// https://syzkaller.appspot.com/bug?id=4c9c1b7813a6d4531a2782a893874061affc24bb
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <setjmp.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>

#include <linux/futex.h>
#include <linux/loop.h>

static unsigned long long procid;

static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* ctx)
{
  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);
  }
  exit(sig);
}

static void install_segv_handler(void)
{
  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 void sleep_ms(uint64_t ms)
{
  usleep(ms * 1000);
}

static uint64_t current_time_ms(void)
{
  struct timespec ts;
  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    exit(1);
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

static void thread_start(void* (*fn)(void*), void* arg)
{
  pthread_t th;
  pthread_attr_t attr;
  pthread_attr_init(&attr);
  pthread_attr_setstacksize(&attr, 128 << 10);
  int i;
  for (i = 0; i < 100; i++) {
    if (pthread_create(&th, &attr, fn, arg) == 0) {
      pthread_attr_destroy(&attr);
      return;
    }
    if (errno == EAGAIN) {
      usleep(50);
      continue;
    }
    break;
  }
  exit(1);
}

typedef struct {
  int state;
} event_t;

static void event_init(event_t* ev)
{
  ev->state = 0;
}

static void event_reset(event_t* ev)
{
  ev->state = 0;
}

static void event_set(event_t* ev)
{
  if (ev->state)
    exit(1);
  __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE);
  syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000);
}

static void event_wait(event_t* ev)
{
  while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0);
}

static int event_isset(event_t* ev)
{
  return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE);
}

static int event_timedwait(event_t* ev, uint64_t timeout)
{
  uint64_t start = current_time_ms();
  uint64_t now = start;
  for (;;) {
    uint64_t remain = timeout - (now - start);
    struct timespec ts;
    ts.tv_sec = remain / 1000;
    ts.tv_nsec = (remain % 1000) * 1000 * 1000;
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts);
    if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
      return 1;
    now = current_time_ms();
    if (now - start > timeout)
      return 0;
  }
}

struct fs_image_segment {
  void* data;
  uintptr_t size;
  uintptr_t offset;
};

#define IMAGE_MAX_SEGMENTS 4096
#define IMAGE_MAX_SIZE (129 << 20)

#define sys_memfd_create 319

static unsigned long fs_image_segment_check(unsigned long size,
                                            unsigned long nsegs, long segments)
{
  unsigned long i;
  struct fs_image_segment* segs = (struct fs_image_segment*)segments;
  if (nsegs > IMAGE_MAX_SEGMENTS)
    nsegs = IMAGE_MAX_SEGMENTS;
  for (i = 0; i < nsegs; i++) {
    if (segs[i].size > IMAGE_MAX_SIZE)
      segs[i].size = IMAGE_MAX_SIZE;
    segs[i].offset %= IMAGE_MAX_SIZE;
    if (segs[i].offset > IMAGE_MAX_SIZE - segs[i].size)
      segs[i].offset = IMAGE_MAX_SIZE - segs[i].size;
    if (size < segs[i].offset + segs[i].offset)
      size = segs[i].offset + segs[i].offset;
  }
  if (size > IMAGE_MAX_SIZE)
    size = IMAGE_MAX_SIZE;
  return size;
}

static long syz_mount_image(volatile long fsarg, volatile long dir,
                            volatile unsigned long size,
                            volatile unsigned long nsegs,
                            volatile long segments, volatile long flags,
                            volatile long optsarg)
{
  char loopname[64], fs[32], opts[256];
  int loopfd, err = 0, res = -1;
  unsigned long i;
  NONFAILING(size = fs_image_segment_check(size, nsegs, segments));
  int memfd = syscall(sys_memfd_create, "syz_mount_image", 0);
  if (memfd == -1) {
    err = errno;
    goto error;
  }
  if (ftruncate(memfd, size)) {
    err = errno;
    goto error_close_memfd;
  }
  for (i = 0; i < nsegs; i++) {
    struct fs_image_segment* segs = (struct fs_image_segment*)segments;
    int res1 = 0;
    NONFAILING(res1 =
                   pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset));
    if (res1 < 0) {
    }
  }
  snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid);
  loopfd = open(loopname, O_RDWR);
  if (loopfd == -1) {
    err = errno;
    goto error_close_memfd;
  }
  if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
    if (errno != EBUSY) {
      err = errno;
      goto error_close_loop;
    }
    ioctl(loopfd, LOOP_CLR_FD, 0);
    usleep(1000);
    if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
      err = errno;
      goto error_close_loop;
    }
  }
  mkdir((char*)dir, 0777);
  memset(fs, 0, sizeof(fs));
  NONFAILING(strncpy(fs, (char*)fsarg, sizeof(fs) - 1));
  memset(opts, 0, sizeof(opts));
  NONFAILING(strncpy(opts, (char*)optsarg, sizeof(opts) - 32));
  if (strcmp(fs, "iso9660") == 0) {
    flags |= MS_RDONLY;
  } else if (strncmp(fs, "ext", 3) == 0) {
    if (strstr(opts, "errors=panic") || strstr(opts, "errors=remount-ro") == 0)
      strcat(opts, ",errors=continue");
  } else if (strcmp(fs, "xfs") == 0) {
    strcat(opts, ",nouuid");
  }
  if (mount(loopname, (char*)dir, fs, flags, opts)) {
    err = errno;
    goto error_clear_loop;
  }
  res = 0;
error_clear_loop:
  ioctl(loopfd, LOOP_CLR_FD, 0);
error_close_loop:
  close(loopfd);
error_close_memfd:
  close(memfd);
error:
  errno = err;
  return res;
}

struct thread_t {
  int created, call;
  event_t ready, done;
};

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 (;;) {
    event_wait(&th->ready);
    event_reset(&th->ready);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    event_set(&th->done);
  }
  return 0;
}

static void loop(void)
{
  int i, call, thread;
  for (call = 0; call < 10; call++) {
    for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0]));
         thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        event_init(&th->ready);
        event_init(&th->done);
        event_set(&th->done);
        thread_start(thr, th);
      }
      if (!event_isset(&th->done))
        continue;
      event_reset(&th->done);
      th->call = call;
      __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
      event_set(&th->ready);
      event_timedwait(&th->done, 45 + (call == 6 ? 100 : 0));
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
}

uint64_t r[4] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff,
                 0xffffffffffffffff};

void execute_call(int call)
{
  intptr_t res;
  switch (call) {
  case 0:
    res = syscall(__NR_socket, 0x10ul, 3ul, 0);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    NONFAILING(*(uint64_t*)0x20000180 = 0);
    NONFAILING(*(uint32_t*)0x20000188 = 0);
    NONFAILING(*(uint64_t*)0x20000190 = 0x200000c0);
    NONFAILING(*(uint64_t*)0x200000c0 = 0x20000780);
    NONFAILING(memcpy((void*)0x20000780, "\x34\x00\x00\x00\x10\x00\x01\x04\x53"
                                         "\x93\x00\x00\x00\x00\x00\x00\x00\x00"
                                         "\x00\x00",
                      20));
    NONFAILING(*(uint32_t*)0x20000794 = -1);
    NONFAILING(memcpy(
        (void*)0x20000798,
        "\xdd\xff\xff\xff\xff\xff\xff\xff\x14\x00\x12\x00\x0c\x00\x01\x00\x62"
        "\x72\x69\x64\x67\x65\x00\x00\x04\x00\x02\x00\x4a\x7b\xcd\xad\x64\x5e"
        "\x2b\x4f\x43\x6b\x01\x4d\xbe\x92\xb1\x39\x58\x8c\x1b\x6a\x23\x8e\x3c"
        "\x4a\xd8\xaa\xf5\x0c\x71\xa9\x03\xef\xb4\xed\x6f\x54\x9d\x62\x0c\xab"
        "\x62\xd9\x81\xeb\x6d\x37\x49\x23\xa2\xb1\x59\x74\x49\x33\x19\x02\xca"
        "\x8b\xdf\x6a\x7b\x12\x8f\xe8\x47\x6d\x4d\x66\x52\x03\x77\x56\xd0\xac"
        "\x81\x39\x9a\xc0\x58\x2b\x15\x1d\x14\x1f\xe8\x3e\xd1\xd9\x13\x2a\xb0"
        "\x2d\x67\xc1\xc5\xac\xd5\x78\x9c\x48\x93\xdb\x25\xc5\x63\x0c\xca\x8a"
        "\x43\x0a\xef\xf8\x3d\xd7\x77\x0e\x54\x85\xb3\x58\x0e\x6c\x37\xcd\xf7"
        "\x8e\xba\xbc\x56\xf5\x54\xff\x14\x19\x6f\xa3\x47\x77\x4c\x41\x5a\xcd"
        "\xeb\x04\x6e\x3c\xf8\xa5\xaf\xb7\x0f\x63\x8e\xf5\x19\x60\x46\x04\xbd"
        "\xd8\xaf\x70\xdd\x52\xc2\x6f\x6c\x60\x3b\x8f\x3e\x34\xd0\x21\xaf\x63"
        "\xb3\xcf\xa8\x31\x6e\x16\xc3\x8c\xa7\x2e\x58\xc3\x56\xfd\xe8\x76\x43"
        "\xe8\xb8\x09\x31\x8f\x8d\x22\x2c\xe6\x52\x17\x9a\x6f\x2f\xbc\xde\xd4"
        "\x2f\xa3\xaa\x39\x4a\xde\x7d\xfe\x43\x9c\x64\x79\x60\x55\x28\x72\x6a"
        "\x06\x8c",
        257));
    NONFAILING(*(uint64_t*)0x200000c8 = 0x34);
    NONFAILING(*(uint64_t*)0x20000198 = 1);
    NONFAILING(*(uint64_t*)0x200001a0 = 0);
    NONFAILING(*(uint64_t*)0x200001a8 = 0);
    NONFAILING(*(uint32_t*)0x200001b0 = 0);
    syscall(__NR_sendmsg, r[0], 0x20000180ul, 0ul);
    break;
  case 2:
    res = syscall(__NR_pipe, 0x20000180ul);
    if (res != -1) {
      NONFAILING(r[1] = *(uint32_t*)0x20000180);
      NONFAILING(r[2] = *(uint32_t*)0x20000184);
    }
    break;
  case 3:
    res = syscall(__NR_socket, 2ul, 2ul, 0);
    if (res != -1)
      r[3] = res;
    break;
  case 4:
    syscall(__NR_close, r[3]);
    break;
  case 5:
    syscall(__NR_socket, 0x10ul, 3ul, 0);
    break;
  case 6:
    NONFAILING(memcpy((void*)0x20000040, "ext2\000", 5));
    syz_mount_image(0x20000040, 0, 0, 0, 0, 0, 0);
    break;
  case 7:
    NONFAILING(*(uint64_t*)0x200000c0 = 0);
    NONFAILING(*(uint32_t*)0x200000c8 = 0);
    NONFAILING(*(uint64_t*)0x200000d0 = 0x20000200);
    NONFAILING(*(uint64_t*)0x20000200 = 0x20000000);
    NONFAILING(memcpy((void*)0x20000000, "\x48\x00\x00\x00\x10\x00\x1f\xff\x00"
                                         "\x00\x05\x00\x00\x00\x00\x00\x00\x00"
                                         "\x00\x00",
                      20));
    NONFAILING(*(uint32_t*)0x20000014 = -1);
    NONFAILING(memcpy((void*)0x20000018, "\x00\x00\x00\x00\x00\x00\x18\x00\x28"
                                         "\x00\x12\x80\x0a\x00\x01\x00\x76\x78"
                                         "\x6c\x61\x6e\x00\x00\x00\x18\x00\x02"
                                         "\x80\x14\x00\x10",
                      31));
    NONFAILING(*(uint64_t*)0x20000208 = 3);
    NONFAILING(*(uint64_t*)0x200000d8 = 1);
    NONFAILING(*(uint64_t*)0x200000e0 = 0);
    NONFAILING(*(uint64_t*)0x200000e8 = 0);
    NONFAILING(*(uint32_t*)0x200000f0 = 0);
    syscall(__NR_sendmsg, -1, 0x200000c0ul, 0ul);
    break;
  case 8:
    syscall(__NR_write, r[2], 0x20000000ul, 0xfffffeccul);
    break;
  case 9:
    syscall(__NR_splice, r[1], 0ul, r[3], 0ul, 0x4ffe2ul, 0ul);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0ul);
  install_segv_handler();
  loop();
  return 0;
}