// https://syzkaller.appspot.com/bug?id=d2cc7cb679cf1215914d6f967ee598a8af7563b4
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/prctl.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/futex.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;
}

static void use_temporary_dir(void)
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    exit(1);
  if (chmod(tmpdir, 0777))
    exit(1);
  if (chdir(tmpdir))
    exit(1);
}

static void thread_start(void* (*fn)(void*), void* arg)
{
  pthread_t th;
  pthread_attr_t attr;
  pthread_attr_init(&attr);
  pthread_attr_setstacksize(&attr, 128 << 10);
  int i = 0;
  for (; i < 100; i++) {
    if (pthread_create(&th, &attr, fn, arg) == 0) {
      pthread_attr_destroy(&attr);
      return;
    }
    if (errno == EAGAIN) {
      usleep(50);
      continue;
    }
    break;
  }
  exit(1);
}

typedef struct {
  int state;
} event_t;

static void event_init(event_t* ev)
{
  ev->state = 0;
}

static void event_reset(event_t* ev)
{
  ev->state = 0;
}

static void event_set(event_t* ev)
{
  if (ev->state)
    exit(1);
  __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE);
  syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000);
}

static void event_wait(event_t* ev)
{
  while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0);
}

static int event_isset(event_t* ev)
{
  return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE);
}

static int event_timedwait(event_t* ev, uint64_t timeout)
{
  uint64_t start = current_time_ms();
  uint64_t now = start;
  for (;;) {
    uint64_t remain = timeout - (now - start);
    struct timespec ts;
    ts.tv_sec = remain / 1000;
    ts.tv_nsec = (remain % 1000) * 1000 * 1000;
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts);
    if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
      return 1;
    now = current_time_ms();
    if (now - start > timeout)
      return 0;
  }
}

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;
}

#define FS_IOC_SETFLAGS _IOW('f', 2, long)
static void remove_dir(const char* dir)
{
  int iter = 0;
  DIR* dp = 0;
retry:
  while (umount2(dir, MNT_DETACH | UMOUNT_NOFOLLOW) == 0) {
  }
  dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EMFILE) {
      exit(1);
    }
    exit(1);
  }
  struct dirent* ep = 0;
  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);
    while (umount2(filename, MNT_DETACH | UMOUNT_NOFOLLOW) == 0) {
    }
    struct stat st;
    if (lstat(filename, &st))
      exit(1);
    if (S_ISDIR(st.st_mode)) {
      remove_dir(filename);
      continue;
    }
    int i;
    for (i = 0;; i++) {
      if (unlink(filename) == 0)
        break;
      if (errno == EPERM) {
        int fd = open(filename, O_RDONLY);
        if (fd != -1) {
          long flags = 0;
          if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) {
          }
          close(fd);
          continue;
        }
      }
      if (errno == EROFS) {
        break;
      }
      if (errno != EBUSY || i > 100)
        exit(1);
      if (umount2(filename, MNT_DETACH | UMOUNT_NOFOLLOW))
        exit(1);
    }
  }
  closedir(dp);
  for (int i = 0;; i++) {
    if (rmdir(dir) == 0)
      break;
    if (i < 100) {
      if (errno == EPERM) {
        int fd = open(dir, O_RDONLY);
        if (fd != -1) {
          long flags = 0;
          if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) {
          }
          close(fd);
          continue;
        }
      }
      if (errno == EROFS) {
        break;
      }
      if (errno == EBUSY) {
        if (umount2(dir, MNT_DETACH | UMOUNT_NOFOLLOW))
          exit(1);
        continue;
      }
      if (errno == ENOTEMPTY) {
        if (iter < 100) {
          iter++;
          goto retry;
        }
      }
    }
    exit(1);
  }
}

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");
  if (symlink("/dev/binderfs", "./binderfs")) {
  }
}

struct thread_t {
  int created, call;
  event_t ready, done;
};

static struct thread_t threads[16];
static void execute_call(int call);
static int running;

static void* thr(void* arg)
{
  struct thread_t* th = (struct thread_t*)arg;
  for (;;) {
    event_wait(&th->ready);
    event_reset(&th->ready);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    event_set(&th->done);
  }
  return 0;
}

static void execute_one(void)
{
  int i, call, thread;
  for (call = 0; call < 7; call++) {
    for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0]));
         thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        event_init(&th->ready);
        event_init(&th->done);
        event_set(&th->done);
        thread_start(thr, th);
      }
      if (!event_isset(&th->done))
        continue;
      event_reset(&th->done);
      th->call = call;
      __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
      event_set(&th->ready);
      event_timedwait(&th->done, 50);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter = 0;
  for (;; iter++) {
    char cwdbuf[32];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      exit(1);
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      if (chdir(cwdbuf))
        exit(1);
      setup_test();
      execute_one();
      exit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      sleep_ms(1);
      if (current_time_ms() - start < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
    remove_dir(cwdbuf);
  }
}

uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff};

void execute_call(int call)
{
  intptr_t res = 0;
  switch (call) {
  case 0:
    memcpy((void*)0x20000100, "./file0\000", 8);
    res = syscall(__NR_open, 0x20000100ul, 0x40c2ul, 0ul);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    syscall(__NR_openat, 0xffffffffffffff9cul, 0ul, 0x3f00ul, 0ul);
    break;
  case 2:
    memcpy((void*)0x20000080, "./file0\000", 8);
    res = syscall(__NR_open, 0x20000080ul, 0ul, 0ul);
    if (res != -1)
      r[1] = res;
    break;
  case 3:
    memcpy(
        (void*)0x20000600,
        "\x34\xfd\x98\xaa\x1d\x0e\x7a\xde\xc9\x37\xa5\xf3\x31\xa7\x5f\x48\x79"
        "\x34\xf5\x02\x42\xa0\x75\x19\x44\x93\x69\x72\x89\x6c\x29\xa5\x06\x8c"
        "\x8e\xcb\xa1\xaa\x0a\x4e\x2a\x63\x1b\x51\x80\xe1\xfb\xde\x79\xf4\x50"
        "\x2d\xc4\xc4\xa1\xfb\xa9\xdc\xd9\xed\x83\xe6\x39\xae\xfa\x1b\x87\x63"
        "\x1c\x33\xd1\xa8\x2c\xb0\xc0\x03\x56\x76\xdd\xfe\xb0\xfe\x79\x84\xd7"
        "\x51\x9b\x0f\x83\x9d\x49\x7f\xc9\xd6\x4e\xf1\x4d\x1d\xe2\x22\x20\xff"
        "\x26\x23\xdf\x49\x50\x13\x4b\x9f\xb7\x34\xa5\x2a\xda\xd9\x5f\x13\x1c"
        "\xce\x36\x72\xa9\xd7\xd7\xb4\x00\xd2\xc6\x28\x10\xb5\xf2\x03\x51\x63"
        "\x93\x30\x94\x81\x07\xbf\x8d\x45\x34\xa0\x3a\xc3\x89\x45\x5c\x54\xd8"
        "\xeb\x4d\x60\x9b\x3e\x85\x8b\x72\x13\xb3\x8e\xb0\x1f\x0e\xea\xba\x37"
        "\x39\xae\x92\x79\x16\xe2\x8d\xa6\xa7\x9a\x3f\xd5\xe3\x2d\x30\xab\x30"
        "\xbf\x95\x9d\x45\x96\xe5\xff\xbf\xf6\x78\x9a\x65\x0b\x9e\x7d\x24\x8d"
        "\x1b\xa8\x68\x01\x23\x36\xa4\xf3\xef\x8f\xab\x07\xa8\xf5\xb8\x1b\xb0"
        "\xbc\x45\xb2\x17\x45\x38\x31\x5c\xa1\x2b\x7c\x72\x3b\x21\x57\x56\x25"
        "\x64\xa8\xa1\xf1\x9d\x28\x17\x9f\x8c\x56\x54\x48\xe0\xe9\x21\xb8\xc3"
        "\xe6\xfc\x4a\xda\xaf\xa8\xb9\x29\xad\x07\x7f\x63\x33\x25\xb6\xa6\xf7"
        "\x1a\x58\x6c\xab\xc4\x88\x3e\x03\xe1\x93\x15\xf9\x46\xb2\x77\x85\x85"
        "\x93\xa7\x36\x7e\x23\x22\x02\xfe\x9a\xd6\x56\xc6\x76\x8a\x15\x17\xda"
        "\x7f\x04\x98\xb4\x8c\xb0\x78\xe9\x29\xfb\x11\xdb\x0c\xc5\x51\xf7\x54"
        "\xbf\xfc\x48\x59\xdd\x89\xa3\x96\x91\x5c\xc8\x09\xb0\x7d\x44\x85\x73"
        "\x09\x84\x09\xea\x21\x37\x10\x56\xf6\x7e\xf4\x11\x4e\xc1\x05\x47\xf4"
        "\x98\xd2\x45\x13\xfe\x59\x43\x08\xbf\x02\x28\x68\xad\x21\xe8\x5b\xba"
        "\x81\x19\x42\xfd\xc4\x51\x61\xa1\xa8\xa7\xfe\x00\xd5\xc6\xb0\x5e\xd7"
        "\x95\x4f\x63\x1b\xbd\x12\xa5\xc9\xa5\xcf\xa5\x96\x5e\x05\x95\xde\x60"
        "\x8b\x04\xeb\xe0\x2b\x3f\xcb\xf3\xb9\xf5\x78\x07\xa1\xa7\xad\x85\x28"
        "\x99\x2e\x2e\xc6\x59\x49\xda\x2f\x4a\x04\x78\xdf\xd3\xae\x52\x63\x9c"
        "\x15\xd8\xae\xaa\x35\x1d\xa6\xd3\x93\xb5\x8c\x77\x21\x68\xfa\xe6\x04"
        "\xd0\x97\xfe\xf4\xd6\xb9\x36\x0e\xb1\x69\xa0\xb0\xee\x70\xcd\xc2\x24"
        "\x35\xa0\x03\xe6\x86\x98\xf6\x1b\x3b\x63\xb1\xf5\x10\x11\xbc\x8f\x4e"
        "\xf9\x44\xc1\xde\x82\x17\x85\xf6\x70\x12\x4a\x1c\x6e\xd1\x83\x35\xd6"
        "\x34\x12",
        512);
    syscall(__NR_write, r[0], 0x20000600ul, 0x200ul);
    break;
  case 4:
    syscall(__NR_sendfile, r[0], r[1], 0ul, 0x7fffff2eul);
    break;
  case 5:
    memcpy((void*)0x20000040, "./file0\000", 8);
    res = syscall(__NR_open, 0x20000040ul, 0x141042ul, 0ul);
    if (res != -1)
      r[2] = res;
    break;
  case 6:
    syscall(__NR_sendfile, r[2], r[0], 0ul, 0xffffff02ul);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
  syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul);
  syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
  for (procid = 0; procid < 6; procid++) {
    if (fork() == 0) {
      use_temporary_dir();
      loop();
    }
  }
  sleep(1000000);
  return 0;
}