From patchwork Wed Apr 8 11:29:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fredrik Strupe X-Patchwork-Id: 11479859 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 074D092C for ; Wed, 8 Apr 2020 11:29:54 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D95FA20747 for ; Wed, 8 Apr 2020 11:29:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="jL286Zob" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D95FA20747 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=strupe.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:References:To:From:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6ULffPI3SM/mMUulGYcLX2nYps1A8g7I1DlkGFsraqE=; b=jL286Zob/8NmaR QTrqZ8C+41Yokcr3jDXM5Tc+pjVpc3QG5KO40aWP+mLQObwEiEG+XbY8sbeNLDJIi3Fqya2JfcFtS 6zT0Zsqmwoz9qkHeutIRgJ4k7WYzLOpA5rn5EsOwjrt89uABO9rhcoJPXacIEV17NALjccuZNI3Ys QAExX6aX+nQUNY+U/mfuUL8KSh56QjK9G/JB//0THVFsTsOZABOekInJgB8Peh2s+GHFe/C/ZfwtP dEHAL5luExS0B+mAwjQfw1/sz3n6OpCRzwZFlXdFK44igS/spWM7trhgBX7ymdle+c+HcetpCD66G M6GoZAMpuNri+FZs2VtQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jM8tz-0006bV-E7; Wed, 08 Apr 2020 11:29:51 +0000 Received: from relay10.mail.gandi.net ([217.70.178.230]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jM8tw-0006al-61 for linux-arm-kernel@lists.infradead.org; Wed, 08 Apr 2020 11:29:50 +0000 Received: from [192.168.1.123] (cm-84.210.220.251.getinternet.no [84.210.220.251]) (Authenticated sender: fredrik@strupe.net) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 08F1E240008; Wed, 8 Apr 2020 11:29:42 +0000 (UTC) Subject: [PATCH v2] arm64: armv8_deprecated: Fix undef_hook mask for thumb setend From: Fredrik Strupe To: Catalin Marinas References: <911db2f1-e078-a460-32ee-154a0b4de5d4@strupe.net> <20200407092744.GA2665@gaia> <0d7b582a-1bd0-9db2-2fdc-04fc887f64c6@strupe.net> <20200408090111.GA27331@gaia> <9979396e-5d01-0cfe-722f-3a4f6e81dc01@strupe.net> Message-ID: Date: Wed, 8 Apr 2020 13:29:41 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <9979396e-5d01-0cfe-722f-3a4f6e81dc01@strupe.net> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200408_042948_358820_FC056540 X-CRM114-Status: GOOD ( 15.29 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low trust [217.70.178.230 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: will.deacon@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Suzuki K Poulose Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org For thumb instructions, call_undef_hook() in traps.c first reads a u16, and if the u16 indicates a T32 instruction (u16 >= 0xe800), a second u16 is read, which then makes up the the lower half-word of a T32 instruction. For T16 instructions, the second u16 is not read, which makes the resulting u32 opcode always have the upper half set to 0. However, having the upper half of instr_mask in the undef_hook set to 0 masks out the upper half of all thumb instructions - both T16 and T32. This results in trapped T32 instructions with the lower half-word equal to the T16 encoding of setend (b650) being matched, even though the upper half-word is not 0000 and thus indicates a T32 opcode. An example of such a T32 instruction is eaa0b650, which should raise a SIGILL since T32 instructions with an eaa prefix are unallocated as per Arm ARM, but instead works as a SETEND because the second half-word is set to b650. This patch fixes the issue by extending instr_mask to include the upper u32 half, which will still match T16 instructions where the upper half is 0, but not T32 instructions. Signed-off-by: Fredrik Strupe Cc: Catalin Marinas Cc: Will Deacon Fixes: 2d888f48e056 ("arm64: Emulate SETEND for AArch32 tasks") --- arch/arm64/kernel/armv8_deprecated.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c index 9d3442d62..8c06dfee0 100644 --- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -609,7 +609,7 @@ static struct undef_hook setend_hooks[] = { }, { /* Thumb mode */ - .instr_mask = 0x0000fff7, + .instr_mask = 0xfffffff7, .instr_val = 0x0000b650, .pstate_mask = (PSR_AA32_T_BIT | PSR_AA32_MODE_MASK), .pstate_val = (PSR_AA32_T_BIT | PSR_AA32_MODE_USR),