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 69724C43219 for ; Fri, 3 Dec 2021 10:06:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379773AbhLCKJl (ORCPT ); Fri, 3 Dec 2021 05:09:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351346AbhLCKJk (ORCPT ); Fri, 3 Dec 2021 05:09:40 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F849C06173E; Fri, 3 Dec 2021 02:06:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=a/ys6cskAlNWsULashfoqrEixGaH4KiNUxE+1OiguW0=; b=J0VIv2PGI2YMODNat75+3pt+oG /murTVznnyShQpHUdjfI7fVlowa5qhKNmHF1NCj283L/0bVE9Nd1trwDldCbTlwcaznPlMfdIKTSe 8sHNMAMEhlMLgA4Q0kgaEbFp5exVv813ND6187LX9qdsSu/YIq93W7lExi80GQ/Lf9uyjWLusP1lS zwrATFYnDJRV7SN9B+EES34aX7F3M41Mnqm5Z+DkcpdAZJxEJw9N72oAZRzqt7DwneDuKoiPtbrFG LQbccx5+9SZgqeSkh891Jn9Ekcwwcb/2ImzdLtwGsGdUy4E3wjQCwnHTMbhszn42EiXpV3tPMyQ8g b7Mc3oIg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mt5Rz-00884w-4M; Fri, 03 Dec 2021 10:05:55 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id AF99230001C; Fri, 3 Dec 2021 11:05:54 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 98C2B2B36B3B2; Fri, 3 Dec 2021 11:05:54 +0100 (CET) Date: Fri, 3 Dec 2021 11:05:54 +0100 From: Peter Zijlstra To: Alexander Lobakin Cc: linux-hardening@vger.kernel.org, x86@kernel.org, Jesse Brandeburg , Kristen Carlson Accardi , Kees Cook , Miklos Szeredi , Ard Biesheuvel , Tony Luck , Bruce Schlobohm , Jessica Yu , kernel test robot , Miroslav Benes , Evgenii Shatokhin , Jonathan Corbet , Masahiro Yamada , Michal Marek , Nick Desaulniers , Herbert Xu , "David S. Miller" , Thomas Gleixner , Will Deacon , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Andy Lutomirski , Arnd Bergmann , Josh Poimboeuf , Nathan Chancellor , Masami Hiramatsu , Marios Pomonis , Sami Tolvanen , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, live-patching@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH v8 08/14] livepatch: only match unique symbols when using FG-KASLR Message-ID: References: <20211202223214.72888-1-alexandr.lobakin@intel.com> <20211202223214.72888-9-alexandr.lobakin@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211202223214.72888-9-alexandr.lobakin@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 02, 2021 at 11:32:08PM +0100, Alexander Lobakin wrote: > If any type of function granular randomization is enabled, the sympos > algorithm will fail, as it will be impossible to resolve symbols when > there are duplicates using the previous symbol position. > > We could override sympos to 0, but make it more clear to the user > and bail out if the symbol is not unique. Since we're going lots of horrendous things already, why can't we fix this duplicate nonsense too?