// https://syzkaller.appspot.com/bug?id=c8baf7fc53c98268f450cb196098fdb502aa071c
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <pwd.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/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#ifndef SYS_mkdir
#define SYS_mkdir 136
#endif
#ifndef SYS_mmap
#define SYS_mmap 197
#endif
#ifndef SYS_open
#define SYS_open 5
#endif
#ifndef SYS_swapctl
#define SYS_swapctl 271
#endif
#ifndef SYS_truncate
#define SYS_truncate 200
#endif

static unsigned long long procid;

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_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 void kill_and_wait(int pid, int* status)
{
  kill(pid, SIGKILL);
  while (waitpid(-1, status, 0) != pid) {
  }
}

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 execute_one(void);

#define WAIT_FLAGS 0

static void loop(void)
{
  int iter = 0;
  for (;; iter++) {
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      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;
    }
  }
}

void execute_one(void)
{
  NONFAILING(memcpy((void*)0x20000480, "./file0\000", 8));
  syscall(SYS_open, /*file=*/0x20000480ul, /*flags=*/0x80400000000206ul,
          /*mode=*/0ul);
  NONFAILING(memcpy((void*)0x20000040, "./file0\000", 8));
  syscall(SYS_truncate, /*file=*/0x20000040ul, /*pad=*/0ul,
          /*len=*/0x80000001ul);
  NONFAILING(memcpy((void*)0x20000000, "./file0\000", 8));
  syscall(SYS_mkdir, /*path=*/0x20000000ul, /*mode=*/0ul);
  syscall(SYS_swapctl, /*cmd=*/1ul, /*arg=*/0x20000000ul, /*misc=*/1);
  NONFAILING(memcpy((void*)0x200000c0, "./file0\000", 8));
  syscall(SYS_open, /*file=*/0x200000c0ul, /*flags=*/0ul, /*mode=*/0ul);
  syscall(SYS_swapctl, /*cmd=*/2ul, /*arg=*/0x200000c0ul, /*misc=*/0);
}
int main(void)
{
  syscall(SYS_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=*/3ul,
          /*flags=*/0x1012ul, /*fd=*/-1, /*pad=*/0ul, /*offset=*/0ul);
  install_segv_handler();
  for (procid = 0; procid < 6; procid++) {
    if (fork() == 0) {
      loop();
    }
  }
  sleep(1000000);
  return 0;
}