Author: Jason Molenda Date: 2025-06-30T21:27:53-07:00 New Revision: e94c6091c93a72e9b81cf8d6394495d043b409d4
URL: https://github.com/llvm/llvm-project/commit/e94c6091c93a72e9b81cf8d6394495d043b409d4 DIFF: https://github.com/llvm/llvm-project/commit/e94c6091c93a72e9b81cf8d6394495d043b409d4.diff LOG: [lldb][Mach-O] Fix several bugs in x86_64 Mach-O corefile (#146460) reading, and one bug in the new RegisterContextUnifiedCore class. The PR I landed a few days ago to allow Mach-O corefiles to augment their registers with additional per-thread registers in metadata exposed a few bugs in the x86_64 corefile reader when running under different CI environments. It also showed a bug in my RegisterContextUnifiedCore class where I wasn't properly handling lookups of unknown registers (e.g. the LLDB_GENERIC_RA when debugging an intel target). The Mach-O x86_64 corefile support would say that it had fpu & exc registers available in every corefile, regardless of whether they were actually present. It would only read the bytes for the first register flavor in the LC_THREAD, the GPRs, but it read them incorrectly, so sometimes you got more register context than you'd expect. The LC_THREAD register context specifies a flavor and the number of uint32_t words; the ObjectFileMachO method would read that number of uint64_t's, exceeding the GPR register space, but it was followed by FPU and then EXC register space so it didn't crash. If you had a corefile with GPR and EXC register bytes, it would be written into the GPR and then FPU register areas, with zeroes filling out the rest of the context. Added: Modified: lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp lldb/source/Plugins/Process/mach-core/RegisterContextUnifiedCore.cpp Removed: ################################################################################ diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp index 4394caf7f31e9..70f954cd5413f 100644 --- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp +++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp @@ -184,46 +184,32 @@ class RegisterContextDarwin_x86_64_Mach : public RegisterContextDarwin_x86_64 { SetError(GPRRegSet, Read, -1); SetError(FPURegSet, Read, -1); SetError(EXCRegSet, Read, -1); - bool done = false; - while (!done) { + while (offset < data.GetByteSize()) { int flavor = data.GetU32(&offset); if (flavor == 0) - done = true; - else { - uint32_t i; - uint32_t count = data.GetU32(&offset); - switch (flavor) { - case GPRRegSet: - for (i = 0; i < count; ++i) - (&gpr.rax)[i] = data.GetU64(&offset); - SetError(GPRRegSet, Read, 0); - done = true; - - break; - case FPURegSet: - // TODO: fill in FPU regs.... - // SetError (FPURegSet, Read, -1); - done = true; - - break; - case EXCRegSet: - exc.trapno = data.GetU32(&offset); - exc.err = data.GetU32(&offset); - exc.faultvaddr = data.GetU64(&offset); - SetError(EXCRegSet, Read, 0); - done = true; - break; - case 7: - case 8: - case 9: - // fancy flavors that encapsulate of the above flavors... - break; - - default: - done = true; - break; - } + break; + uint32_t count = data.GetU32(&offset); + switch (flavor) { + case GPRRegSet: { + uint32_t *gpr_data = reinterpret_cast<uint32_t *>(&gpr.rax); + for (uint32_t i = 0; i < count && offset < data.GetByteSize(); ++i) + gpr_data[i] = data.GetU32(&offset); + SetError(GPRRegSet, Read, 0); + } break; + case FPURegSet: + // TODO: fill in FPU regs.... + SetError(FPURegSet, Read, -1); + break; + case EXCRegSet: + exc.trapno = data.GetU32(&offset); + exc.err = data.GetU32(&offset); + exc.faultvaddr = data.GetU64(&offset); + SetError(EXCRegSet, Read, 0); + break; + default: + offset += count * 4; + break; } } } @@ -353,11 +339,11 @@ class RegisterContextDarwin_x86_64_Mach : public RegisterContextDarwin_x86_64 { } protected: - int DoReadGPR(lldb::tid_t tid, int flavor, GPR &gpr) override { return 0; } + int DoReadGPR(lldb::tid_t tid, int flavor, GPR &gpr) override { return -1; } - int DoReadFPU(lldb::tid_t tid, int flavor, FPU &fpu) override { return 0; } + int DoReadFPU(lldb::tid_t tid, int flavor, FPU &fpu) override { return -1; } - int DoReadEXC(lldb::tid_t tid, int flavor, EXC &exc) override { return 0; } + int DoReadEXC(lldb::tid_t tid, int flavor, EXC &exc) override { return -1; } int DoWriteGPR(lldb::tid_t tid, int flavor, const GPR &gpr) override { return 0; diff --git a/lldb/source/Plugins/Process/mach-core/RegisterContextUnifiedCore.cpp b/lldb/source/Plugins/Process/mach-core/RegisterContextUnifiedCore.cpp index 16568f788c202..449f85bc3f52a 100644 --- a/lldb/source/Plugins/Process/mach-core/RegisterContextUnifiedCore.cpp +++ b/lldb/source/Plugins/Process/mach-core/RegisterContextUnifiedCore.cpp @@ -262,7 +262,9 @@ size_t RegisterContextUnifiedCore::GetRegisterCount() { const RegisterInfo * RegisterContextUnifiedCore::GetRegisterInfoAtIndex(size_t reg) { - return &m_register_infos[reg]; + if (reg < m_register_infos.size()) + return &m_register_infos[reg]; + return nullptr; } size_t RegisterContextUnifiedCore::GetRegisterSetCount() { @@ -270,7 +272,9 @@ size_t RegisterContextUnifiedCore::GetRegisterSetCount() { } const RegisterSet *RegisterContextUnifiedCore::GetRegisterSet(size_t set) { - return &m_register_sets[set]; + if (set < m_register_sets.size()) + return &m_register_sets[set]; + return nullptr; } bool RegisterContextUnifiedCore::ReadRegister( _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
