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 B475EC25B48 for ; Thu, 26 Oct 2023 10:25:49 +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=ZyX3dszi; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4SGMQ433lLz3dD2 for ; Thu, 26 Oct 2023 21:25:48 +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=ZyX3dszi; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2604:1380:4601:e00::1; helo=ams.source.kernel.org; envelope-from=will@kernel.org; receiver=lists.ozlabs.org) Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::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 4SGMP14CXhz3dWl for ; Thu, 26 Oct 2023 21:24:53 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id 17FABB8077C; Thu, 26 Oct 2023 10:24:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F1DD8C433C8; Thu, 26 Oct 2023 10:24:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698315889; bh=WN2YIA4Ghusd7FbmcNZrWw/oKLuywPkap4tOfxaAQ4k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZyX3dsziPkRUXG2UWwCRe9pQvhY4J8EKCi1UMJicG8n+1K8kuqLhkCHInfodKwhzx IGdZJx3E0WGYfJuhn5slU+daxFVHZfLRqURf8zRCQM4mPgPcJg6TqmPoqs/pWtOypa aGTSZPjPNBzHwtWONSwhXj/25YMcitUcojHP1kRQ49c14Z4eV6Kpw2ampGhmL7G6Sm v7J3Ia4FdxDhFLmdhSb20AH9mufPj5bcJmpVjmk+yiUwvbVfd/gsYS5NT3Ej9E93W4 br849v8H22PcC0TOPiwgXMZFArfvyVNNVM97V2kwDBdHjqJI1bEYt3iRHEo7Tm6Bk9 Y3kn5Rw8Exupg== Date: Thu, 26 Oct 2023 11:24:39 +0100 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: <20231026102438.GA6924@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231026085800.GK2824@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 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 > > > @@ -20,6 +20,7 @@ > > > #include > > > #include > > > #include > > > +#include > > > > > > #include > > > #include > > > @@ -108,46 +109,38 @@ static int __init module_init_limits(void) > > > > > > return 0; > > > } > > > -subsys_initcall(module_init_limits); > > > > > > -void *module_alloc(unsigned long size) > > > +static struct execmem_params execmem_params __ro_after_init = { > > > + .ranges = { > > > + [EXECMEM_DEFAULT] = { > > > + .flags = EXECMEM_KASAN_SHADOW, > > > + .alignment = MODULE_ALIGN, > > > + }, > > > + }, > > > +}; > > > + > > > +struct execmem_params __init *execmem_arch_params(void) > > > { > > > - void *p = NULL; > > > + struct execmem_range *r = &execmem_params.ranges[EXECMEM_DEFAULT]; > > > > > > - /* > > > - * Where possible, prefer to allocate within direct branch range of the > > > - * kernel such that no PLTs are necessary. > > > - */ > > > > Why are you removing this comment? I think you could just move it next > > to the part where we set a 128MiB range. > > Oops, my bad. Will add it back. Thanks. > > > - 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. Will