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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4D88C27C4F for ; Thu, 13 Jun 2024 14:42:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6C7CE6B00A6; Thu, 13 Jun 2024 10:42:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 64F8B6B00A8; Thu, 13 Jun 2024 10:42:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4C9026B00A9; Thu, 13 Jun 2024 10:42:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 28BBD6B00A6 for ; Thu, 13 Jun 2024 10:42:05 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id D74E41C00E9 for ; Thu, 13 Jun 2024 14:42:04 +0000 (UTC) X-FDA: 82226130168.07.FAD7CFF Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf01.hostedemail.com (Postfix) with ESMTP id 1991F40029 for ; Thu, 13 Jun 2024 14:42:01 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=l0X+9SQa; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf01.hostedemail.com: domain of kees@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=kees@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1718289720; a=rsa-sha256; cv=none; b=JXsZ3zkRDBWS2swT1vDUHiGZwI05eXx2vzjnctCgmWZTdl7lyLGPtRIM56YG/FrczA8+2J MrOFQ8TXPj/Icx+pk3PLv7KmCQpwSG5ipjwli/hwJ/NpK1vRegNWipHZHfGLWMvhNFE364 pokGRwgAI/4UFEcIrnTgjPhpFCZEONc= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=l0X+9SQa; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf01.hostedemail.com: domain of kees@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=kees@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1718289720; h=from:from:sender: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:dkim-signature; bh=ACFVvNaX3G/ox9xG1Uy/w4Xl9pAIQHV/YBQ2KPd9Jns=; b=4+egmZJn1OO7v3CVPG7SKRkfybC9yEdiMXEIHKgGEX/kzJb4ITALISRIq4MmRu5DVu+fSk uBolNb6T+LY33ysSLkwFdtT8ixD1TlNt3YlK1oCNKVux+2C45oA3CMFT+MHkLPa8dPt9wi 2pG+lZOJbACew0LnhF0v9z+gnlVPmVA= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 0D90161B77; Thu, 13 Jun 2024 14:42:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F4A3C32786; Thu, 13 Jun 2024 14:42:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718289720; bh=ACFVvNaX3G/ox9xG1Uy/w4Xl9pAIQHV/YBQ2KPd9Jns=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=l0X+9SQaNpGCWmkkBAZ7shYcXdgSpZu+aUMz3+S/S19z58NSYHB5fqogcVlIrXPet WlubJrnF8ClOA7jaWL3zQ9OAxLH8++4VoUIZ3ouolUs5m1E/L+TzoJT8QMSFN5EmQ9 eaI0eMJadaFrHZqdg+SLaTtWMfIp5AJWQw/5B4ZIqJjrEymXnCQiP5bUM9i0DF5m/B cY/evic6wzEPCMo2sdfL2a+3ivOq0E0j9yukC4zcmOt3XEkuEIGBIlt+8Nqt/lR772 pw7T3tQKFL99jOjFFPPFcylBn2TJuWCEv3ROa9MuLsOEtsgeAcFwZBjkJ+ZMMAUR0n bUsVZjtsXkLVA== Date: Thu, 13 Jun 2024 07:42:01 -0700 From: Kees Cook To: Ard Biesheuvel , Steven Rostedt CC: Mike Rapoport , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Lorenzo Stoakes , linux-mm@kvack.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Tony Luck , "Guilherme G. Piccoli" , linux-hardening@vger.kernel.org, Guenter Roeck , Ross Zwisler , wklin@google.com, Vineeth Remanan Pillai , Joel Fernandes , Suleiman Souhlal , Linus Torvalds , Catalin Marinas , Will Deacon Subject: =?US-ASCII?Q?Re=3A_=5BPATCH_v3_2/2=5D_pstore/ramoops=3A_Add?= =?US-ASCII?Q?_ramoops=2Emem=5Fname=3D_command_line_option?= User-Agent: K-9 Mail for Android In-Reply-To: References: <20240611144911.327227285@goodmis.org> <20240611144949.703297941@goodmis.org> <202406121145.8860502D7@keescook> <20240612145228.5bf426e0@rorschach.local.home> <20240613092642.385461d5@rorschach.local.home> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 1991F40029 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: w6t5grzurtobayzu3xfcxgnxsrcqx631 X-HE-Tag: 1718289721-671219 X-HE-Meta: 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 hUyjwoQ1 0bFBCIZyJR5bjxkbYRJDv0CNsOA2hrG1cDLu9AFpVZu22G3O+Bp/0YHVq0lgtZ1HKwX9UDb/WyMcd3l4ewCOa5q5O8CtleGvDWTZwtDwzKX1gQWXEmlyeiiPX5ZCrCGLHEP1mScsxetOIFy/fM1BgYaHOFZ8WVmywFwWJihzmaHGkptEOAH0zNSGDBPbXsO7BTFaZyV0fXZNM229JDWotZAIiYVA6WGzD+LAVXBM+x+Qw3Wdhn6o7LlKvYTbqCXqMaCpkr7V6xhNH2sil/rXaRnc4bsK9DYhEyovDTYED3c6RUWphVCDBUajgfpLuWT121iNP9j6YK+xWCLdB6oipJLny0euiZDNk6uB20OTA5KhTqvVJ+JPhZqg36GEfYynp+YzrRP+EeqWuGQVdYMcXa7Wt0oTQWZLjXg6H X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On June 13, 2024 7:06:47 AM PDT, Ard Biesheuvel wrote: >On Thu, 13 Jun 2024 at 15:26, Steven Rostedt wrot= e: >> >> On Thu, 13 Jun 2024 08:11:48 +0200 >> Ard Biesheuvel wrote: >> > > >> > > I've added one more comment to v5, with that fixed I can take this= =2E >> > > >> > >> > So how is this supposed to work wrt to the rigid 'no user visible >> > regressions' rule, given that this whole thing is a best effort thing >> >> This has nothing to do with user space=2E The kernel command line has >> broken in the past=2E If you update the kernel, you can update the >> command line=2E There's no "no user visible regressions" rule=2E It's >> "Don't break user space"=2E This has nothing to do with user space=2E >> >> > to begin with=2E This needs at least a huge disclaimer that this rule >> > does not apply, and if this works today, there is no guarantee that i= t >> > will keep working on newer kernels=2E Otherwise, you will be making t= he >> > job of the people who work on the boot code significantly more >> > difficult=2E And even then, I wonder whether Linus and #regzcop are >> > going to honour such a disclaimer=2E >> >> Again, this has nothing to do with user space=2E The rule Linus talks >> about is breaking user space=2E This is about kernel debugging=2E Somet= hing >> *completely different*! >> >> > >> > So this belongs downstream, unless some guarantees can be provided >> > that this functionality is exempt from the usual regression policies= =2E >> >> I disagree=2E kexec/kdump also has the same issues=2E >> > >Fair enough=2E As long as it is documented that there is no guarantee >that this will keep working over a kernel upgrade, then I have no >objections=2E Yeah, I should better document this for pstore as a whole, but I've alread= y made the call that cross-kernel-versison operation is best effort=2E -Kees --=20 Kees Cook