userfaultfd: report UFFDIO_ZEROPAGE as available for shmem VMAs

Now when shmem VMAs can be filled with zero page via userfaultfd we can
report that UFFDIO_ZEROPAGE is available for those VMAs

Link: http://lkml.kernel.org/r/1497939652-16528-7-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mike Rapoport 2017-09-06 16:23:12 -07:00 committed by Linus Torvalds
parent 8fb44e5403
commit ce53e8e6f2

View File

@ -1194,7 +1194,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
struct uffdio_register __user *user_uffdio_register;
unsigned long vm_flags, new_flags;
bool found;
bool non_anon_pages;
bool basic_ioctls;
unsigned long start, end, vma_end;
user_uffdio_register = (struct uffdio_register __user *) arg;
@ -1260,7 +1260,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
* Search for not compatible vmas.
*/
found = false;
non_anon_pages = false;
basic_ioctls = false;
for (cur = vma; cur && cur->vm_start < end; cur = cur->vm_next) {
cond_resched();
@ -1299,8 +1299,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
/*
* Note vmas containing huge pages
*/
if (is_vm_hugetlb_page(cur) || vma_is_shmem(cur))
non_anon_pages = true;
if (is_vm_hugetlb_page(cur))
basic_ioctls = true;
found = true;
}
@ -1371,7 +1371,7 @@ out_unlock:
* userland which ioctls methods are guaranteed to
* succeed on this range.
*/
if (put_user(non_anon_pages ? UFFD_API_RANGE_IOCTLS_BASIC :
if (put_user(basic_ioctls ? UFFD_API_RANGE_IOCTLS_BASIC :
UFFD_API_RANGE_IOCTLS,
&user_uffdio_register->ioctls))
ret = -EFAULT;