// https://syzkaller.appspot.com/bug?id=b31b2c5e67537a11009a11871c714d4e5eb5e689
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/futex.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

__attribute__((noreturn)) static void doexit(int status)
{
  volatile unsigned i;
  syscall(__NR_exit_group, status);
  for (i = 0;; i++) {
  }
}
#include <stdint.h>
#include <string.h>

const int kFailStatus = 67;
const int kRetryStatus = 69;

static void fail(const char* msg, ...)
{
  int e = errno;
  va_list args;
  va_start(args, msg);
  vfprintf(stderr, msg, args);
  va_end(args);
  fprintf(stderr, " (errno %d)\n", e);
  doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus);
}

static uint64_t current_time_ms()
{
  struct timespec ts;

  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    fail("clock_gettime failed");
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

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()
{
  int iter;
  for (iter = 0;; iter++) {
    int pid = fork();
    if (pid < 0)
      fail("loop fork failed");
    if (pid == 0) {
      prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
      setpgrp();
      test();
      doexit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      int res = waitpid(-1, &status, __WALL | WNOHANG);
      if (res == pid)
        break;
      usleep(1000);
      if (current_time_ms() - start > 5 * 1000) {
        kill(-pid, SIGKILL);
        kill(pid, SIGKILL);
        while (waitpid(-1, &status, __WALL) != pid) {
        }
        break;
      }
    }
  }
}

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;
      }
    }
  }
}

#ifndef __NR_mmap
#define __NR_mmap 192
#endif
#ifndef __NR_pread64
#define __NR_pread64 180
#endif
#ifndef __NR_readv
#define __NR_readv 145
#endif
#ifndef __NR_socket
#define __NR_socket 359
#endif
#ifndef __NR_setsockopt
#define __NR_setsockopt 366
#endif
#undef __NR_mmap
#define __NR_mmap __NR_mmap2

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, 0, 0x4c);
    break;
  case 3:
    *(uint32_t*)0x20917fb0 = 0x20131f47;
    *(uint32_t*)0x20917fb4 = 6;
    *(uint32_t*)0x20917fb8 = 0x20a87f2b;
    *(uint32_t*)0x20917fbc = 0x62;
    syscall(__NR_readv, r[0], 0x20917fb0, 2);
    break;
  case 4:
    r[1] = syscall(__NR_socket, 0xa, 2, 0);
    break;
  case 5:
    *(uint16_t*)0x20b82000 = 0xa;
    *(uint16_t*)0x20b82002 = htobe16(0x4e21);
    *(uint32_t*)0x20b82004 = 4;
    *(uint64_t*)0x20b82008 = htobe64(0);
    *(uint64_t*)0x20b82010 = htobe64(1);
    *(uint32_t*)0x20b82018 = 0x83;
    *(uint16_t*)0x20b8201c = 0xa;
    *(uint16_t*)0x20b8201e = htobe16(0x4e23);
    *(uint32_t*)0x20b82020 = 0xfffff000;
    *(uint8_t*)0x20b82024 = 0;
    *(uint8_t*)0x20b82025 = 0;
    *(uint8_t*)0x20b82026 = 0;
    *(uint8_t*)0x20b82027 = 0;
    *(uint8_t*)0x20b82028 = 0;
    *(uint8_t*)0x20b82029 = 0;
    *(uint8_t*)0x20b8202a = 0;
    *(uint8_t*)0x20b8202b = 0;
    *(uint8_t*)0x20b8202c = 0;
    *(uint8_t*)0x20b8202d = 0;
    *(uint8_t*)0x20b8202e = 0;
    *(uint8_t*)0x20b8202f = 0;
    *(uint8_t*)0x20b82030 = 0;
    *(uint8_t*)0x20b82031 = 0;
    *(uint8_t*)0x20b82032 = 0;
    *(uint8_t*)0x20b82033 = 0;
    *(uint32_t*)0x20b82034 = 2;
    *(uint16_t*)0x20b82038 = 1;
    *(uint32_t*)0x20b8203c = 9;
    *(uint32_t*)0x20b82040 = 0x101;
    *(uint32_t*)0x20b82044 = 0x1000;
    *(uint32_t*)0x20b82048 = 0;
    *(uint32_t*)0x20b8204c = 7;
    *(uint32_t*)0x20b82050 = 7;
    *(uint32_t*)0x20b82054 = 0;
    *(uint32_t*)0x20b82058 = 0x7ff;
    syscall(__NR_setsockopt, r[1], 0x29, 0xd2, 0x20b82000, 0x5c);
    break;
  }
}

void test()
{
  memset(r, -1, sizeof(r));
  execute(6);
  collide = 1;
  execute(6);
}

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