if (errno == ENOENT)
if (errno == ENOENT  || errno == EACCES)
__readonly_area (const char *ptr, size_t size){  const void *ptr_end = ptr + size;  FILE *fp = fopen ("/proc/self/maps", "rc");  if (fp == NULL)    {      if (errno == ENOENT)	/* It is the system administrator's choice to not have /proc	   available to this process (e.g., because it runs in a chroot	   environment.  Don't fail in this case.  */	return 1;      return -1;    }  /* We need no locking.  */  __fsetlocking (fp, FSETLOCKING_BYCALLER);  char *line = NULL;  size_t linelen = 0;  while (! feof_unlocked (fp))    {      if (_IO_getdelim (&line, &linelen, '\n', fp) <= 0)	break;      char *p;      uintptr_t from = strtoul (line, &p, 16);      if (p == line || *p++ != '-')	break;      char *q;      uintptr_t to = strtoul (p, &q, 16);      if (q == p || *q++ != ' ')	break;      if (from < (uintptr_t) ptr_end && to > (uintptr_t) ptr)	{	  /* Found an entry that at least partially covers the area.  */	  if (*q++ != 'r' || *q++ != '-')	    break;	  if (from <= (uintptr_t) ptr && to >= (uintptr_t) ptr_end)	    {	      size = 0;	      break;	    }	  else if (from <= (uintptr_t) ptr)	    size -= to - (uintptr_t) ptr;	  else if (to >= (uintptr_t) ptr_end)	    size -= (uintptr_t) ptr_end - from;	  else	    size -= to - from;	  if (!size)	    break;	}    }  fclose (fp);  free (line);  /* If the whole area between ptr and ptr_end is covered by read-only     VMAs, return 1.  Otherwise return -1.  */  return size == 0 ? 1 : -1;}