As it's a wrapper function, so i think it would be a good idea to mark the freed pointer to NULL.The advantages can be:
1. Dangling pointer usage can be caught, if any existing.
2. Unexpected behaviour due to double free can be eradicated. -- manual page for free says "if free(ptr) has already been called before, undefined behavior occurs. If ptr is NULL, no operation is performed."
File Name: memory.c
/** \brief Wrapper for free(3), sanity checks the supplied pointer */
void u_free (void *ptr)
ptr = NULL;