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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C880DC4332F for ; Mon, 30 Oct 2023 07:01:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230458AbjJ3HBR (ORCPT ); Mon, 30 Oct 2023 03:01:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbjJ3HBQ (ORCPT ); Mon, 30 Oct 2023 03:01:16 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B19191; Mon, 30 Oct 2023 00:01:14 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30B1CC433C7; Mon, 30 Oct 2023 07:01:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698649274; bh=EmJn7V2xcCxlebppxaDAhU12OFutDZWRBy0vMaSrWuA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fyer+0uyv1jhu2jxdwK+n1O2/sIgGI7ezOwxQC871hHJ3Cd/JKl9lBlO3pXltUpO2 tybWUbFkw8nG3yYnKj5NWsk/KsMeh5cYt2Zf06cFoE4cK0SwwSOQ0meQsCZJmwrLES ZjfIwnoeXu/25/54cCJrG0ThSOL/VsSYVOr1W/9QTaMgDvrgblTvcHPZrDSbxEy8fw AT95UrDI+b348FRlIe6JpCkizTZtGaE3kNe+nAOZWv5ZyGWJevSARlVxf0OsNjI/Uk BM7kNTKVl9T3dS3d/hE9ctd5XEbBUeRh4TuIA6DuyqF/4ni+SgBncpCAAQy/vXTAcB 87xr+yc2RIXWg== Date: Mon, 30 Oct 2023 09:00:53 +0200 From: Mike Rapoport To: Will Deacon Cc: linux-kernel@vger.kernel.org, Andrew Morton , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Catalin Marinas , Christophe Leroy , "David S. Miller" , Dinh Nguyen , Heiko Carstens , Helge Deller , Huacai Chen , Kent Overstreet , Luis Chamberlain , Mark Rutland , Michael Ellerman , Nadav Amit , "Naveen N. Rao" , Palmer Dabbelt , Puranjay Mohan , Rick Edgecombe , Russell King , Song Liu , Steven Rostedt , Thomas Bogendoerfer , Thomas Gleixner , bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev, netdev@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v3 04/13] mm/execmem, arch: convert remaining overrides of module_alloc to execmem Message-ID: <20231030070053.GL2824@kernel.org> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231026102438.GA6924@willie-the-truck> Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org 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. > Will -- Sincerely yours, Mike.