From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.cs.ucla.edu (mail.cs.ucla.edu [131.179.128.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D4C0013C9C4 for ; Thu, 28 Aug 2025 13:43:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=131.179.128.66 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756388610; cv=none; b=C9v734pSfcHgVmcObqLqqc5PXmXBqtgidsDLc+2Ccyayx9vpjlccNz+YSFlag79j+FeJgalBvoZMfP7VEqDbm2svK+tf0jrXycFothDOg5TdhcZKPzKghoP//KX0Fu68XlD5ksexgQ7EM2XJ4/KhExXpauOh/rV/khbepNg/6IA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756388610; c=relaxed/simple; bh=Gfp1kWMiqlQaDH75GF0a0OajZGhAwbWmYbkx1zy/YVg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qyw5yXw1wZNRzXqsn/zkeajWgCifvwgilLvVmg/MRpU23BwlcG50WsUP2GolEukss7F7YnnIsbKu4XcmI4q2jskAx3iDtb5C+yR2nhbWucB4nXz5hy6hhE5umjS2BtxYeLNfsT9+HfOMQ6qlE7vuqgRyELNlZKczA3a6U97kRVw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=cs.ucla.edu; spf=pass smtp.mailfrom=cs.ucla.edu; dkim=pass (2048-bit key) header.d=cs.ucla.edu header.i=@cs.ucla.edu header.b=mVlaH1s7; arc=none smtp.client-ip=131.179.128.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=cs.ucla.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cs.ucla.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cs.ucla.edu header.i=@cs.ucla.edu header.b="mVlaH1s7" Received: from localhost (localhost [127.0.0.1]) by mail.cs.ucla.edu (Postfix) with ESMTP id 32E793C0149F6; Thu, 28 Aug 2025 06:43:28 -0700 (PDT) Received: from mail.cs.ucla.edu ([127.0.0.1]) by localhost (mail.cs.ucla.edu [127.0.0.1]) (amavis, port 10032) with ESMTP id eQJYZaxMe1Js; Thu, 28 Aug 2025 06:43:28 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by mail.cs.ucla.edu (Postfix) with ESMTP id 088E63C32B0FD; Thu, 28 Aug 2025 06:43:28 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.cs.ucla.edu 088E63C32B0FD DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cs.ucla.edu; s=9D0B346E-2AEB-11ED-9476-E14B719DCE6C; t=1756388608; bh=frJuCsg5GjM12xqGOoW6BxFOcUJwQm4Yl907MoZaibQ=; h=Message-ID:Date:MIME-Version:To:From; b=mVlaH1s7MnZGfkc3L2DzbncFg8apDiJolH4xlGAa/Jb9MQeS2qQGOlAGcD8srztQ0 NwP1AwYzj6WoXKuOR/88iev2DFaSD3U8APFmYc0meq+hsKc6fgrMh3W+fbdyk7/O6N I0vpx7NIHqUoEeybnUttmeNy6vZNyffMR+AGqMCwAQlS0Ltmmk1UGVvqjD0lQ3M59+ VtJxcL4P8lYxJFMgwPIoiAAdkusmp4DpqcZJVTVlaEDCWsa6wzo3v8Lri7rDNTNl9A 0jH6FNAiy9FjGgFJ6X7EZT2t4nmhAW/hORdm6GiEUBIHtHzPTDJmHMisVy7tQkizEB 6t91LvkQBUJaw== X-Virus-Scanned: amavis at mail.cs.ucla.edu Received: from mail.cs.ucla.edu ([127.0.0.1]) by localhost (mail.cs.ucla.edu [127.0.0.1]) (amavis, port 10026) with ESMTP id 6pgaj_F-W9ds; Thu, 28 Aug 2025 06:43:27 -0700 (PDT) Received: from penguin.cs.ucla.edu (47-154-18-19.fdr01.snmn.ca.ip.frontiernet.net [47.154.18.19]) by mail.cs.ucla.edu (Postfix) with ESMTPSA id D367C3C0149F6; Thu, 28 Aug 2025 06:43:27 -0700 (PDT) Message-ID: Date: Thu, 28 Aug 2025 06:43:27 -0700 Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4] linux: Add openat2 (BZ 31664) To: Aleksa Sarai Cc: Adhemerval Zanella Netto , Arjun Shankar , libc-alpha@sourceware.org, linux-api@vger.kernel.org References: <2c5ae756-c624-4855-9afb-7b8e8ce91011@linaro.org> <828f6dfb-7402-45e1-a9ed-9e17b6356c5c@linaro.org> <2025-08-25.1756160579-pudgy-swank-chard-regalia-j3jdtD@cyphar.com> <5c3b9baf-76b4-40d7-87fb-9b8dd5afd1ee@cs.ucla.edu> <2025-08-26.1756212515-wealthy-molten-melody-nobody-a5HmWg@cyphar.com> <6432a34d-fba9-414e-ad38-d3354fa0d775@cs.ucla.edu> <2025-08-27.1756273344-decaf-ominous-thrift-twinge-h1gGBI@cyphar.com> <5c9fa556-da00-4b76-8a70-8e2d1dddd92d@cs.ucla.edu> <2025-08-27-perky-glossy-dam-spindle-kPpnnk@cyphar.com> <5cbd7011-9c2a-4a23-bbce-84c100877cdb@cs.ucla.edu> <2025-08-28-foreign-swampy-comments-arbor-nOkpXI@cyphar.com> Content-Language: en-US From: Paul Eggert Organization: UCLA Computer Science Department In-Reply-To: <2025-08-28-foreign-swampy-comments-arbor-nOkpXI@cyphar.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2025-08-28 01:42, Aleksa Sarai wrote: >> I still fail to understand how a hypothetical "give me the supported flags" >> openat2 flag would be useful enough to justify complicating the openat2 API >> today. > My only concern is that it would break recompiles if/when we change it > back. OK, but from what I can see there's no identified possibility that openat2 will modify the objects its arguments point to, just as there's no identified possibility that plain openat will do so (in a hypothetical extension to remove unnecessary slashes from its filename argument, say). In that case it's pretty clear that glibc should mark the open_how argument as pointer-to-const, just as glibc already marks the filename argument.