IB/core: Use memdup_user() rather than duplicating its implementation

* Reuse existing functionality from memdup_user() instead of keeping
  duplicate source code.

  This issue was detected by using the Coccinelle software.

* The local variable "ret" will be set to an appropriate value a bit later.
  Thus omit the explicit initialisation at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 8e90dd2..e1f9673 100644 (file)
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2115,22 +2115,17 @@ static inline bool ib_is_udata_cleared(struct ib_udata *udata,
                                       size_t len)
 {
        const void __user *p = udata->inbuf + offset;
-       bool ret = false;
+       bool ret;
        u8 *buf;
 
        if (len > USHRT_MAX)
                return false;
 
-       buf = kmalloc(len, GFP_KERNEL);
-       if (!buf)
+       buf = memdup_user(p, len);
+       if (IS_ERR(buf))
                return false;
 
-       if (copy_from_user(buf, p, len))
-               goto free;
-
        ret = !memchr_inv(buf, 0, len);
-
-free:
        kfree(buf);
        return ret;
 }