text: // general protection fault in hrtimer_try_to_cancel
  // https://syzkaller.appspot.com/bug?id=6bfb30abbbdee95159eb
  // status:0
  // autogenerated by syzkaller (https://github.com/google/syzkaller)
  
  #define _GNU_SOURCE
  
  #include <dirent.h>
  #include <endian.h>
  #include <errno.h>
  #include <fcntl.h>
  #include <pthread.h>
  #include <signal.h>
  #include <stdarg.h>
  #include <stdbool.h>
  #include <stdint.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <sys/mman.h>
  #include <sys/prctl.h>
  #include <sys/stat.h>
  #include <sys/syscall.h>
  #include <sys/types.h>
  #include <sys/wait.h>
  #include <time.h>
  #include <unistd.h>
  
  #include <linux/futex.h>
  
  static unsigned long long procid;
  
  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 = 0;
    for (; 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;
    }
  }
  
  static bool write_file(const char* file, const char* what, ...)
  {
    char buf[1024];
    va_list args;
    va_start(args, what);
    vsnprintf(buf, sizeof(buf), what, args);
    va_end(args);
    buf[sizeof(buf) - 1] = 0;
    int len = strlen(buf);
    int fd = open(file, O_WRONLY | O_CLOEXEC);
    if (fd == -1)
      return false;
    if (write(fd, buf, len) != len) {
      int err = errno;
      close(fd);
      errno = err;
      return false;
    }
    close(fd);
    return true;
  }
  
  #define SIZEOF_IO_URING_SQE 64
  #define SIZEOF_IO_URING_CQE 16
  #define SQ_HEAD_OFFSET 0
  #define SQ_TAIL_OFFSET 64
  #define SQ_RING_MASK_OFFSET 256
  #define SQ_RING_ENTRIES_OFFSET 264
  #define SQ_FLAGS_OFFSET 276
  #define SQ_DROPPED_OFFSET 272
  #define CQ_HEAD_OFFSET 128
  #define CQ_TAIL_OFFSET 192
  #define CQ_RING_MASK_OFFSET 260
  #define CQ_RING_ENTRIES_OFFSET 268
  #define CQ_RING_OVERFLOW_OFFSET 284
  #define CQ_FLAGS_OFFSET 280
  #define CQ_CQES_OFFSET 320
  
  struct io_sqring_offsets {
    uint32_t head;
    uint32_t tail;
    uint32_t ring_mask;
    uint32_t ring_entries;
    uint32_t flags;
    uint32_t dropped;
    uint32_t array;
    uint32_t resv1;
    uint64_t resv2;
  };
  
  struct io_cqring_offsets {
    uint32_t head;
    uint32_t tail;
    uint32_t ring_mask;
    uint32_t ring_entries;
    uint32_t overflow;
    uint32_t cqes;
    uint64_t resv[2];
  };
  
  struct io_uring_params {
    uint32_t sq_entries;
    uint32_t cq_entries;
    uint32_t flags;
    uint32_t sq_thread_cpu;
    uint32_t sq_thread_idle;
    uint32_t features;
    uint32_t resv[4];
    struct io_sqring_offsets sq_off;
    struct io_cqring_offsets cq_off;
  };
  
  #define IORING_OFF_SQ_RING 0
  #define IORING_OFF_SQES 0x10000000ULL
  
  #define sys_io_uring_setup 425
  static long syz_io_uring_setup(volatile long a0, volatile long a1,
                                 volatile long a2, volatile long a3,
                                 volatile long a4, volatile long a5)
  {
    uint32_t entries = (uint32_t)a0;
    struct io_uring_params* setup_params = (struct io_uring_params*)a1;
    void* vma1 = (void*)a2;
    void* vma2 = (void*)a3;
    void** ring_ptr_out = (void**)a4;
    void** sqes_ptr_out = (void**)a5;
    uint32_t fd_io_uring = syscall(sys_io_uring_setup, entries, setup_params);
    uint32_t sq_ring_sz =
        setup_params->sq_off.array + setup_params->sq_entries * sizeof(uint32_t);
    uint32_t cq_ring_sz = setup_params->cq_off.cqes +
                          setup_params->cq_entries * SIZEOF_IO_URING_CQE;
    uint32_t ring_sz = sq_ring_sz > cq_ring_sz ? sq_ring_sz : cq_ring_sz;
    *ring_ptr_out = mmap(vma1, ring_sz, PROT_READ | PROT_WRITE,
                         MAP_SHARED | MAP_POPULATE | MAP_FIXED, fd_io_uring,
                         IORING_OFF_SQ_RING);
    uint32_t sqes_sz = setup_params->sq_entries * SIZEOF_IO_URING_SQE;
    *sqes_ptr_out =
        mmap(vma2, sqes_sz, PROT_READ | PROT_WRITE,
             MAP_SHARED | MAP_POPULATE | MAP_FIXED, fd_io_uring, IORING_OFF_SQES);
    return fd_io_uring;
  }
  
  static long syz_io_uring_submit(volatile long a0, volatile long a1,
                                  volatile long a2, volatile long a3)
  {
    char* ring_ptr = (char*)a0;
    char* sqes_ptr = (char*)a1;
    char* sqe = (char*)a2;
    uint32_t sqes_index = (uint32_t)a3;
    uint32_t sq_ring_entries = *(uint32_t*)(ring_ptr + SQ_RING_ENTRIES_OFFSET);
    uint32_t cq_ring_entries = *(uint32_t*)(ring_ptr + CQ_RING_ENTRIES_OFFSET);
    uint32_t sq_array_off =
        (CQ_CQES_OFFSET + cq_ring_entries * SIZEOF_IO_URING_CQE + 63) & ~63;
    if (sq_ring_entries)
      sqes_index %= sq_ring_entries;
    char* sqe_dest = sqes_ptr + sqes_index * SIZEOF_IO_URING_SQE;
    memcpy(sqe_dest, sqe, SIZEOF_IO_URING_SQE);
    uint32_t sq_ring_mask = *(uint32_t*)(ring_ptr + SQ_RING_MASK_OFFSET);
    uint32_t* sq_tail_ptr = (uint32_t*)(ring_ptr + SQ_TAIL_OFFSET);
    uint32_t sq_tail = *sq_tail_ptr & sq_ring_mask;
    uint32_t sq_tail_next = *sq_tail_ptr + 1;
    uint32_t* sq_array = (uint32_t*)(ring_ptr + sq_array_off);
    *(sq_array + sq_tail) = sqes_index;
    __atomic_store_n(sq_tail_ptr, sq_tail_next, __ATOMIC_RELEASE);
    return 0;
  }
  
  static void kill_and_wait(int pid, int* status)
  {
    kill(-pid, SIGKILL);
    kill(pid, SIGKILL);
    for (int i = 0; i < 100; i++) {
      if (waitpid(-1, status, WNOHANG | __WALL) == pid)
        return;
      usleep(1000);
    }
    DIR* dir = opendir("/sys/fs/fuse/connections");
    if (dir) {
      for (;;) {
        struct dirent* ent = readdir(dir);
        if (!ent)
          break;
        if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0)
          continue;
        char abort[300];
        snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort",
                 ent->d_name);
        int fd = open(abort, O_WRONLY);
        if (fd == -1) {
          continue;
        }
        if (write(fd, abort, 1) < 0) {
        }
        close(fd);
      }
      closedir(dir);
    } else {
    }
    while (waitpid(-1, status, __WALL) != pid) {
    }
  }
  
  static void setup_test()
  {
    prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
    setpgrp();
    write_file("/proc/self/oom_score_adj", "1000");
  }
  
  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 execute_one(void)
  {
    int i, call, thread;
    int collide = 0;
  again:
    for (call = 0; call < 3; 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);
        if (collide && (call % 2) == 0)
          break;
        event_timedwait(&th->done, 50);
        break;
      }
    }
    for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
      sleep_ms(1);
    if (!collide) {
      collide = 1;
      goto again;
    }
  }
  
  static void execute_one(void);
  
  #define WAIT_FLAGS __WALL
  
  static void loop(void)
  {
    int iter = 0;
    for (;; iter++) {
      int pid = fork();
      if (pid < 0)
        exit(1);
      if (pid == 0) {
        setup_test();
        execute_one();
        exit(0);
      }
      int status = 0;
      uint64_t start = current_time_ms();
      for (;;) {
        if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
          break;
        sleep_ms(1);
        if (current_time_ms() - start < 5000) {
          continue;
        }
        kill_and_wait(pid, &status);
        break;
      }
    }
  }
  
  uint64_t r[2] = {0x0, 0x0};
  
  void execute_call(int call)
  {
    intptr_t res = 0;
    switch (call) {
    case 0:
      *(uint32_t*)0x20001604 = 0;
      *(uint32_t*)0x20001608 = 2;
      *(uint32_t*)0x2000160c = 0;
      *(uint32_t*)0x20001610 = 0;
      *(uint32_t*)0x20001618 = 0;
      memset((void*)0x2000161c, 0, 12);
      res = -1;
      res = syz_io_uring_setup(0x2deb, 0x20001600, 0x20002000, 0x20ffb000,
                               0x20000100, 0x20000000);
      if (res != -1) {
        r[0] = *(uint64_t*)0x20000100;
        r[1] = *(uint64_t*)0x20000000;
      }
      break;
    case 1:
      memcpy((void*)0x20002040, "./file0/file0\000", 14);
      syscall(__NR_openat, 0xffffff9c, 0x20002040ul, 0ul, 0ul);
      break;
    case 2:
      *(uint8_t*)0x200001c0 = 0xb;
      *(uint8_t*)0x200001c1 = 0;
      *(uint16_t*)0x200001c2 = 0;
      *(uint32_t*)0x200001c4 = 0;
      *(uint64_t*)0x200001c8 = 0xa;
      *(uint64_t*)0x200001d0 = 0x20000140;
      *(uint64_t*)0x20000140 = 0;
      *(uint64_t*)0x20000148 = 0x989680;
      *(uint32_t*)0x200001d8 = 1;
      *(uint32_t*)0x200001dc = 0;
      *(uint64_t*)0x200001e0 = 0;
      *(uint16_t*)0x200001e8 = 0;
      *(uint16_t*)0x200001ea = 0;
      memset((void*)0x200001ec, 0, 20);
      syz_io_uring_submit(r[0], r[1], 0x200001c0, 0);
      break;
    }
  }
  int main(void)
  {
    syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
    syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul);
    syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
    for (procid = 0; procid < 6; procid++) {
      if (fork() == 0) {
        loop();
      }
    }
    sleep(1000000);
    return 0;
  }
  