// https://syzkaller.appspot.com/bug?id=f775d15f3d6f727b2af84ed78e8e2af92d456aab
// 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 <linux/loop.h>
#include <pthread.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 <unistd.h>

extern unsigned long long procid;

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

#define IMAGE_MAX_SEGMENTS 4096
#define IMAGE_MAX_SIZE (32 << 20)

#define SYZ_memfd_create 319

static uintptr_t syz_mount_image(uintptr_t fs, uintptr_t dir, uintptr_t size,
                                 uintptr_t nsegs, uintptr_t segments,
                                 uintptr_t flags, uintptr_t opts)
{
  char loopname[64];
  int loopfd, err = 0, res = -1;
  uintptr_t 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;
  int memfd = syscall(SYZ_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++) {
    if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 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);
  if (strcmp((char*)fs, "iso9660") == 0)
    flags |= MS_RDONLY;
  if (mount(loopname, (char*)dir, (char*)fs, flags, (char*)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;
}

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 (running)
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

unsigned long long procid;
void execute_call(int call)
{
  switch (call) {
  case 0:
    memcpy((void*)0x20000000, "reiserfs", 9);
    memcpy((void*)0x20000100, "./file0", 8);
    *(uint64_t*)0x20000200 = 0x20010000;
    memcpy((void*)0x20010000,
           "\x00\x04\x00\x00\xec\x01\x00\x00\x13\x02\x00\x00\x12\x00\x00\x00"
           "\x00\x00\x00\x00\x00\x02\x00\x00\x00\x01\x00\x00\x36\x49\x6c\x67"
           "\xe1\x00\x00\x00\x1e\x00\x00\x00\x00\x00\x00\x00\x00\x10\xcc\x03"
           "\x02\x00\x01\x00\x52\x65\x49\x73\x45\x72\x33\x46\x73\x00\x00\x00"
           "\x03\x00\x00\x00\x02\x00\x01\x00",
           72);
    *(uint64_t*)0x20000208 = 0x48;
    *(uint64_t*)0x20000210 = 0x10000;
    *(uint64_t*)0x20000218 = 0x20010100;
    *(uint64_t*)0x20000220 = 0;
    *(uint64_t*)0x20000228 = 0x100c0;
    *(uint64_t*)0x20000230 = 0x20010200;
    *(uint64_t*)0x20000238 = 0;
    *(uint64_t*)0x20000240 = 0x11000;
    *(uint64_t*)0x20000248 = 0x20011200;
    memcpy((void*)0x20011200,
           "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x12\x00\x00\x00"
           "\x00\x00\x00\x00\x00\x02\x00\x00\x00\x01\x00\x00\x36\x49\x6c\x67"
           "\xe1\x00\x00\x00\x1e\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",
           64);
    *(uint64_t*)0x20000250 = 0x40;
    *(uint64_t*)0x20000258 = 0x212000;
    *(uint64_t*)0x20000260 = 0x20011300;
    memcpy((void*)0x20011300,
           "\x01\x00\x02\x00\x5c\x0f\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
           "\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00"
           "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x2c\x00\xd4\x0f\x01\x00"
           "\x01\x00\x00\x00\x02\x00\x00\x00\x01\x00\x00\x00\xf4\x01\x00\x00"
           "\x02\x00\x30\x00\xa4\x0f\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",
           96);
    *(uint64_t*)0x20000268 = 0x60;
    *(uint64_t*)0x20000270 = 0x213000;
    *(uint64_t*)0x20000278 = 0x20011400;
    memcpy((void*)0x20011400,
           "\x00\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00"
           "\x28\x00\x04\x00\x02\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00"
           "\x20\x00\x04\x00\x2e\x2e\x00\x00\x00\x00\x00\x00\x2e\x00\x00\x00"
           "\x00\x00\x00\x00\xed\x41\x00\x00\x03\x00\x00\x00\x30\x00\x00\x00"
           "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x65\x2a\xbd\x5a"
           "\x65\x2a\xbd\x5a\x65\x2a\xbd\x5a\x01\x00\x00\x00\x00\x00\x00\x00",
           96);
    *(uint64_t*)0x20000280 = 0x60;
    *(uint64_t*)0x20000288 = 0x213fa0;
    *(uint8_t*)0x20011500 = 0;
    syz_mount_image(0x20000000, 0x20000100, 0, 6, 0x20000200, 0, 0x20011500);
    break;
  }
}

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

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