// https://syzkaller.appspot.com/bug?id=5aa94f1e557739f58b236ca7c62e6e11af314694
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <fcntl.h>
#include <linux/futex.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <unistd.h>

static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2)
{
  if (a0 == 0xc || a0 == 0xb) {
    char buf[128];
    sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1,
            (uint8_t)a2);
    return open(buf, O_RDWR, 0);
  } else {
    char buf[1024];
    char* hash;
    strncpy(buf, (char*)a0, sizeof(buf) - 1);
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 0);
  }
}

static uintptr_t syz_open_procfs(uintptr_t a0, uintptr_t a1)
{

  char buf[128];
  memset(buf, 0, sizeof(buf));
  if (a0 == 0) {
    snprintf(buf, sizeof(buf), "/proc/self/%s", (char*)a1);
  } else if (a0 == (uintptr_t)-1) {
    snprintf(buf, sizeof(buf), "/proc/thread-self/%s", (char*)a1);
  } else {
    snprintf(buf, sizeof(buf), "/proc/self/task/%d/%s", (int)a0, (char*)a1);
  }
  int fd = open(buf, O_RDWR);
  if (fd == -1)
    fd = open(buf, O_RDONLY);
  return fd;
}

static void execute_one();
extern unsigned long long procid;

void loop()
{
  while (1) {
    execute_one();
  }
}

struct thread_t {
  int created, running, call;
  pthread_t th;
};

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 (;;) {
    while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE))
      syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE);
    syscall(SYS_futex, &th->running, FUTEX_WAKE);
  }
  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;
        pthread_attr_t attr;
        pthread_attr_init(&attr);
        pthread_attr_setstacksize(&attr, 128 << 10);
        pthread_create(&th->th, &attr, thr, th);
      }
      if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) {
        th->call = call;
        __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
        __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE);
        syscall(SYS_futex, &th->running, FUTEX_WAKE);
        if (collide && call % 2)
          break;
        struct timespec ts;
        ts.tv_sec = 0;
        ts.tv_nsec = 20 * 1000 * 1000;
        syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts);
        if (running)
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    memcpy((void*)0x20000200, "/dev/loop#", 11);
    res = syz_open_dev(0x20000200, 0, 0);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    syscall(__NR_ioctl, r[0], 0x4c06, r[0]);
    break;
  case 2:
    memcpy((void*)0x20000080,
           "\x2f\x65\x78\x65\x00\x00\x00\x00\x9e\xf3\x78\xd5\xeb\xfe\xf1\x95"
           "\x53\x4c\xd6\x00\x04\x09\x00\x4b\xdd\xd9\xde\x91\xbe\x10\xee\xbf"
           "\x00\x0e\xe9\xa9\x0f\x79\x80\x58\x43\x9e\xd5\x54\xfa\x07\x42\x4a"
           "\xde\xe9\x01\xd2\xda\x75\xaf\x1f\x02\x00\xf5\xab\x26\xd7\xa0\x71"
           "\xfb\x35\x33\x1c\xe3\x9c\x5a\x34\xd1\x86\xd1\x80\xa9\x64\xdb\x49"
           "\xbf\xff\x5f\x73\xbd\x3c\x85\x97\x1c\x33\xb1\x55\x85\x3d\xb0\x5d"
           "\x38\x87\x84\x99\xcd\x39\xf6\xc8\xc3\x30\xff\xa1\xec\x74\x23\x92"
           "\xac\x77\x99\x81\xc8\xab\xaa\x00\x00\x00\x00",
           123);
    res = syz_open_procfs(0, 0x20000080);
    if (res != -1)
      r[1] = res;
    break;
  case 3:
    syscall(__NR_ioctl, r[0], 0x4c00, r[1]);
    break;
  }
}

void execute_one()
{
  execute(4);
  collide = 1;
  execute(4);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  for (;;) {
    loop();
  }
}