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=-2.4 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT 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 B0CA2C4646D for ; Fri, 10 Aug 2018 17:42:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 64F5322429 for ; Fri, 10 Aug 2018 17:42:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Qkbzckh7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 64F5322429 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728178AbeHJUMr (ORCPT ); Fri, 10 Aug 2018 16:12:47 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:40872 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727381AbeHJUMr (ORCPT ); Fri, 10 Aug 2018 16:12:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=V8RdC5qmKJ8AGHFUOg59Pn9TQgr5sGwRDgnvNqYW7dc=; b=Qkbzckh7P98BYxal74QNbgVYe 9vIvitp7RNVOK7cawUlKur+Y5ZSbYYIun/untQCi4lAHa6r2UK0B+TuMamcy96wcYgzj4/6+hmZXJ nqqesLqL4W5fEbajUCwKrq6Saw2YoHXn9DaKw/tlAOGCTwBFe48mIRj0+D4LUqYAsuOvP9xXQp4SV WWukynckxH2L/h+6f1LTw7dgB58aPSWuGgwKfhAI1DEW+l/ZyuduTl6eSig9HGQflnh90PIQBBF3s WxWY5wfGUZLZL/72E9E8lYRs3pGw/nOuxy6Ho7uCRy+tq7CIA1JsmCsv9m0cg8ttZIGPPjrhh6HrX dUtn595FQ==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1foBQ6-0007Qb-MH; Fri, 10 Aug 2018 17:41:50 +0000 Date: Fri, 10 Aug 2018 10:41:50 -0700 From: Matthew Wilcox To: Yang Shi Cc: mhocko@kernel.org, ldufour@linux.vnet.ibm.com, kirill@shutemov.name, vbabka@suse.cz, akpm@linux-foundation.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC v7 PATCH 1/4] mm: refactor do_munmap() to extract the common part Message-ID: <20180810174150.GA6487@bombadil.infradead.org> References: <1533857763-43527-1-git-send-email-yang.shi@linux.alibaba.com> <1533857763-43527-2-git-send-email-yang.shi@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1533857763-43527-2-git-send-email-yang.shi@linux.alibaba.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 10, 2018 at 07:36:00AM +0800, Yang Shi wrote: > +static inline bool addr_ok(unsigned long start, size_t len) Maybe munmap_range_ok()? Otherwise some of the conditions here don't make sense for such a generic sounding function. > { > - unsigned long end; > - struct vm_area_struct *vma, *prev, *last; > - > if ((offset_in_page(start)) || start > TASK_SIZE || len > TASK_SIZE-start) > - return -EINVAL; > + return false; > > - len = PAGE_ALIGN(len); > - if (len == 0) > - return -EINVAL; > + if (PAGE_ALIGN(len) == 0) > + return false; > + > + return true; > +} > + > +/* > + * munmap_lookup_vma: find the first overlap vma and split overlap vmas. > + * @mm: mm_struct > + * @start: start address > + * @end: end address > + * > + * returns the pointer to vma, NULL or err ptr when spilt_vma returns error. kernel-doc prefers: * Return: %NULL if no VMA overlaps this range. An ERR_PTR if an * overlapping VMA could not be split. Otherwise a pointer to the first * VMA which overlaps the range. > + */ > +static struct vm_area_struct *munmap_lookup_vma(struct mm_struct *mm, > + unsigned long start, unsigned long end) > +{ > + struct vm_area_struct *vma, *prev, *last; > > /* Find the first overlapping VMA */ > vma = find_vma(mm, start); > if (!vma) > - return 0; > - prev = vma->vm_prev; > - /* we have start < vma->vm_end */ > + return NULL; > > + /* we have start < vma->vm_end */ Can you remove the duplicate spaces here?