> +	/*
> +	 * These arrays are used when the number of open files is
> +	 * <= 1024, and are then pointed to by the pointers above.
> +	 */
> +	uint32_t	fd_dhimap[NDENTRIES >> NDENTRYSHIFT];
> +	uint32_t	fd_dlomap[NDENTRIES];

if it's your intent,
fdexpand() shouldn't do malloc() unless nfiles > 1024 and
tests in fdcopy() and fdfree() are wrong.

also, rather than abusing NDENTRIES here,
i think code like followings are more clear.

#define	NDFILE_BITMAP	1024
	uint32_t	fd_dhimap[NDHISLOTS(NDFILE_BITMAP)];
	uint32_t	fd_dlomap[NDLOSLOTS(NDFILE_BITMAP)];

YAMAMOTO Takashi