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=-6.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_PASS,URIBL_BLOCKED autolearn=ham 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 48169C43387 for ; Thu, 3 Jan 2019 17:05:37 +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 199562070D for ; Thu, 3 Jan 2019 17:05:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Lwmx6s2L" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 199562070D 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: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=QjQgrcrfRFs3btoegVwzbg0gs6B5GJWG2tvBSOaqkog=; b=Lwmx6s2LLCMd89 4i9vo2KB/5wrIGbUM3Y4vnyykQAwv7i779NnITYU2ZebGFE8skk4pGJS8AHbpVBfpMJkayNJkYCHj EJzQT7cFAq6VsP1yL88g9lJrWAmZgMRjod6zs/jyKV8bAL7HwmwGZaYyEL8EzYhDXMER50oPrRcC+ 04Qf5q3jKQnb1l6NBNIaxJeZWjKqjM1kqSg3DhG7tuOoaMpsYWWw/jMeWjXFnT1w1HS+9EVKuRyzf jdGQy9Qw4I1J98JHH8RzzQvgWeoHw/Y81S8yz0nmKs88gOW7MfGbaDRYDJVVGHazxzd6+SBgTvpcl G0BxvL4d8QQuQewhU1JA==; 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 1gf6Qy-0005lo-01; Thu, 03 Jan 2019 17:05:28 +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 1gf6Qu-0005kz-De for linux-arm-kernel@lists.infradead.org; Thu, 03 Jan 2019 17:05:25 +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 A5A8615AD; Thu, 3 Jan 2019 09:05:21 -0800 (PST) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6B8AB3F5D4; Thu, 3 Jan 2019 09:05:20 -0800 (PST) Subject: Re: [PATCH 1/3] arm64: kprobes: Move extable address check into arch_prepare_kprobe() To: Masami Hiramatsu References: <154502881646.30629.9938335052821665530.stgit@devbox> <154502884653.30629.3172839440883293817.stgit@devbox> From: James Morse Message-ID: Date: Thu, 3 Jan 2019 17:05:18 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <154502884653.30629.3172839440883293817.stgit@devbox> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190103_090524_466187_9EC1F24A X-CRM114-Status: GOOD ( 15.34 ) 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: Pratyush Anand , Catalin Marinas , Will Deacon , linux-kernel , "David A . Long" , 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 Hi! On 17/12/2018 06:40, Masami Hiramatsu wrote: > Move extable address check into arch_prepare_kprobe() from > arch_within_kprobe_blacklist(). I'm trying to work out the pattern for what should go in the blacklist, and what should be rejected by the arch code. It seems address-ranges should be blacklisted as the contents don't matter. easy-example: the idmap text. The arch code should also reject instructions that can't be probed from arch_prepare_kprobe(). easy-example: exclusive load or store. > Please do not blacklisting instructions on exception_table, > since it is a kind of architectural unsupported instruction. This doesn't fit the pattern, ... what should it be? The instructions in the exception_table don't matter, its the address that indicates there is a fixup for page-faults that occur here. We don't need to look at the instruction to determine this, why can't we treated these as a blacklisted range? Thanks, James > diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c > index 2a5b338b2542..b2d4b7428ebc 100644 > --- a/arch/arm64/kernel/probes/kprobes.c > +++ b/arch/arm64/kernel/probes/kprobes.c > @@ -102,6 +102,10 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) > > if (in_exception_text(probe_addr)) > return -EINVAL; > + > + if (search_exception_tables(probe_addr)) > + return -EINVAL; > + > if (probe_addr >= (unsigned long) __start_rodata && > probe_addr <= (unsigned long) __end_rodata) > return -EINVAL; > @@ -477,8 +481,7 @@ bool arch_within_kprobe_blacklist(unsigned long addr) > (addr >= (unsigned long)__entry_text_start && > addr < (unsigned long)__entry_text_end) || > (addr >= (unsigned long)__idmap_text_start && > - addr < (unsigned long)__idmap_text_end) || > - !!search_exception_tables(addr)) > + addr < (unsigned long)__idmap_text_end)) > return true; > > if (!is_kernel_in_hyp_mode()) { > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel