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 18432CD98FC for ; Wed, 11 Oct 2023 08:11:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229973AbjJKILy (ORCPT ); Wed, 11 Oct 2023 04:11:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229957AbjJKILx (ORCPT ); Wed, 11 Oct 2023 04:11:53 -0400 Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0453092; Wed, 11 Oct 2023 01:11:52 -0700 (PDT) Received: by mail-ej1-x62c.google.com with SMTP id a640c23a62f3a-9b64b98656bso1106031966b.0; Wed, 11 Oct 2023 01:11:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697011910; x=1697616710; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=SGMCBTNusP70u42LHRRik7B8Z00QtRCIGDUylj6XYAw=; b=LFYbXMJdLFFKofPQfcjP5sKBAQDQwxOWuYH0r2LYwIXKj4xCvBTzqnFekiKAz7hoDD W50CxgIR7YJZYucTb0tuADchb7pnfJ+LCuBWNuWWZWcvjU/becloK6Dr2U3jzh7uTt1K AQfflP+b+tPORpyuEGeYR/nSObmb0wUIgKvzjC62dqNHnj6fQ4AamTYsf+i73WcXeBQD Blq0QA1XYDonToqG8VkbLhIxzM6YWXTQd5sPIPzUxR17F6+3E1MTpz+2/uaimL8mZbvZ yvpruf1qLIjH5pMuDa8ZM5fqP3OMkeTacWpyK+93kybAViFLbk9WQVVIUJjZVQE7W6V8 I0/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697011910; x=1697616710; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=SGMCBTNusP70u42LHRRik7B8Z00QtRCIGDUylj6XYAw=; b=b8FbygDjUfvOvnOyCVmlY6MDL9xM1+yeaVjnBcnwKTrT8BnVwhpgFy+3qYehrOq66T 07NK3CLcsRcrYgdwSleWEdctHL1DKhOMLchD5/dLlVYNzBI26QDuVZ68QaH2ngC2/dNQ 4v9t5KgUQD+TGmEQKH9DKFGeog/DH3yhhCKp4rCBDZ4DWtknVlT054b6GlKxmI6Uut1t y7bAk7dcildidZyNZGQ80biqT3Pi9NqsNXLo3fDrJqYh7bIsY3NITDCM/Yjzd3yErK70 TWNMjbcawYlEnDQYq9LqaPYUTl1cGeeDiGu1cWB9o3JnasF0niBbY5aCGxCqMB8VX47o ya7w== X-Gm-Message-State: AOJu0YymqR3Y1g6+Hm7ZxG3agec/R+f+Kd58sun9QgBEWi/kFp3C/IJs vIwmOjL16iR7jAMI+7yDs8g9hzjPsaQ= X-Google-Smtp-Source: AGHT+IFS+xbyocKw0Ozogs/0xDvDxQz/wVDmhkbPI4KM123komulCh92pmTaWVBwf0yt3SKYqf8ORw== X-Received: by 2002:a17:906:3050:b0:9ad:df85:97ae with SMTP id d16-20020a170906305000b009addf8597aemr16960697ejd.66.1697011910095; Wed, 11 Oct 2023 01:11:50 -0700 (PDT) Received: from gmail.com (1F2EF405.nat.pool.telekom.hu. [31.46.244.5]) by smtp.gmail.com with ESMTPSA id la18-20020a170906ad9200b0099cd008c1a4sm9501500ejb.136.2023.10.11.01.11.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Oct 2023 01:11:48 -0700 (PDT) Sender: Ingo Molnar Date: Wed, 11 Oct 2023 10:11:46 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, Fei Yang , stable@vger.kernel.org Subject: Re: [PATCHv2] x86/alternatives: Disable KASAN in apply_alternatives() Message-ID: References: <20231011065849.19075-1-kirill.shutemov@linux.intel.com> <20231011074616.GL14330@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231011074616.GL14330@noisy.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org * Peter Zijlstra wrote: > > DPRINTK(ALT, "alt table %px, -> %px", start, end); > > + > > + /* > > + * In the case CONFIG_X86_5LEVEL=y, KASAN_SHADOW_START is defined using > > + * cpu_feature_enabled(X86_FEATURE_LA57) and is therefore patched here. > > + * During the process, KASAN becomes confused and triggers > > because of partial LA57 convertion .. Not all LA57 related sites are patched yet at this point, and KASAN sees a weird & broken mixture of LA48 and LA57 runtime semantics, right? Ie. as far as KASAN is concerned, the LA48 -> LA57 behavioral switchover must be atomic, but during the kernel code patching process it isn't. Thanks, Ingo