tools/lldbmacros/core/kernelcore.py

   1
   2 """ Please make sure you read the README COMPLETELY BEFORE reading anything below.
   3     It is very critical that you read coding guidelines in Section E in README file.
   4 """
   5
   6 from cvalue import *
   7 from lazytarget import *
   8 from configuration import *
   9 import caching
  10 import lldb
  11
  12 def IterateTAILQ_HEAD(headval, element_name):
  13     """ iterate over a TAILQ_HEAD in kernel. refer to bsd/sys/queue.h
  14         params:
  15             headval     - value : value object representing the head of the list
  16             element_name- str          :  string name of the field which holds the list links.
  17         returns:
  18             A generator does not return. It is used for iterating.
  19             value : an object that is of type as headval->tqh_first. Always a pointer object
  20         example usage:
  21           list_head = kern.GetGlobalVariable('mountlist')
  22           for entryobj in IterateTAILQ_HEAD(list_head, 'mnt_list'):
  23             print GetEntrySummary(entryobj)
  24     """
  25     iter_val = headval.tqh_first
  26     while unsigned(iter_val) != 0 :
  27         yield iter_val
  28         iter_val = iter_val.__getattr__(element_name).tqe_next
  29     #end of yield loop
  30
  31 def IterateLinkedList(element, field_name):
  32     """ iterate over a linked list.
  33         This is equivalent to elt = element; while(elt) { do_work(elt); elt = elt-><field_name>; }
  34         params:
  35             element - value : value object representing element in the list.
  36             field_name - str       : name of field that holds pointer to next element
  37         returns: Nothing. This is used as iterable
  38         example usage:
  39             first_zone = kern.GetGlobalVariable('first_zone')
  40             for zone in IterateLinkedList(first_zone, 'next_zone'):
  41                 print GetZoneSummary(zone)
  42     """
  43     elt = element
  44     while unsigned(elt) != 0:
  45         yield elt
  46         elt = elt.__getattr__(field_name)
  47     #end of while loop
  48
  49 def IterateListEntry(element, element_type, field_name):
  50     """ iterate over a list as defined with LIST_HEAD in bsd/sys/queue.h
  51         params:
  52             element      - value : Value object for lh_first
  53             element_type - str   : Type of the next element
  54             field_name   - str   : Name of the field in next element's structure
  55         returns:
  56             A generator does not return. It is used for iterating
  57             value  : an object thats of type (element_type) head->le_next. Always a pointer object
  58         example usage:
  59             headp = kern.globals.initproc.p_children
  60             for pp in IterateListEntry(headp, 'struct proc *', 'p_sibling'):
  61                 print GetProcInfo(pp)
  62     """
  63     elt = element.lh_first
  64     if type(element_type) == str:
  65         element_type = gettype(element_type)
  66     while unsigned(elt) != 0:
  67         yield elt
  68         next_el = elt.__getattr__(field_name).le_next
  69         elt = cast(next_el, element_type)
  70
  71 def IterateQueue(queue_head, element_ptr_type, element_field_name):
  72     """ iterate over a queue in kernel of type queue_head_t. refer to osfmk/kern/queue.h
  73         params:
  74             queue_head         - value : Value object for queue_head.
  75             element_ptr_type       - lldb.SBType : a pointer type of the element 'next' points to. Typically its structs like thread, task etc..
  76                                - str         : OR a string describing the type. ex. 'task *'
  77             element_field_name - str : name of the field in target struct.
  78         returns:
  79             A generator does not return. It is used for iterating.
  80             value  : an object thats of type (element_type) queue_head->next. Always a pointer object
  81         example usage:
  82             for page_meta in IterateQueue(kern.globals.first_zone.pages.all_free, 'struct zone_page_metadata *', 'pages'):
  83                 print page_meta
  84     """
  85     if type(element_ptr_type) == str :
  86         element_ptr_type = gettype(element_ptr_type)
  87
  88     queue_head = queue_head.GetSBValue()
  89     queue_head_addr = 0x0
  90     if queue_head.TypeIsPointerType():
  91         queue_head_addr = queue_head.GetValueAsUnsigned()
  92     else:
  93         queue_head_addr = queue_head.GetAddress().GetLoadAddress(LazyTarget.GetTarget())
  94     cur_elt = queue_head.GetChildMemberWithName('next')
  95     while True:
  96
  97         if not cur_elt.IsValid() or cur_elt.GetValueAsUnsigned() == 0 or cur_elt.GetValueAsUnsigned() == queue_head_addr:
  98             break
  99         elt = cur_elt.Cast(element_ptr_type)
 100         yield value(elt)
 101         cur_elt = elt.GetChildMemberWithName(element_field_name).GetChildMemberWithName('next')
 102
 103
 104
 105 class KernelTarget(object):
 106     """ A common kernel object that provides access to kernel objects and information.
 107         The class holds global lists for  task, terminated_tasks, procs, zones, zombroc etc.
 108         It also provides a way to symbolicate an address or create a value from an address.
 109     """
 110     def __init__(self, debugger):
 111         """ Initialize the kernel debugging environment.
 112             Target properties like architecture and connectedness are lazy-evaluted.
 113         """
 114         self._debugger = debugger # This holds an lldb.SBDebugger object for debugger state
 115         self._threads_list = []
 116         self._tasks_list = []
 117         self._coalitions_list = []
 118         self._allproc = []
 119         self._terminated_tasks_list = []
 120         self._zones_list = []
 121         self._zombproc_list = []
 122         self._kernel_types_cache = {} #this will cache the Type objects as and when requested.
 123         self._version = None
 124         self._arch = None
 125         self._ptrsize = None # pointer size of kernel, not userspace
 126         self.symbolicator = None
 127         class _GlobalVariableFind(object):
 128             def __init__(self, kern):
 129                 self._xnu_kernobj_12obscure12 = kern
 130             def __getattr__(self, name):
 131                 v = self._xnu_kernobj_12obscure12.GetGlobalVariable(name)
 132                 if not v.GetSBValue().IsValid():
 133                     raise ValueError('no such global variable by name: %s '%str(name))
 134                 return v
 135         self.globals = _GlobalVariableFind(self)
 136         LazyTarget.Initialize(debugger)
 137
 138     def _GetSymbolicator(self):
 139         """ Internal function: To initialize the symbolication from lldb.utils
 140         """
 141         if not self.symbolicator is None:
 142             return self.symbolicator
 143
 144         from lldb.utils import symbolication
 145         symbolicator = symbolication.Symbolicator()
 146         symbolicator.target = LazyTarget.GetTarget()
 147         self.symbolicator = symbolicator
 148         return self.symbolicator
 149
 150     def Symbolicate(self, addr):
 151         """ simple method to get name of function/variable from an address. this is equivalent of gdb 'output /a 0xaddress'
 152             params:
 153                 addr - int : typically hex value like 0xffffff80002c0df0
 154             returns:
 155                 str - '' if no symbol found else the symbol name.
 156             Note: this function only finds the first symbol. If you expect multiple symbol conflict please use SymbolicateFromAddress()
 157         """
 158         ret_str = ''
 159         syms = self.SymbolicateFromAddress(addr)
 160         if len(syms) > 0:
 161             ret_str +=syms[0].GetName()
 162         return ret_str
 163
 164     def SymbolicateFromAddress(self, addr):
 165         """ symbolicates any given address based on modules loaded in the target.
 166             params:
 167                 addr - int : typically hex value like 0xffffff80002c0df0
 168             returns:
 169                 [] of SBSymbol: In case we don't find anything than empty array is returned.
 170                       Note: a type of symbol can be figured out by gettype() function of SBSymbol.
 171             example usage:
 172                 syms = kern.Symbolicate(0xffffff80002c0df0)
 173                 for s in syms:
 174                   if s.GetType() == lldb.eSymbolTypeCode:
 175                     print "Function", s.GetName()
 176                   if s.GetType() == lldb.eSymbolTypeData:
 177                     print "Variable", s.GetName()
 178         """
 179         if type(int(1)) != type(addr):
 180             if str(addr).strip().find("0x") == 0 :
 181                 addr = int(addr, 16)
 182             else:
 183                 addr = int(addr)
 184         ret_array = []
 185         symbolicator = self._GetSymbolicator()
 186         syms = symbolicator.symbolicate(addr)
 187         if not syms:
 188             return ret_array
 189         for s in syms:
 190             ret_array.append(s.get_symbol_context().symbol)
 191         return ret_array
 192
 193     def IsDebuggerConnected(self):
 194         proc_state = LazyTarget.GetProcess().state
 195         if proc_state == lldb.eStateInvalid : return False
 196         if proc_state in [lldb.eStateStopped, lldb.eStateSuspended] : return True
 197
 198     def GetGlobalVariable(self, name):
 199         """ Get the value object representation for a kernel global variable
 200             params:
 201               name : str - name of the variable. ex. version
 202             returns: value - python object representing global variable.
 203             raises : Exception in case the variable is not found.
 204         """
 205         return value(LazyTarget.GetTarget().FindGlobalVariables(name, 0).GetValueAtIndex(0))
 206
 207     def GetLoadAddressForSymbol(self, name):
 208         """ Get the load address of a symbol in the kernel.
 209             params:
 210               name : str - name of the symbol to lookup
 211             returns: int - the load address as an integer. Use GetValueFromAddress to cast to a value.
 212             raises : LookupError - if the symbol is not found.
 213         """
 214         name = str(name)
 215         target = LazyTarget.GetTarget()
 216         syms_arr = target.FindSymbols(name)
 217         if syms_arr.IsValid() and len(syms_arr) > 0:
 218             symbol = syms_arr[0].GetSymbol()
 219             if symbol.IsValid():
 220                 return int(symbol.GetStartAddress().GetLoadAddress(target))
 221
 222         raise LookupError("Symbol not found: " + name)
 223
 224     def GetValueFromAddress(self, addr, type_str = 'void *'):
 225         """ convert a address to value
 226             params:
 227                 addr - int : typically hex value like 0xffffff80008dc390
 228                 type_str - str: type to cast to. Default type will be void *
 229             returns:
 230                 value : a value object which has address as addr and type is type_str
 231         """
 232         obj = value(self.globals.version.GetSBValue().CreateValueFromExpression(None,'(void *)'+str(addr)))
 233         obj = cast(obj, type_str)
 234         return obj
 235
 236     def GetValueAsType(self, v, t):
 237         """ Retrieves a global variable 'v' of type 't' wrapped in a vue object.
 238             If 'v' is an address, creates a vue object of the appropriate type.
 239             If 'v' is a name, looks for the global variable and asserts its type.
 240             Throws:
 241                 NameError - If 'v' cannot be found
 242                 TypeError - If 'v' is of the wrong type
 243         """
 244         if islong(v):
 245             return self.GetValueFromAddress(v, t)
 246         else:
 247             var = LazyTarget.GetTarget().FindGlobalVariables(v, 1)[0]
 248             if not var:
 249                 raise NameError("Failed to find global variable '{0}'".format(v))
 250             if var.GetTypeName() != t:
 251                 raise TypeError("{0} must be of type '{1}', not '{2}'".format(v, t, var.GetTypeName()))
 252             return value(var)
 253
 254     def _GetIterator(self, iter_head_name, next_element_name='next', iter_head_type=None):
 255         """ returns an iterator for a collection in kernel memory.
 256             params:
 257                 iter_head_name - str : name of queue_head or list head variable.
 258                 next_element_name - str : name of the element that leads to next element.
 259                                           for ex. in struct zone list 'next_zone' is the linking element.
 260             returns:
 261                 iterable : typically used in conjunction with "for varname in iterable:"
 262         """
 263         head_element = self.GetGlobalVariable(iter_head_name)
 264         return head_element.GetSBValue().linked_list_iter(next_element_name)
 265
 266     def TruncPage(self, addr):
 267         return (addr & ~(unsigned(self.GetGlobalVariable("page_size")) - 1))
 268
 269     def RoundPage(self, addr):
 270         return trunc_page(addr + unsigned(self.GetGlobalVariable("page_size")) - 1)
 271
 272     def StraddlesPage(self, addr, size):
 273         if size > unsigned(self.GetGlobalVariable("page_size")):
 274             return True
 275         val = ((addr + size) & (unsigned(self.GetGlobalVariable("page_size"))-1))
 276         return (val < size and val > 0)
 277
 278     def PhysToKernelVirt(self, addr):
 279         if self.arch == 'x86_64':
 280             return (addr + unsigned(self.GetGlobalVariable('physmap_base')))
 281         elif self.arch == 'arm' or self.arch == 'arm64':
 282             return (addr - unsigned(self.GetGlobalVariable("gPhysBase")) + unsigned(self.GetGlobalVariable("gVirtBase")))
 283         else:
 284             raise ValueError("PhysToVirt does not support {0}".format(arch))
 285
 286     def __getattribute__(self, name):
 287         if name == 'zones' :
 288             self._zones_list = caching.GetDynamicCacheData("kern._zones_list", [])
 289             if len(self._zones_list) > 0: return self._zones_list
 290             first_zone = self.GetGlobalVariable('first_zone')
 291             for z in IterateLinkedList(first_zone, 'next_zone'):
 292                 self._zones_list.append(z)
 293             caching.SaveDynamicCacheData("kern._zones_list", self._zones_list)
 294             return self._zones_list
 295
 296         if name == 'threads' :
 297             self._threads_list = caching.GetDynamicCacheData("kern._threads_list", [])
 298             if len(self._threads_list) > 0 : return self._threads_list
 299             thread_queue_head = self.GetGlobalVariable('threads')
 300             thread_type = LazyTarget.GetTarget().FindFirstType('thread')
 301             thread_ptr_type = thread_type.GetPointerType()
 302             for th in IterateQueue(thread_queue_head, thread_ptr_type, 'threads'):
 303                 self._threads_list.append(th)
 304             caching.SaveDynamicCacheData("kern._threads_list", self._threads_list)
 305             return self._threads_list
 306
 307         if name == 'tasks' :
 308             self._tasks_list = caching.GetDynamicCacheData("kern._tasks_list", [])
 309             if len(self._tasks_list) > 0 : return self._tasks_list
 310             task_queue_head = self.GetGlobalVariable('tasks')
 311             task_type = LazyTarget.GetTarget().FindFirstType('task')
 312             task_ptr_type = task_type.GetPointerType()
 313             for tsk in IterateQueue(task_queue_head, task_ptr_type, 'tasks'):
 314                 self._tasks_list.append(tsk)
 315             caching.SaveDynamicCacheData("kern._tasks_list", self._tasks_list)
 316             return self._tasks_list
 317
 318         if name == 'coalitions' :
 319             self._coalitions_list = caching.GetDynamicCacheData("kern._coalitions_list", [])
 320             if len(self._coalitions_list) > 0 : return self._coalitions_list
 321             coalition_queue_head = self.GetGlobalVariable('coalitions')
 322             coalition_type = LazyTarget.GetTarget().FindFirstType('coalition')
 323             coalition_ptr_type = coalition_type.GetPointerType()
 324             for tsk in IterateQueue(coalition_queue_head, coalition_ptr_type, 'coalitions'):
 325                 self._coalitions_list.append(tsk)
 326             caching.SaveDynamicCacheData("kern._coalitions_list", self._coalitions_list)
 327             return self._coalitions_list
 328
 329         if name == 'terminated_tasks' :
 330             self._terminated_tasks_list = caching.GetDynamicCacheData("kern._terminated_tasks_list", [])
 331             if len(self._terminated_tasks_list) > 0 : return self._terminated_tasks_list
 332             task_queue_head = self.GetGlobalVariable('terminated_tasks')
 333             task_type = LazyTarget.GetTarget().FindFirstType('task')
 334             task_ptr_type = task_type.GetPointerType()
 335             for tsk in IterateQueue(task_queue_head, task_ptr_type, 'tasks'):
 336                 self._terminated_tasks_list.append(tsk)
 337             caching.SaveDynamicCacheData("kern._terminated_tasks_list", self._terminated_tasks_list)
 338             return self._terminated_tasks_list
 339
 340         if name == 'procs' :
 341             self._allproc = caching.GetDynamicCacheData("kern._allproc", [])
 342             if len(self._allproc) > 0 : return self._allproc
 343             all_proc_head = self.GetGlobalVariable('allproc')
 344             proc_val = cast(all_proc_head.lh_first, 'proc *')
 345             while proc_val != 0:
 346                 self._allproc.append(proc_val)
 347                 proc_val = cast(proc_val.p_list.le_next, 'proc *')
 348             caching.SaveDynamicCacheData("kern._allproc", self._allproc)
 349             return self._allproc
 350
 351         if name == 'interrupt_stats' :
 352             self._interrupt_stats_list = caching.GetDynamicCacheData("kern._interrupt_stats_list", [])
 353             if len(self._interrupt_stats_list) > 0 : return self._interrupt_stats_list
 354             interrupt_stats_head = self.GetGlobalVariable('gInterruptAccountingDataList')
 355             interrupt_stats_type = LazyTarget.GetTarget().FindFirstType('IOInterruptAccountingData')
 356             interrupt_stats_ptr_type = interrupt_stats_type.GetPointerType()
 357             for interrupt_stats_obj in IterateQueue(interrupt_stats_head, interrupt_stats_ptr_type, 'chain'):
 358                 self._interrupt_stats_list.append(interrupt_stats_obj)
 359             caching.SaveDynamicCacheData("kern._interrupt_stats", self._interrupt_stats_list)
 360             return self._interrupt_stats_list
 361
 362         if name == 'zombprocs' :
 363             self._zombproc_list = caching.GetDynamicCacheData("kern._zombproc_list", [])
 364             if len(self._zombproc_list) > 0 : return self._zombproc_list
 365             zproc_head = self.GetGlobalVariable('zombproc')
 366             proc_val = cast(zproc_head.lh_first, 'proc *')
 367             while proc_val != 0:
 368                 self._zombproc_list.append(proc_val)
 369                 proc_val = cast(proc_val.p_list.le_next, 'proc *')
 370             caching.SaveDynamicCacheData("kern._zombproc_list", self._zombproc_list)
 371             return self._zombproc_list
 372
 373         if name == 'version' :
 374             self._version = caching.GetStaticCacheData("kern.version", None)
 375             if self._version != None : return self._version
 376             self._version = str(self.GetGlobalVariable('version'))
 377             caching.SaveStaticCacheData("kern.version", self._version)
 378             return self._version
 379
 380         if name == 'arch' :
 381             self._arch = caching.GetStaticCacheData("kern.arch", None)
 382             if self._arch != None : return self._arch
 383             arch = LazyTarget.GetTarget().triple.split('-')[0]
 384             if arch in ('armv7', 'armv7s', 'armv7k'):
 385                 self._arch = 'arm'
 386             else:
 387                 self._arch = arch
 388             caching.SaveStaticCacheData("kern.arch", self._arch)
 389             return self._arch
 390
 391         if name == 'ptrsize' :
 392             self._ptrsize = caching.GetStaticCacheData("kern.ptrsize", None)
 393             if self._ptrsize != None : return self._ptrsize
 394             arch = LazyTarget.GetTarget().triple.split('-')[0]
 395             if arch in ('x86_64', 'arm64'):
 396                 self._ptrsize = 8
 397             else:
 398                 self._ptrsize = 4
 399             caching.SaveStaticCacheData("kern.ptrsize", self._ptrsize)
 400             return self._ptrsize
 401
 402         return object.__getattribute__(self, name)
 403