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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 4A36BC2D0EA for ; Wed, 8 Apr 2020 09:58:32 +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 1DC6020753 for ; Wed, 8 Apr 2020 09:58:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="VO+4O+C2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DC6020753 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+infradead-linux-arm-kernel=archiver.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:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=LrYItCVtMI093CUgmeAlXrR9rO5INBgVL6L9pFyBbTU=; b=VO+4O+C2EC1abx LOVJ2qWS6bW5tN84HyWWKvczp9dHiAnHTH+ji9j/3tL1cPc8p+sXrLvNMSGyD0CEFy4+isSwSh5HK Ek+AE4l39TOM01HfSv0t5x8dPigPIpecN6THOCTCv2B2v8Dm2SeWhXSovjuAVfEsF0xebB7bm5xiK WtwQakywJYzCdssgJ2VeZkcCFPW3TLoAiSzOqGY6dTkx0ty7NN/u9fdF+kr+pecpS0EsBLMx3ljSF Gt9jtSJX2UV8V9FZDh/0HfLSX3Ol9/TwgGEL2MhB3H6ACW1a0ZTpguv8NlKfjEAAzK8IcmbT2Sj86 slU9xmM07cp52NebmNhg==; 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 1jM7TY-00020L-Mt; Wed, 08 Apr 2020 09:58:28 +0000 Received: from relay3-d.mail.gandi.net ([217.70.183.195]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jM7TV-0001zQ-OQ for linux-arm-kernel@lists.infradead.org; Wed, 08 Apr 2020 09:58:27 +0000 X-Originating-IP: 84.210.220.251 Received: from [192.168.1.123] (cm-84.210.220.251.getinternet.no [84.210.220.251]) (Authenticated sender: fredrik@strupe.net) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id EEA966000F; Wed, 8 Apr 2020 09:58:17 +0000 (UTC) Subject: Re: [PATCH] arm64: armv8_deprecated: Fix undef_hook mask for thumb setend To: Catalin Marinas References: <911db2f1-e078-a460-32ee-154a0b4de5d4@strupe.net> <20200407092744.GA2665@gaia> <0d7b582a-1bd0-9db2-2fdc-04fc887f64c6@strupe.net> <20200408090111.GA27331@gaia> From: Fredrik Strupe Message-ID: <9979396e-5d01-0cfe-722f-3a4f6e81dc01@strupe.net> Date: Wed, 8 Apr 2020 11:58:15 +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: <20200408090111.GA27331@gaia> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200408_025825_931263_B82AA6CC X-CRM114-Status: GOOD ( 19.25 ) 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 08.04.2020 11:01, Catalin Marinas wrote: > On Tue, Apr 07, 2020 at 01:18:21PM +0200, Fredrik Strupe wrote: >> (Sorry for duplicate, something went terribly wrong with the formatting of >> the previous email.) > > It's still wrong here with tabs converted to spaces. The patch doesn't > apply. Could you please send the patch separately as a v2? It looks fine > otherwise. > > Thanks. > Alright, let's hope third time's the charm. Fredrik --- 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), -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel