// https://syzkaller.appspot.com/bug?id=c14270323f22e896228f470164aac59114d388be
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <linux/futex.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <sys/prctl.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 <errno.h>
#include <setjmp.h>
#include <signal.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string.h>
#include <sys/stat.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 void exitf(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(kRetryStatus);
}

static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* uctx)
{
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) &&
      (addr < prog_start || addr > prog_end)) {
    _longjmp(segv_env, 1);
  }
  doexit(sig);
}

static void install_segv_handler()
{
  struct sigaction sa;

  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = SIG_IGN;
  syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8);
  syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8);

  memset(&sa, 0, sizeof(sa));
  sa.sa_sigaction = segv_handler;
  sa.sa_flags = SA_NODEFER | SA_SIGINFO;
  sigaction(SIGSEGV, &sa, NULL);
  sigaction(SIGBUS, &sa, NULL);
}

#define NONFAILING(...)                                                        \
  {                                                                            \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    }                                                                          \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
  }

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 void use_temporary_dir()
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    fail("failed to mkdtemp");
  if (chmod(tmpdir, 0777))
    fail("failed to chmod");
  if (chdir(tmpdir))
    fail("failed to chdir");
}

static void remove_dir(const char* dir)
{
  DIR* dp;
  struct dirent* ep;
  int iter = 0;
retry:
  while (umount2(dir, MNT_DETACH) == 0) {
  }
  dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EMFILE) {
      exitf("opendir(%s) failed due to NOFILE, exiting", dir);
    }
    exitf("opendir(%s) failed", dir);
  }
  while ((ep = readdir(dp))) {
    if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
      continue;
    char filename[FILENAME_MAX];
    snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
    while (umount2(filename, MNT_DETACH) == 0) {
    }
    struct stat st;
    if (lstat(filename, &st))
      exitf("lstat(%s) failed", filename);
    if (S_ISDIR(st.st_mode)) {
      remove_dir(filename);
      continue;
    }
    int i;
    for (i = 0;; i++) {
      if (unlink(filename) == 0)
        break;
      if (errno == EROFS) {
        break;
      }
      if (errno != EBUSY || i > 100)
        exitf("unlink(%s) failed", filename);
      if (umount2(filename, MNT_DETACH))
        exitf("umount(%s) failed", filename);
    }
  }
  closedir(dp);
  int i;
  for (i = 0;; i++) {
    if (rmdir(dir) == 0)
      break;
    if (i < 100) {
      if (errno == EROFS) {
        break;
      }
      if (errno == EBUSY) {
        if (umount2(dir, MNT_DETACH))
          exitf("umount(%s) failed", dir);
        continue;
      }
      if (errno == ENOTEMPTY) {
        if (iter < 100) {
          iter++;
          goto retry;
        }
      }
    }
    exitf("rmdir(%s) failed", dir);
  }
}

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

static void loop()
{
  int iter;
  for (iter = 0;; iter++) {
    char cwdbuf[32];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      fail("failed to mkdir");
    int pid = fork();
    if (pid < 0)
      fail("clone failed");
    if (pid == 0) {
      prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
      setpgrp();
      if (chdir(cwdbuf))
        fail("failed to chdir");
      execute_one();
      int fd;
      for (fd = 3; fd < 30; fd++)
        close(fd);
      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)
        continue;
      kill(-pid, SIGKILL);
      kill(pid, SIGKILL);
      while (waitpid(-1, &status, __WALL) != pid) {
      }
      break;
    }
    remove_dir(cwdbuf);
  }
}

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 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);
        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[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0x0};
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    res = syscall(__NR_pipe2, 0x20000000, 0);
    if (res != -1) {
      NONFAILING(r[0] = *(uint32_t*)0x20000000);
      NONFAILING(r[1] = *(uint32_t*)0x20000004);
    }
    break;
  case 1:
    NONFAILING(*(uint32_t*)0x200000c0 = 0x62);
    NONFAILING(*(uint8_t*)0x200000c4 = 7);
    NONFAILING(*(uint16_t*)0x200000c5 = -1);
    NONFAILING(*(uint16_t*)0x200000c7 = 0x55);
    NONFAILING(memcpy(
        (void*)0x200000c9,
        "\x65\x74\x68\x30\x65\x6d\x31\xc3\x60\x9e\x6e\xd9\xa7\x3b\x13\x44\x1a"
        "\x17\xec\x3e\x11\xba\x03\x13\x50\x64\x37\xad\x8f\x03\x60\x51\xbd\xe3"
        "\x62\x88\x3f\xf1\x75\x1b\x24\x53\x1c\x8d\x59\x27\x08\x1d\xe9\x6a\x18"
        "\x12\x43\xe1\x22\x96\x54\xb2\x2d\x5c\xb6\x05\x13\x36\x2a\x8f\xeb\xc3"
        "\x19\x5f\x6c\x13\x76\x07\xfa\x00\xef\xeb\xcf\x5f\xc9\x7c\xfb\x5e\x5e",
        85));
    NONFAILING(*(uint32_t*)0x2000011e = 0);
    syscall(__NR_write, r[1], 0x200000c0, 0x62);
    break;
  case 2:
    NONFAILING(memcpy((void*)0x20000440, "./file0", 8));
    syscall(__NR_mkdir, 0x20000440, 0);
    break;
  case 3:
    NONFAILING(*(uint32_t*)0x20000200 = 0xc);
    res = syscall(__NR_getsockopt, 0xffffff9c, 1, 0x11, 0x200001c0, 0x20000200);
    if (res != -1)
      NONFAILING(r[2] = *(uint32_t*)0x200001c8);
    break;
  case 4:
    NONFAILING(memcpy((void*)0x200005c0, "./file0", 8));
    NONFAILING(memcpy((void*)0x20000180, "9p", 3));
    NONFAILING(memcpy((void*)0x20000240, "trans=fd,", 9));
    NONFAILING(memcpy((void*)0x20000249, "rfdno", 5));
    NONFAILING(*(uint8_t*)0x2000024e = 0x3d);
    NONFAILING(sprintf((char*)0x2000024f, "0x%016llx", (long long)r[0]));
    NONFAILING(*(uint8_t*)0x20000261 = 0x2c);
    NONFAILING(memcpy((void*)0x20000262, "wfdno", 5));
    NONFAILING(*(uint8_t*)0x20000267 = 0x3d);
    NONFAILING(sprintf((char*)0x20000268, "0x%016llx", (long long)r[0]));
    NONFAILING(*(uint8_t*)0x2000027a = 0x2c);
    NONFAILING(memcpy((void*)0x2000027b, "mmap", 4));
    NONFAILING(*(uint8_t*)0x2000027f = 0x2c);
    NONFAILING(memcpy((void*)0x20000280, "cache=none", 10));
    NONFAILING(*(uint8_t*)0x2000028a = 0x2c);
    NONFAILING(memcpy((void*)0x2000028b, "cachetag", 8));
    NONFAILING(*(uint8_t*)0x20000293 = 0x3d);
    NONFAILING(memcpy((void*)0x20000294, "]procvmnet0/", 12));
    NONFAILING(*(uint8_t*)0x200002a0 = 0x2c);
    NONFAILING(memcpy((void*)0x200002a1, "cache=loose", 11));
    NONFAILING(*(uint8_t*)0x200002ac = 0x2c);
    NONFAILING(memcpy((void*)0x200002ad, "cache=fscache", 13));
    NONFAILING(*(uint8_t*)0x200002ba = 0x2c);
    NONFAILING(memcpy((void*)0x200002bb, "access=client", 13));
    NONFAILING(*(uint8_t*)0x200002c8 = 0x2c);
    NONFAILING(memcpy((void*)0x200002c9, "version=9p2000", 14));
    NONFAILING(*(uint8_t*)0x200002d7 = 0x2c);
    NONFAILING(memcpy((void*)0x200002d8, "dfltgid", 7));
    NONFAILING(*(uint8_t*)0x200002df = 0x3d);
    NONFAILING(sprintf((char*)0x200002e0, "0x%016llx", (long long)r[2]));
    NONFAILING(*(uint8_t*)0x200002f2 = 0x2c);
    NONFAILING(memcpy((void*)0x200002f3, "version=9p2000.L", 16));
    NONFAILING(*(uint8_t*)0x20000303 = 0x2c);
    NONFAILING(*(uint8_t*)0x20000304 = 0);
    syscall(__NR_mount, 0, 0x200005c0, 0x20000180, 0, 0x20000240);
    break;
  }
}

void execute_one()
{
  execute(5);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  install_segv_handler();
  char* cwd = get_current_dir_name();
  for (;;) {
    if (chdir(cwd))
      fail("failed to chdir");
    use_temporary_dir();
    loop();
  }
}