Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / fs / sysfs / file.c

diff --git a/kernel/fs/sysfs/file.c b/kernel/fs/sysfs/file.c
index f35523d..b803213 100644 (file)
--- a/kernel/fs/sysfs/file.c
+++ b/kernel/fs/sysfs/file.c
@@ -114,9 +114,15 @@ static ssize_t sysfs_kf_read(struct kernfs_open_file *of, char *buf,
         * If buf != of->prealloc_buf, we don't know how
         * large it is, so cannot safely pass it to ->show
         */
-       if (pos || WARN_ON_ONCE(buf != of->prealloc_buf))
+       if (WARN_ON_ONCE(buf != of->prealloc_buf))
                return 0;
        len = ops->show(kobj, of->kn->priv, buf);
+       if (pos) {
+               if (len <= pos)
+                       return 0;
+               len -= pos;
+               memmove(buf, buf + pos, len);
+       }
        return min(count, len);
 }