quoted

-               memcpy(p, abs_timeout, sizeof(struct timespec));
+               memcpy(p, abs_timeout, sizeof(struct timespec64));

Since you're changing this line, how about changing it to the following:

  memcpy(p, abs_timeout, sizeof(*p));

quoted

        else
-               memset(p, 0, sizeof(struct timespec));
+               memset(p, 0, sizeof(struct timespec64));

Same here.

Sure, that seems fine to me.
I will post an update.

-Deepa