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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00,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 3987CC433E4 for ; Tue, 14 Jul 2020 19:00:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 173682240B for ; Tue, 14 Jul 2020 19:00:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594753224; bh=QQPLdQsHm8zskkrD67gBus4xmrYf5opoihyze2dADgw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SyjxUWfoo/R0YJ/1FVOOpQ9MLhoss3Shvit+PxQAilvEwf6lgbgXVlSNjWgBISKh/ NtYLdTXfQzI8zeOrDiTHCMthy19llJA25D3F5HUFFFseXNmNf3ws3+m+t6T3P8FBzt K6tKbWYD5K23FI0SJj/TF5+Ph3a+MIQEWZyNkeZg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730858AbgGNTAW (ORCPT ); Tue, 14 Jul 2020 15:00:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:59284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731363AbgGNTAW (ORCPT ); Tue, 14 Jul 2020 15:00:22 -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 41E5B2240B; Tue, 14 Jul 2020 19:00:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594753221; bh=QQPLdQsHm8zskkrD67gBus4xmrYf5opoihyze2dADgw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HyPRkjm1tUapovJSag/wYAXQe7idOSzrFLtOezPW9uLztLlL1e9hMdFOOO5gWOzt+ ojY9CElPuHD/7Rw+uijWFimyVYdCmoleMRFETdYLdqkQpRTBVMiGzVePl/Qv5RWVK6 zFAZL/gReaP1bwRYHLS0dx43RXSmrV1vuSoq7PVM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Zyngier , Mark Rutland , Will Deacon Subject: [PATCH 5.7 157/166] arm64: Introduce a way to disable the 32bit vdso Date: Tue, 14 Jul 2020 20:45:22 +0200 Message-Id: <20200714184123.341424853@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200714184115.844176932@linuxfoundation.org> References: <20200714184115.844176932@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marc Zyngier commit 97884ca8c2925d14c32188e865069f21378b4b4f upstream. We have a class of errata (grouped under the ARM64_WORKAROUND_1418040 banner) that force the trapping of counter access from 32bit EL0. We would normally disable the whole vdso for such defect, except that it would disable it for 64bit userspace as well, which is a shame. Instead, add a new vdso_clock_mode, which signals that the vdso isn't usable for compat tasks. This gets checked in the new vdso_clocksource_ok() helper, now provided for the 32bit vdso. Signed-off-by: Marc Zyngier Acked-by: Mark Rutland Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200706163802.1836732-2-maz@kernel.org Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/vdso/clocksource.h | 7 +++++-- arch/arm64/include/asm/vdso/compat_gettimeofday.h | 8 +++++++- 2 files changed, 12 insertions(+), 3 deletions(-) --- a/arch/arm64/include/asm/vdso/clocksource.h +++ b/arch/arm64/include/asm/vdso/clocksource.h @@ -2,7 +2,10 @@ #ifndef __ASM_VDSOCLOCKSOURCE_H #define __ASM_VDSOCLOCKSOURCE_H -#define VDSO_ARCH_CLOCKMODES \ - VDSO_CLOCKMODE_ARCHTIMER +#define VDSO_ARCH_CLOCKMODES \ + /* vdso clocksource for both 32 and 64bit tasks */ \ + VDSO_CLOCKMODE_ARCHTIMER, \ + /* vdso clocksource for 64bit tasks only */ \ + VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT #endif --- a/arch/arm64/include/asm/vdso/compat_gettimeofday.h +++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h @@ -111,7 +111,7 @@ static __always_inline u64 __arch_get_hw * update. Return something. Core will do another round and then * see the mode change and fallback to the syscall. */ - if (clock_mode == VDSO_CLOCKMODE_NONE) + if (clock_mode != VDSO_CLOCKMODE_ARCHTIMER) return 0; /* @@ -152,6 +152,12 @@ static __always_inline const struct vdso return ret; } +static inline bool vdso_clocksource_ok(const struct vdso_data *vd) +{ + return vd->clock_mode == VDSO_CLOCKMODE_ARCHTIMER; +} +#define vdso_clocksource_ok vdso_clocksource_ok + #endif /* !__ASSEMBLY__ */ #endif /* __ASM_VDSO_GETTIMEOFDAY_H */