KMEM_REDZONE_PATTERN
buftagp->bt_redzone != KMEM_REDZONE_PATTERN) {
if (buftagp->bt_redzone == KMEM_REDZONE_PATTERN)
btp->bt_redzone = KMEM_REDZONE_PATTERN;
btp->bt_redzone = KMEM_REDZONE_PATTERN;
if (btp->bt_redzone != KMEM_REDZONE_PATTERN) {
btp->bt_redzone = KMEM_REDZONE_PATTERN;