdm75skywhCM0z hk0y3w7S829Y0cac3Uv+GTLG90pNsG5aCETusoFUSDbIvJfFi8tAoMO/0A== X-Google-Smtp-Source: AGHT+IGmUgxCwjKKk4fRjQZ3QFBxo1C9TGpkUXKKlOIo+LRs0DH77pCQh4TH3rTB+Y6ASFwqEXgnTw== X-Received: by 2002:a17:902:d54a:b0:215:758c:52e8 with SMTP id d9443c01a7336-21d9934b5d4mr155013855ad.12.1737743871036; Fri, 24 Jan 2025 10:37:51 -0800 (PST) Received: from hermes.local (204-195-96-226.wavecable.com. [204.195.96.226]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-21da414df4dsm19602915ad.194.2025.01.24.10.37.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Jan 2025 10:37:50 -0800 (PST) Date: Fri, 24 Jan 2025 10:37:48 -0800 From: Stephen Hemminger To: Bruce Richardson Cc: Morten =?UTF-8?B?QnLDuHJ1cA==?= , Subject: Re: [PATCH] build: force gcc to initialize padding bits Message-ID: <20250124103748.6b9b85fa@hermes.local> In-Reply-To: References: <20250123172048.134417-1-stephen@networkplumber.org> <98CBD80474FA8B44BF855DF32C47DC35E9F9E6@smartserver.smartshare.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On Fri, 24 Jan 2025 09:38:20 +0000 Bruce Richardson wrote: > > > > Does this flag give us additional guarantees of padding being > zero-initialized that were there before? From my reading of the gcc doc[1], > "..padding-bits=union" corresponds to the old behaviour, right? > > This also means we will have different padding behaviour on clang and gcc, > since clang (at least v18 on my board) doesn't support this flag. Do we see > any issues with that? > > /Bruce I chose the setting based on some email with the Linux kernel hardening project and their choice. Clang decided to fix and just do the right thing. https://github.com/llvm/llvm-project/commit/7a086e1b2dc05f54afae3591614feede727601fa