shared_region
static struct shared_region *
ATF_REQUIRE_EQ(ftruncate(fd, sizeof(struct shared_region)), 0);
void *rv = mmap(NULL, sizeof(struct shared_region),
put_shared_region(struct shared_region *r)
ATF_REQUIRE_EQ(munmap(r, sizeof(struct shared_region)), 0);
struct shared_region *master_region, *slave_region;