X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=fs%2Fuserfaultfd.c;h=37df7c9eedb1527089466f45a930c69d8bab1925;hb=a8803e6c177f490fe5624397b07f4eb05a15f532;hp=d7f54e535294b725db8f02c514bd8b8be81576a5;hpb=dc3ecfc9819a96b2a6700b01443347b01e07a13b;p=linux-2.6-microblaze.git

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index d7f54e535294..37df7c9eedb1 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1460,7 +1460,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
 			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),
@@ -1834,13 +1835,12 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx,
 	if (copy_from_user(&uffdio_api, buf, sizeof(uffdio_api)))
 		goto out;
 	features = uffdio_api.features;
-	if (uffdio_api.api != UFFD_API || (features & ~UFFD_API_FEATURES)) {
-		memset(&uffdio_api, 0, sizeof(uffdio_api));
-		if (copy_to_user(buf, &uffdio_api, sizeof(uffdio_api)))
-			goto out;
-		ret = -EINVAL;
-		goto out;
-	}
+	ret = -EINVAL;
+	if (uffdio_api.api != UFFD_API || (features & ~UFFD_API_FEATURES))
+		goto err_out;
+	ret = -EPERM;
+	if ((features & UFFD_FEATURE_EVENT_FORK) && !capable(CAP_SYS_PTRACE))
+		goto err_out;
 	/* report all available features and ioctls to userland */
 	uffdio_api.features = UFFD_API_FEATURES;
 	uffdio_api.ioctls = UFFD_API_IOCTLS;
@@ -1853,6 +1853,11 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx,
 	ret = 0;
 out:
 	return ret;
+err_out:
+	memset(&uffdio_api, 0, sizeof(uffdio_api));
+	if (copy_to_user(buf, &uffdio_api, sizeof(uffdio_api)))
+		ret = -EFAULT;
+	goto out;
 }
 
 static long userfaultfd_ioctl(struct file *file, unsigned cmd,