linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mike Rapoport <rppt@linux.ibm.com>
To: Peter Xu <peterx@redhat.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	David Hildenbrand <david@redhat.com>,
	Hugh Dickins <hughd@google.com>, Maya Gokhale <gokhale2@llnl.gov>,
	Jerome Glisse <jglisse@redhat.com>,
	Pavel Emelyanov <xemul@virtuozzo.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Martin Cracauer <cracauer@cons.org>, Shaohua Li <shli@fb.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	Denis Plotnikov <dplotnikov@virtuozzo.com>,
	Mike Rapoport <rppt@linux.vnet.ibm.com>,
	Marty McFadden <mcfadden8@llnl.gov>, Mel Gorman <mgorman@suse.de>,
	"Kirill A . Shutemov" <kirill@shutemov.name>,
	"Dr . David Alan Gilbert" <dgilbert@redhat.com>
Subject: Re: [PATCH v3 26/28] userfaultfd: wp: declare _UFFDIO_WRITEPROTECT conditionally
Date: Fri, 22 Mar 2019 23:43:47 +0200	[thread overview]
Message-ID: <20190322214346.GC9303@rapoport-lnx> (raw)
In-Reply-To: <20190320020642.4000-27-peterx@redhat.com>

On Wed, Mar 20, 2019 at 10:06:40AM +0800, Peter Xu wrote:
> Only declare _UFFDIO_WRITEPROTECT if the user specified
> UFFDIO_REGISTER_MODE_WP and if all the checks passed.  Then when the
> user registers regions with shmem/hugetlbfs we won't expose the new
> ioctl to them.  Even with complete anonymous memory range, we'll only
> expose the new WP ioctl bit if the register mode has MODE_WP.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>

> ---
>  fs/userfaultfd.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
> index f1f61a0278c2..7f87e9e4fb9b 100644
> --- a/fs/userfaultfd.c
> +++ b/fs/userfaultfd.c
> @@ -1456,14 +1456,24 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
>  	up_write(&mm->mmap_sem);
>  	mmput(mm);
>  	if (!ret) {
> +		__u64 ioctls_out;
> +
> +		ioctls_out = basic_ioctls ? UFFD_API_RANGE_IOCTLS_BASIC :
> +		    UFFD_API_RANGE_IOCTLS;
> +
> +		/*
> +		 * Declare the WP ioctl only if the WP mode is
> +		 * specified and all checks passed with the range
> +		 */
> +		if (!(uffdio_register.mode & UFFDIO_REGISTER_MODE_WP))
> +			ioctls_out &= ~((__u64)1 << _UFFDIO_WRITEPROTECT);
> +
>  		/*
>  		 * Now that we scanned all vmas we can already tell
>  		 * userland which ioctls methods are guaranteed to
>  		 * succeed on this range.
>  		 */
> -		if (put_user(basic_ioctls ? UFFD_API_RANGE_IOCTLS_BASIC :
> -			     UFFD_API_RANGE_IOCTLS,
> -			     &user_uffdio_register->ioctls))
> +		if (put_user(ioctls_out, &user_uffdio_register->ioctls))
>  			ret = -EFAULT;
>  	}
>  out:
> -- 
> 2.17.1
> 

-- 
Sincerely yours,
Mike.


  reply	other threads:[~2019-03-22 21:44 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-20  2:06 [PATCH v3 00/28] userfaultfd: write protection support Peter Xu
2019-03-20  2:06 ` [PATCH v3 01/28] mm: gup: rename "nonblocking" to "locked" where proper Peter Xu
2019-03-20  2:06 ` [PATCH v3 02/28] mm: userfault: return VM_FAULT_RETRY on signals Peter Xu
2019-03-20  2:06 ` [PATCH v3 03/28] userfaultfd: don't retake mmap_sem to emulate NOPAGE Peter Xu
2019-03-20  2:06 ` [PATCH v3 04/28] mm: allow VM_FAULT_RETRY for multiple times Peter Xu
2019-04-18 20:11   ` Jerome Glisse
2019-04-19  6:00     ` Peter Xu
2019-03-20  2:06 ` [PATCH v3 05/28] mm: gup: " Peter Xu
2019-03-20  2:06 ` [PATCH v3 06/28] userfaultfd: wp: add helper for writeprotect check Peter Xu
2019-03-20  2:06 ` [PATCH v3 07/28] userfaultfd: wp: hook userfault handler to write protection fault Peter Xu
2019-04-18 20:03   ` Jerome Glisse
2019-03-20  2:06 ` [PATCH v3 08/28] userfaultfd: wp: add WP pagetable tracking to x86 Peter Xu
2019-03-20  2:06 ` [PATCH v3 09/28] userfaultfd: wp: userfaultfd_pte/huge_pmd_wp() helpers Peter Xu
2019-03-20  2:06 ` [PATCH v3 10/28] userfaultfd: wp: add UFFDIO_COPY_MODE_WP Peter Xu
2019-03-20  2:06 ` [PATCH v3 11/28] mm: merge parameters for change_protection() Peter Xu
2019-03-20  2:06 ` [PATCH v3 12/28] userfaultfd: wp: apply _PAGE_UFFD_WP bit Peter Xu
2019-03-20  2:06 ` [PATCH v3 13/28] mm: export wp_page_copy() Peter Xu
2019-03-20  2:06 ` [PATCH v3 14/28] userfaultfd: wp: handle COW properly for uffd-wp Peter Xu
2019-04-18 20:51   ` Jerome Glisse
2019-04-19  6:26     ` Peter Xu
2019-04-19 15:02       ` Jerome Glisse
2019-04-22 12:20         ` Peter Xu
2019-04-22 14:54           ` Jerome Glisse
2019-04-23  3:00             ` Peter Xu
2019-04-23 15:34               ` Jerome Glisse
2019-04-24  8:38                 ` Peter Xu
2019-03-20  2:06 ` [PATCH v3 15/28] userfaultfd: wp: drop _PAGE_UFFD_WP properly when fork Peter Xu
2019-03-20  2:06 ` [PATCH v3 16/28] userfaultfd: wp: add pmd_swp_*uffd_wp() helpers Peter Xu
2019-03-20  2:06 ` [PATCH v3 17/28] userfaultfd: wp: support swap and page migration Peter Xu
2019-04-18 20:59   ` Jerome Glisse
2019-04-19  7:42     ` Peter Xu
2019-04-19 15:08       ` Jerome Glisse
2019-04-22 12:23         ` Peter Xu
2019-03-20  2:06 ` [PATCH v3 18/28] khugepaged: skip collapse if uffd-wp detected Peter Xu
2019-03-20  2:06 ` [PATCH v3 19/28] userfaultfd: introduce helper vma_find_uffd Peter Xu
2019-03-20  2:06 ` [PATCH v3 20/28] userfaultfd: wp: support write protection for userfault vma range Peter Xu
2019-03-20  2:06 ` [PATCH v3 21/28] userfaultfd: wp: add the writeprotect API to userfaultfd ioctl Peter Xu
2019-03-20  2:06 ` [PATCH v3 22/28] userfaultfd: wp: enabled write protection in userfaultfd API Peter Xu
2019-03-22 21:37   ` Mike Rapoport
2019-03-20  2:06 ` [PATCH v3 23/28] userfaultfd: wp: don't wake up when doing write protect Peter Xu
2019-03-20  2:06 ` [PATCH v3 24/28] userfaultfd: wp: UFFDIO_REGISTER_MODE_WP documentation update Peter Xu
2019-03-22 21:46   ` Mike Rapoport
2019-03-20  2:06 ` [PATCH v3 25/28] userfaultfd: wp: fixup swap entries in change_pte_range Peter Xu
2019-04-18 21:01   ` Jerome Glisse
2019-03-20  2:06 ` [PATCH v3 26/28] userfaultfd: wp: declare _UFFDIO_WRITEPROTECT conditionally Peter Xu
2019-03-22 21:43   ` Mike Rapoport [this message]
2019-03-20  2:06 ` [PATCH v3 27/28] userfaultfd: selftests: refactor statistics Peter Xu
2019-03-20  2:06 ` [PATCH v3 28/28] userfaultfd: selftests: add write-protect test Peter Xu
2019-04-09  6:08 ` [PATCH v3 00/28] userfaultfd: write protection support Peter Xu
2019-04-18 21:07   ` Jerome Glisse
2019-04-19  7:53     ` Peter Xu

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=20190322214346.GC9303@rapoport-lnx \
    --to=rppt@linux.ibm.com \
    --cc=aarcange@redhat.com \
    --cc=cracauer@cons.org \
    --cc=david@redhat.com \
    --cc=dgilbert@redhat.com \
    --cc=dplotnikov@virtuozzo.com \
    --cc=gokhale2@llnl.gov \
    --cc=hannes@cmpxchg.org \
    --cc=hughd@google.com \
    --cc=jglisse@redhat.com \
    --cc=kirill@shutemov.name \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mcfadden8@llnl.gov \
    --cc=mgorman@suse.de \
    --cc=mike.kravetz@oracle.com \
    --cc=peterx@redhat.com \
    --cc=rppt@linux.vnet.ibm.com \
    --cc=shli@fb.com \
    --cc=xemul@virtuozzo.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).