From patchwork Thu Jan 11 13:38:19 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Maydell X-Patchwork-Id: 859138 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3zHS6P2cgHz9s8J for ; Fri, 12 Jan 2018 00:54:21 +1100 (AEDT) Received: from localhost ([::1]:44228 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eZdJD-0003i0-C3 for incoming@patchwork.ozlabs.org; Thu, 11 Jan 2018 08:54:19 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52355) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eZd48-0007aR-K6 for qemu-devel@nongnu.org; Thu, 11 Jan 2018 08:38:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eZd47-0000FF-KE for qemu-devel@nongnu.org; Thu, 11 Jan 2018 08:38:44 -0500 Received: from orth.archaic.org.uk ([2001:8b0:1d0::2]:45858) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eZd47-0000Dl-Dx for qemu-devel@nongnu.org; Thu, 11 Jan 2018 08:38:43 -0500 Received: from pm215 by orth.archaic.org.uk with local (Exim 4.89) (envelope-from ) id 1eZd46-0005lR-DT for qemu-devel@nongnu.org; Thu, 11 Jan 2018 13:38:42 +0000 From: Peter Maydell To: qemu-devel@nongnu.org Date: Thu, 11 Jan 2018 13:38:19 +0000 Message-Id: <1515677902-23436-24-git-send-email-peter.maydell@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1515677902-23436-1-git-send-email-peter.maydell@linaro.org> References: <1515677902-23436-1-git-send-email-peter.maydell@linaro.org> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2001:8b0:1d0::2 Subject: [Qemu-devel] [PULL 23/26] linux-user/arm/nwfpe: Check coprocessor number for FPA emulation X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Our copy of the nwfpe code for emulating of the old FPA11 floating point unit doesn't check the coprocessor number in the instruction when it emulates it. This means that we might treat some instructions which should really UNDEF as being FPA11 instructions by accident. The kernel's copy of the nwfpe code doesn't make this error; I suspect the bug was noticed and fixed as part of the process of mainlining the nwfpe code more than a decade ago. Add a check that the coprocessor number (which is always in bits [11:8] of the instruction) is either 1 or 2, which is where the FPA11 lives. Reported-by: Richard Henderson Signed-off-by: Peter Maydell --- linux-user/arm/nwfpe/fpa11.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/linux-user/arm/nwfpe/fpa11.c b/linux-user/arm/nwfpe/fpa11.c index 441e3b1..f6f8163 100644 --- a/linux-user/arm/nwfpe/fpa11.c +++ b/linux-user/arm/nwfpe/fpa11.c @@ -137,8 +137,17 @@ unsigned int EmulateAll(unsigned int opcode, FPA11* qfpa, CPUARMState* qregs) unsigned int nRc = 0; // unsigned long flags; FPA11 *fpa11; + unsigned int cp; // save_flags(flags); sti(); + /* Check that this is really an FPA11 instruction: the coprocessor + * field in bits [11:8] must be 1 or 2. + */ + cp = (opcode >> 8) & 0xf; + if (cp != 1 && cp != 2) { + return 0; + } + qemufpa=qfpa; user_registers=qregs;