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 X-Spam-Level: X-Spam-Status: No, score=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 708C7C433DB for ; Fri, 26 Feb 2021 17:48:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4132D64E7A for ; Fri, 26 Feb 2021 17:48:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230164AbhBZRsd (ORCPT ); Fri, 26 Feb 2021 12:48:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229622AbhBZRsN (ORCPT ); Fri, 26 Feb 2021 12:48:13 -0500 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44AA1C061574 for ; Fri, 26 Feb 2021 09:47:33 -0800 (PST) Received: by mail-pl1-x632.google.com with SMTP id 17so5666475pli.10 for ; Fri, 26 Feb 2021 09:47:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=K0LiJMFsZzonxRiACJX9bTxGPskMvO8X+dFkrCpK9f8=; b=flBMYTva+Ub7O2J4tf0pmjGVcRRmsH028DAWb+FJ5ZTaVZH3/wd50QU4ehT1YPn+3I Iix8MWa6WAR3JGYqbXgh2ZAgYBifslyGpfHIcg9i2qsfHPTAL62Gq5FiRd73StFnRaMa ii4vyNgpJFbBMMCxAPA4M59qvHkJyQaxID5oJy4ScRsOF2iU9mhFQ3RQbZfMC3zK0o5G /RURL3EiOTXKQIL8XquJi75X3DYnIIXzMOmF699893Sjpb+ErSgEvMaAPQTMQJeSnxiU 6Ewk1ZawmvKwXfCxvd9hzc6zZdjx0aiFMcPdQsWNZyMPLUyxjYZwBEeXhQWEubpaoNd7 xGNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=K0LiJMFsZzonxRiACJX9bTxGPskMvO8X+dFkrCpK9f8=; b=EblukSvSy4bVIuPedBDwhPLhfBDY9DkDRY0XhrYHBMNBlQeKiFJRQwv38VtBei0Kpe TeZHCsbhGncInTi911jeh8m+WC48K/5gwYy9hAGTOOVnrVt6KqfZ9AmWZF32ahXeeae4 mtrEegb6rVINr5BNO6a311PO1//5SJnlKX/fNZsox6nqOW/dD7cTS56lGy+ucCOVZBWb GtFmklLEQkjKvKlnxizAV8xU3YJclmjoEfsRVCi2fK1U3TduhRLednYqwqyf83b031tR tjSd68IRvscu3i1L6CU4Jn1hZLkvzZPuLLJ3shoFUN7x85smmZvuXdK9fW84+M5/u3q4 Ay+w== X-Gm-Message-State: AOAM533OTfd4WVWUOpRfbhxYpbz8SK8tMiABNpLRXKdDRydI7ZdMF3gn KP6kiZ6iLqM7cJyfWlzoF0yQ/w== X-Google-Smtp-Source: ABdhPJw16OL6xdvgFPC+h6kiZu1Jjno2uNAyLXCqNtPonj3qIVLXIlapOY5pgH5rUlbisZjLDIO4Zg== X-Received: by 2002:a17:90a:f68b:: with SMTP id cl11mr4449383pjb.187.1614361652700; Fri, 26 Feb 2021 09:47:32 -0800 (PST) Received: from google.com ([2620:15c:f:10:e190:bf4c:e355:6c55]) by smtp.gmail.com with ESMTPSA id 7sm9924571pfh.142.2021.02.26.09.47.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 26 Feb 2021 09:47:32 -0800 (PST) Date: Fri, 26 Feb 2021 09:47:25 -0800 From: Sean Christopherson To: Nadav Amit Cc: Linux-MM , LKML , Hugh Dickins , Andy Lutomirski , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , Borislav Petkov , Andrew Morton , x86@kernel.org Subject: Re: [RFC 1/6] vdso/extable: fix calculation of base Message-ID: References: <20210225072910.2811795-1-namit@vmware.com> <20210225072910.2811795-2-namit@vmware.com> <2CDFE432-90D3-43EE-BA9F-2CFEB8BB343C@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2CDFE432-90D3-43EE-BA9F-2CFEB8BB343C@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 26, 2021, Nadav Amit wrote: > > > On Feb 25, 2021, at 1:16 PM, Sean Christopherson wrote: > > It's been literally years since I wrote this code, but I distinctly remember the > > addresses being relative to the base. I also remember testing multiple entries, > > but again, that was a long time ago. > > > > Assuming things have changed, or I was flat out wrong, the comment above the > > macro magic should also be updated. > > > > /* > > * Inject exception fixup for vDSO code. Unlike normal exception fixup, > > * vDSO uses a dedicated handler the addresses are relative to the overall > > * exception table, not each individual entry. > > */ > > I will update the comment. I am not very familiar with pushsection stuff, > but the offsets were wrong. > > Since you say you checked it, I wonder whether it can somehow be caused > by having exception table entries defined from multiple object files. Oooh, I think that would do it. Have you checked what happens if there are multiple object files and multiple fixups within an object file? > Anyhow, this change follows the kernel’s (not vDSO) exception table > scheme.