// https://syzkaller.appspot.com/bug?id=29c998d14238f256fe48b097cf2409c66e5b411b
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <errno.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

const int kFailStatus = 67;
const int kRetryStatus = 69;

__attribute__((noreturn)) static void doexit(int status)
{
  volatile unsigned i;
  syscall(__NR_exit_group, status);
  for (i = 0;; i++) {
  }
}

__attribute__((noreturn)) static void fail(const char* msg, ...)
{
  int e = errno;
  fflush(stdout);
  va_list args;
  va_start(args, msg);
  vfprintf(stderr, msg, args);
  va_end(args);
  fprintf(stderr, " (errno %d)\n", e);
  doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus);
}

__attribute__((noreturn)) static void exitf(const char* msg, ...)
{
  int e = errno;
  fflush(stdout);
  va_list args;
  va_start(args, msg);
  vfprintf(stderr, msg, args);
  va_end(args);
  fprintf(stderr, " (errno %d)\n", e);
  doexit(kRetryStatus);
}

static void use_temporary_dir()
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    fail("failed to mkdtemp");
  if (chmod(tmpdir, 0777))
    fail("failed to chmod");
  if (chdir(tmpdir))
    fail("failed to chdir");
}

static void remove_dir(const char* dir)
{
  DIR* dp;
  struct dirent* ep;
  int iter = 0;
retry:
  dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EMFILE) {
      exitf("opendir(%s) failed due to NOFILE, exiting");
    }
    exitf("opendir(%s) failed", dir);
  }
  while ((ep = readdir(dp))) {
    if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
      continue;
    char filename[FILENAME_MAX];
    snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
    struct stat st;
    if (lstat(filename, &st))
      exitf("lstat(%s) failed", filename);
    if (S_ISDIR(st.st_mode)) {
      remove_dir(filename);
      continue;
    }
    int i;
    for (i = 0;; i++) {
      if (unlink(filename) == 0)
        break;
      if (errno == EROFS) {
        break;
      }
      if (errno != EBUSY || i > 100)
        exitf("unlink(%s) failed", filename);
      if (umount2(filename, MNT_DETACH))
        exitf("umount(%s) failed", filename);
    }
  }
  closedir(dp);
  int i;
  for (i = 0;; i++) {
    if (rmdir(dir) == 0)
      break;
    if (i < 100) {
      if (errno == EROFS) {
        break;
      }
      if (errno == EBUSY) {
        if (umount2(dir, MNT_DETACH))
          exitf("umount(%s) failed", dir);
        continue;
      }
      if (errno == ENOTEMPTY) {
        if (iter < 100) {
          iter++;
          goto retry;
        }
      }
    }
    exitf("rmdir(%s) failed", dir);
  }
}

static uint64_t current_time_ms()
{
  struct timespec ts;

  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    fail("clock_gettime failed");
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

static void test();

void loop()
{
  int iter;
  for (iter = 0;; iter++) {
    char cwdbuf[256];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      fail("failed to mkdir");
    int pid = fork();
    if (pid < 0)
      fail("clone failed");
    if (pid == 0) {
      prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
      setpgrp();
      if (chdir(cwdbuf))
        fail("failed to chdir");
      test();
      doexit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      int res = waitpid(-1, &status, __WALL | WNOHANG);
      if (res == pid)
        break;
      usleep(1000);
      if (current_time_ms() - start > 5 * 1000) {
        kill(-pid, SIGKILL);
        kill(pid, SIGKILL);
        while (waitpid(-1, &status, __WALL) != pid) {
        }
        break;
      }
    }
    remove_dir(cwdbuf);
  }
}

long r[27];
void* thr(void* arg)
{
  switch ((long)arg) {
  case 0:
    r[0] = syscall(__NR_mmap, 0x20000000ul, 0x1000ul, 0x3ul, 0x32ul,
                   0xfffffffffffffffful, 0x0ul);
    break;
  case 1:
    *(uint32_t*)0x20000000 = (uint32_t)0x3;
    *(uint16_t*)0x20000004 = (uint16_t)0x10001;
    *(uint16_t*)0x20000006 = (uint16_t)0x2;
    *(uint16_t*)0x20000008 = (uint16_t)0x101;
    *(uint32_t*)0x20e91000 = (uint32_t)0xa;
    r[6] = syscall(__NR_getsockopt, 0xfffffffffffffffful, 0x84ul,
                   0x16ul, 0x20000000ul, 0x20e91000ul);
    break;
  case 2:
    r[7] = syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul,
                   0xfffffffffffffffful, 0x0ul);
    break;
  case 3:
    *(uint32_t*)0x20196000 = (uint32_t)0x0;
    r[9] = syscall(__NR_accept4, 0xfffffffffffffffful, 0x20000000ul,
                   0x20196000ul, 0x80800ul);
    break;
  case 4:
    r[10] = syscall(__NR_setsockopt, r[9], 0x107ul, 0x5ul, 0x20000000ul,
                    0x0ul);
    break;
  case 5:
    *(uint32_t*)0x2024cf0f = (uint32_t)0x0;
    *(uint32_t*)0x2024cf13 = (uint32_t)0x0;
    *(uint32_t*)0x20368ffc = (uint32_t)0x8;
    r[14] = syscall(__NR_getsockopt, 0xfffffffffffffffful, 0x84ul,
                    0x1bul, 0x2024cf0ful, 0x20368ffcul);
    break;
  case 6:
    r[15] = syscall(__NR_setsockopt, 0xfffffffffffffffful, 0x1ul, 0x0ul,
                    0x0ul, 0x0ul);
    break;
  case 7:
    *(uint32_t*)0x20001000 = (uint32_t)0x10000;
    *(uint32_t*)0x20001004 = (uint32_t)0x4;
    *(uint32_t*)0x20001008 = (uint32_t)0x10000;
    *(uint32_t*)0x2000100c = (uint32_t)0x4;
    r[20] = syscall(__NR_setsockopt, 0xfffffffffffffffful, 0x84ul,
                    0x0ul, 0x20001000ul, 0x10ul);
    break;
  case 8:
    r[21] = syscall(__NR_socket, 0x11ul, 0x80003ul, 0x8ul);
    break;
  case 9:
    *(uint16_t*)0x20cdeffc = (uint16_t)0x8001;
    *(uint8_t*)0x20cdeffe = (uint8_t)0x3;
    *(uint8_t*)0x20cdefff = (uint8_t)0x1000;
    r[25] = syscall(__NR_setsockopt, r[21], 0x107ul, 0x12ul,
                    0x20cdeffcul, 0x4ul);
    break;
  case 10:
    r[26] = syscall(__NR_setsockopt, r[21], 0x107ul, 0x5ul,
                    0x20001000ul, 0x47eul);
    break;
  }
  return 0;
}

void test()
{
  long i;
  pthread_t th[22];

  memset(r, -1, sizeof(r));
  for (i = 0; i < 11; i++) {
    pthread_create(&th[i], 0, thr, (void*)i);
    usleep(rand() % 10000);
  }
  usleep(rand() % 100000);
}

int main()
{
  int i;
  for (i = 0; i < 8; i++) {
    if (fork() == 0) {
      use_temporary_dir();
      loop();
      return 0;
    }
  }
  sleep(1000000);
  return 0;
}