From: Andy Lutomirski <luto@kernel.org>
To: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Dan Williams <dan.j.williams@intel.com>,
Michal Hocko <mhocko@suse.com>,
Keith Busch <keith.busch@intel.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
alexander.h.duyck@linux.intel.com,
Weiny Ira <ira.weiny@intel.com>,
Andrey Konovalov <andreyknvl@google.com>,
arunks@codeaurora.org, Vlastimil Babka <vbabka@suse.cz>,
Christoph Lameter <cl@linux.com>, Rik van Riel <riel@surriel.com>,
Kees Cook <keescook@chromium.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Nicholas Piggin <npiggin@gmail.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Shakeel Butt <shakeelb@google.com>, Roman Gushchin <guro@fb.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Hugh Dickins <hughd@google.com>,
Jerome Glisse <jglisse@redhat.com>,
Mel Gorman <mgorman@techsingularity.net>,
daniel.m.jordan@oracle.com, Jann Horn <jannh@google.com>,
Adam Borowski <kilobyte@angband.pl>,
Linux API <linux-api@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>
Subject: Re: [PATCH v2 0/7] mm: process_vm_mmap() -- syscall for duplication a process mapping
Date: Thu, 23 May 2019 09:19:01 -0700 [thread overview]
Message-ID: <CALCETrWzuH3=Uh91UeGwpCj28kjQ82Lj2OTuXm7_3d871PyZSA@mail.gmail.com> (raw)
In-Reply-To: <67d1321e-ffd6-24a3-407f-cd26c82e46b8@virtuozzo.com>
On Tue, May 21, 2019 at 10:44 AM Kirill Tkhai <ktkhai@virtuozzo.com> wrote:
>
> On 21.05.2019 19:43, Andy Lutomirski wrote:
> > On Tue, May 21, 2019 at 8:52 AM Kirill Tkhai <ktkhai@virtuozzo.com> wrote:
> >>
> >> On 21.05.2019 17:43, Andy Lutomirski wrote:
> > Do you mean that the code you sent rejects this case? If so, please
> > document it. In any case, I looked at the code, and it seems to be
> > trying to handle MAP_SHARED and MAP_ANONYMOUS. I don't see where it
> > would reject copying a vDSO.
>
> I prohibit all the VMAs, which contain on of flags: VM_HUGETLB|VM_DONTEXPAND|VM_PFNMAP|VM_IO.
> I'll check carefully, whether it's enough for vDSO.
I think you could make the new syscall a lot more comprehensible bg
restricting it to just MAP_ANONYMOUS, by making it unmap the source,
or possibly both. If the new syscall unmaps the source (in order so
that the source is gone before the newly mapped pages become
accessible), then you avoid issues in which you need to define
sensible semantics for what happens if both copies are accessed
simultaneously.
--Andy
next prev parent reply other threads:[~2019-05-23 16:19 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-20 14:00 [PATCH v2 0/7] mm: process_vm_mmap() -- syscall for duplication a process mapping Kirill Tkhai
2019-05-20 14:00 ` [PATCH v2 1/7] mm: Add process_vm_mmap() syscall declaration Kirill Tkhai
2019-05-21 0:28 ` Ira Weiny
2019-05-21 8:29 ` Kirill Tkhai
2019-05-20 14:00 ` [PATCH v2 2/7] mm: Extend copy_vma() Kirill Tkhai
2019-05-21 8:18 ` Kirill A. Shutemov
2019-05-21 8:48 ` Kirill Tkhai
2019-05-20 14:00 ` [PATCH v2 3/7] mm: Extend copy_page_range() Kirill Tkhai
2019-05-20 14:00 ` [PATCH v2 4/7] mm: Export round_hint_to_min() Kirill Tkhai
2019-05-20 14:00 ` [PATCH v2 5/7] mm: Introduce may_mmap_overlapped_region() helper Kirill Tkhai
2019-05-20 14:00 ` [PATCH v2 6/7] mm: Introduce find_vma_filter_flags() helper Kirill Tkhai
2019-05-20 14:00 ` [PATCH v2 7/7] mm: Add process_vm_mmap() Kirill Tkhai
2019-05-21 14:43 ` [PATCH v2 0/7] mm: process_vm_mmap() -- syscall for duplication a process mapping Andy Lutomirski
2019-05-21 15:52 ` Kirill Tkhai
2019-05-21 15:59 ` Kirill Tkhai
2019-05-21 16:20 ` Jann Horn
2019-05-21 17:03 ` Kirill Tkhai
2019-05-21 17:28 ` Jann Horn
2019-05-22 10:03 ` Kirill Tkhai
2019-05-21 16:43 ` Andy Lutomirski
2019-05-21 17:44 ` Kirill Tkhai
2019-05-23 16:19 ` Andy Lutomirski [this message]
2019-05-24 10:36 ` Kirill Tkhai
2019-05-22 15:22 ` Kirill A. Shutemov
2019-05-23 16:11 ` Kirill Tkhai
2019-05-24 10:45 ` Kirill Tkhai
2019-05-24 11:52 ` Kirill A. Shutemov
2019-05-24 14:00 ` Kirill Tkhai
2019-05-27 23:30 ` Kirill A. Shutemov
2019-05-28 9:15 ` Kirill Tkhai
2019-05-28 16:15 ` Kirill A. Shutemov
2019-05-29 14:33 ` Kirill Tkhai
2019-06-03 14:38 ` Kirill Tkhai
2019-06-03 14:56 ` Kirill Tkhai
2019-06-03 17:47 ` Kirill A. Shutemov
2019-06-04 9:32 ` Kirill Tkhai
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='CALCETrWzuH3=Uh91UeGwpCj28kjQ82Lj2OTuXm7_3d871PyZSA@mail.gmail.com' \
--to=luto@kernel.org \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=alexander.h.duyck@linux.intel.com \
--cc=andreyknvl@google.com \
--cc=arunks@codeaurora.org \
--cc=cl@linux.com \
--cc=dan.j.williams@intel.com \
--cc=daniel.m.jordan@oracle.com \
--cc=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=ira.weiny@intel.com \
--cc=jannh@google.com \
--cc=jglisse@redhat.com \
--cc=keescook@chromium.org \
--cc=keith.busch@intel.com \
--cc=kilobyte@angband.pl \
--cc=kirill.shutemov@linux.intel.com \
--cc=ktkhai@virtuozzo.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mgorman@techsingularity.net \
--cc=mhocko@suse.com \
--cc=npiggin@gmail.com \
--cc=riel@surriel.com \
--cc=shakeelb@google.com \
--cc=vbabka@suse.cz \
/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).