From: Pavel Emelyanov <xemul@parallels.com>
To: Oleg Nesterov <oleg@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>,
Benjamin LaHaise <bcrl@kvack.org>,
Hugh Dickins <hughd@google.com>, Jeff Moyer <jmoyer@redhat.com>,
Kirill Shutemov <kirill.shutemov@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
<linux-kernel@vger.kernel.org>, Andy Lutomirski <luto@kernel.org>
Subject: Re: vdso && f_op->mremap (Was: special_mapping_fault() is broken)
Date: Tue, 23 Jun 2015 18:04:43 +0300 [thread overview]
Message-ID: <5589758B.6030804@parallels.com> (raw)
In-Reply-To: <20150623004744.GA11212@redhat.com>
On 06/23/2015 03:47 AM, Oleg Nesterov wrote:
> On 06/21, Oleg Nesterov wrote:
>>
>> Forgot to add Andy...
>
> Add Pavel ;)
>
> I never understood why ->mremap() lives in file_operations, not in
> vm_operations_struct. To me vma->vm_file->f_op in move_vma() just
> looks strange, vma->vm_ops->mremap(new_vma) looks "obviously better".
>
> And afaics more useful. CRIU remaps vdso, but this does not update
> mm->context.vdso. OK, probably this does not matter currently, CRIU
> can't c/r the compat tasks, and 64-bit apps do not use context.vdso.
Yup, the context.vdso exists not for all vdso-s. There should have been
a patch for power arch adding this change.
> Afaics. Still, I think we might want to have special_mapping_remap()
> and we can't do this because ->vm_file == NULL.
For aio (the single for now mapping with mremap callback) the vm_file
is not NULL.
> And perhaps other architectures can depend on the "correct" value
> in >context.vdso more then x86, I dunno...
>
> In short. Shouldn't we move ->mremap() to vm_operations_struct before
> it has another user? We need to fix aio.c, but this is trivial.
>
> No?
I will be OK with this change :)
-- Pavel
next prev parent reply other threads:[~2015-06-23 15:05 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-21 21:07 [PATCH 0/3] special_mapping_fault() is broken Oleg Nesterov
2015-06-21 21:07 ` [PATCH 1/3] mm: introduce vma_is_anonymous(vma) helper Oleg Nesterov
2015-06-21 21:07 ` [PATCH 2/3] mmap: fix the usage of ->vm_pgoff in special_mapping paths Oleg Nesterov
2015-06-21 21:07 ` [PATCH 3/3] mremap: fix the wrong !vma->vm_file check in copy_vma() Oleg Nesterov
2015-06-21 21:19 ` [PATCH 0/3] special_mapping_fault() is broken Oleg Nesterov
2015-06-23 0:47 ` vdso && f_op->mremap (Was: special_mapping_fault() is broken) Oleg Nesterov
2015-06-23 1:09 ` Linus Torvalds
2015-06-23 1:26 ` Andy Lutomirski
2015-06-23 15:04 ` Pavel Emelyanov [this message]
2015-06-23 17:03 ` Oleg Nesterov
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=5589758B.6030804@parallels.com \
--to=xemul@parallels.com \
--cc=akpm@linux-foundation.org \
--cc=bcrl@kvack.org \
--cc=hughd@google.com \
--cc=jmoyer@redhat.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=oleg@redhat.com \
--cc=torvalds@linux-foundation.org \
--cc=viro@ZenIV.linux.org.uk \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.