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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 567E4C4332F for ; Tue, 7 Nov 2023 10:45:50 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=EfHMKmIU; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4SPlHc2HP7z3cS5 for ; Tue, 7 Nov 2023 21:45:48 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=EfHMKmIU; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2604:1380:4641:c500::1; helo=dfw.source.kernel.org; envelope-from=will@kernel.org; receiver=lists.ozlabs.org) Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4SPlGg3cZmz2xdh for ; Tue, 7 Nov 2023 21:44:59 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 3E35061161; Tue, 7 Nov 2023 10:44:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6AF0EC433C7; Tue, 7 Nov 2023 10:44:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699353896; bh=6KvSSAyHzV1t/xzun1oJg0AqCmYPNZNoG1yjrk+2N5g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EfHMKmIUi7LClGqSTR82uTGSALdsGhooGkAQNBOKzdAx9XrKCS32CwP6rRNlINeJp fTBcOh2CbrNgz5T9wN8X4IfDIz30xCLXq2htrhQAdC3JQhS9flLyk/+pf5MtKIc1uc JGySGdYEdfIvLpVTQJXhgpJr9YrJTitMM+csMdn+xILBQI2oGOVjB/sYO87FSSlzde FSNahA1CtFFCQyIxON1Z1I4OewRIeg1rULpA/yqisw7axPef9I0RY6dTvW/rbObEf0 ODLYbBKyXYy654yF6yL9+/nSFia7MKf5WBhUfT/JXvT2gH/1if2QXy5oq+hmLNVTje IOMZOtUYIwdeQ== Date: Tue, 7 Nov 2023 10:44:47 +0000 From: Will Deacon To: Mike Rapoport Subject: Re: [PATCH v3 04/13] mm/execmem, arch: convert remaining overrides of module_alloc to execmem Message-ID: <20231107104446.GA19133@willie-the-truck> References: <20230918072955.2507221-1-rppt@kernel.org> <20230918072955.2507221-5-rppt@kernel.org> <20231023171420.GA4041@willie-the-truck> <20231026085800.GK2824@kernel.org> <20231026102438.GA6924@willie-the-truck> <20231030070053.GL2824@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231030070053.GL2824@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , x86@kernel.org, Catalin Marinas , linux-mips@vger.kernel.org, Song Liu , Luis Chamberlain , sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, Nadav Amit , linux-s390@vger.kernel.org, Helge Deller , Huacai Chen , Russell King , "Naveen N. Rao" , linux-trace-kernel@vger.kernel.org, Heiko Carstens , Steven Rostedt , loongarch@lists.linux.dev, Thomas Gleixner , bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Thomas Bogendoerfer , linux-parisc@vger.kernel.org, Puranjay Mohan , linux-mm@kvack.org, netdev@vger.kernel.org, Kent Overstreet , linux-kernel@vger.kernel.org, Dinh Nguyen , =?iso-8859-1?Q?Bj=F6rn_ T=F6pel?= , Palmer Dabbelt , Andrew Morton , Rick Edgecombe , linuxppc-dev@lists.ozlabs.org, "David S. Miller" , linux-modules@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Oct 30, 2023 at 09:00:53AM +0200, Mike Rapoport wrote: > On Thu, Oct 26, 2023 at 11:24:39AM +0100, Will Deacon wrote: > > On Thu, Oct 26, 2023 at 11:58:00AM +0300, Mike Rapoport wrote: > > > On Mon, Oct 23, 2023 at 06:14:20PM +0100, Will Deacon wrote: > > > > On Mon, Sep 18, 2023 at 10:29:46AM +0300, Mike Rapoport wrote: > > > > > diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c > > > > > index dd851297596e..cd6320de1c54 100644 > > > > > --- a/arch/arm64/kernel/module.c > > > > > +++ b/arch/arm64/kernel/module.c > > ... > > > > > > - if (module_direct_base) { > > > > > - p = __vmalloc_node_range(size, MODULE_ALIGN, > > > > > - module_direct_base, > > > > > - module_direct_base + SZ_128M, > > > > > - GFP_KERNEL | __GFP_NOWARN, > > > > > - PAGE_KERNEL, 0, NUMA_NO_NODE, > > > > > - __builtin_return_address(0)); > > > > > - } > > > > > + module_init_limits(); > > > > > > > > Hmm, this used to be run from subsys_initcall(), but now you're running > > > > it _really_ early, before random_init(), so randomization of the module > > > > space is no longer going to be very random if we don't have early entropy > > > > from the firmware or the CPU, which is likely to be the case on most SoCs. > > > > > > Well, it will be as random as KASLR. Won't that be enough? > > > > I don't think that's true -- we have the 'kaslr-seed' property for KASLR, > > but I'm not seeing anything like that for the module randomisation and I > > also don't see why we need to set these limits so early. > > x86 needs execmem initialized before ftrace_init() so I thought it would be > best to setup execmem along with most of MM in mm_core_init(). > > I'll move execmem initialization for !x86 to a later point, say > core_initcall. Thanks, Mike. Will