From: Peter Xu <peterx@redhat.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: Hugh Dickins <hughd@google.com>, Maya Gokhale <gokhale2@llnl.gov>,
Jerome Glisse <jglisse@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
peterx@redhat.com, Martin Cracauer <cracauer@cons.org>,
Denis Plotnikov <dplotnikov@virtuozzo.com>,
Shaohua Li <shli@fb.com>, Andrea Arcangeli <aarcange@redhat.com>,
Pavel Emelyanov <xemul@parallels.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Marty McFadden <mcfadden8@llnl.gov>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Mel Gorman <mgorman@suse.de>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
Rik van Riel <riel@redhat.com>
Subject: [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range
Date: Mon, 21 Jan 2019 15:57:04 +0800 [thread overview]
Message-ID: <20190121075722.7945-7-peterx@redhat.com> (raw)
In-Reply-To: <20190121075722.7945-1-peterx@redhat.com>
From: Shaohua Li <shli@fb.com>
Add API to enable/disable writeprotect a vma range. Unlike mprotect,
this doesn't split/merge vmas.
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
include/linux/userfaultfd_k.h | 2 ++
mm/userfaultfd.c | 52 +++++++++++++++++++++++++++++++++++
2 files changed, 54 insertions(+)
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 38f748e7186e..e82f3156f4e9 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -37,6 +37,8 @@ extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
unsigned long dst_start,
unsigned long len,
bool *mmap_changing);
+extern int mwriteprotect_range(struct mm_struct *dst_mm,
+ unsigned long start, unsigned long len, bool enable_wp);
/* mm helpers */
static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 458acda96f20..c38903f501c7 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -615,3 +615,55 @@ ssize_t mfill_zeropage(struct mm_struct *dst_mm, unsigned long start,
{
return __mcopy_atomic(dst_mm, start, 0, len, true, mmap_changing);
}
+
+int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
+ unsigned long len, bool enable_wp)
+{
+ struct vm_area_struct *dst_vma;
+ pgprot_t newprot;
+ int err;
+
+ /*
+ * Sanitize the command parameters:
+ */
+ BUG_ON(start & ~PAGE_MASK);
+ BUG_ON(len & ~PAGE_MASK);
+
+ /* Does the address range wrap, or is the span zero-sized? */
+ BUG_ON(start + len <= start);
+
+ down_read(&dst_mm->mmap_sem);
+
+ /*
+ * Make sure the vma is not shared, that the dst range is
+ * both valid and fully within a single existing vma.
+ */
+ err = -EINVAL;
+ dst_vma = find_vma(dst_mm, start);
+ if (!dst_vma || (dst_vma->vm_flags & VM_SHARED))
+ goto out_unlock;
+ if (start < dst_vma->vm_start ||
+ start + len > dst_vma->vm_end)
+ goto out_unlock;
+
+ if (!dst_vma->vm_userfaultfd_ctx.ctx)
+ goto out_unlock;
+ if (!userfaultfd_wp(dst_vma))
+ goto out_unlock;
+
+ if (!vma_is_anonymous(dst_vma))
+ goto out_unlock;
+
+ if (enable_wp)
+ newprot = vm_get_page_prot(dst_vma->vm_flags & ~(VM_WRITE));
+ else
+ newprot = vm_get_page_prot(dst_vma->vm_flags);
+
+ change_protection(dst_vma, start, start + len, newprot,
+ !enable_wp, 0);
+
+ err = 0;
+out_unlock:
+ up_read(&dst_mm->mmap_sem);
+ return err;
+}
--
2.17.1
next prev parent reply other threads:[~2019-01-21 7:58 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-21 7:56 [PATCH RFC 00/24] userfaultfd: write protection support Peter Xu
2019-01-21 7:56 ` [PATCH RFC 01/24] mm: gup: rename "nonblocking" to "locked" where proper Peter Xu
2019-01-21 10:20 ` Mike Rapoport
2019-01-21 7:57 ` [PATCH RFC 02/24] mm: userfault: return VM_FAULT_RETRY on signals Peter Xu
2019-01-21 15:40 ` Jerome Glisse
2019-01-22 6:10 ` Peter Xu
2019-01-21 7:57 ` [PATCH RFC 03/24] mm: allow VM_FAULT_RETRY for multiple times Peter Xu
2019-01-21 15:55 ` Jerome Glisse
2019-01-22 8:22 ` Peter Xu
2019-01-22 16:53 ` Jerome Glisse
2019-01-23 2:12 ` Peter Xu
2019-01-23 2:39 ` Jerome Glisse
2019-01-24 5:45 ` Peter Xu
2019-01-21 7:57 ` [PATCH RFC 04/24] mm: gup: " Peter Xu
2019-01-21 16:24 ` Jerome Glisse
2019-01-24 7:05 ` Peter Xu
2019-01-24 15:34 ` Jerome Glisse
2019-01-25 2:49 ` Peter Xu
2019-01-21 7:57 ` [PATCH RFC 05/24] userfaultfd: wp: add helper for writeprotect check Peter Xu
2019-01-21 10:23 ` Mike Rapoport
2019-01-22 8:31 ` Peter Xu
2019-01-21 7:57 ` Peter Xu [this message]
2019-01-21 10:20 ` [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range Mike Rapoport
2019-01-22 8:55 ` Peter Xu
2019-01-21 14:05 ` Jerome Glisse
2019-01-22 9:39 ` Peter Xu
2019-01-22 17:02 ` Jerome Glisse
2019-01-23 2:17 ` Peter Xu
2019-01-23 2:43 ` Jerome Glisse
2019-01-24 5:47 ` Peter Xu
2019-01-21 7:57 ` [PATCH RFC 07/24] userfaultfd: wp: add the writeprotect API to userfaultfd ioctl Peter Xu
2019-01-21 10:42 ` Mike Rapoport
2019-01-24 4:56 ` Peter Xu
2019-01-24 7:27 ` Mike Rapoport
2019-01-24 9:28 ` Peter Xu
2019-01-25 7:54 ` Mike Rapoport
2019-01-25 10:12 ` Peter Xu
2019-01-21 7:57 ` [PATCH RFC 08/24] userfaultfd: wp: hook userfault handler to write protection fault Peter Xu
2019-01-21 7:57 ` [PATCH RFC 09/24] userfaultfd: wp: enabled write protection in userfaultfd API Peter Xu
2019-01-21 7:57 ` [PATCH RFC 10/24] userfaultfd: wp: add WP pagetable tracking to x86 Peter Xu
2019-01-21 15:09 ` Jerome Glisse
2019-01-24 5:16 ` Peter Xu
2019-01-24 15:40 ` Jerome Glisse
2019-01-25 3:30 ` Peter Xu
2019-01-21 7:57 ` [PATCH RFC 11/24] userfaultfd: wp: userfaultfd_pte/huge_pmd_wp() helpers Peter Xu
2019-01-21 7:57 ` [PATCH RFC 12/24] userfaultfd: wp: add UFFDIO_COPY_MODE_WP Peter Xu
2019-01-21 7:57 ` [PATCH RFC 13/24] mm: merge parameters for change_protection() Peter Xu
2019-01-21 13:54 ` Jerome Glisse
2019-01-24 5:22 ` Peter Xu
2019-01-21 7:57 ` [PATCH RFC 14/24] userfaultfd: wp: apply _PAGE_UFFD_WP bit Peter Xu
2019-01-21 7:57 ` [PATCH RFC 15/24] mm: export wp_page_copy() Peter Xu
2019-01-21 7:57 ` [PATCH RFC 16/24] userfaultfd: wp: handle COW properly for uffd-wp Peter Xu
2019-01-21 7:57 ` [PATCH RFC 17/24] userfaultfd: wp: drop _PAGE_UFFD_WP properly when fork Peter Xu
2019-01-21 7:57 ` [PATCH RFC 18/24] userfaultfd: wp: add pmd_swp_*uffd_wp() helpers Peter Xu
2019-01-21 7:57 ` [PATCH RFC 19/24] userfaultfd: wp: support swap and page migration Peter Xu
2019-01-21 7:57 ` [PATCH RFC 20/24] userfaultfd: wp: don't wake up when doing write protect Peter Xu
2019-01-21 11:10 ` Mike Rapoport
2019-01-24 5:36 ` Peter Xu
2019-01-21 7:57 ` [PATCH RFC 21/24] khugepaged: skip collapse if uffd-wp detected Peter Xu
2019-01-21 7:57 ` [PATCH RFC 22/24] userfaultfd: wp: UFFDIO_REGISTER_MODE_WP documentation update Peter Xu
2019-01-21 7:57 ` [PATCH RFC 23/24] userfaultfd: selftests: refactor statistics Peter Xu
2019-01-21 7:57 ` [PATCH RFC 24/24] userfaultfd: selftests: add write-protect test Peter Xu
2019-01-21 14:33 ` [PATCH RFC 00/24] userfaultfd: write protection support David Hildenbrand
2019-01-22 3:18 ` Peter Xu
2019-01-22 8:59 ` David Hildenbrand
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