Author: aleksandr.urakov Date: Wed Feb 6 00:48:30 2019 New Revision: 353281
URL: http://llvm.org/viewvc/llvm-project?rev=353281&view=rev Log: [x64] Process the B field of the REX prefix correctly for the PUSH and POP instructions Summary: This patch makes `x86AssemblyInspectionEngine` to process zero value of the `B` field of the `REX` prefix in a correct way for `PUSH` and `POP` instructions. MSVC sometimes emits `pushq %rbp` instruction as `0x40 0x55`, and it was not parsed correctly before. Reviewers: jasonmolenda, labath Reviewed By: jasonmolenda, labath Subscribers: abidh, lldb-commits Tags: #lldb Differential Revision: https://reviews.llvm.org/D57745 Modified: lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp lldb/trunk/unittests/UnwindAssembly/x86/Testx86AssemblyInspectionEngine.cpp Modified: lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp?rev=353281&r1=353280&r2=353281&view=diff ============================================================================== --- lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp (original) +++ lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp Wed Feb 6 00:48:30 2019 @@ -364,8 +364,8 @@ bool x86AssemblyInspectionEngine::push_r uint8_t *p = m_cur_insn; int regno_prefix_bit = 0; // If we have a rex prefix byte, check to see if a B bit is set - if (m_wordsize == 8 && *p == 0x41) { - regno_prefix_bit = 1 << 3; + if (m_wordsize == 8 && (*p & 0xfe) == 0x40) { + regno_prefix_bit = (*p & 1) << 3; p++; } if (*p >= 0x50 && *p <= 0x57) { @@ -562,8 +562,8 @@ bool x86AssemblyInspectionEngine::pop_re uint8_t *p = m_cur_insn; int regno_prefix_bit = 0; // If we have a rex prefix byte, check to see if a B bit is set - if (m_wordsize == 8 && *p == 0x41) { - regno_prefix_bit = 1 << 3; + if (m_wordsize == 8 && (*p & 0xfe) == 0x40) { + regno_prefix_bit = (*p & 1) << 3; p++; } if (*p >= 0x58 && *p <= 0x5f) { Modified: lldb/trunk/unittests/UnwindAssembly/x86/Testx86AssemblyInspectionEngine.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/unittests/UnwindAssembly/x86/Testx86AssemblyInspectionEngine.cpp?rev=353281&r1=353280&r2=353281&view=diff ============================================================================== --- lldb/trunk/unittests/UnwindAssembly/x86/Testx86AssemblyInspectionEngine.cpp (original) +++ lldb/trunk/unittests/UnwindAssembly/x86/Testx86AssemblyInspectionEngine.cpp Wed Feb 6 00:48:30 2019 @@ -1415,6 +1415,34 @@ TEST_F(Testx86AssemblyInspectionEngine, EXPECT_EQ(-8, regloc.GetOffset()); } +TEST_F(Testx86AssemblyInspectionEngine, TestPushRBPWithREX) { + UnwindPlan::Row::RegisterLocation regloc; + UnwindPlan::RowSP row_sp; + + uint8_t data[] = { + 0x40, 0x55, // pushq %rbp + 0x90 // nop + }; + + AddressRange sample_range(0x1000, sizeof(data)); + UnwindPlan unwind_plan(eRegisterKindLLDB); + + std::unique_ptr<x86AssemblyInspectionEngine> engine64 = Getx86_64Inspector(); + EXPECT_TRUE(engine64->GetNonCallSiteUnwindPlanFromAssembly( + data, sizeof(data), sample_range, unwind_plan)); + + row_sp = unwind_plan.GetRowForFunctionOffset(2); + + EXPECT_EQ(2ull, row_sp->GetOffset()); + EXPECT_TRUE(row_sp->GetCFAValue().GetRegisterNumber() == k_rsp); + EXPECT_TRUE(row_sp->GetCFAValue().IsRegisterPlusOffset() == true); + EXPECT_EQ(16, row_sp->GetCFAValue().GetOffset()); + + EXPECT_TRUE(row_sp->GetRegisterInfo(k_rbp, regloc)); + EXPECT_TRUE(regloc.IsAtCFAPlusOffset()); + EXPECT_EQ(-16, regloc.GetOffset()); +} + TEST_F(Testx86AssemblyInspectionEngine, TestPushESI) { UnwindPlan::Row::RegisterLocation regloc; UnwindPlan::RowSP row_sp; @@ -1913,6 +1941,32 @@ TEST_F(Testx86AssemblyInspectionEngine, EXPECT_FALSE(row_sp->GetRegisterInfo(k_ebp, regloc)); } +TEST_F(Testx86AssemblyInspectionEngine, TestPopRBPWithREX) { + UnwindPlan::Row::RegisterLocation regloc; + UnwindPlan::RowSP row_sp; + AddressRange sample_range; + UnwindPlan unwind_plan(eRegisterKindLLDB); + std::unique_ptr<x86AssemblyInspectionEngine> engine = Getx86_64Inspector(); + + uint8_t data[] = { + 0x40, 0x55, // pushq %rbp + 0x40, 0x5d, // popq %rbp + 0x90 // nop + }; + + sample_range = AddressRange(0x1000, sizeof(data)); + + EXPECT_TRUE(engine->GetNonCallSiteUnwindPlanFromAssembly( + data, sizeof(data), sample_range, unwind_plan)); + + row_sp = unwind_plan.GetRowForFunctionOffset(4); + EXPECT_EQ(4ull, row_sp->GetOffset()); + EXPECT_TRUE(row_sp->GetCFAValue().GetRegisterNumber() == k_rsp); + EXPECT_TRUE(row_sp->GetCFAValue().IsRegisterPlusOffset() == true); + EXPECT_EQ(8, row_sp->GetCFAValue().GetOffset()); + EXPECT_FALSE(row_sp->GetRegisterInfo(k_rbp, regloc)); +} + TEST_F(Testx86AssemblyInspectionEngine, TestPopESI) { UnwindPlan::Row::RegisterLocation regloc; UnwindPlan::RowSP row_sp; _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
