linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Yu Zhao <yuzhao@google.com>, Andy Lutomirski <luto@kernel.org>,
	Peter Xu <peterx@redhat.com>, Pavel Emelyanov <xemul@openvz.org>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	Mike Rapoport <rppt@linux.vnet.ibm.com>,
	Minchan Kim <minchan@kernel.org>, Will Deacon <will@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Hugh Dickins <hughd@google.com>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Matthew Wilcox <willy@infradead.org>,
	Oleg Nesterov <oleg@redhat.com>, Jann Horn <jannh@google.com>,
	Kees Cook <keescook@chromium.org>,
	John Hubbard <jhubbard@nvidia.com>,
	Leon Romanovsky <leonro@nvidia.com>, Jan Kara <jack@suse.cz>,
	Kirill Tkhai <ktkhai@virtuozzo.com>
Subject: Re: [PATCH 0/2] page_count can't be used to decide when wp_page_copy
Date: Thu, 7 Jan 2021 16:25:25 -0400	[thread overview]
Message-ID: <20210107202525.GD504133@ziepe.ca> (raw)
In-Reply-To: <20210107200402.31095-1-aarcange@redhat.com>

On Thu, Jan 07, 2021 at 03:04:00PM -0500, Andrea Arcangeli wrote:

> vmsplice syscall API is insecure allowing long term GUP PINs without
> privilege.

Lots of places are relying on pin_user_pages long term pins of memory,
and cannot be converted to notifiers.

I don't think it is reasonable to just declare that insecure and
requires privileges, it is a huge ABI break.

FWIW, vhost tries to use notifiers as a replacement for GUP, and I
think it ended up quite strange and complicated. It is hard to
maintain performance when every access to the pages needs to hold some
protection against parallel invalidation.

Jason

  parent reply	other threads:[~2021-01-07 20:26 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-25  9:25 [RFC PATCH v2 0/2] mm: fix races due to deferred TLB flushes Nadav Amit
2020-12-25  9:25 ` [RFC PATCH v2 1/2] mm/userfaultfd: fix memory corruption due to writeprotect Nadav Amit
2021-01-04 12:22   ` Peter Zijlstra
2021-01-04 19:24     ` Andrea Arcangeli
2021-01-04 19:35       ` Nadav Amit
2021-01-04 20:19         ` Andrea Arcangeli
2021-01-04 20:39           ` Nadav Amit
2021-01-04 21:01             ` Andrea Arcangeli
2021-01-04 21:26               ` Nadav Amit
2021-01-05 18:45                 ` Andrea Arcangeli
2021-01-05 19:05                   ` Nadav Amit
2021-01-05 19:45                     ` Andrea Arcangeli
2021-01-05 20:06                       ` Nadav Amit
2021-01-05 21:06                         ` Andrea Arcangeli
2021-01-05 21:43                           ` Peter Xu
2021-01-05  8:13       ` Peter Zijlstra
2021-01-05  8:52         ` Nadav Amit
2021-01-05 14:26           ` Peter Zijlstra
2021-01-05  8:58       ` Peter Zijlstra
2021-01-05  9:22         ` Nadav Amit
2021-01-05 17:58         ` Andrea Arcangeli
2021-01-05 15:08   ` Peter Xu
2021-01-05 18:08     ` Andrea Arcangeli
2021-01-05 18:41       ` Peter Xu
2021-01-05 18:55         ` Andrea Arcangeli
2021-01-05 19:07     ` Nadav Amit
2021-01-05 19:43       ` Peter Xu
2020-12-25  9:25 ` [RFC PATCH v2 2/2] fs/task_mmu: acquire mmap_lock for write on soft-dirty cleanup Nadav Amit
2021-01-05 15:08   ` Will Deacon
2021-01-05 18:20   ` Andrea Arcangeli
2021-01-05 19:26     ` Nadav Amit
2021-01-05 20:39       ` Andrea Arcangeli
2021-01-05 21:20         ` Yu Zhao
2021-01-05 21:22         ` Nadav Amit
2021-01-05 22:16           ` Will Deacon
2021-01-06  0:29             ` Andrea Arcangeli
2021-01-06  0:02           ` Andrea Arcangeli
2021-01-07 20:04           ` [PATCH 0/2] page_count can't be used to decide when wp_page_copy Andrea Arcangeli
2021-01-07 20:04             ` [PATCH 1/2] mm: proc: Invalidate TLB after clearing soft-dirty page state Andrea Arcangeli
2021-01-07 20:04             ` [PATCH 2/2] mm: soft_dirty: userfaultfd: introduce wrprotect_tlb_flush_pending Andrea Arcangeli
2021-01-07 20:17               ` Linus Torvalds
2021-01-07 20:25                 ` Linus Torvalds
2021-01-07 20:58                 ` Andrea Arcangeli
2021-01-07 21:29                   ` Linus Torvalds
2021-01-07 21:53                     ` John Hubbard
2021-01-07 22:00                       ` Linus Torvalds
2021-01-07 22:14                         ` John Hubbard
2021-01-07 22:20                           ` Linus Torvalds
2021-01-07 22:24                             ` Linus Torvalds
2021-01-07 22:37                               ` John Hubbard
2021-01-15 11:27                       ` Jan Kara
2021-01-07 22:31                     ` Andrea Arcangeli
2021-01-07 22:42                       ` Linus Torvalds
2021-01-07 22:51                         ` Linus Torvalds
2021-01-07 23:48                           ` Andrea Arcangeli
2021-01-08  0:25                             ` Linus Torvalds
2021-01-08 12:48                               ` Will Deacon
2021-01-08 16:14                                 ` Andrea Arcangeli
2021-01-08 17:39                                   ` Linus Torvalds
2021-01-08 17:53                                     ` Andrea Arcangeli
2021-01-08 19:25                                       ` Linus Torvalds
2021-01-09  0:12                                         ` Andrea Arcangeli
2021-01-08 17:30                                 ` Linus Torvalds
2021-01-07 23:28                         ` Andrea Arcangeli
2021-01-07 21:36               ` kernel test robot
2021-01-07 20:25             ` Jason Gunthorpe [this message]
2021-01-07 20:32               ` [PATCH 0/2] page_count can't be used to decide when wp_page_copy Linus Torvalds
2021-01-07 21:05                 ` Linus Torvalds
2021-01-07 22:02                   ` Andrea Arcangeli
2021-01-07 22:17                     ` Linus Torvalds
2021-01-07 22:56                       ` Andrea Arcangeli
2021-01-09 19:32                   ` Matthew Wilcox
2021-01-09 19:46                     ` Linus Torvalds
2021-01-15 14:30                       ` Jan Kara
2021-01-07 21:54                 ` Andrea Arcangeli
2021-01-07 21:45               ` Andrea Arcangeli
2021-01-08 13:36                 ` Jason Gunthorpe
2021-01-08 17:00                   ` Andrea Arcangeli
2021-01-08 18:19                     ` Jason Gunthorpe
2021-01-08 18:31                       ` Andy Lutomirski
2021-01-08 18:38                         ` Linus Torvalds
2021-01-08 23:34                         ` Andrea Arcangeli
2021-01-09 19:03                           ` Andy Lutomirski
2021-01-09 19:15                             ` Linus Torvalds
2021-01-08 18:59                       ` Linus Torvalds
2021-01-08 22:43                       ` Andrea Arcangeli
2021-01-09  0:42                         ` Jason Gunthorpe
2021-01-09  2:50                           ` Andrea Arcangeli
2021-01-11 14:30                             ` Jason Gunthorpe
2021-01-13 21:56                           ` Jerome Glisse
2021-01-13 23:39                             ` Jason Gunthorpe
2021-01-14  2:35                               ` Jerome Glisse
     [not found]                     ` <20210109034958.6928-1-hdanton@sina.com>
2021-01-11 14:39                       ` Jason Gunthorpe
2021-01-05 21:55         ` [RFC PATCH v2 2/2] fs/task_mmu: acquire mmap_lock for write on soft-dirty cleanup Peter Xu
2021-03-02 22:13 ` [RFC PATCH v2 0/2] mm: fix races due to deferred TLB flushes Peter Xu
2021-03-02 22:14   ` Nadav Amit

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210107202525.GD504133@ziepe.ca \
    --to=jgg@ziepe.ca \
    --cc=aarcange@redhat.com \
    --cc=hughd@google.com \
    --cc=jack@suse.cz \
    --cc=jannh@google.com \
    --cc=jhubbard@nvidia.com \
    --cc=keescook@chromium.org \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=ktkhai@virtuozzo.com \
    --cc=leonro@nvidia.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@kernel.org \
    --cc=mike.kravetz@oracle.com \
    --cc=minchan@kernel.org \
    --cc=oleg@redhat.com \
    --cc=peterx@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rppt@linux.vnet.ibm.com \
    --cc=torvalds@linux-foundation.org \
    --cc=will@kernel.org \
    --cc=willy@infradead.org \
    --cc=xemul@openvz.org \
    --cc=yuzhao@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).