diff options
| author | Mike Rapoport <rppt@linux.vnet.ibm.com> | 2017-02-23 02:43:40 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-23 03:41:28 +0300 |
| commit | cac673292b9b39493bb0ff526b96c83ace6fdcd0 (patch) | |
| tree | 7d8dbcd6cabcdf35cc2866b672c65be98cc1e5be /fs/userfaultfd.c | |
| parent | cfda05267f7bd02b5ae5ac6a37fbbdf3b9c41b57 (diff) | |
| download | linux-cac673292b9b39493bb0ff526b96c83ace6fdcd0.tar.xz | |
userfaultfd: shmem: allow registration of shared memory ranges
Expand the userfaultfd_register/unregister routines to allow shared
memory VMAs.
Currently, there is no UFFDIO_ZEROPAGE and write-protection support for
shared memory VMAs, which is reflected in ioctl methods supported by
uffdio_register.
Link: http://lkml.kernel.org/r/20161216144821.5183-34-aarcange@redhat.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/userfaultfd.c')
| -rw-r--r-- | fs/userfaultfd.c | 21 |
1 files changed, 7 insertions, 14 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 593135c296bc..18406158e13f 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1098,7 +1098,8 @@ static __always_inline int validate_range(struct mm_struct *mm, static inline bool vma_can_userfault(struct vm_area_struct *vma) { - return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma); + return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) || + vma_is_shmem(vma); } static int userfaultfd_register(struct userfaultfd_ctx *ctx, @@ -1111,7 +1112,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, struct uffdio_register __user *user_uffdio_register; unsigned long vm_flags, new_flags; bool found; - bool huge_pages; + bool non_anon_pages; unsigned long start, end, vma_end; user_uffdio_register = (struct uffdio_register __user *) arg; @@ -1175,13 +1176,9 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, /* * Search for not compatible vmas. - * - * FIXME: this shall be relaxed later so that it doesn't fail - * on tmpfs backed vmas (in addition to the current allowance - * on anonymous vmas). */ found = false; - huge_pages = false; + non_anon_pages = false; for (cur = vma; cur && cur->vm_start < end; cur = cur->vm_next) { cond_resched(); @@ -1220,8 +1217,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, /* * Note vmas containing huge pages */ - if (is_vm_hugetlb_page(cur)) - huge_pages = true; + if (is_vm_hugetlb_page(cur) || vma_is_shmem(cur)) + non_anon_pages = true; found = true; } @@ -1292,7 +1289,7 @@ out_unlock: * userland which ioctls methods are guaranteed to * succeed on this range. */ - if (put_user(huge_pages ? UFFD_API_RANGE_IOCTLS_HPAGE : + if (put_user(non_anon_pages ? UFFD_API_RANGE_IOCTLS_BASIC : UFFD_API_RANGE_IOCTLS, &user_uffdio_register->ioctls)) ret = -EFAULT; @@ -1352,10 +1349,6 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, /* * Search for not compatible vmas. - * - * FIXME: this shall be relaxed later so that it doesn't fail - * on tmpfs backed vmas (in addition to the current allowance - * on anonymous vmas). */ found = false; ret = -EINVAL; |