From patchwork Thu Apr 16 13:24:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 227538 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 D29C0C2BB55 for ; Thu, 16 Apr 2020 15:53:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B135620732 for ; Thu, 16 Apr 2020 15:53:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587052389; bh=bFUCpEEVzOrm1acvZr3Ly3iJYoGVkZhsua8izAbxhqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FoDrwF411MvguOqKzWFUvw0nWcHfMra4CZfCxVxz8a5NuPGdL0iD4dhf68EVwMgvo 72kkIvV+wKxuXaKLBUlfKYaHXvMpVSt7WtxubcnWQTBvKiD9jD4RDCBYwsm8AmKvSu 16iYzbYxxF6AjpM0QMJyGrNOfjSumfQ6+r3MIvIc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2506771AbgDPPwp (ORCPT ); Thu, 16 Apr 2020 11:52:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:43732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2896559AbgDPNcz (ORCPT ); Thu, 16 Apr 2020 09:32:55 -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 0DA5D22251; Thu, 16 Apr 2020 13:31:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587043910; bh=bFUCpEEVzOrm1acvZr3Ly3iJYoGVkZhsua8izAbxhqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OQK0sZiaaGjJm8v7zU2SHzD46mUleB2cYhSbzGdvqhJZeVTyC7ODHaKmG6IG/vzxJ 8De/WKGIaL3hlIp9lwgklYDONueT2rQSVr5m3yUg0f6oPeeI6KW+xEF8uP176vcTG3 rJJzocePKiI34CRl+mpOE21qlhezulitNvPILn48= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Ellerman , Andrew Donnellan Subject: [PATCH 4.19 124/146] powerpc/powernv/idle: Restore AMR/UAMOR/AMOR after idle Date: Thu, 16 Apr 2020 15:24:25 +0200 Message-Id: <20200416131259.520587819@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131242.353444678@linuxfoundation.org> References: <20200416131242.353444678@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: Michael Ellerman commit 53a712bae5dd919521a58d7bad773b949358add0 upstream. In order to implement KUAP (Kernel Userspace Access Protection) on Power9 we will be using the AMR, and therefore indirectly the UAMOR/AMOR. So save/restore these regs in the idle code. Signed-off-by: Michael Ellerman [ajd: Backport to 4.19 tree, CVE-2020-11669] Signed-off-by: Andrew Donnellan Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/idle_book3s.S | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -170,8 +170,11 @@ core_idle_lock_held: bne- core_idle_lock_held blr -/* Reuse an unused pt_regs slot for IAMR */ +/* Reuse some unused pt_regs slots for AMR/IAMR/UAMOR/UAMOR */ +#define PNV_POWERSAVE_AMR _TRAP #define PNV_POWERSAVE_IAMR _DAR +#define PNV_POWERSAVE_UAMOR _DSISR +#define PNV_POWERSAVE_AMOR RESULT /* * Pass requested state in r3: @@ -205,8 +208,16 @@ pnv_powersave_common: SAVE_NVGPRS(r1) BEGIN_FTR_SECTION + mfspr r4, SPRN_AMR mfspr r5, SPRN_IAMR + mfspr r6, SPRN_UAMOR + std r4, PNV_POWERSAVE_AMR(r1) std r5, PNV_POWERSAVE_IAMR(r1) + std r6, PNV_POWERSAVE_UAMOR(r1) +BEGIN_FTR_SECTION_NESTED(42) + mfspr r7, SPRN_AMOR + std r7, PNV_POWERSAVE_AMOR(r1) +END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42) END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) mfcr r5 @@ -935,12 +946,20 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) REST_GPR(2, r1) BEGIN_FTR_SECTION - /* IAMR was saved in pnv_powersave_common() */ + /* These regs were saved in pnv_powersave_common() */ + ld r4, PNV_POWERSAVE_AMR(r1) ld r5, PNV_POWERSAVE_IAMR(r1) + ld r6, PNV_POWERSAVE_UAMOR(r1) + mtspr SPRN_AMR, r4 mtspr SPRN_IAMR, r5 + mtspr SPRN_UAMOR, r6 +BEGIN_FTR_SECTION_NESTED(42) + ld r7, PNV_POWERSAVE_AMOR(r1) + mtspr SPRN_AMOR, r7 +END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42) /* - * We don't need an isync here because the upcoming mtmsrd is - * execution synchronizing. + * We don't need an isync here after restoring IAMR because the upcoming + * mtmsrd is execution synchronizing. */ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)