From patchwork Fri Feb 26 15:20:15 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Maydell X-Patchwork-Id: 8438551 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 535C3C0553 for ; Fri, 26 Feb 2016 15:32:08 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AD68620392 for ; Fri, 26 Feb 2016 15:32:07 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 037322038F for ; Fri, 26 Feb 2016 15:32:07 +0000 (UTC) Received: from localhost ([::1]:50540 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZKNC-0001TS-BV for patchwork-qemu-devel@patchwork.kernel.org; Fri, 26 Feb 2016 10:32:06 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37302) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZKC2-0007Tq-9Q for qemu-devel@nongnu.org; Fri, 26 Feb 2016 10:20:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aZKC1-0004mi-F2 for qemu-devel@nongnu.org; Fri, 26 Feb 2016 10:20:34 -0500 Received: from orth.archaic.org.uk ([2001:8b0:1d0::2]:55998) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZKC1-0004mY-8q for qemu-devel@nongnu.org; Fri, 26 Feb 2016 10:20:33 -0500 Received: from pm215 by orth.archaic.org.uk with local (Exim 4.84) (envelope-from ) id 1aZKC0-0003ND-RG for qemu-devel@nongnu.org; Fri, 26 Feb 2016 15:20:32 +0000 From: Peter Maydell To: qemu-devel@nongnu.org Date: Fri, 26 Feb 2016 15:20:15 +0000 Message-Id: <1456500025-28761-11-git-send-email-peter.maydell@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1456500025-28761-1-git-send-email-peter.maydell@linaro.org> References: <1456500025-28761-1-git-send-email-peter.maydell@linaro.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:8b0:1d0::2 Subject: [Qemu-devel] [PULL 10/20] target-arm: Make mode switches from Hyp via CPS and MRS illegal X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Mode switches from Hyp to any other mode via the CPS and MRS instructions are illegal mode switches (though obviously switching via exception return is valid). Add this check to bad_mode_switch(). Signed-off-by: Peter Maydell Reviewed-by: Sergey Fedorov Message-id: 1455556977-3644-11-git-send-email-peter.maydell@linaro.org --- target-arm/helper.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index ff5f895..24ea48e 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -5200,12 +5200,20 @@ void arm_cp_reset_ignore(CPUARMState *env, const ARMCPRegInfo *opaque) /* Helper coprocessor reset function for do-nothing-on-reset registers */ } -static int bad_mode_switch(CPUARMState *env, int mode) +static int bad_mode_switch(CPUARMState *env, int mode, CPSRWriteType write_type) { /* Return true if it is not valid for us to switch to * this CPU mode (ie all the UNPREDICTABLE cases in * the ARM ARM CPSRWriteByInstr pseudocode). */ + + /* Changes to or from Hyp via MSR and CPS are illegal. */ + if (write_type == CPSRWriteByInstr && + ((env->uncached_cpsr & CPSR_M) == ARM_CPU_MODE_HYP || + mode == ARM_CPU_MODE_HYP)) { + return 1; + } + switch (mode) { case ARM_CPU_MODE_USR: case ARM_CPU_MODE_SYS: @@ -5324,7 +5332,7 @@ void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask, if (write_type != CPSRWriteRaw && (env->uncached_cpsr & CPSR_M) != CPSR_USER && ((env->uncached_cpsr ^ val) & mask & CPSR_M)) { - if (bad_mode_switch(env, val & CPSR_M)) { + if (bad_mode_switch(env, val & CPSR_M, write_type)) { /* Attempt to switch to an invalid mode: this is UNPREDICTABLE in * v7, and has defined behaviour in v8: * + leave CPSR.M untouched