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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 77DDCC433EF for ; Thu, 2 Dec 2021 10:08:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=F468YeHkBfeFdbkgpjw4b5XyMx/NMzU6MqbQJcFau7g=; b=I1/bIRFx2l/ntc S8+lCcEirZErpGXo1UnA3MXtmqCglCnCPajtaI/lZah6pMjuvFmnJuF9fCCdQPWlw+uxivyNF2VEV IRyyjrNnRMgYWnpPP8yMtrdqEA04HuV06LDGH2+yBVaQfa6GTnH3YdyyXfCFGPLa+o0Lksf+kFWUz W6aBewZbNZFHUXRFs23824R4uqf+wzj9cRzhBbFwd2N01pHBcwHSV9XKnoiQtCmIW2+17xWOweD82 vbZigC1jtLwlGdKIYZi4pjoJCWxPYHPrgLoUvh9DQWlnfk3GB86Bv5LIC4WElMm4quCpMa1tf9l2Z 9a3ku9/wpHkIhVum4QGw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1msizQ-00Bkqh-Jr; Thu, 02 Dec 2021 10:06:56 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1msizN-00Bkpx-A3; Thu, 02 Dec 2021 10:06:54 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 77CDF142F; Thu, 2 Dec 2021 02:06:51 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.65.131]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A503D3F7D7; Thu, 2 Dec 2021 02:06:49 -0800 (PST) Date: Thu, 2 Dec 2021 10:06:47 +0000 From: Mark Rutland To: Kuan-Ying Lee Cc: Catalin Marinas , Will Deacon , Jonathan Corbet , Matthias Brugger , chinwen.chang@mediatek.com, nicholas.tang@mediatek.com, james.hsu@mediatek.com, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org Subject: Re: [PATCH v2] arm64: update PAC description for kernel Message-ID: References: <20211201034014.20048-1-Kuan-Ying.Lee@mediatek.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211201034014.20048-1-Kuan-Ying.Lee@mediatek.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211202_020653_442945_12C08269 X-CRM114-Status: GOOD ( 21.87 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Dec 01, 2021 at 11:40:10AM +0800, Kuan-Ying Lee wrote: > Remove the paragraph which has nothing to do with the kernel and > add PAC description related to kernel. > > Suggested-by: Mark Rutland > Signed-off-by: Kuan-Ying Lee This looks good to me. Catalin/Will, did you want to pick this, or do you want Jonathan to do so? Mark. > --- > v1 -> v2: > - Remove compiler option description > - Add PAC description for kernel > > Documentation/arm64/pointer-authentication.rst | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/Documentation/arm64/pointer-authentication.rst b/Documentation/arm64/pointer-authentication.rst > index f127666ea3a8..e5dad2e40aa8 100644 > --- a/Documentation/arm64/pointer-authentication.rst > +++ b/Documentation/arm64/pointer-authentication.rst > @@ -53,11 +53,10 @@ The number of bits that the PAC occupies in a pointer is 55 minus the > virtual address size configured by the kernel. For example, with a > virtual address size of 48, the PAC is 7 bits wide. > > -Recent versions of GCC can compile code with APIAKey-based return > -address protection when passed the -msign-return-address option. This > -uses instructions in the HINT space (unless -march=armv8.3-a or higher > -is also passed), and such code can run on systems without the pointer > -authentication extension. > +When ARM64_PTR_AUTH_KERNEL is selected, the kernel will be compiled > +with HINT space pointer authentication instructions protecting > +function returns. Kernels built with this option will work on hardware > +with or without pointer authentication support. > > In addition to exec(), keys can also be reinitialized to random values > using the PR_PAC_RESET_KEYS prctl. A bitmask of PR_PAC_APIAKEY, > -- > 2.18.0 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel