// https://syzkaller.appspot.com/bug?id=630ebccafbca582c59fd98f6474a05fcfe09505b
// 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_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 (__atomic_load_n(&running, __ATOMIC_RELAXED))
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

uint64_t r[5] = {0x0, 0xffffffffffffffff, 0xffffffffffffffff, 0x0,
                 0xffffffffffffffff};
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    res = syscall(__NR_getpgrp, 0);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    syscall(__NR_ptrace, 5, r[0], 0x20000000, 7);
    break;
  case 2:
    memcpy((void*)0x20000040, "ns/cgroup", 10);
    syz_open_procfs(r[0], 0x20000040);
    break;
  case 3:
    *(uint32_t*)0x200000c0 = 0x1c;
    res = syscall(__NR_accept, -1, 0x20000080, 0x200000c0);
    if (res != -1)
      r[1] = res;
    break;
  case 4:
    syscall(__NR_ioctl, r[1], 0x8905, 0x20000100);
    break;
  case 5:
    memcpy((void*)0x20000140, "/dev/ptmx", 10);
    res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000140, 1, 0);
    if (res != -1)
      r[2] = res;
    break;
  case 6:
    *(uint32_t*)0x20000180 = 9;
    syscall(__NR_ioctl, r[2], 0x541a, 0x20000180);
    break;
  case 7:
    *(uint16_t*)0x200001c0 = 0xfffb;
    *(uint16_t*)0x200001c2 = 1;
    *(uint16_t*)0x200001c4 = 6;
    syscall(__NR_ioctl, r[2], 0x5603, 0x200001c0);
    break;
  case 8:
    res = syscall(__NR_ioctl, r[2], 0x5429, 0x20000200);
    if (res != -1)
      r[3] = *(uint32_t*)0x20000200;
    break;
  case 9:
    memcpy((void*)0x20000240, "\x6e\x61\x74\x00\x00\x00\x00\x00\x00\x00\x00\x00"
                              "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
                              "\x00\x00\x00\x00\x00\x00\x00\x00",
           32);
    *(uint32_t*)0x20000260 = 0;
    *(uint32_t*)0x20000264 = 0;
    *(uint32_t*)0x20000268 = 0;
    *(uint32_t*)0x2000026c = 0;
    *(uint32_t*)0x20000270 = 0;
    *(uint32_t*)0x20000274 = 0;
    *(uint32_t*)0x20000278 = 0;
    *(uint32_t*)0x2000027c = 0;
    *(uint32_t*)0x20000280 = 0;
    *(uint32_t*)0x20000284 = 0;
    *(uint32_t*)0x20000288 = 0;
    *(uint32_t*)0x2000028c = 0;
    *(uint32_t*)0x20000290 = 0;
    *(uint32_t*)0x200002c0 = 0x54;
    syscall(__NR_getsockopt, r[1], 0x29, 0x40, 0x20000240, 0x200002c0);
    break;
  case 10:
    memcpy((void*)0x20000300, "fd/4", 5);
    res = syz_open_procfs(r[3], 0x20000300);
    if (res != -1)
      r[4] = res;
    break;
  case 11:
    syscall(__NR_read, r[4], 0x20000800, 8);
    break;
  case 12:
    syscall(__NR_read, r[4], 0x20000e40, 8);
    break;
  }
}

void execute_one()
{
  execute(13);
  collide = 1;
  execute(13);
}

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