testing/kernel-cache-tests/kext-vtable-patching/test.py

   1 #!/usr/bin/python2.7
   2
   3 import os
   4 import KernelCollection
   5
   6 # This verifies that a kext can bind to another kext
   7 # foo.kext exports foo and bar.kext uses it
   8
   9 def check(kernel_cache):
  10     kernel_cache.buildKernelCollection("x86_64", "/kext-vtable-patching/main.kc", "/kext-vtable-patching/main.kernel", "/kext-vtable-patching/extensions", ["com.apple.foo", "com.apple.bar"], [])
  11     kernel_cache.analyze("/kext-vtable-patching/main.kc", ["-layout", "-arch", "x86_64"])
  12
  13     assert len(kernel_cache.dictionary()["dylibs"]) == 3
  14     assert kernel_cache.dictionary()["dylibs"][0]["name"] == "com.apple.kernel"
  15     assert kernel_cache.dictionary()["dylibs"][1]["name"] == "com.apple.bar"
  16     assert kernel_cache.dictionary()["dylibs"][2]["name"] == "com.apple.foo"
  17
  18     # Get the addresses for the symbols we are looking at.  This will make it easier to work out the fixup slots
  19     kernel_cache.analyze("/kext-vtable-patching/main.kc", ["-symbols", "-arch", "x86_64"])
  20
  21     # From bar, find the vtable and its override of foo()
  22     # Bar::foo()
  23     assert kernel_cache.dictionary()["dylibs"][1]["global-symbols"][3]["name"] == "__ZN3Bar3fooEv"
  24     assert kernel_cache.dictionary()["dylibs"][1]["global-symbols"][3]["vmAddr"] == "0x16F10"
  25
  26     # From foo, we want to know where the vtable is, and the foo() and fooUsed0() slots in that vtable
  27     # Foo::foo()
  28     assert kernel_cache.dictionary()["dylibs"][2]["global-symbols"][6]["name"] == "__ZN3Foo3fooEv"
  29     assert kernel_cache.dictionary()["dylibs"][2]["global-symbols"][6]["vmAddr"] == "0x17ED0"
  30     # Foo::fooUsed0()
  31     assert kernel_cache.dictionary()["dylibs"][2]["global-symbols"][7]["name"] == "__ZN3Foo8fooUsed0Ev"
  32     assert kernel_cache.dictionary()["dylibs"][2]["global-symbols"][7]["vmAddr"] == "0x17EF0"
  33
  34
  35     # Check the fixups
  36     kernel_cache.analyze("/kext-vtable-patching/main.kc", ["-fixups", "-arch", "x86_64"])
  37
  38     # In vtable for Foo, we match the entry for Foo::foo() by looking for its value on the RHS of the fixup
  39     assert kernel_cache.dictionary()["fixups"]["0x1D3E0"] == "kc(0) + 0x17ED0"
  40     # Then the following fixup should be to Foo::fooUsed0()
  41     assert kernel_cache.dictionary()["fixups"]["0x1D3E8"] == "kc(0) + 0x17EF0"
  42
  43     # Now in bar, again match the entry for its Bar::foo() symbol
  44     assert kernel_cache.dictionary()["fixups"]["0x1D150"] == "kc(0) + 0x16F10"
  45     # And if the patching was correct, then following entry should be to Foo::fooUsed0()
  46     assert kernel_cache.dictionary()["fixups"]["0x1D158"] == "kc(0) + 0x17EF0"
  47
  48
  49 # [~]> xcrun -sdk macosx.internal cc -arch x86_64 -Wl,-static -mkernel -nostdlib -Wl,-e,__start -Wl,-pie main.cpp -Wl,-pagezero_size,0x0 -o main.kernel -Wl,-image_base,0x10000 -Wl,-segaddr,__HIB,0x4000 -Wl,-add_split_seg_info -Wl,-install_name,/usr/lib/swift/split.seg.v2.hack -iwithsysroot /System/Library/Frameworks/Kernel.framework/Headers -Wl,-sectcreate,__LINKINFO,__symbolsets,SymbolSets.plist -Wl,-segprot,__LINKINFO,r--,r--
  50 # [~]> xcrun -sdk macosx.internal cc -arch x86_64 -Wl,-kext -mkernel -nostdlib -Wl,-add_split_seg_info -Wl,-no_data_const foo.cpp -o extensions/foo.kext/foo -iwithsysroot /System/Library/Frameworks/Kernel.framework/Headers -DFOO_USED=1
  51 # [~]> xcrun -sdk macosx.internal cc -arch x86_64 -Wl,-kext -mkernel -nostdlib -Wl,-add_split_seg_info -Wl,-no_data_const bar.cpp -o extensions/bar.kext/bar -iwithsysroot /System/Library/Frameworks/Kernel.framework/Headers
  52 # [~]> rm -r extensions/*.kext/*.ld
  53