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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 8E0D8C433DF for ; Sat, 17 Oct 2020 23:14:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6168F208E4 for ; Sat, 17 Oct 2020 23:14:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602976452; bh=f5CCkANMVT19gApMAe7FnKgAv0Hukgr+Bo/TXSkzKMA=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=SUEvscbRtRqi2AYwKBnO9IdhUpyN8Hc5YlxrTUitXgEsCXfKmsyUc/rptz42zhUri 9GEjW/kLkxfAMLVBL2MC8QwMh6p5fLueHOvGIiIabaaGG616uIXBysWz0T9T6Cc1Wc UcczyvqlNyRnMYwp8Icovb1OaCOQKePfl5l/YkQ4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439890AbgJQXOM (ORCPT ); Sat, 17 Oct 2020 19:14:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:47864 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439878AbgJQXOL (ORCPT ); Sat, 17 Oct 2020 19:14:11 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id ACA1420897; Sat, 17 Oct 2020 23:14:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602976449; bh=f5CCkANMVT19gApMAe7FnKgAv0Hukgr+Bo/TXSkzKMA=; h=Date:From:To:Subject:In-Reply-To:From; b=sBegiK50yBBpN0N/fQlPnwRmDjA2MknrG751J2jEsuKDEYkkMmGA3TtDGkgnyc5ZM Ynbs7pwYiS3jYtC60BgZB0g7aejI4YRd8UYjJEcuXgmTWGCoYJfQkSFmz1VJMRm+1L JzDlXdzgIVscM2UQtIO/SJyU6qtELGV4mjbr0S5Q= Date: Sat, 17 Oct 2020 16:14:09 -0700 From: Andrew Morton To: akpm@linux-foundation.org, Liam.Howlett@Oracle.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 11/40] mm/mmap: add inline munmap_vma_range() for code readability Message-ID: <20201017231409.Qiho8zkqA%akpm@linux-foundation.org> In-Reply-To: <20201017161314.88890b87fae7446ccc13c902@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: "Liam R. Howlett" Subject: mm/mmap: add inline munmap_vma_range() for code readability There are two locations that have a block of code for munmapping a vma range. Change those two locations to use a function and add meaningful comments about what happens to the arguments, which was unclear in the previous code. Link: http://lkml.kernel.org/r/20200818154707.2515169-2-Liam.Howlett@Oracle.com Signed-off-by: Liam R. Howlett Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton --- mm/mmap.c | 48 +++++++++++++++++++++++++++++++++--------------- 1 file changed, 33 insertions(+), 15 deletions(-) --- a/mm/mmap.c~mm-mmap-add-inline-munmap_vma_range-for-code-readability +++ a/mm/mmap.c @@ -575,6 +575,33 @@ static inline struct vm_area_struct *vma return vma->vm_next; } + +/* + * munmap_vma_range() - munmap VMAs that overlap a range. + * @mm: The mm struct + * @start: The start of the range. + * @len: The length of the range. + * @pprev: pointer to the pointer that will be set to previous vm_area_struct + * @rb_link: the rb_node + * @rb_parent: the parent rb_node + * + * Find all the vm_area_struct that overlap from @start to + * @end and munmap them. Set @pprev to the previous vm_area_struct. + * + * Returns: -ENOMEM on munmap failure or 0 on success. + */ +static inline int +munmap_vma_range(struct mm_struct *mm, unsigned long start, unsigned long len, + struct vm_area_struct **pprev, struct rb_node ***link, + struct rb_node **parent, struct list_head *uf) +{ + + while (find_vma_links(mm, start, start + len, pprev, link, parent)) + if (do_munmap(mm, start, len, uf)) + return -ENOMEM; + + return 0; +} static unsigned long count_vma_pages_range(struct mm_struct *mm, unsigned long addr, unsigned long end) { @@ -1721,13 +1748,9 @@ unsigned long mmap_region(struct file *f return -ENOMEM; } - /* Clear old maps */ - while (find_vma_links(mm, addr, addr + len, &prev, &rb_link, - &rb_parent)) { - if (do_munmap(mm, addr, len, uf)) - return -ENOMEM; - } - + /* Clear old maps, set up prev, rb_link, rb_parent, and uf */ + if (munmap_vma_range(mm, addr, len, &prev, &rb_link, &rb_parent, uf)) + return -ENOMEM; /* * Private writable mapping: check memory availability */ @@ -3063,14 +3086,9 @@ static int do_brk_flags(unsigned long ad if (error) return error; - /* - * Clear old maps. this also does some error checking for us - */ - while (find_vma_links(mm, addr, addr + len, &prev, &rb_link, - &rb_parent)) { - if (do_munmap(mm, addr, len, uf)) - return -ENOMEM; - } + /* Clear old maps, set up prev, rb_link, rb_parent, and uf */ + if (munmap_vma_range(mm, addr, len, &prev, &rb_link, &rb_parent, uf)) + return -ENOMEM; /* Check against address space limits *after* clearing old maps... */ if (!may_expand_vm(mm, flags, len >> PAGE_SHIFT)) _