From patchwork Mon Feb 15 17:22:55 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Maydell X-Patchwork-Id: 8317191 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4B66E9F6E4 for ; Mon, 15 Feb 2016 17:26:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B38452039E for ; Mon, 15 Feb 2016 17:26:43 +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 09E602034E for ; Mon, 15 Feb 2016 17:26:43 +0000 (UTC) Received: from localhost ([::1]:34554 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aVMv4-0006SN-9S for patchwork-qemu-devel@patchwork.kernel.org; Mon, 15 Feb 2016 12:26:42 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57163) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aVMrd-0000ZP-1h for qemu-devel@nongnu.org; Mon, 15 Feb 2016 12:23:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aVMrc-0007oz-3q for qemu-devel@nongnu.org; Mon, 15 Feb 2016 12:23:08 -0500 Received: from mnementh.archaic.org.uk ([2001:8b0:1d0::1]:57358) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aVMrb-0007mW-T8; Mon, 15 Feb 2016 12:23:08 -0500 Received: from pm215 by mnementh.archaic.org.uk with local (Exim 4.84) (envelope-from ) id 1aVMrS-0000xt-8i; Mon, 15 Feb 2016 17:22:58 +0000 From: Peter Maydell To: qemu-devel@nongnu.org Date: Mon, 15 Feb 2016 17:22:55 +0000 Message-Id: <1455556977-3644-10-git-send-email-peter.maydell@linaro.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1455556977-3644-1-git-send-email-peter.maydell@linaro.org> References: <1455556977-3644-1-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::1 Cc: "Edgar E. Iglesias" , Sergey Fedorov , qemu-arm@nongnu.org, patches@linaro.org Subject: [Qemu-devel] [PATCH 09/11] target-arm: In v8, make illegal AArch32 mode changes set PSTATE.IL 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 In v8, the illegal mode changes which are UNPREDICTABLE in v7 are given architected behaviour: * the mode field is unchanged * PSTATE.IL is set (so any subsequent instructions will UNDEF) * any other CPSR fields are written to as normal This is pretty much the same behaviour we picked for our UNPREDICTABLE handling, with the exception that for v8 we need to set the IL bit. Signed-off-by: Peter Maydell Reviewed-by: Sergey Fedorov --- target-arm/helper.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index e7b3eb3..69e93a2 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -5291,11 +5291,20 @@ void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask, (env->uncached_cpsr & CPSR_M) != CPSR_USER && ((env->uncached_cpsr ^ val) & mask & CPSR_M)) { if (bad_mode_switch(env, val & CPSR_M)) { - /* Attempt to switch to an invalid mode: this is UNPREDICTABLE. - * We choose to ignore the attempt and leave the CPSR M field - * untouched. + /* Attempt to switch to an invalid mode: this is UNPREDICTABLE in + * v7, and has defined behaviour in v8: + * + leave CPSR.M untouched + * + allow changes to the other CPSR fields + * + set PSTATE.IL + * For user changes via the GDB stub, we don't set PSTATE.IL, + * as this would be unnecessarily harsh for a user error. */ mask &= ~CPSR_M; + if (write_type != CPSRWriteByGDBStub && + arm_feature(env, ARM_FEATURE_V8)) { + mask |= CPSR_IL; + val |= CPSR_IL; + } } else { switch_mode(env, val & CPSR_M); }