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 B7D5EC0218D for ; Tue, 28 Jan 2025 10:01:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2FA2C2801F2; Tue, 28 Jan 2025 05:01:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 281832801E3; Tue, 28 Jan 2025 05:01:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0FC772801F2; Tue, 28 Jan 2025 05:01:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id E25F02801E3 for ; Tue, 28 Jan 2025 05:01:21 -0500 (EST) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 7BD2044D03 for ; Tue, 28 Jan 2025 10:01:21 +0000 (UTC) X-FDA: 83056417962.11.4E8AC7B Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf13.hostedemail.com (Postfix) with ESMTP id C955B20016 for ; Tue, 28 Jan 2025 10:01:19 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Bx7V38So; spf=pass (imf13.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1738058479; 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=QP7XxJ6Qr0/ecZq8j3OAaCKlA5Lvhwlpzy7j9900yC0=; b=MSTDXoGm55pLXhejx5zVWrbxREwSPy/UnXLaV0U3n0Ur2OlZo9rx90S/sZo0nBTZh4ne34 XusmmgFRoLZxymrpS17sifpfFUWiyNr8N3trE6V8Q6/oHjCpCQJIRz0evFspRqWuW2jhpi hk2X4NXd8+CX8tu702rAp6w4FoTAjr8= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1738058479; a=rsa-sha256; cv=none; b=17JXrjUZ9f5ahIQz/vsoQ34b6v2WrLgN8qyV1ipNCYSa/NQLx1q/GImABAEV7+fiyCoFnA LWkrVyA6r2X71n34fJnjEWr7PuvfQcH7GfsFfoE4RV4jcEwtMXHuv45tIJjkom575isxHa 1bh9EwUx19CREcM7hLQnnBDgKYoAhzw= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Bx7V38So; spf=pass (imf13.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id C79005C4786; Tue, 28 Jan 2025 10:00:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE0C8C4CED3; Tue, 28 Jan 2025 10:01:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738058478; bh=H+G3TtSN5z2rPg9q7jaqw3zaBc0K+irN0EUiSSVdGVI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Bx7V38SoAhETd9sc3qxV33PkV4fbZ9U+nWfMSuyj7aAE4t36vZLBolyqeF4nbGBta XbN1Q+pDjEpEFtKJHmktZXdqMYusjeXUsBpMTU7b6k5chsugMb3GDVaN7OIdra9mNc LgS+jr+iGKrULxB2qPNZHewWubD6EIpyvgyZNsdxQFtO0jyXH5V+jnnZUMM6ltJCFZ S0bl1WgjGqJhnkUL6gVfjpKxam708lIRTpj76NinsW/OGobdYd4Lb21/LvZ8ubl/cT FoOzOIdBgb8magf0NcV37KSZIgUUV04fADb6slWXhE+UMBFk+i/daHvsFfa4nWGW8m oHJUjwuGUTj7g== Date: Tue, 28 Jan 2025 12:00:56 +0200 From: Mike Rapoport To: Petr Pavlu Cc: x86@kernel.org, Andrew Morton , Andy Lutomirski , Anton Ivanov , Borislav Petkov , Brendan Higgins , Daniel Gomez , Daniel Thompson , Dave Hansen , David Gow , Douglas Anderson , Ingo Molnar , Jason Wessel , Jiri Kosina , Joe Lawrence , Johannes Berg , Josh Poimboeuf , "Kirill A. Shutemov" , Lorenzo Stoakes , Luis Chamberlain , Mark Rutland , Masami Hiramatsu , Miroslav Benes , "H. Peter Anvin" , Peter Zijlstra , Petr Mladek , Rae Moar , Richard Weinberger , Sami Tolvanen , Shuah Khan , Song Liu , Steven Rostedt , Thomas Gleixner , kgdb-bugreport@lists.sourceforge.net, kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-um@lists.infradead.org, live-patching@vger.kernel.org Subject: Re: [PATCH v3 6/9] module: switch to execmem API for remapping as RW and restoring ROX Message-ID: References: <20250126074733.1384926-1-rppt@kernel.org> <20250126074733.1384926-7-rppt@kernel.org> <021665c5-b017-415f-ad2b-0131dcc81068@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <021665c5-b017-415f-ad2b-0131dcc81068@suse.com> X-Stat-Signature: hcpsu3spfx8qo3ixyps11zn79xo4b3nm X-Rspam-User: X-Rspamd-Queue-Id: C955B20016 X-Rspamd-Server: rspam03 X-HE-Tag: 1738058479-126255 X-HE-Meta: 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 scyer+Gu kSMIEZOKwbaZyeQfizV8BjpAc+x3PPKRKV+HDF4+Fv/shAc+bZYVeY9RBIr1cowL9QRqwCkvy8XR1drnBs1faRVtGPWgeXbGSU/5y3wL9LP9JTFkM3eXI7iA144X2iscf5OZEm24Ud5rZIkN7l5lrfVrnkADpfdFwRrC1RrIPak+HIecEvWJ66srx3jPW1UTRU0d0zPTowtkcXPqbf1QSw0/+FAIt8wB457o2Q0PgQVdGmjJxa47mSzzizkrhAsxHm17maa46K9/xc7OUPXVw/it8XQ== 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 Mon, Jan 27, 2025 at 01:50:31PM +0100, Petr Pavlu wrote: > On 1/26/25 08:47, Mike Rapoport wrote: > > From: "Mike Rapoport (Microsoft)" > > > > Instead of using writable copy for module text sections, temporarily remap > > the memory allocated from execmem's ROX cache as writable and restore its > > ROX permissions after the module is formed. > > > > This will allow removing nasty games with writable copy in alternatives > > patching on x86. > > > > Signed-off-by: Mike Rapoport (Microsoft) > > [...] > > > +static void module_memory_restore_rox(struct module *mod) > > +{ > > + for_class_mod_mem_type(type, text) { > > + struct module_memory *mem = &mod->mem[type]; > > + > > + if (mem->is_rox) > > + execmem_restore_rox(mem->base, mem->size); > > + } > > +} > > + > > Can the execmem_restore_rox() call here fail? I realize that there isn't > much that the module loader can do if that happens, but should it be > perhaps logged as a warning? It won't fail at this point. set_memory APIs may fail if they need to split a large page and could not allocate a new page table, but here all the splits were already done at module_memory_alloc() time. > -- > Thanks, > Petr -- Sincerely yours, Mike.