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=-3.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,PDS_BTC_ID,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 A46C7C432C0 for ; Tue, 3 Dec 2019 14:25:39 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6D29F20674 for ; Tue, 3 Dec 2019 14:25:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="BlJfO5T6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D29F20674 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54512 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ic97R-0001Sn-Lo for qemu-devel@archiver.kernel.org; Tue, 03 Dec 2019 09:25:37 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56568) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ic8sZ-0003GB-Cm for qemu-devel@nongnu.org; Tue, 03 Dec 2019 09:10:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ic8sR-000817-6h for qemu-devel@nongnu.org; Tue, 03 Dec 2019 09:10:09 -0500 Received: from mail-oi1-x242.google.com ([2607:f8b0:4864:20::242]:35207) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1ic8qN-0001Nj-O0 for qemu-devel@nongnu.org; Tue, 03 Dec 2019 09:10:07 -0500 Received: by mail-oi1-x242.google.com with SMTP id k196so3381342oib.2 for ; Tue, 03 Dec 2019 06:07:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=/CnwmbUFWRsqWL2N14UyvLbg9Cdi2y+1OqJISDKJtjw=; b=BlJfO5T6fkfYo1fKkjLYeImj5Q96TDjDI6FnqyphfcPqiN4MNwsZ2tbxNd8rOfEHys FyVbL8XqQ4NXLyKFt1f9Rjl/BAJ3fUJrCXJnVZylGOzLOPMOM8q4YstgwXFcyR/Etx9w 6HWNyJqkQB40DhSlxb/12LkgHuoY5H/hf+4I3ERP/pz+sTNEJli7I7rOdY/m5gB2ikyl Eb6SEfRBl1aqKDkbp77oZtLFtSnfpULHMx/WSIQOPaaEhRI+gYxvsT81SSkOuWJbGxRt edQFqqZejHYb8vuVOWg61B9mh1M+bzaphg1Sq6RBUFfg6cxdpLoIWOSO9zE60p3yuTVK hFpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=/CnwmbUFWRsqWL2N14UyvLbg9Cdi2y+1OqJISDKJtjw=; b=MK1yNwxjnlCJN8OQI5BT33WRaCK4t+KMJ10pj/Gh6J70/aC97FNML8z4HF+/If2R09 ZekiP8X1t0Jx+92QFMAyNXmaOMdSr8bXSnQGXSxX1ul/b164e4019ypxBolUAvwzJBcc rUnNinhpq3PLt4iDmaH+3ZFOlXfkwHIVvGBX1OUimfXsCOBZRr25M3nab8FxmIdB9igT y1p0lUJ5kaa5R49jS79Yuvz5WoJozNr493scXh16NeVDY90cJtxbAwQ6RqTB8lJ0GSHA 8UdExUzRSr4BGrVA2TKB7M2g8D9Glqs711n5FFEya30MbmLruqExEpXtEmK0na7Y68aL JK7w== X-Gm-Message-State: APjAAAWkl+QtS1eVPcoHmN7O/tRPvGbAcH/nFos36npcJ9tzOtRzC+SM uutZIHn7oMO50aymozOe2v80ZItvCttH3sfgBaC0/Q== X-Google-Smtp-Source: APXvYqwFJQnHO1LQABxtrSdrdrgcEOZsuOrGVnYMXS9ocaRVq8MJK+19WwpfY3vXFPZhRRveWvtJx/kYnnR54TXyX1c= X-Received: by 2002:aca:edd5:: with SMTP id l204mr3760486oih.98.1575382075765; Tue, 03 Dec 2019 06:07:55 -0800 (PST) MIME-Version: 1.0 References: <20191011134744.2477-1-richard.henderson@linaro.org> <20191011134744.2477-6-richard.henderson@linaro.org> In-Reply-To: <20191011134744.2477-6-richard.henderson@linaro.org> From: Peter Maydell Date: Tue, 3 Dec 2019 14:07:44 +0000 Message-ID: Subject: Re: [PATCH v5 05/22] target/arm: Suppress tag check for sp+offset To: Richard Henderson Content-Type: text/plain; charset="UTF-8" X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::242 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-arm , QEMU Developers Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 11 Oct 2019 at 14:49, Richard Henderson wrote: > > R0078 specifies that base register, or base register plus immediate > offset, is unchecked when the base register is SP. It looks like rule-numbers didn't make it into the final Arm ARM, so I guess the reference here would just be to section D6.8.1 ? Also, this phrasing is slightly ambiguous about whether the "when base is SP" condition applies to both "base register" and "base register + immediate", or just to the last of the two; the correct reading is the latter of these (and the D6.8.1 Arm ARM text is in error; trust the pseudocode here). We could perhaps say something like: D6.8.1 specifies that accesses are tag-unchecked for loads and stores (including exclusives, compare-and-swap, etc) whose addresses are: * base-register only, where the base register is SP * base-register plus immediate, where the base register is SP (not including reg+imm with writeback addressing forms) and also that literal (pc-relative) loads are tag-unchecked. > Signed-off-by: Richard Henderson > --- > v2: Include writeback addresses as checked. The load-literal case is implicitly tag-unchecked because the address calculation doesn't go via clean_data_tbi(), right? Reviewed-by: Peter Maydell thanks -- PMM