// https://syzkaller.appspot.com/bug?id=d4463a2d3563cdc5823b22d4e115144d0af7e88c
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <arpa/inet.h>
#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include <linux/genetlink.h>
#include <linux/if_addr.h>
#include <linux/if_link.h>
#include <linux/in6.h>
#include <linux/neighbour.h>
#include <linux/net.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/veth.h>

static unsigned long long procid;

static void sleep_ms(uint64_t ms)
{
  usleep(ms * 1000);
}

static uint64_t current_time_ms(void)
{
  struct timespec ts;
  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    exit(1);
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

#define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off))
#define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len)               \
  *(type*)(addr) =                                                             \
      htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) |           \
            (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len))))

static bool write_file(const char* file, const char* what, ...)
{
  char buf[1024];
  va_list args;
  va_start(args, what);
  vsnprintf(buf, sizeof(buf), what, args);
  va_end(args);
  buf[sizeof(buf) - 1] = 0;
  int len = strlen(buf);
  int fd = open(file, O_WRONLY | O_CLOEXEC);
  if (fd == -1)
    return false;
  if (write(fd, buf, len) != len) {
    int err = errno;
    close(fd);
    errno = err;
    return false;
  }
  close(fd);
  return true;
}

struct nlmsg {
  char* pos;
  int nesting;
  struct nlattr* nested[8];
  char buf[4096];
};

static void netlink_init(struct nlmsg* nlmsg, int typ, int flags,
                         const void* data, int size)
{
  memset(nlmsg, 0, sizeof(*nlmsg));
  struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf;
  hdr->nlmsg_type = typ;
  hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
  memcpy(hdr + 1, data, size);
  nlmsg->pos = (char*)(hdr + 1) + NLMSG_ALIGN(size);
}

static void netlink_attr(struct nlmsg* nlmsg, int typ, const void* data,
                         int size)
{
  struct nlattr* attr = (struct nlattr*)nlmsg->pos;
  attr->nla_len = sizeof(*attr) + size;
  attr->nla_type = typ;
  if (size > 0)
    memcpy(attr + 1, data, size);
  nlmsg->pos += NLMSG_ALIGN(attr->nla_len);
}

static void netlink_nest(struct nlmsg* nlmsg, int typ)
{
  struct nlattr* attr = (struct nlattr*)nlmsg->pos;
  attr->nla_type = typ;
  nlmsg->pos += sizeof(*attr);
  nlmsg->nested[nlmsg->nesting++] = attr;
}

static void netlink_done(struct nlmsg* nlmsg)
{
  struct nlattr* attr = nlmsg->nested[--nlmsg->nesting];
  attr->nla_len = nlmsg->pos - (char*)attr;
}

static int netlink_send_ext(struct nlmsg* nlmsg, int sock, uint16_t reply_type,
                            int* reply_len, bool dofail)
{
  if (nlmsg->pos > nlmsg->buf + sizeof(nlmsg->buf) || nlmsg->nesting)
    exit(1);
  struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf;
  hdr->nlmsg_len = nlmsg->pos - nlmsg->buf;
  struct sockaddr_nl addr;
  memset(&addr, 0, sizeof(addr));
  addr.nl_family = AF_NETLINK;
  ssize_t n = sendto(sock, nlmsg->buf, hdr->nlmsg_len, 0,
                     (struct sockaddr*)&addr, sizeof(addr));
  if (n != (ssize_t)hdr->nlmsg_len) {
    if (dofail)
      exit(1);
    return -1;
  }
  n = recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0);
  if (reply_len)
    *reply_len = 0;
  if (n < 0) {
    if (dofail)
      exit(1);
    return -1;
  }
  if (n < (ssize_t)sizeof(struct nlmsghdr)) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  if (hdr->nlmsg_type == NLMSG_DONE)
    return 0;
  if (reply_len && hdr->nlmsg_type == reply_type) {
    *reply_len = n;
    return 0;
  }
  if (n < (ssize_t)(sizeof(struct nlmsghdr) + sizeof(struct nlmsgerr))) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  if (hdr->nlmsg_type != NLMSG_ERROR) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  errno = -((struct nlmsgerr*)(hdr + 1))->error;
  return -errno;
}

static int netlink_send(struct nlmsg* nlmsg, int sock)
{
  return netlink_send_ext(nlmsg, sock, 0, NULL, true);
}

static int netlink_query_family_id(struct nlmsg* nlmsg, int sock,
                                   const char* family_name, bool dofail)
{
  struct genlmsghdr genlhdr;
  memset(&genlhdr, 0, sizeof(genlhdr));
  genlhdr.cmd = CTRL_CMD_GETFAMILY;
  netlink_init(nlmsg, GENL_ID_CTRL, 0, &genlhdr, sizeof(genlhdr));
  netlink_attr(nlmsg, CTRL_ATTR_FAMILY_NAME, family_name,
               strnlen(family_name, GENL_NAMSIZ - 1) + 1);
  int n = 0;
  int err = netlink_send_ext(nlmsg, sock, GENL_ID_CTRL, &n, dofail);
  if (err < 0) {
    return -1;
  }
  uint16_t id = 0;
  struct nlattr* attr = (struct nlattr*)(nlmsg->buf + NLMSG_HDRLEN +
                                         NLMSG_ALIGN(sizeof(genlhdr)));
  for (; (char*)attr < nlmsg->buf + n;
       attr = (struct nlattr*)((char*)attr + NLMSG_ALIGN(attr->nla_len))) {
    if (attr->nla_type == CTRL_ATTR_FAMILY_ID) {
      id = *(uint16_t*)(attr + 1);
      break;
    }
  }
  if (!id) {
    errno = EINVAL;
    return -1;
  }
  recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0);
  return id;
}

static void netlink_add_device_impl(struct nlmsg* nlmsg, const char* type,
                                    const char* name, bool up)
{
  struct ifinfomsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  if (up)
    hdr.ifi_flags = hdr.ifi_change = IFF_UP;
  netlink_init(nlmsg, RTM_NEWLINK, NLM_F_EXCL | NLM_F_CREATE, &hdr,
               sizeof(hdr));
  if (name)
    netlink_attr(nlmsg, IFLA_IFNAME, name, strlen(name));
  netlink_nest(nlmsg, IFLA_LINKINFO);
  netlink_attr(nlmsg, IFLA_INFO_KIND, type, strlen(type));
}

static void netlink_device_change(struct nlmsg* nlmsg, int sock,
                                  const char* name, bool up, const char* master,
                                  const void* mac, int macsize,
                                  const char* new_name)
{
  struct ifinfomsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  if (up)
    hdr.ifi_flags = hdr.ifi_change = IFF_UP;
  hdr.ifi_index = if_nametoindex(name);
  netlink_init(nlmsg, RTM_NEWLINK, 0, &hdr, sizeof(hdr));
  if (new_name)
    netlink_attr(nlmsg, IFLA_IFNAME, new_name, strlen(new_name));
  if (master) {
    int ifindex = if_nametoindex(master);
    netlink_attr(nlmsg, IFLA_MASTER, &ifindex, sizeof(ifindex));
  }
  if (macsize)
    netlink_attr(nlmsg, IFLA_ADDRESS, mac, macsize);
  int err = netlink_send(nlmsg, sock);
  if (err < 0) {
  }
}

static struct nlmsg nlmsg;

static void kill_and_wait(int pid, int* status)
{
  kill(-pid, SIGKILL);
  kill(pid, SIGKILL);
  for (int i = 0; i < 100; i++) {
    if (waitpid(-1, status, WNOHANG | __WALL) == pid)
      return;
    usleep(1000);
  }
  DIR* dir = opendir("/sys/fs/fuse/connections");
  if (dir) {
    for (;;) {
      struct dirent* ent = readdir(dir);
      if (!ent)
        break;
      if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0)
        continue;
      char abort[300];
      snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort",
               ent->d_name);
      int fd = open(abort, O_WRONLY);
      if (fd == -1) {
        continue;
      }
      if (write(fd, abort, 1) < 0) {
      }
      close(fd);
    }
    closedir(dir);
  } else {
  }
  while (waitpid(-1, status, __WALL) != pid) {
  }
}

static void setup_test()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  write_file("/proc/self/oom_score_adj", "1000");
}

#define NL802154_CMD_SET_SHORT_ADDR 11
#define NL802154_ATTR_IFINDEX 3
#define NL802154_ATTR_SHORT_ADDR 10

static const char* setup_802154()
{
  const char* error = NULL;
  int sock_generic = -1;
  int sock_route = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
  if (sock_route == -1) {
    error = "socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE) failed";
    goto fail;
  }
  sock_generic = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC);
  if (sock_generic == -1) {
    error = "socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC) failed";
    goto fail;
  }
  {
    int nl802154_family_id =
        netlink_query_family_id(&nlmsg, sock_generic, "nl802154", true);
    if (nl802154_family_id < 0) {
      error = "netlink_query_family_id failed";
      goto fail;
    }
    for (int i = 0; i < 2; i++) {
      char devname[] = "wpan0";
      devname[strlen(devname) - 1] += i;
      uint64_t hwaddr = 0xaaaaaaaaaaaa0002 + (i << 8);
      uint16_t shortaddr = 0xaaa0 + i;
      int ifindex = if_nametoindex(devname);
      struct genlmsghdr genlhdr;
      memset(&genlhdr, 0, sizeof(genlhdr));
      genlhdr.cmd = NL802154_CMD_SET_SHORT_ADDR;
      netlink_init(&nlmsg, nl802154_family_id, 0, &genlhdr, sizeof(genlhdr));
      netlink_attr(&nlmsg, NL802154_ATTR_IFINDEX, &ifindex, sizeof(ifindex));
      netlink_attr(&nlmsg, NL802154_ATTR_SHORT_ADDR, &shortaddr,
                   sizeof(shortaddr));
      if (netlink_send(&nlmsg, sock_generic) < 0) {
        error = "NL802154_CMD_SET_SHORT_ADDR failed";
        goto fail;
      }
      netlink_device_change(&nlmsg, sock_route, devname, true, 0, &hwaddr,
                            sizeof(hwaddr), 0);
      if (i == 0) {
        netlink_add_device_impl(&nlmsg, "lowpan", "lowpan0", false);
        netlink_done(&nlmsg);
        netlink_attr(&nlmsg, IFLA_LINK, &ifindex, sizeof(ifindex));
        if (netlink_send(&nlmsg, sock_route) < 0) {
          error = "netlink: adding device lowpan0 type lowpan link wpan0";
          goto fail;
        }
      }
    }
  }
fail:
  close(sock_route);
  close(sock_generic);
  return error;
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter = 0;
  for (;; iter++) {
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      setup_test();
      execute_one();
      exit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      sleep_ms(10);
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      if (current_time_ms() - start < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
  }
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};

void execute_one(void)
{
  intptr_t res = 0;
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  //  socket$nl_route arguments: [
  //    domain: const = 0x10 (8 bytes)
  //    type: const = 0x3 (8 bytes)
  //    proto: const = 0x0 (4 bytes)
  //  ]
  //  returns sock_nl_route
  res = syscall(__NR_socket, /*domain=*/0x10ul, /*type=*/3ul, /*proto=*/0);
  if (res != -1)
    r[0] = res;
  //  socket$nl_route arguments: [
  //    domain: const = 0x10 (8 bytes)
  //    type: const = 0x3 (8 bytes)
  //    proto: const = 0x0 (4 bytes)
  //  ]
  //  returns sock_nl_route
  syscall(__NR_socket, /*domain=*/0x10ul, /*type=*/3ul, /*proto=*/0);
  //  sendmsg$nl_route arguments: [
  //    fd: sock_nl_route (resource)
  //    msg: ptr[in, msghdr_netlink[netlink_msg_route]] {
  //      msghdr_netlink[netlink_msg_route] {
  //        addr: nil
  //        addrlen: len = 0x0 (4 bytes)
  //        pad = 0x0 (4 bytes)
  //        vec: ptr[in, iovec[in, netlink_msg_route]] {
  //          iovec[in, netlink_msg_route] {
  //            addr: ptr[in, netlink_msg_route] {
  //              union netlink_msg_route {
  //                newlink: netlink_msg_t[const[RTM_NEWLINK, int16],
  //                ifinfomsg[AF_UNSPEC], ifla_policy] {
  //                  len: len = 0x30 (4 bytes)
  //                  type: const = 0x10 (2 bytes)
  //                  flags: netlink_msg_flags = 0x801 (2 bytes)
  //                  seq: int32 = 0x0 (4 bytes)
  //                  pid: int32 = 0x0 (4 bytes)
  //                  payload: ifinfomsg[AF_UNSPEC] {
  //                    ifi_family: const = 0x0 (1 bytes)
  //                    __ifi_pad: const = 0x0 (1 bytes)
  //                    ifi_type: const = 0x0 (2 bytes)
  //                    ifi_index: ifindex (resource)
  //                    ifi_flags: net_device_flags = 0x0 (4 bytes)
  //                    ifi_change: net_device_flags = 0x200e3 (4 bytes)
  //                  }
  //                  attrs: array[ifla_policy] {
  //                    union ifla_policy {
  //                      IFLA_MASTER: nlattr_t[const[IFLA_MASTER, int16],
  //                      ifindex] {
  //                        nla_len: offsetof = 0x8 (2 bytes)
  //                        nla_type: const = 0xa (2 bytes)
  //                        payload: ifindex (resource)
  //                        size: buffer: {} (length 0x0)
  //                      }
  //                    }
  //                    union ifla_policy {
  //                      IFLA_GROUP: nlattr_t[const[IFLA_GROUP, int16], int32]
  //                      {
  //                        nla_len: offsetof = 0x8 (2 bytes)
  //                        nla_type: const = 0x1b (2 bytes)
  //                        payload: int32 = 0x0 (4 bytes)
  //                        size: buffer: {} (length 0x0)
  //                      }
  //                    }
  //                  }
  //                }
  //              }
  //            }
  //            len: len = 0x30 (8 bytes)
  //          }
  //        }
  //        vlen: const = 0x1 (8 bytes)
  //        ctrl: const = 0x0 (8 bytes)
  //        ctrllen: const = 0x0 (8 bytes)
  //        f: send_flags = 0x0 (4 bytes)
  //        pad = 0x0 (4 bytes)
  //      }
  //    }
  //    f: send_flags = 0x0 (8 bytes)
  //  ]
  *(uint64_t*)0x2000000004c0 = 0;
  *(uint32_t*)0x2000000004c8 = 0;
  *(uint64_t*)0x2000000004d0 = 0x200000000080;
  *(uint64_t*)0x200000000080 = 0x200000000000;
  *(uint32_t*)0x200000000000 = 0x30;
  *(uint16_t*)0x200000000004 = 0x10;
  *(uint16_t*)0x200000000006 = 0x801;
  *(uint32_t*)0x200000000008 = 0;
  *(uint32_t*)0x20000000000c = 0;
  *(uint8_t*)0x200000000010 = 0;
  *(uint8_t*)0x200000000011 = 0;
  *(uint16_t*)0x200000000012 = 0;
  *(uint32_t*)0x200000000014 = 0;
  *(uint32_t*)0x200000000018 = 0;
  *(uint32_t*)0x20000000001c = 0x200e3;
  *(uint16_t*)0x200000000020 = 8;
  *(uint16_t*)0x200000000022 = 0xa;
  *(uint32_t*)0x200000000024 = 0;
  *(uint16_t*)0x200000000028 = 8;
  *(uint16_t*)0x20000000002a = 0x1b;
  *(uint32_t*)0x20000000002c = 0;
  *(uint64_t*)0x200000000088 = 0x30;
  *(uint64_t*)0x2000000004d8 = 1;
  *(uint64_t*)0x2000000004e0 = 0;
  *(uint64_t*)0x2000000004e8 = 0;
  *(uint32_t*)0x2000000004f0 = 0;
  syscall(__NR_sendmsg, /*fd=*/r[0], /*msg=*/0x2000000004c0ul, /*f=*/0ul);
  //  socket$nl_generic arguments: [
  //    domain: const = 0x10 (8 bytes)
  //    type: const = 0x3 (8 bytes)
  //    proto: const = 0x10 (4 bytes)
  //  ]
  //  returns sock_nl_generic
  res = syscall(__NR_socket, /*domain=*/0x10ul, /*type=*/3ul, /*proto=*/0x10);
  if (res != -1)
    r[1] = res;
  //  sendmsg$nl_generic arguments: [
  //    fd: sock_nl_generic (resource)
  //    msg: ptr[in, msghdr_netlink[netlink_msg_t[netlink_random_msg_type,
  //    genlmsghdr, nl_generic_attr]]] {
  //      msghdr_netlink[netlink_msg_t[netlink_random_msg_type, genlmsghdr,
  //      nl_generic_attr]] {
  //        addr: nil
  //        addrlen: len = 0x0 (4 bytes)
  //        pad = 0x0 (4 bytes)
  //        vec: ptr[in, iovec[in, netlink_msg_t[netlink_random_msg_type,
  //        genlmsghdr, nl_generic_attr]]] {
  //          iovec[in, netlink_msg_t[netlink_random_msg_type, genlmsghdr,
  //          nl_generic_attr]] {
  //            addr: ptr[in, netlink_msg_t[netlink_random_msg_type, genlmsghdr,
  //            nl_generic_attr]] {
  //              netlink_msg_t[netlink_random_msg_type, genlmsghdr,
  //              nl_generic_attr] {
  //                len: len = 0x18 (4 bytes)
  //                type: int16 = 0x26 (2 bytes)
  //                flags: netlink_msg_flags = 0x1 (2 bytes)
  //                seq: int32 = 0x7fffd (4 bytes)
  //                pid: int32 = 0x1000 (4 bytes)
  //                payload: genlmsghdr {
  //                  cmd: int8 = 0x6 (1 bytes)
  //                  version: const = 0x0 (1 bytes)
  //                  reserved: const = 0x0 (2 bytes)
  //                }
  //                attrs: array[nl_generic_attr] {
  //                  union nl_generic_attr {
  //                    nested: nlattr_tt[int16:14[0:NETLINK_MAX_ATTRIBUTES], 0,
  //                    1, array[nl_generic_attr]] {
  //                      nla_len: offsetof = 0x4 (2 bytes)
  //                      nla_type: int16 = 0x1 (1 bytes)
  //                      NLA_F_NET_BYTEORDER: const = 0x0 (0 bytes)
  //                      NLA_F_NESTED: const = 0x1 (1 bytes)
  //                      payload: array[nl_generic_attr] {
  //                      }
  //                      size: buffer: {} (length 0x0)
  //                    }
  //                  }
  //                }
  //              }
  //            }
  //            len: len = 0x18 (8 bytes)
  //          }
  //        }
  //        vlen: const = 0x1 (8 bytes)
  //        ctrl: const = 0x0 (8 bytes)
  //        ctrllen: const = 0x0 (8 bytes)
  //        f: send_flags = 0x400c801 (4 bytes)
  //        pad = 0x0 (4 bytes)
  //      }
  //    }
  //    f: send_flags = 0x4008090 (8 bytes)
  //  ]
  *(uint64_t*)0x200000000140 = 0;
  *(uint32_t*)0x200000000148 = 0;
  *(uint64_t*)0x200000000150 = 0x200000000000;
  *(uint64_t*)0x200000000000 = 0x200000000080;
  *(uint32_t*)0x200000000080 = 0x18;
  *(uint16_t*)0x200000000084 = 0x26;
  *(uint16_t*)0x200000000086 = 1;
  *(uint32_t*)0x200000000088 = 0x7fffd;
  *(uint32_t*)0x20000000008c = 0x1000;
  *(uint8_t*)0x200000000090 = 6;
  *(uint8_t*)0x200000000091 = 0;
  *(uint16_t*)0x200000000092 = 0;
  *(uint16_t*)0x200000000094 = 4;
  STORE_BY_BITMASK(uint16_t, , 0x200000000096, 1, 0, 14);
  STORE_BY_BITMASK(uint16_t, , 0x200000000097, 0, 6, 1);
  STORE_BY_BITMASK(uint16_t, , 0x200000000097, 1, 7, 1);
  *(uint64_t*)0x200000000008 = 0x18;
  *(uint64_t*)0x200000000158 = 1;
  *(uint64_t*)0x200000000160 = 0;
  *(uint64_t*)0x200000000168 = 0;
  *(uint32_t*)0x200000000170 = 0x400c801;
  syscall(__NR_sendmsg, /*fd=*/r[1], /*msg=*/0x200000000140ul,
          /*f=MSG_ZEROCOPY|MSG_PROBE|MSG_MORE|MSG_EOR*/ 0x4008090ul);
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  const char* reason;
  (void)reason;
  if ((reason = setup_802154()))
    printf("the reproducer may not work as expected: 802154 injection setup "
           "failed: %s\n",
           reason);
  for (procid = 0; procid < 5; procid++) {
    if (fork() == 0) {
      loop();
    }
  }
  sleep(1000000);
  return 0;
}