From patchwork Thu Oct 3 15:52:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 175114 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp543101ill; Thu, 3 Oct 2019 09:19:26 -0700 (PDT) X-Google-Smtp-Source: APXvYqy80nDFSjKOdq9zKlwxbdHzVPQe5bXtMA2t3Ip1qkod5wQmu3nqt4b7S0K1ReVXvEAS69tT X-Received: by 2002:a17:906:90d4:: with SMTP id v20mr8636742ejw.189.1570119565943; Thu, 03 Oct 2019 09:19:25 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1570119565; cv=none; d=google.com; s=arc-20160816; b=qCE1D9hKJGaXFYwEbpcP7ZbtWyD7PEh0moD5UffkxXYnkwpTcr2zVg2AbuR6fw7NAn P0xFxE3uibKrbe4qbWX6q1a6vDvYZ3lrlPO9c3Q2zMjHulH13AOEZmYgMZBYFDBM3Tlw BuoHqjMSyTTKbT1kOV76EYbg8K2HGUmGnn/lZ3NHZZMt5b1zeYwaESmNRIR7plk0FqT/ Ohsxsv5zXuUZhL7NyFq183oF0UNl0exdW75Gc2EPJHVbVvleJ7TcI2ffuKuG2gHNo6D5 r76QaoFyMjzFQHk3PvkeowApxL+iZQLGUtTHS0/7Z97DoF9voYKdqRo3LpmGWQ59j83K /RLA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=9pUp8RyE+XXL5os/Cu61Mh8Sq3I3VsACfPOYVMs9tZ8=; b=aLluF4PpnSYn4+KoKzSat2nOJJnAlBXoSvGJHSh8fivDpH7hmbfcGd6QeFlZxuopPz k1Gk14LtmXj6tWxmUdvH3im017W/A5+DBaqwpejc37l1I34UQxrqydie5fGoqcZl1V30 S71uFbhTb4Dl/Yy3PGjr9HEdI6Ff3IdzXWlUw+bx6wYvR0Us+KWdPZx9DTYeN139tG0g kgOyyPF1jnhkSCxh2aOXTGslNNky73IrWY6NWXCuEfXopYc1nWiRcU8h6BjcfcVzAx1e whWK/kKkm5cP1sjZLQVlGnFM35b0ATv5FNUs8DHmpz4jjxiI1f2b6B06B2f7ShHIlCHn 3yIA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=LjMnI3+n; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id ot41si1444054ejb.215.2019.10.03.09.19.25; Thu, 03 Oct 2019 09:19:25 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=LjMnI3+n; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388174AbfJCQTY (ORCPT + 14 others); Thu, 3 Oct 2019 12:19:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:46324 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387497AbfJCQTV (ORCPT ); Thu, 3 Oct 2019 12:19:21 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BD0EB2054F; Thu, 3 Oct 2019 16:19:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570119561; bh=URUZzsuEtvmqgS69CvYyDYYGVRNJ0Jzif+eoUQ1PBvo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LjMnI3+nj6LVEp5O7KAsMdqFeFfecUu2MUy9oz5tTd2KfdJpPdlhYcUxub48IE8xd fopLl8IQxUo7FGoZfshKM6OfDVYIMcqw0YX7lLMJhGomsS7OOofjhRAOJZsOpNv8Ji WIM2V0wfe7wvpcsG4il79QXb8Oizf/bzXsLmNKd4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Rutland , Catalin Marinas , James Morse , Will Deacon , Sasha Levin Subject: [PATCH 4.19 109/211] arm64: kpti: ensure patched kernel text is fetched from PoU Date: Thu, 3 Oct 2019 17:52:55 +0200 Message-Id: <20191003154512.244293884@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154447.010950442@linuxfoundation.org> References: <20191003154447.010950442@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mark Rutland [ Upstream commit f32c7a8e45105bd0af76872bf6eef0438ff12fb2 ] While the MMUs is disabled, I-cache speculation can result in instructions being fetched from the PoC. During boot we may patch instructions (e.g. for alternatives and jump labels), and these may be dirty at the PoU (and stale at the PoC). Thus, while the MMU is disabled in the KPTI pagetable fixup code we may load stale instructions into the I-cache, potentially leading to subsequent crashes when executing regions of code which have been modified at runtime. Similarly to commit: 8ec41987436d566f ("arm64: mm: ensure patched kernel text is fetched from PoU") ... we can invalidate the I-cache after enabling the MMU to prevent such issues. The KPTI pagetable fixup code itself should be clean to the PoC per the boot protocol, so no maintenance is required for this code. Signed-off-by: Mark Rutland Cc: Catalin Marinas Reviewed-by: James Morse Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/mm/proc.S | 9 +++++++++ 1 file changed, 9 insertions(+) -- 2.20.1 diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 8cce091b6c21e..ec6aa18633162 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -294,6 +294,15 @@ skip_pgd: msr sctlr_el1, x18 isb + /* + * Invalidate the local I-cache so that any instructions fetched + * speculatively from the PoC are discarded, since they may have + * been dynamically patched at the PoU. + */ + ic iallu + dsb nsh + isb + /* Set the flag to zero to indicate that we're all done */ str wzr, [flag_ptr] ret