From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Easton Subject: Re: [PATCH] mm/mincore: allow for making sys_mincore() privileged Date: Sun, 6 Jan 2019 11:33:36 +0000 Message-ID: <20190106113336.GA31214@ip-172-31-15-78> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: linux-api@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 > >