Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
From: akpm@linux-foundation.org
To: aarcange@redhat.com, akpm@linux-foundation.org,
	linux-mm@kvack.org, mm-commits@vger.kernel.org,
	richardw.yang@linux.intel.com, torvalds@linux-foundation.org
Subject: [patch 148/158] fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register()
Date: Sat, 30 Nov 2019 17:57:58 -0800
Message-ID: <20191201015758.51WEakx-u%akpm@linux-foundation.org> (raw)

From: Andrea Arcangeli <aarcange@redhat.com>
Subject: fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register()

If the registration is repeated without VM_UFFD_MISSING or VM_UFFD_WP they
need to be cleared.  Currently setting UFFDIO_REGISTER_MODE_WP returns
-EINVAL, so this patch is a noop until the UFFDIO_REGISTER_MODE_WP support
is applied.

Link: http://lkml.kernel.org/r/20191004232834.GP13922@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/userfaultfd.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/userfaultfd.c~uffd-wp-clear-vm_uffd_missing-or-vm_uffd_wp-during-userfaultfd_register
+++ a/fs/userfaultfd.c
@@ -1460,7 +1460,8 @@ static int userfaultfd_register(struct u
 			start = vma->vm_start;
 		vma_end = min(end, vma->vm_end);
 
-		new_flags = (vma->vm_flags & ~vm_flags) | vm_flags;
+		new_flags = (vma->vm_flags &
+			     ~(VM_UFFD_MISSING|VM_UFFD_WP)) | vm_flags;
 		prev = vma_merge(mm, prev, start, vma_end, new_flags,
 				 vma->anon_vma, vma->vm_file, vma->vm_pgoff,
 				 vma_policy(vma),
_


                 reply index

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publically 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=20191201015758.51WEakx-u%akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=aarcange@redhat.com \
    --cc=linux-mm@kvack.org \
    --cc=mm-commits@vger.kernel.org \
    --cc=richardw.yang@linux.intel.com \
    --cc=torvalds@linux-foundation.org \
    /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

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org
	public-inbox-index linux-mm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git