// https://syzkaller.appspot.com/bug?id=a1d74e82a88d285ec1ba0999fc4b898c84f0fc92
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <setjmp.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

static __thread int clone_ongoing;
static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* ctx)
{
  if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) {
    exit(sig);
  }
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0;
  int valid = addr < prog_start || addr > prog_end;
  if (skip && valid) {
    _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(...)                                                        \
  ({                                                                           \
    int ok = 1;                                                                \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    } else                                                                     \
      ok = 0;                                                                  \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    ok;                                                                        \
  })

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;
}

static int inject_fault(int nth)
{
  int fd;
  fd = open("/proc/thread-self/fail-nth", O_RDWR);
  if (fd == -1)
    exit(1);
  char buf[16];
  sprintf(buf, "%d", nth);
  if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf))
    exit(1);
  return fd;
}

static const char* setup_fault()
{
  int fd = open("/proc/self/make-it-fail", O_WRONLY);
  if (fd == -1)
    return "CONFIG_FAULT_INJECTION is not enabled";
  close(fd);
  fd = open("/proc/thread-self/fail-nth", O_WRONLY);
  if (fd == -1)
    return "kernel does not have systematic fault injection support";
  close(fd);
  static struct {
    const char* file;
    const char* val;
    bool fatal;
  } files[] = {
      {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true},
      {"/sys/kernel/debug/fail_futex/ignore-private", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false},
  };
  unsigned i;
  for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) {
    if (!write_file(files[i].file, files[i].val)) {
      if (files[i].fatal)
        return "failed to write fault injection file";
    }
  }
  return NULL;
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};

int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  const char* reason;
  (void)reason;
  if ((reason = setup_fault()))
    printf("the reproducer may not work as expected: fault injection setup "
           "failed: %s\n",
           reason);
  install_segv_handler();
  intptr_t res = 0;
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  res = syscall(__NR_socket, /*domain=*/0x10ul, /*type=*/3ul, /*proto=*/0);
  if (res != -1)
    r[0] = res;
  NONFAILING(*(uint64_t*)0x20000100 = 0);
  NONFAILING(*(uint32_t*)0x20000108 = 0);
  NONFAILING(*(uint64_t*)0x20000110 = 0x200000c0);
  NONFAILING(*(uint64_t*)0x200000c0 = 0x20000140);
  NONFAILING(*(uint32_t*)0x20000140 = 0x1c);
  NONFAILING(*(uint16_t*)0x20000144 = 0x68);
  NONFAILING(*(uint16_t*)0x20000146 = 0x78e9);
  NONFAILING(*(uint32_t*)0x20000148 = 0);
  NONFAILING(*(uint32_t*)0x2000014c = 0);
  NONFAILING(*(uint8_t*)0x20000150 = 0xa);
  NONFAILING(*(uint8_t*)0x20000151 = 0);
  NONFAILING(*(uint8_t*)0x20000152 = 0);
  NONFAILING(*(uint8_t*)0x20000153 = 0);
  NONFAILING(*(uint32_t*)0x20000154 = 0);
  NONFAILING(*(uint16_t*)0x20000158 = 4);
  NONFAILING(*(uint16_t*)0x2000015a = 4);
  NONFAILING(*(uint64_t*)0x200000c8 = 0x1c);
  NONFAILING(*(uint64_t*)0x20000118 = 1);
  NONFAILING(*(uint64_t*)0x20000120 = 0);
  NONFAILING(*(uint64_t*)0x20000128 = 0);
  NONFAILING(*(uint32_t*)0x20000130 = 0);
  syscall(__NR_sendmsg, /*fd=*/r[0], /*msg=*/0x20000100ul, /*f=*/0ul);
  res = syscall(__NR_socket, /*domain=*/0x10ul, /*type=*/3ul, /*proto=*/0);
  if (res != -1)
    r[1] = res;
  NONFAILING(*(uint64_t*)0x20000000 = 0);
  NONFAILING(*(uint32_t*)0x20000008 = 0);
  NONFAILING(*(uint64_t*)0x20000010 = 0x200001c0);
  NONFAILING(*(uint64_t*)0x200001c0 = 0x20000300);
  NONFAILING(*(uint32_t*)0x20000300 = 0x24);
  NONFAILING(*(uint16_t*)0x20000304 = 0x68);
  NONFAILING(*(uint16_t*)0x20000306 = 1);
  NONFAILING(*(uint32_t*)0x20000308 = 2);
  NONFAILING(*(uint32_t*)0x2000030c = 0x7ffffffc);
  NONFAILING(*(uint8_t*)0x20000310 = 0);
  NONFAILING(*(uint8_t*)0x20000311 = 0);
  NONFAILING(*(uint8_t*)0x20000312 = 0);
  NONFAILING(*(uint8_t*)0x20000313 = 0);
  NONFAILING(*(uint32_t*)0x20000314 = 0);
  NONFAILING(*(uint16_t*)0x20000318 = 0xc);
  NONFAILING(*(uint16_t*)0x2000031a = 2);
  NONFAILING(*(uint32_t*)0x2000031c = 1);
  NONFAILING(*(uint8_t*)0x20000320 = 4);
  NONFAILING(*(uint8_t*)0x20000321 = 0);
  NONFAILING(*(uint16_t*)0x20000322 = 0);
  NONFAILING(*(uint64_t*)0x200001c8 = 0x24);
  NONFAILING(*(uint64_t*)0x20000018 = 1);
  NONFAILING(*(uint64_t*)0x20000020 = 0);
  NONFAILING(*(uint64_t*)0x20000028 = 0);
  NONFAILING(*(uint32_t*)0x20000030 = 0x24008000);
  inject_fault(5);
  syscall(__NR_sendmsg, /*fd=*/r[1], /*msg=*/0x20000000ul,
          /*f=MSG_NOSIGNAL*/ 0x4000ul);
  return 0;
}