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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 49368C468C1 for ; Mon, 10 Jun 2019 04:38:23 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 CAE14206C3 for ; Mon, 10 Jun 2019 04:38:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CAE14206C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45MgP85mlGzDqQZ for ; Mon, 10 Jun 2019 14:38:20 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=anshuman.khandual@arm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 45MgM03HvfzDqPK for ; Mon, 10 Jun 2019 14:36:28 +1000 (AEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9C058337; Sun, 9 Jun 2019 21:36:26 -0700 (PDT) Received: from [10.162.42.131] (p8cg001049571a15.blr.arm.com [10.162.42.131]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A664B3F557; Sun, 9 Jun 2019 21:36:16 -0700 (PDT) Subject: Re: [RFC V3] mm: Generalize and rename notify_page_fault() as kprobe_page_fault() To: Dave Hansen , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <1559903655-5609-1-git-send-email-anshuman.khandual@arm.com> <6e095842-0f7f-f428-653d-2b6e98fea6b3@intel.com> From: Anshuman Khandual Message-ID: Date: Mon, 10 Jun 2019 10:06:34 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <6e095842-0f7f-f428-653d-2b6e98fea6b3@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Michal Hocko , linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , Catalin Marinas , Dave Hansen , Will Deacon , Paul Mackerras , sparclinux@vger.kernel.org, linux-s390@vger.kernel.org, Yoshinori Sato , x86@kernel.org, Russell King , Matthew Wilcox , Ingo Molnar , Fenghua Yu , Stephen Rothwell , Andrey Konovalov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Tony Luck , Heiko Carstens , Martin Schwidefsky , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 06/07/2019 08:36 PM, Dave Hansen wrote: > On 6/7/19 3:34 AM, Anshuman Khandual wrote: >> +static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs, >> + unsigned int trap) >> +{ >> + int ret = 0; >> + >> + /* >> + * To be potentially processing a kprobe fault and to be allowed >> + * to call kprobe_running(), we have to be non-preemptible. >> + */ >> + if (kprobes_built_in() && !preemptible() && !user_mode(regs)) { >> + if (kprobe_running() && kprobe_fault_handler(regs, trap)) >> + ret = 1; >> + } >> + return ret; >> +} > > Nits: Other that taking the nice, readable, x86 one and globbing it onto > a single line, looks OK to me. It does seem a _bit_ silly to go to the > trouble of converting to 'bool' and then using 0/1 and an 'int' > internally instead of true/false and a bool, though. It's also not a Changing to 'bool'... > horrible thing to add a single line comment to this sucker to say: > > /* returns true if kprobes handled the fault */ > Picking this in-code comment. > In any case, and even if you don't clean any of this up: > > Reviewed-by: Dave Hansen > Thanks !