// https://syzkaller.appspot.com/bug?id=b31b2c5e67537a11009a11871c714d4e5eb5e689
// 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 test();

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

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;
      }
    }
  }
}

long r[2];
void execute_call(int call)
{
  switch (call) {
  case 0:
    syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0);
    break;
  case 1:
    memcpy((void*)0x20bb8000, "net/ip6_mr_cache", 17);
    r[0] = syz_open_procfs(0, 0x20bb8000);
    break;
  case 2:
    syscall(__NR_pread64, r[0], 0x20caef7b, 0x85, 0x4c);
    break;
  case 3:
    r[1] = syscall(__NR_socket, 0xa, 2, 0);
    break;
  case 4:
    *(uint16_t*)0x20978fa4 = 0xa;
    *(uint16_t*)0x20978fa6 = htobe16(0x4e20);
    *(uint32_t*)0x20978fa8 = 0;
    *(uint8_t*)0x20978fac = 0;
    *(uint8_t*)0x20978fad = 0;
    *(uint8_t*)0x20978fae = 0;
    *(uint8_t*)0x20978faf = 0;
    *(uint8_t*)0x20978fb0 = 0;
    *(uint8_t*)0x20978fb1 = 0;
    *(uint8_t*)0x20978fb2 = 0;
    *(uint8_t*)0x20978fb3 = 0;
    *(uint8_t*)0x20978fb4 = 0;
    *(uint8_t*)0x20978fb5 = 0;
    *(uint8_t*)0x20978fb6 = 0;
    *(uint8_t*)0x20978fb7 = 0;
    *(uint8_t*)0x20978fb8 = 0;
    *(uint8_t*)0x20978fb9 = 0;
    *(uint8_t*)0x20978fba = 0;
    *(uint8_t*)0x20978fbb = 0;
    *(uint32_t*)0x20978fbc = 0;
    *(uint16_t*)0x20978fc0 = 0xa;
    *(uint16_t*)0x20978fc2 = htobe16(0x4e20);
    *(uint32_t*)0x20978fc4 = 0;
    *(uint8_t*)0x20978fc8 = 0;
    *(uint8_t*)0x20978fc9 = 0;
    *(uint8_t*)0x20978fca = 0;
    *(uint8_t*)0x20978fcb = 0;
    *(uint8_t*)0x20978fcc = 0;
    *(uint8_t*)0x20978fcd = 0;
    *(uint8_t*)0x20978fce = 0;
    *(uint8_t*)0x20978fcf = 0;
    *(uint8_t*)0x20978fd0 = 0;
    *(uint8_t*)0x20978fd1 = 0;
    *(uint8_t*)0x20978fd2 = 0;
    *(uint8_t*)0x20978fd3 = 0;
    *(uint8_t*)0x20978fd4 = 0;
    *(uint8_t*)0x20978fd5 = 0;
    *(uint8_t*)0x20978fd6 = 0;
    *(uint8_t*)0x20978fd7 = 0;
    *(uint32_t*)0x20978fd8 = 0;
    *(uint16_t*)0x20978fdc = 0;
    *(uint32_t*)0x20978fe0 = 0xf67;
    *(uint32_t*)0x20978fe4 = 0;
    *(uint32_t*)0x20978fe8 = 0;
    *(uint32_t*)0x20978fec = 0;
    *(uint32_t*)0x20978ff0 = 0;
    *(uint32_t*)0x20978ff4 = 0;
    *(uint32_t*)0x20978ff8 = 0;
    *(uint32_t*)0x20978ffc = 0;
    syscall(__NR_setsockopt, r[1], 0x29, 0xd2, 0x20978fa4, 0x5c);
    break;
  }
}

void test()
{
  memset(r, -1, sizeof(r));
  execute(5);
  collide = 1;
  execute(5);
}

int main()
{
  for (;;) {
    loop();
  }
}