From patchwork Thu Oct 3 15:52:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 175157 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp576675ill; Thu, 3 Oct 2019 09:45:52 -0700 (PDT) X-Google-Smtp-Source: APXvYqw/tyiFX4ryQiiNUI/fQSenOB9L60DkzAIg1WzEfcXlwYRAKoo3xmgxp/7Skhgo8vG8A3CF X-Received: by 2002:a17:906:e251:: with SMTP id gq17mr8576226ejb.85.1570121152778; Thu, 03 Oct 2019 09:45:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1570121152; cv=none; d=google.com; s=arc-20160816; b=uzH4D37lHGF4K9xNMWSK59EaLOEN8zN5NOrjEAq/kyJWSgkn/QykdypJe/GBWMO8A5 kABYym9cr+oNurCys1xi/+sHbv+t0vBkgfhZF7/r3erVea7oWZ9H7SE9av8TsF9tppg+ ObZGob/cz4fZM/znvtK+JK4M6ij05tfkySMNx1APVRsTEaSe3VtlYlBvOsxzMIypYqUm aUK61ZNDLm0dbjk4C+Ur1K04TLx1CHFglLTilBQb+XaOtSjzKXgWeEHtOFS2EZvttYTz Y8fTkvvewJDa2EklT8DaKNuAvFXo/ISPC8vLAxjYp8q4AIf3jJ09FOYJ6DjEdeknOCWb EJtw== 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=DLqJJounhdfcftV6O9nHbeZhACqsm8NU7fqVE2mEU7g=; b=LegHnodo1MruqPWxAZ8Qdz1toRdOwYZZaeyQo5Y5eNcRDtbM2PGTPR5SBcHOxDGpdh 8FZcptfB/fE7GBbNYdospKhQTA+VyANbShmojEHswfetmL5pvH+xDo1OwrMjEywbhMUk pQzNLCQkjK7/DH2X6PaBbH2mHzVlvfDZ+c9Zfgt/zkfSCnIrJEEJmZX6M/4wixL7Ij/l uUfUSL+Os/KOCjjHGa8sDh6k5QaNUlffTCTjRkEE2uKEJgPcz4tGuNX0lvNT2ynaINm8 ARpm9SJ5rhqUIcxv853DXM2vFwWR/ER5s64Gp+6lOR7mZ35AwixfDS4WZ7oMyxo/8Zgg gEGA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=aQbGvJoQ; 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 f6si1551969ejx.293.2019.10.03.09.45.52; Thu, 03 Oct 2019 09:45:52 -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=aQbGvJoQ; 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 S2392516AbfJCQpv (ORCPT + 14 others); Thu, 3 Oct 2019 12:45:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:58580 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404313AbfJCQpu (ORCPT ); Thu, 3 Oct 2019 12:45:50 -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 72E73215EA; Thu, 3 Oct 2019 16:45:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570121149; bh=jFyrjGVt0cRFDQk6Fgliyx+XUAerjBChFSMocGjBCxw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aQbGvJoQBp0CBs0FpYGDApykgiV4IqK5Z8H8JUC2M4vG5+rQBdnlQHdv+eWUBCoaA KM/AU2w1HU0Rnfvy4R7pkWFyQXOKxA8BWoSRdlPnCBqfh3Gew55sj3NSmJ3Y/7m2OL A7jHOa8zhPNCO6FnaDGIIt5yhTyySVrPkXIep3q0= 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 5.3 171/344] arm64: kpti: ensure patched kernel text is fetched from PoU Date: Thu, 3 Oct 2019 17:52:16 +0200 Message-Id: <20191003154557.091909530@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154540.062170222@linuxfoundation.org> References: <20191003154540.062170222@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 7dbf2be470f6c..28a8f7b87ff06 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -286,6 +286,15 @@ 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