sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched...

[mirror_ubuntu-artful-kernel.git] / mm / userfaultfd.c

diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 1e5c2f94e8a3299a47c3ba5bda9e6f59ea8afbf0..479e631d43c2f609466b1dee97ca2d0314ae12ba 100644 (file)
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/mm.h>
+#include <linux/sched/signal.h>
 #include <linux/pagemap.h>
 #include <linux/rmap.h>
 #include <linux/swap.h>
@@ -197,22 +198,25 @@ retry:
         * retry, dst_vma will be set to NULL and we must lookup again.
         */
        if (!dst_vma) {
-               err = -EINVAL;
+               err = -ENOENT;
                dst_vma = find_vma(dst_mm, dst_start);
                if (!dst_vma || !is_vm_hugetlb_page(dst_vma))
                        goto out_unlock;
-
-               if (vma_hpagesize != vma_kernel_pagesize(dst_vma))
-                       goto out_unlock;
-
                /*
-                * Make sure the remaining dst range is both valid and
-                * fully within a single existing vma.
+                * Only allow __mcopy_atomic_hugetlb on userfaultfd
+                * registered ranges.
                 */
+               if (!dst_vma->vm_userfaultfd_ctx.ctx)
+                       goto out_unlock;
+
                if (dst_start < dst_vma->vm_start ||
                    dst_start + len > dst_vma->vm_end)
                        goto out_unlock;
 
+               err = -EINVAL;
+               if (vma_hpagesize != vma_kernel_pagesize(dst_vma))
+                       goto out_unlock;
+
                vm_shared = dst_vma->vm_flags & VM_SHARED;
        }
 
@@ -220,12 +224,6 @@ retry:
                    (len - copied) & (vma_hpagesize - 1)))
                goto out_unlock;
 
-       /*
-        * Only allow __mcopy_atomic_hugetlb on userfaultfd registered ranges.
-        */
-       if (!dst_vma->vm_userfaultfd_ctx.ctx)
-               goto out_unlock;
-
        /*
         * If not shared, ensure the dst_vma has a anon_vma.
         */
@@ -404,22 +402,35 @@ retry:
         * Make sure the vma is not shared, that the dst range is
         * both valid and fully within a single existing vma.
         */
-       err = -EINVAL;
+       err = -ENOENT;
        dst_vma = find_vma(dst_mm, dst_start);
        if (!dst_vma)
                goto out_unlock;
        /*
-        * shmem_zero_setup is invoked in mmap for MAP_ANONYMOUS|MAP_SHARED but
-        * it will overwrite vm_ops, so vma_is_anonymous must return false.
+        * Be strict and only allow __mcopy_atomic on userfaultfd
+        * registered ranges to prevent userland errors going
+        * unnoticed. As far as the VM consistency is concerned, it
+        * would be perfectly safe to remove this check, but there's
+        * no useful usage for __mcopy_atomic ouside of userfaultfd
+        * registered ranges. This is after all why these are ioctls
+        * belonging to the userfaultfd and not syscalls.
         */
-       if (WARN_ON_ONCE(vma_is_anonymous(dst_vma) &&
-           dst_vma->vm_flags & VM_SHARED))
+       if (!dst_vma->vm_userfaultfd_ctx.ctx)
                goto out_unlock;
 
        if (dst_start < dst_vma->vm_start ||
            dst_start + len > dst_vma->vm_end)
                goto out_unlock;
 
+       err = -EINVAL;
+       /*
+        * shmem_zero_setup is invoked in mmap for MAP_ANONYMOUS|MAP_SHARED but
+        * it will overwrite vm_ops, so vma_is_anonymous must return false.
+        */
+       if (WARN_ON_ONCE(vma_is_anonymous(dst_vma) &&
+           dst_vma->vm_flags & VM_SHARED))
+               goto out_unlock;
+
        /*
         * If this is a HUGETLB vma, pass off to appropriate routine
         */
@@ -427,18 +438,6 @@ retry:
                return  __mcopy_atomic_hugetlb(dst_mm, dst_vma, dst_start,
                                                src_start, len, zeropage);
 
-       /*
-        * Be strict and only allow __mcopy_atomic on userfaultfd
-        * registered ranges to prevent userland errors going
-        * unnoticed. As far as the VM consistency is concerned, it
-        * would be perfectly safe to remove this check, but there's
-        * no useful usage for __mcopy_atomic ouside of userfaultfd
-        * registered ranges. This is after all why these are ioctls
-        * belonging to the userfaultfd and not syscalls.
-        */
-       if (!dst_vma->vm_userfaultfd_ctx.ctx)
-               goto out_unlock;
-
        if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma))
                goto out_unlock;