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Bug fix: Argument register will be renamed by register_renaming_pass. #79

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Bug fix: Argument register will be renamed by register_renaming_pass. #79

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5 changes: 5 additions & 0 deletions VTIL-Compiler/optimizer/register_renaming_pass.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -111,6 +111,11 @@ namespace vtil::optimizer
//
if ( i->is_volatile() )
return fail();

// If source is being accessed by a vxcall instruction, fail.
//
if ( mask && i->base == &ins::vxcall )
return fail();
}

// If destination is used by the instruction, fail.
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40 changes: 40 additions & 0 deletions VTIL-Tests/dummy.cpp
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Expand Up @@ -285,6 +285,46 @@ DOCTEST_TEST_CASE("Optimization register_renaming_pass")
CHECK(ins.operands[1].imm().ival == 0x1);
}

DOCTEST_TEST_CASE("Optimization register_renaming_pass vxcall")
{
vtil::logger::log("\n\n>> %s \n", __FUNCTION__);

auto block = vtil::basic_block::begin(0x1337);

vtil::register_desc reg_ecx(vtil::register_physical, registers::cx, vtil::arch::bit_count, 0);

auto sr0 = block->owner->alloc(vtil::arch::bit_count);

// The ecx register here is a potential function argument, register_renaming_pass should not work here.
block->mov(reg_ecx, (uintptr_t)0x880000);
block->vxcall((uintptr_t)0x10000);

auto block2 = block->fork(0x2000);
block2->mov(sr0, reg_ecx);
block2->mov(reg_ecx, (uintptr_t)1);
block2->mov(reg_ecx, sr0);
block2->vxcall((uintptr_t)0x10000);

auto block3 = block2->fork(0x3000);
block3->vexit(0ull); // marks the end of a basic_block

vtil::logger::log(":: Before:\n");
vtil::debug::dump(block->owner);

vtil::optimizer::register_renaming_pass{}(block->owner);

vtil::logger::log(":: After:\n");
vtil::debug::dump(block->owner);

auto ins = (*block)[0];

// mov ecx, 0x880000
CHECK(ins.base == &vtil::ins::mov);
CHECK(ins.operands.size() == 2);
CHECK(ins.operands[0].reg().local_id == registers::cx);
CHECK(ins.operands[1].imm().ival == 0x880000);
}

DOCTEST_TEST_CASE("Optimization symbolic_rewrite_pass<true>")
{
vtil::logger::log("\n\n>> %s \n", __FUNCTION__);
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