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AArch64: fix ldrb size #1433

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merged 2 commits into from
May 16, 2019
Merged

AArch64: fix ldrb size #1433

merged 2 commits into from
May 16, 2019

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nkaretnikov
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@nkaretnikov nkaretnikov commented May 14, 2019 •
edited by offlinemark
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@nkaretnikov nkaretnikov force-pushed the aarch64-fix-ldrb-size branch from d4eba39 to d308f3f Compare May 14, 2019 13:10
@nkaretnikov
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Force-pushed after changing the test constant to a more suitable value.

@nkaretnikov
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On AArch64, the symbolic tests work by setting a register to a symbolic value. For load instructions, this register is the stack pointer. Turns out, it's not enough as the memory can also be symbolic. This PR adds a test for one pair of store/load instructions and fixes a related bug (incorrect load due to a size mismatch between the loaded value and target register).

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BTW, you can trigger the bug by reverting the top commit and running the new test:

# git revert @
# nosetests -s tests/native/test_aarch64cpu.py:Aarch64SymInstructions -m 'test_strb_ldrb_imm_base32'
[...]
  File "/manticore/manticore/native/cpu/aarch64.py", line 3249, in LDRB
    cpu._LDRB_immediate(reg_op, mem_op, mimm_op)
  File "/manticore/manticore/native/cpu/aarch64.py", line 3222, in _LDRB_immediate
    cpu._ldr_str_immediate(reg_op, mem_op, mimm_op, ldr=True, size=8)
  File "/manticore/manticore/native/cpu/aarch64.py", line 1024, in _ldr_str_immediate
    reg_op.write(result)
  File "/manticore/manticore/native/cpu/aarch64.py", line 5438, in write
    self.cpu.regfile.write(self.reg, value)
  File "/manticore/manticore/native/cpu/aarch64.py", line 194, in write
    assert value.size == size
AssertionError

ehennenfent
ehennenfent approved these changes May 14, 2019
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LGTM! Appreciate you adding a test for this.

@ehennenfent ehennenfent merged commit 65b7314 into trailofbits:master May 16, 2019
ekilmer added a commit that referenced this pull request May 17, 2019
@ekilmer
Merge branch 'master' into native-arb-cf-redirect-detector
c831760 
* master: (28 commits)
  AArch64: fix ldrb size (#1433)
  System Call Audit (#1384)
  ManticoreBase refactor (#1385)
  Add missing checks for ARM boundaries (#1429)
  aarch64: add instruction tests: T-U (#1423)
  aarch64: add instruction tests: M-S (#1422)
  aarch64: add instruction tests: C-L (#1421)
  aarch64: add instruction tests: A-B (#1420)
  aarch64: add everything except instructions (#1418)
  fixup: support ARM64 in '_reg_name'
  Revert "fixup: remove x86-specific code from '_reg_name'"
  review: avoid wildcard imports
  review: rename the file
  fixup: remove x86-specific code from '_reg_name'
  fixup: do not use relative imports
  Generates a more sensible symbolic default for constructor arguments (#1414)
  aarch64: add instructions
  aarch64: add everything except instructions
  Switches the Travis-CI badge from .org to .com (#1416)
  Performance optimization : use set instead of list (#1415)
  ...
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@ehennenfent ehennenfent ehennenfent approved these changes

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@nkaretnikov @ehennenfent