From nobody Wed Mar 23 22:16:36 2022 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 045031A24474; Wed, 23 Mar 2022 22:16:39 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4KP2kt6RpLz3GFL; Wed, 23 Mar 2022 22:16:38 +0000 (UTC) (envelope-from jhb@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1648073798; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lIBdU7vAfCv3Y4dLT5a96eG7Te/6FBo3kKz/GIIv7j8=; b=lC2Ur8C4jXWDE0Cir0kZYatjzlC/Rz/QABM85nKKDOYqb40cUywFL5tW6vWr+dtaDGqR1H zjsJFBSYsTsCP+S+mThthJw3M+OPP16E0tybRXDakwh3xL710v8mDCEfe1qiLjO/URYZ8A d/zMkRBwYgMQ19Y0wE6AShlU42s7mcnZKNKLDt3vsOTU9b/+Z2m3AtqZqaiy8779s1ARm8 kMt29fLerwAE5BDMSjJEbMD9aUEN7VidnyFJPAAo3nuM7WHGFP0rqULU8gU6wivPT4M8hI pa7A3oELUAu2mJV9dgm6IjEdN4eVhcCF8lYYkPffvtg8fMMDqHDHJ/ZIFX+paw== Received: from [10.0.1.4] (ralph.baldwin.cx [66.234.199.215]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: jhb) by smtp.freebsd.org (Postfix) with ESMTPSA id 2F6F428CE0; Wed, 23 Mar 2022 22:16:38 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Message-ID: Date: Wed, 23 Mar 2022 15:16:36 -0700 List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-main@freebsd.org X-BeenThere: dev-commits-src-main@freebsd.org MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: git: 6713be315900 - main - Add NT_ARM_ADDR_MASK Content-Language: en-US To: Jessica Clarke , Andrew Turner Cc: "src-committers@freebsd.org" , "dev-commits-src-all@freebsd.org" , "dev-commits-src-main@freebsd.org" References: <202202221727.21MHR4dv022628@gitrepo.freebsd.org> <2C1219E1-9F36-4FDC-95B1-AD6DC9F0C215@freebsd.org> From: John Baldwin In-Reply-To: <2C1219E1-9F36-4FDC-95B1-AD6DC9F0C215@freebsd.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1648073798; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lIBdU7vAfCv3Y4dLT5a96eG7Te/6FBo3kKz/GIIv7j8=; b=upxLXuvK1THThD3U13R6CUFTwcXBf34iXWfXZgtSKAWBFAxD2pdWh6dgmwTbT7vjt0ru8p JLAlosgqMYCCZeUY8cLLuW62ZOIFXy8RahTCn3sjQ7jiCfzylUlxTuk/ngyrgVk62B6PQQ QKAhdbuf1Yn040UrIo+YBd0PWlambqjkldPZeIpLFm5u9MPikhw7Id5mOm3/qDz2StmWPt RA8xJIr7BetLmF9dIYTXxFZz9xQwDXfACqp+0RBVoV4tbmcRwZgBy7TGQWk4AM8KcR/tJc R8rAw1crQAPsKUwDG+9Ksnw9nYynWoIdv4HqO7rqOCJ8+eSsxvgh5wKkIQBqng== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1648073798; a=rsa-sha256; cv=none; b=QAYD+kG/TFliAX1XmknF/UU0gpfDLeTlGYYco/v/iM4sh+PRfPZ62ijSRwbCD1cI/rASsg KXfkvPtLX8Ft6Y8sEh/36idzIra/OBcxKKA+/DQQxBjPBAhrGPt1KzyFNvsshtD405dBb9 aOHG1RyDCiYTkC9LWGUEiOHSNwcbkAYZ6DlhvhAmIyiw9oOigAvAjBdJTzU/G/kjn9FErF 10MYGioQ/ZizvzTXN43H0H6t3RLj9CYaOO+fk98iEYXfadctfL3O3XB+08dNfjBQec+ptb ZbakuWfIeg2xMPF7v5pwwmXZcXVJjdK0Z5iH75JPKJobqc8gw8KlXkNImjiGEg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N On 2/22/22 9:59 AM, Jessica Clarke wrote: > On 22 Feb 2022, at 17:27, Andrew Turner wrote: >> >> The branch main has been updated by andrew: >> >> URL: https://cgit.FreeBSD.org/src/commit/?id=6713be3159000783f7aacf3ea90d6c6878c44da0 >> >> commit 6713be3159000783f7aacf3ea90d6c6878c44da0 >> Author: Andrew Turner >> AuthorDate: 2021-08-30 16:43:22 +0000 >> Commit: Andrew Turner >> CommitDate: 2022-02-22 17:10:35 +0000 >> >> Add NT_ARM_ADDR_MASK >> >> This can be used by debuggers to find which bits in a virtual address >> should be masked off to get a canonical address. This is currently used >> by the Pointer Authentication Code support to get its mask. It could also >> be used if we support Top Byte Ignore for the same purpose. >> >> Reviewed by: kib >> Sponsored by: The FreeBSD Foundation >> Differential Revision: https://reviews.freebsd.org/D34302 > > This definition seems backwards? In Linux it’s NT_ARM_PAC_MASK, i.e. > the mask for the PAC bits, but you’ve called it NT_ARM_ADDR_MASK here, > which sounds like the mask you apply to get the address bits, but it’s > not, you apply the negation of this mask to get the address bits. In that sense, it's identical to NT_ARM_PAC_MASK on Linux (same actual contents and layout). Given that, using a different name seems gratuitous vs reusing the existing name as we did for NT_X86_XSTATE, NT_ARM_VFP, NT_PPC_VMX, NT_ARM_TLS, etc. If the content of the note was different, then a different name might be warranted, but if the content and purpose of the note are the same, then it's not clear why we need a different name for the constant. -- John Baldwin