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 5F5B4C4345F for ; Fri, 12 Apr 2024 21:00:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C0AEC6B0096; Fri, 12 Apr 2024 17:00:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B93986B0098; Fri, 12 Apr 2024 17:00:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A34336B0099; Fri, 12 Apr 2024 17:00:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 7CA0C6B0096 for ; Fri, 12 Apr 2024 17:00:22 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 45B47A0FD3 for ; Fri, 12 Apr 2024 21:00:22 +0000 (UTC) X-FDA: 82002097884.21.52A8255 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf09.hostedemail.com (Postfix) with ESMTP id 4474014000C for ; Fri, 12 Apr 2024 21:00:19 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=lFsV9t9s; spf=pass (imf09.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1712955619; a=rsa-sha256; cv=none; b=5qOoItQZQs6AYUPiWtggPgzBPHlSXstljYIYFNtTtr2ZAdjXQcmzP1u17INBe5QlPQ/UMm xW4j0e1lfXheDV/jEoHX2E8fGilmS7XMU+qqO9XMrnv5/5LFHv8FWIZFTL438f3/Mfcd9R x2+hPWMAZvcEt17fDGwquWcNigkiDWs= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=lFsV9t9s; spf=pass (imf09.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1712955619; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Ng192+jd6+vzKFPpGDmI8088reQyIhGw/Bb/+1ieXu4=; b=VN5RPOZt3EMERwSBfV8OAeXpvksgwmniOXIRSkunEiUokKt1FXaAW1adDeQUaBCdepwyDL YsTj+dDwHOSHOuq9R7j+xPj1U5EH29Y3c0ah+iptD4aUZ1nixGktEqlBh9DyiuyMiDB2Cx PQpWy2PMmcNvQODID3qMMqMscqLlCMM= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 0D7F76190B; Fri, 12 Apr 2024 21:00:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6111BC2BD11; Fri, 12 Apr 2024 21:00:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712955617; bh=ufExrA51nJyDuRZXOc6Zqlx89622UOkI5PEpjDpkuFg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lFsV9t9s6+jpzEwEmP+dIWWBhZTPFt/rJGzOY6NZzVIQABiZruk5OcirG5RfZyaI9 27ZctoEN1U22XtTW9xZ5n2pIr06PaWb7bBC0Ni0SuZ0eaMoA79uJvs+gZCbYIrBCxU TNq6G2mAbVIwDgOLIvHsBPwMzdFHb9/8gYHG+Oo2gPoaqHB1W2zpKXBMA/95RDgTtM eNEGMhpqyDatnIsgX649O4JJVbadReziMgJhiahKHqaIvlVFPd5G0Qg9iQLKZTcdiE 4a4Z0QCDgYqvDj1lB6ZUvihWCdBiervg3/7lJMb7zUF2FgPIlc6qipDc4Qe9sQMnTy xlxJ/gPTg75BQ== Date: Fri, 12 Apr 2024 23:59:07 +0300 From: Mike Rapoport To: Kees Cook Cc: Steven Rostedt , 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: Re: [POC][RFC][PATCH 1/2] mm/x86: Add wildcard * option as memmap=nn*align:name Message-ID: References: <20240409210254.660888920@goodmis.org> <20240409211351.075320273@goodmis.org> <202404091521.B63E85D@keescook> <20240409191156.5f92a15c@gandalf.local.home> <202404091638.2F98764A41@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202404091638.2F98764A41@keescook> X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 4474014000C X-Stat-Signature: swm4a8gjzar7gy74sopfs7byi9zhokjc X-Rspam-User: X-HE-Tag: 1712955619-165027 X-HE-Meta: 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 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 Tue, Apr 09, 2024 at 04:41:24PM -0700, Kees Cook wrote: > On Tue, Apr 09, 2024 at 07:11:56PM -0400, Steven Rostedt wrote: > > On Tue, 9 Apr 2024 15:23:07 -0700 > > Kees Cook wrote: > > > > > Do we need to involve e820 at all? I think it might be possible to just > > > have pstore call request_mem_region() very early? Or does KASLR make > > > that unstable? > > > > Yeah, would that give the same physical memory each boot, and can we > > guarantee that KASLR will not map the kernel over the previous location? > > Hm, no, for physical memory it needs to get excluded very early, which > means e820. Whatever memory is reserved in arch/x86/kernel/e820.c, that happens after kaslr, so to begin with, a new memmap parameter should be also added to parse_memmap in arch/x86/boot/compressed/kaslr.c to ensure the same physical address will be available after KASLR. More generally, memmap= is x86 specific and a bit of a hack. Why won't you add a new kernel parameter that will be parsed in, say, mm/mm_init.c and will create the mmap_map (or whatever it will be named) and reserve that memory in memblock rather than in e820? This still will require update to arch/x86/boot/compressed/kaslr.c of course. > So, yeah, your proposal makes sense. I'm not super excited > about this be x86-only though. What does arm64 for for memmap? > > -- > Kees Cook > -- Sincerely yours, Mike.