Extend grokdump with basic interactive shell capabilities.

tools/grokdump.py

 #!/usr/bin/env python
 #
 # Copyright 2011 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
 #       with the distribution.
 #     * Neither the name of Google Inc. nor the names of its
 #       contributors may be used to endorse or promote products derived
 #       from this software without specific prior written permission.
 #
 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+import cmd
 import ctypes
 import mmap
 import optparse
 import os
 import disasm
 import sys
 import types
 import codecs
 import re
+import struct
 
 
 USAGE="""usage: %prog [OPTION]...
 
 Minidump analyzer.
 
 Shows the processor state at the point of exception including the
 stack of the active thread and the referenced objects in the V8
 heap. Code objects are disassembled and the addresses linked from the
 stack (pushed return addresses) are marked with "=>".
@@ skipping 388 matching lines @@
   def ReadUIntPtr(self, address):
     if self.arch == MD_CPU_ARCHITECTURE_AMD64:
       return self.ReadU64(address)
     elif self.arch == MD_CPU_ARCHITECTURE_X86:
       return self.ReadU32(address)
 
   def ReadBytes(self, address, size):
     location = self.FindLocation(address)
     return self.minidump[location:location + size]
 
+  def _ReadWord(self, location):
+    if self.arch == MD_CPU_ARCHITECTURE_AMD64:
+      return ctypes.c_uint64.from_buffer(self.minidump, location).value
+    elif self.arch == MD_CPU_ARCHITECTURE_X86:
+      return ctypes.c_uint32.from_buffer(self.minidump, location).value
+
+  def ForEachMemoryRegion(self, cb):
+    if self.memory_list64 is not None:
+      for r in self.memory_list64.ranges:
+        location = self.memory_list64.base_rva + offset
+        cb(self, r.start, r.size, location)
+        offset += r.size
+
+    if self.memory_list is not None:
+      for r in self.memory_list.ranges:
+        cb(self, r.start, r.memory.data_size, r.memory.rva)
+
+  def FindWord(self, word):
+    def search_inside_region(reader, start, size, location):
+      for loc in xrange(location, location + size):
+        if reader._ReadWord(loc) == word:
+          slot = start + (loc - location)
+          print "%s: %s" % (reader.FormatIntPtr(slot),
+                            reader.FormatIntPtr(word))
+
+    self.ForEachMemoryRegion(search_inside_region)
+
   def FindLocation(self, address):
     offset = 0
     if self.memory_list64 is not None:
       for r in self.memory_list64.ranges:
         if r.start <= address < r.start + r.size:
           return self.memory_list64.base_rva + offset + address - r.start
         offset += r.size
     if self.memory_list is not None:
       for r in self.memory_list.ranges:
         if r.start <= address < r.start + r.memory.data_size:
@@ skipping 547 matching lines @@
 
 EIP_PROXIMITY = 64
 
 CONTEXT_FOR_ARCH = {
     MD_CPU_ARCHITECTURE_AMD64:
       ['rax', 'rbx', 'rcx', 'rdx', 'rdi', 'rsi', 'rbp', 'rsp', 'rip'],
     MD_CPU_ARCHITECTURE_X86:
       ['eax', 'ebx', 'ecx', 'edx', 'edi', 'esi', 'ebp', 'esp', 'eip']
 }
 
+class InspectionShell(cmd.Cmd):
+  def __init__(self, reader, heap):
+    cmd.Cmd.__init__(self)
+    self.reader = reader
+    self.heap = heap
+    self.prompt = "(grok) "
+
+  def do_dd(self, address):
+    """Interpret memory at the given address (if available)
+     as a sequence of words."""
+    start = int(address, 0)
+    for slot in xrange(start,
+                       start + self.reader.PointerSize() * 10,
+                       self.reader.PointerSize()):
+      maybe_address = self.reader.ReadUIntPtr(slot)
+      heap_object = self.heap.FindObject(maybe_address)
+      print "%s: %s" % (self.reader.FormatIntPtr(slot),
+                        self.reader.FormatIntPtr(maybe_address))
+      if heap_object:
+        heap_object.Print(Printer())
+        print
+
+  def do_s(self, word):
+    "Search for a given word in available memory regions"
+    word = int(word, 0)
+    print "searching for word", word
+    self.reader.FindWord(word)
+
+  def do_list(self, smth):
+    """List all available memory regions."""
+    def print_region(reader, start, size, location):
+      print "%s - %s" % (reader.FormatIntPtr(start),
+                         reader.FormatIntPtr(start + size))
+
+    self.reader.ForEachMemoryRegion(print_region)
+
 def AnalyzeMinidump(options, minidump_name):
   reader = MinidumpReader(options, minidump_name)
   DebugPrint("========================================")
   if reader.exception is None:
     print "Minidump has no exception info"
     return
   print "Exception info:"
   exception_thread = reader.thread_map[reader.exception.thread_id]
   print "  thread id: %d" % exception_thread.id
   print "  code: %08X" % reader.exception.exception.code
@@ skipping 14 matching lines @@
       stack_map[maybe_address] = slot
   heap = V8Heap(reader, stack_map)
 
   print "Disassembly around exception.eip:"
   start = reader.ExceptionIP() - EIP_PROXIMITY
   lines = reader.GetDisasmLines(start, 2 * EIP_PROXIMITY)
   for line in lines:
     print FormatDisasmLine(start, heap, line)
   print
 
-  print "Annotated stack (from exception.esp to bottom):"
-  for slot in xrange(stack_top, stack_bottom, reader.PointerSize()):
-    maybe_address = reader.ReadUIntPtr(slot)
-    heap_object = heap.FindObject(maybe_address)
-    print "%s: %s" % (reader.FormatIntPtr(slot),
-                      reader.FormatIntPtr(maybe_address))
-    if heap_object:
-      heap_object.Print(Printer())
-      print
+  if options.shell:
+    InspectionShell(reader, heap).cmdloop()
+  else:
+    print "Annotated stack (from exception.esp to bottom):"
+    for slot in xrange(stack_top, stack_bottom, reader.PointerSize()):
+      maybe_address = reader.ReadUIntPtr(slot)
+      heap_object = heap.FindObject(maybe_address)
+      print "%s: %s" % (reader.FormatIntPtr(slot),
+                        reader.FormatIntPtr(maybe_address))
+      if heap_object:
+        heap_object.Print(Printer())
+        print
 
   reader.Dispose()
 
 
 if __name__ == "__main__":
   parser = optparse.OptionParser(USAGE)
+  parser.add_option("-s", "--shell", dest="shell", action="store_true")
   options, args = parser.parse_args()
   if len(args) != 1:
     parser.print_help()
     sys.exit(1)
   AnalyzeMinidump(options, args[0])