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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,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 AC102C43387 for ; Sun, 6 Jan 2019 11:33:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 83E89213A2 for ; Sun, 6 Jan 2019 11:33:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726415AbfAFLdl (ORCPT ); Sun, 6 Jan 2019 06:33:41 -0500 Received: from aws.guarana.org ([13.237.110.252]:57648 "EHLO aws.guarana.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726189AbfAFLdl (ORCPT ); Sun, 6 Jan 2019 06:33:41 -0500 Received: by aws.guarana.org (Postfix, from userid 1006) id 705D0A18B4; Sun, 6 Jan 2019 11:33:36 +0000 (UTC) Date: Sun, 6 Jan 2019 11:33:36 +0000 From: Kevin Easton To: Linus Torvalds Cc: Jiri Kosina , Masatake YAMATO , Andrew Morton , Greg KH , Peter Zijlstra , Michal Hocko , linux-mm@kvack.org, Linux List Kernel Mailing , linux-api@vger.kernel.org Subject: Re: [PATCH] mm/mincore: allow for making sys_mincore() privileged Message-ID: <20190106113336.GA31214@ip-172-31-15-78> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 05, 2019 at 01:54:03PM -0800, Linus Torvalds wrote: > On Sat, Jan 5, 2019 at 12:43 PM Jiri Kosina wrote: > > > > > Who actually _uses_ mincore()? That's probably the best guide to what > > > we should do. Maybe they open the file read-only even if they are the > > > owner, and we really should look at file ownership instead. > > > > Yeah, well > > > > https://codesearch.debian.net/search?q=mincore > > > > is a bit too much mess to get some idea quickly I am afraid. > Anyway, the Debian code search just results in mostly non-present > stuff. It's sad that google code search is no more. It was great for > exactly these kinds of questions. If you select the "Group search results by Debian source package" option on the search results page it makes it a lot easier to skim through. It looks to me like Firefox is expecting mincore() not to fail on libraries that it has mapped: https://sources.debian.org/src/firefox-esr/60.4.0esr-1/mozglue/linker/BaseElf.cpp/?hl=98#L98 - Kevin > > The mono runtime seems to have some mono_pages_not_faulted() function, > but I don't know if people use it for file mappings, and I couldn't > find any interesting users of it. > > I didn't find anything that seems to really care, but I gave up after > a few pages of really boring stuff. > > Linus > >