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,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 1AA28C433E1 for ; Mon, 20 Jul 2020 16:32:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E930B206E9 for ; Mon, 20 Jul 2020 16:32:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595262751; bh=wNlxRvebGgShxuJVu8yvMXJi/nodLWBRPPFAXdnm1cc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=puHybgpymrW70Dj8hi5JfIKU5U4e3R+1jrYwgAgL7CrbaURgrCbQANaOCIxQ74WRc QWhiaTFN3LAxoSr+eE8dtkqRtMdEk3BSllHHJM3Ep8ydiJuDsradc1xIhGaaAvx4Uv +OwntciRkAW35t7M0iXg5B03cGPxksdoYYq3qs1Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388881AbgGTQca (ORCPT ); Mon, 20 Jul 2020 12:32:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:56310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731808AbgGTP4m (ORCPT ); Mon, 20 Jul 2020 11:56:42 -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 7E49120734; Mon, 20 Jul 2020 15:56:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595260602; bh=wNlxRvebGgShxuJVu8yvMXJi/nodLWBRPPFAXdnm1cc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GW5Dv/TD/q/TTR9RWLCzOdg0RPITJ67p2E0IPrT8XzdBW+bfLvIVAc4Xr3EPFoGXR VZxrk4USyXzG5BxWyjFR9XiJf15nkmrL27x5T5N+sQvX6SgP8K4J6/w+cqjbdfPDcL CYAguANOx9zq5074YRWCzoKXcxgEcu1rbaguPT2U= 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 5.4 027/215] arm64: Introduce a way to disable the 32bit vdso Date: Mon, 20 Jul 2020 17:35:09 +0200 Message-Id: <20200720152821.472994875@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152820.122442056@linuxfoundation.org> References: <20200720152820.122442056@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marc Zyngier commit 97884ca8c2925d14c32188e865069f21378b4b4f upstream. [this is a redesign rather than a backport] 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: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- arch/arm/include/asm/clocksource.h | 11 ++++++++++- arch/arm/kernel/vdso.c | 2 +- arch/arm64/include/asm/clocksource.h | 5 ++++- arch/arm64/include/asm/vdso/clocksource.h | 14 ++++++++++++++ arch/arm64/include/asm/vdso/compat_gettimeofday.h | 5 +++-- arch/arm64/include/asm/vdso/gettimeofday.h | 6 ++++-- arch/arm64/include/asm/vdso/vsyscall.h | 4 +--- drivers/clocksource/arm_arch_timer.c | 8 ++++---- 8 files changed, 41 insertions(+), 14 deletions(-) --- a/arch/arm/include/asm/clocksource.h +++ b/arch/arm/include/asm/clocksource.h @@ -1,8 +1,17 @@ #ifndef _ASM_CLOCKSOURCE_H #define _ASM_CLOCKSOURCE_H +enum vdso_arch_clockmode { + /* vdso clocksource not usable */ + VDSO_CLOCKMODE_NONE, + /* vdso clocksource usable */ + VDSO_CLOCKMODE_ARCHTIMER, + VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT = VDSO_CLOCKMODE_ARCHTIMER, +}; + struct arch_clocksource_data { - bool vdso_direct; /* Usable for direct VDSO access? */ + /* Usable for direct VDSO access? */ + enum vdso_arch_clockmode clock_mode; }; #endif --- a/arch/arm/kernel/vdso.c +++ b/arch/arm/kernel/vdso.c @@ -281,7 +281,7 @@ static bool tk_is_cntvct(const struct ti if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER)) return false; - if (!tk->tkr_mono.clock->archdata.vdso_direct) + if (tk->tkr_mono.clock->archdata.clock_mode != VDSO_CLOCKMODE_ARCHTIMER) return false; return true; --- a/arch/arm64/include/asm/clocksource.h +++ b/arch/arm64/include/asm/clocksource.h @@ -2,8 +2,11 @@ #ifndef _ASM_CLOCKSOURCE_H #define _ASM_CLOCKSOURCE_H +#include + struct arch_clocksource_data { - bool vdso_direct; /* Usable for direct VDSO access? */ + /* Usable for direct VDSO access? */ + enum vdso_arch_clockmode clock_mode; }; #endif --- /dev/null +++ b/arch/arm64/include/asm/vdso/clocksource.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_VDSOCLOCKSOURCE_H +#define __ASM_VDSOCLOCKSOURCE_H + +enum vdso_arch_clockmode { + /* vdso clocksource not usable */ + VDSO_CLOCKMODE_NONE, + /* 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 @@ -10,6 +10,7 @@ #include #include +#include #include #define __VDSO_USE_SYSCALL ULLONG_MAX @@ -117,10 +118,10 @@ static __always_inline u64 __arch_get_hw u64 res; /* - * clock_mode == 0 implies that vDSO are enabled otherwise + * clock_mode == ARCHTIMER implies that vDSO are enabled otherwise * fallback on syscall. */ - if (clock_mode) + if (clock_mode != VDSO_CLOCKMODE_ARCHTIMER) return __VDSO_USE_SYSCALL; /* --- a/arch/arm64/include/asm/vdso/gettimeofday.h +++ b/arch/arm64/include/asm/vdso/gettimeofday.h @@ -10,6 +10,8 @@ #include #include +#include + #define __VDSO_USE_SYSCALL ULLONG_MAX #define VDSO_HAS_CLOCK_GETRES 1 @@ -71,10 +73,10 @@ static __always_inline u64 __arch_get_hw u64 res; /* - * clock_mode == 0 implies that vDSO are enabled otherwise + * clock_mode != NONE implies that vDSO are enabled otherwise * fallback on syscall. */ - if (clock_mode) + if (clock_mode == VDSO_CLOCKMODE_NONE) return __VDSO_USE_SYSCALL; /* --- a/arch/arm64/include/asm/vdso/vsyscall.h +++ b/arch/arm64/include/asm/vdso/vsyscall.h @@ -24,9 +24,7 @@ struct vdso_data *__arm64_get_k_vdso_dat static __always_inline int __arm64_get_clock_mode(struct timekeeper *tk) { - u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct; - - return use_syscall; + return tk->tkr_mono.clock->archdata.clock_mode; } #define __arch_get_clock_mode __arm64_get_clock_mode --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -69,7 +69,7 @@ static enum arch_timer_ppi_nr arch_timer static bool arch_timer_c3stop; static bool arch_timer_mem_use_virtual; static bool arch_counter_suspend_stop; -static bool vdso_default = true; +static enum vdso_arch_clockmode vdso_default = VDSO_CLOCKMODE_ARCHTIMER; static cpumask_t evtstrm_available = CPU_MASK_NONE; static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM); @@ -560,8 +560,8 @@ void arch_timer_enable_workaround(const * change both the default value and the vdso itself. */ if (wa->read_cntvct_el0) { - clocksource_counter.archdata.vdso_direct = false; - vdso_default = false; + clocksource_counter.archdata.clock_mode = VDSO_CLOCKMODE_NONE; + vdso_default = VDSO_CLOCKMODE_NONE; } } @@ -979,7 +979,7 @@ static void __init arch_counter_register } arch_timer_read_counter = rd; - clocksource_counter.archdata.vdso_direct = vdso_default; + clocksource_counter.archdata.clock_mode = vdso_default; } else { arch_timer_read_counter = arch_counter_get_cntvct_mem; }