From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f69.google.com (mail-pa0-f69.google.com [209.85.220.69]) by kanga.kvack.org (Postfix) with ESMTP id 14ABC6B007E for ; Wed, 1 Jun 2016 20:17:29 -0400 (EDT) Received: by mail-pa0-f69.google.com with SMTP id x1so26214660pav.3 for ; Wed, 01 Jun 2016 17:17:29 -0700 (PDT) Received: from blackbird.sr71.net (www.sr71.net. [198.145.64.142]) by mx.google.com with ESMTP id w1si54172114pfj.95.2016.06.01.17.17.28 for ; Wed, 01 Jun 2016 17:17:28 -0700 (PDT) Subject: Re: [PATCH 5/8] x86, pkeys: allocation/free syscalls References: <20160531152814.36E0B9EE@viggo.jf.intel.com> <20160531152822.FE8D405E@viggo.jf.intel.com> <20160601123705.72a606e7@lwn.net> <574F386A.8070106@sr71.net> From: Dave Hansen Message-ID: <574F7B16.4080906@sr71.net> Date: Wed, 1 Jun 2016 17:17:26 -0700 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: mtk.manpages@gmail.com Cc: Jonathan Corbet , lkml , "x86@kernel.org" , Linux API , linux-arch , "linux-mm@kvack.org" , Linus Torvalds , Andrew Morton , Dave Hansen On 06/01/2016 05:11 PM, Michael Kerrisk (man-pages) wrote: >>> >> >>> >> If I read this right, it doesn't actually remove any pkey restrictions >>> >> that may have been applied while the key was allocated. So there could be >>> >> pages with that key assigned that might do surprising things if the key is >>> >> reallocated for another use later, right? Is that how the API is intended >>> >> to work? >> > >> > Yeah, that's how it works. >> > >> > It's not ideal. It would be _best_ if we during mm_pkey_free(), we >> > ensured that no VMAs under that mm have that vma_pkey() set. But, that >> > search would be potentially expensive (a walk over all VMAs), or would >> > force us to keep a data structure with a count of all the VMAs with a >> > given key. >> > >> > I should probably discuss this behavior in the manpages and address it > s/probably// > > And, did I miss it. Was there an updated man-pages patch in the latest > series? I did not notice it. There have been to changes to the patches that warranted updating the manpages until now. I'll send the update immediately. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org