// https://syzkaller.appspot.com/bug?id=6e999438b5ca079ecbd7d9c23e761327e8d48d8b
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <time.h>
#include <unistd.h>

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

uint64_t current_time_ms()
{
  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()
{
  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);
  if (pthread_create(&th, &attr, fn, arg))
    exit(1);
  pthread_attr_destroy(&attr);
}

typedef struct {
  pthread_mutex_t mu;
  pthread_cond_t cv;
  int state;
} event_t;

static void event_init(event_t* ev)
{
  if (pthread_mutex_init(&ev->mu, 0))
    exit(1);
  if (pthread_cond_init(&ev->cv, 0))
    exit(1);
  ev->state = 0;
}

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

static void event_set(event_t* ev)
{
  pthread_mutex_lock(&ev->mu);
  if (ev->state)
    exit(1);
  ev->state = 1;
  pthread_mutex_unlock(&ev->mu);
  pthread_cond_broadcast(&ev->cv);
}

static void event_wait(event_t* ev)
{
  pthread_mutex_lock(&ev->mu);
  while (!ev->state)
    pthread_cond_wait(&ev->cv, &ev->mu);
  pthread_mutex_unlock(&ev->mu);
}

static int event_isset(event_t* ev)
{
  pthread_mutex_lock(&ev->mu);
  int res = ev->state;
  pthread_mutex_unlock(&ev->mu);
  return res;
}

static int event_timedwait(event_t* ev, uint64_t timeout_ms)
{
  struct timespec ts;
  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    exit(1);
  const uint64_t kNsPerSec = 1000 * 1000 * 1000;
  uint64_t start_ns = (uint64_t)ts.tv_sec * kNsPerSec + (uint64_t)ts.tv_nsec;
  uint64_t timeout_ns = timeout_ms * 1000 * 1000;
  pthread_mutex_lock(&ev->mu);
  for (;;) {
    if (ev->state)
      break;
    if (clock_gettime(CLOCK_MONOTONIC, &ts))
      exit(1);
    uint64_t now_ns = (uint64_t)ts.tv_sec * kNsPerSec + (uint64_t)ts.tv_nsec;
    if (now_ns - start_ns > timeout_ns)
      break;
    uint64_t remain_ns = timeout_ns - (now_ns - start_ns);
    ts.tv_sec = remain_ns / kNsPerSec;
    ts.tv_nsec = remain_ns % kNsPerSec;
    pthread_cond_timedwait(&ev->cv, &ev->mu, &ts);
  }
  int res = ev->state;
  pthread_mutex_unlock(&ev->mu);
  return res;
}

static void loop();
static int do_sandbox_none(void)
{
  loop();
  exit(0);
}

#define do_sandbox_setuid() 0
#define do_sandbox_namespace() 0
#define setup_loop()
#define reset_loop()
#define setup_test()
#define reset_test()

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 int collide;

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(int num_calls)
{
  int call, thread;
  running = 0;
  for (call = 0; call < num_calls; call++) {
    for (thread = 0; thread < 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);
      if (collide && (call % 2) == 0)
        break;
      event_timedwait(&th->done, 25);
      if (__atomic_load_n(&running, __ATOMIC_RELAXED))
        sleep_ms((call == num_calls - 1) ? 10 : 2);
      break;
    }
  }
}

void execute_call(int call)
{
  switch (call) {
  case 0:
    memcpy((void*)0x20000300, "./file0", 8);
    memcpy((void*)0x20000340, "", 1);
    syscall(SYS_proc_create, 0x20000300, 8, 0x20000340, 1, 1);
    break;
  case 1:
    memcpy((void*)0x20000400, "./file0", 8);
    memcpy((void*)0x20000440, "./file0", 8);
    syscall(SYS_nbind, 0x20000400, 8, 0x20000440, 8, 0x10);
    break;
  case 2:
    memcpy((void*)0x20000600, "./file0/file0", 14);
    memcpy((void*)0x20000640, "./file0", 8);
    syscall(SYS_symlink, 0x20000600, 0xe, 0x20000640, 8);
    break;
  }
}

void loop()
{
  execute(3);
  collide = 1;
  execute(3);
}

int main()
{
  syscall(SYS_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  use_temporary_dir();
  do_sandbox_none();
  return 0;
}