Merge branch 'android-4.4-p' of https://android.googlesource.com/kernel/common into lineage-17.1-caf-msm8998

This brings LA.UM.8.4.r1-05900-8x98.0 up to date with
https://android.googlesource.com/kernel/common/ android-4.4-p at commit:
5fd2d19eeb976 Merge 4.4.236 into android-4.4-p

Conflicts:
	drivers/scsi/ufs/ufshcd.c

Change-Id: I22282a0d571bdb72f50d3fc1e2cee4443de1f7f4

1 files changed, 20 insertions, 7 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 245a50f490f6..91a45ef69152 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2017,9 +2017,14 @@ static noinline int copy_to_sk(struct btrfs_root *root,
 		sh.len = item_len;
 		sh.transid = found_transid;
 
-		/* copy search result header */
-		if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
-			ret = -EFAULT;
+		/*
+		 * Copy search result header. If we fault then loop again so we
+		 * can fault in the pages and -EFAULT there if there's a
+		 * problem. Otherwise we'll fault and then copy the buffer in
+		 * properly this next time through
+		 */
+		if (probe_user_write(ubuf + *sk_offset, &sh, sizeof(sh))) {
+			ret = 0;
 			goto out;
 		}
 
@@ -2027,10 +2032,14 @@ static noinline int copy_to_sk(struct btrfs_root *root,
 
 		if (item_len) {
 			char __user *up = ubuf + *sk_offset;
-			/* copy the item */
-			if (read_extent_buffer_to_user(leaf, up,
-						       item_off, item_len)) {
-				ret = -EFAULT;
+			/*
+			 * Copy the item, same behavior as above, but reset the
+			 * * sk_offset so we copy the full thing again.
+			 */
+			if (read_extent_buffer_to_user_nofault(leaf, up,
+						item_off, item_len)) {
+				ret = 0;
+				*sk_offset -= sizeof(sh);
 				goto out;
 			}
 
@@ -2120,6 +2129,10 @@ static noinline int search_ioctl(struct inode *inode,
 	key.offset = sk->min_offset;
 
 	while (1) {
+		ret = fault_in_pages_writeable(ubuf, *buf_size - sk_offset);
+		if (ret)
+			break;
+
 		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
 		if (ret != 0) {
 			if (ret > 0)