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=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 3212FC43387 for ; Mon, 7 Jan 2019 15:00:39 +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 01A772173C for ; Mon, 7 Jan 2019 15:00:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="aqZKe9TZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 01A772173C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com 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:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=r3UOXyTpr8MOqP3AngS+iH/KYd13ZhekXgYRndQxX6o=; b=aqZKe9TZasXOBl BaoOJnwK6kjdwPCFsqSHL/sWW2nggoIg/aWduUBJ11BczbMc/q9GyFotQ8fVv+N2oGVhdLZgpwKrm RHh+22VK7Mo/Y7LYBqRjb7gDcTZJIzQCGSK3LtZ3biLlTufP1tGqnu0/P1+QgNJ4q26kwz2lI874r TGKEpu4g3YOKyN6zp0FTHdTfdI+Ssa+I0NRs6pcb2a8Mazh9SxZsW9lSxY6XPBgAXcuSkDQgtLAte XPxeSjyLUCqAOVQ5+4nV+4BId+iPKhS02OyljOeGkkLmNdU0NcU6i56rTCRb8jB7xpIPsebf8MzOI rtV86Le6FfP6P3XcTIaQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1ggWOI-0004eG-7C; Mon, 07 Jan 2019 15:00:34 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1ggWO8-0004Y2-3F; Mon, 07 Jan 2019 15:00:29 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6372480D; Mon, 7 Jan 2019 07:00:23 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0979E3F5B7; Mon, 7 Jan 2019 07:00:21 -0800 (PST) Date: Mon, 7 Jan 2019 15:00:19 +0000 From: Mark Rutland To: Miles Chen Subject: Re: [PATCH] arm64: trap illegal translations in __virt_to_phys() Message-ID: <20190107150019.GC46743@lakrids.cambridge.arm.com> References: <1546860080-13027-1-git-send-email-miles.chen@mediatek.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1546860080-13027-1-git-send-email-miles.chen@mediatek.com> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190107_070024_162656_EE21E15B X-CRM114-Status: GOOD ( 19.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wsd_upstream@mediatek.com, Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org 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 Mon, Jan 07, 2019 at 07:21:20PM +0800, Miles Chen wrote: > Current __virt_to_phys() only print warning messages for non-linear > addresses. It's hard to catch all warnings by those messages. Why? Are you seeing a large number of warnings somewhere? > So add a VIRTUAL_BUG_ON() to trap all non-linear and non-symbol > addresses (e.g., stack addresses) > > Tested by pass stack addresses and symbol addresses to __pa(). Result: > stack addresses: kernel BUG() Either: * Stacks are vmap'd, and __is_lm_address(stack_addr) is false. We'll produce a WARNING() today (and return a junk physical address). * Stacks are linear mapped, and cannot be distinguished from other linear mapped addresses. The physical address will be valid. ... so I don't understand why you need to change this. > symbol addresses: kernel warning message That should already be the case today, since the kernel image is mapped separately from the linear map, so __is_lm_address(symbol_addr) should be false. > > Maybe we should trap all non-linear address translations in the future. > > Signed-off-by: Miles Chen > --- > arch/arm64/mm/physaddr.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/mm/physaddr.c b/arch/arm64/mm/physaddr.c > index 67a9ba9eaa96..f6b935dad19c 100644 > --- a/arch/arm64/mm/physaddr.c > +++ b/arch/arm64/mm/physaddr.c > @@ -14,6 +14,11 @@ phys_addr_t __virt_to_phys(unsigned long x) > (void *)x, > (void *)x); > > + /* trap all non-linear and non-symbol addresses */ > + VIRTUAL_BUG_ON(!__is_lm_address(x) && > + (x < (unsigned long)KERNEL_START || > + x > (unsigned long)KERNEL_END)); The KERNEL_START and KERNEL_END definitions refer to the kernel image, not the linear map, so it doesn't make any sense to permit those here. It is *not* valid to call __virt_to_phys() with a symbol address. We only support those in __virt_to_phys_nodebug() so that broken code has a chance of stumbling on. If you want the kernel to die immediately when it hits a warning here, please set panic_on_warn. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel