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 AA577C433EF for ; Wed, 22 Dec 2021 18:19:26 +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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Qp9hNTort4kmVXQQ/DX8CisUkUathetP59FxEExFZ8Y=; b=j/dhtKLfsOZKx/ NtTDx0sn7U11itGQEC4RXOHeKdVoIGSoGshcV3oSIXsFaZKXRIPgBaaxVbUCsDUb5tjafba7xp+ZV WDp5+7+abHJAOGHTFe80vZBwOIVWitGbzrBCnnNu7Id7lSoAzyqY9+I9uouRqF52Hvs/uTRbXlHSE VDcERAP5f0pURN7040ZrMpkcgVe5oOiWNrPyW+kTaB3FtUQL+JUJ1H9VG03FAHGzACj9CscC1F2RY AiGisufqK3rOlFaAI0AR/pGf0+fIeGNbnbKCENV503mo7aWvRbunX+n5R5MG/CftbD09c175cPcmg 9LnYp++EDflnOdm6AARw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n06Bq-00B4MG-FN; Wed, 22 Dec 2021 18:18:14 +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 1n06A2-00B3Zu-TG for linux-arm-kernel@lists.infradead.org; Wed, 22 Dec 2021 18:16:24 +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 8163E106F; Wed, 22 Dec 2021 10:16:22 -0800 (PST) Received: from donnerap.arm.com (donnerap.cambridge.arm.com [10.1.196.172]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D1F233F5A1; Wed, 22 Dec 2021 10:16:21 -0800 (PST) From: Andre Przywara To: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org, Jaxson Han Subject: [boot-wrapper PATCH v2 7/9] pointer auth: Document CPU feature bit mask Date: Wed, 22 Dec 2021 18:16:05 +0000 Message-Id: <20211222181607.1203191-8-andre.przywara@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211222181607.1203191-1-andre.przywara@arm.com> References: <20211222181607.1203191-1-andre.przywara@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211222_101623_019181_3FC810E8 X-CRM114-Status: UNSURE ( 9.44 ) X-CRM114-Notice: Please train this message. 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 When checking for the pointer authentication feature, we actually look for *four* different CPUID feature sets. Add a comment to make it more obvious that the 0xff is not a typo. Signed-off-by: Andre Przywara --- arch/aarch64/boot.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S index bfbb6ec..27ba449 100644 --- a/arch/aarch64/boot.S +++ b/arch/aarch64/boot.S @@ -38,7 +38,8 @@ ASM_FUNC(_start) /* Enable pointer authentication if present */ mrs x1, id_aa64isar1_el1 - ldr x2, =(((0xff) << 24) | (0xff << 4)) + /* We check for APA+API and GPA+GPI */ + ldr x2, =((0xff << 24) | (0xff << 4)) and x1, x1, x2 cbz x1, 1f -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel