bool
Disassembler::Disassemble
(
Debugger &debugger,
const ArchSpec &arch,
const char *plugin_name,
const char *flavor,
const ExecutionContext &exe_ctx,
uint32_t num_instructions,
uint32_t num_mixed_context_lines,
uint32_t options,
Stream &strm
)
{
AddressRange range;
StackFrame *frame = exe_ctx.GetFramePtr();
if (frame)
{
SymbolContext sc(frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol));
if (sc.function)
{
range = sc.function->GetAddressRange();
}
else if (sc.symbol && sc.symbol->ValueIsAddress())
{
range.GetBaseAddress() = sc.symbol->GetAddress();
range.SetByteSize (sc.symbol->GetByteSize());
}
else
{
range.GetBaseAddress() = frame->GetFrameCodeAddress();
}
if (range.GetBaseAddress().IsValid() && range.GetByteSize() == 0)
range.SetByteSize (DEFAULT_DISASM_BYTE_SIZE);
}
return Disassemble (debugger,
arch,
plugin_name,
flavor,
exe_ctx,
range,
num_instructions,
num_mixed_context_lines,
options,
strm);
}
bool AddressRange::Extend(const AddressRange &rhs_range) {
addr_t lhs_end_addr = GetBaseAddress().GetFileAddress() + GetByteSize();
addr_t rhs_base_addr = rhs_range.GetBaseAddress().GetFileAddress();
if (!ContainsFileAddress(rhs_range.GetBaseAddress()) &&
lhs_end_addr != rhs_base_addr)
// The ranges don't intersect at all on the right side of this range.
return false;
addr_t rhs_end_addr = rhs_base_addr + rhs_range.GetByteSize();
if (lhs_end_addr >= rhs_end_addr)
// The rhs range totally overlaps this one, nothing to add.
return false;
m_byte_size += rhs_end_addr - lhs_end_addr;
return true;
}
size_t
Disassembler::ParseInstructions
(
const ExecutionContext *exe_ctx,
const AddressRange &range,
DataExtractor& data
)
{
Target *target = exe_ctx->target;
const addr_t byte_size = range.GetByteSize();
if (target == NULL || byte_size == 0 || !range.GetBaseAddress().IsValid())
return 0;
DataBufferHeap *heap_buffer = new DataBufferHeap (byte_size, '\0');
DataBufferSP data_sp(heap_buffer);
Error error;
const size_t bytes_read = target->ReadMemory (range.GetBaseAddress(), heap_buffer->GetBytes(), heap_buffer->GetByteSize(), error);
if (bytes_read > 0)
{
if (bytes_read != heap_buffer->GetByteSize())
heap_buffer->SetByteSize (bytes_read);
data.SetData(data_sp);
if (exe_ctx->process)
{
data.SetByteOrder(exe_ctx->process->GetByteOrder());
data.SetAddressByteSize(exe_ctx->process->GetAddressByteSize());
}
else
{
data.SetByteOrder(target->GetArchitecture().GetDefaultEndian());
data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
}
return DecodeInstructions (data, 0, UINT32_MAX);
}
return 0;
}
lldb::DisassemblerSP
Disassembler::DisassembleRange
(
const ArchSpec &arch,
const char *plugin_name,
const ExecutionContext &exe_ctx,
const AddressRange &range
)
{
lldb::DisassemblerSP disasm_sp;
if (range.GetByteSize() > 0 && range.GetBaseAddress().IsValid())
{
disasm_sp.reset (Disassembler::FindPlugin(arch, plugin_name));
if (disasm_sp)
{
size_t bytes_disassembled = disasm_sp->ParseInstructions (&exe_ctx, range, NULL);
if (bytes_disassembled == 0)
disasm_sp.reset();
}
}
return disasm_sp;
}
void
UnwindPlan::SetPlanValidAddressRange (const AddressRange& range)
{
if (range.GetBaseAddress().IsValid() && range.GetByteSize() != 0)
m_plan_valid_address_range = range;
}
//----------------------------------------------------------------------
// ThreadPlanStepOut: Step out of the current frame
//----------------------------------------------------------------------
ThreadPlanStepOut::ThreadPlanStepOut(
Thread &thread, SymbolContext *context, bool first_insn, bool stop_others,
Vote stop_vote, Vote run_vote, uint32_t frame_idx,
LazyBool step_out_avoids_code_without_debug_info,
bool continue_to_next_branch, bool gather_return_value)
: ThreadPlan(ThreadPlan::eKindStepOut, "Step out", thread, stop_vote,
run_vote),
ThreadPlanShouldStopHere(this), m_step_from_insn(LLDB_INVALID_ADDRESS),
m_return_bp_id(LLDB_INVALID_BREAK_ID),
m_return_addr(LLDB_INVALID_ADDRESS), m_stop_others(stop_others),
m_immediate_step_from_function(nullptr),
m_calculate_return_value(gather_return_value) {
SetFlagsToDefault();
SetupAvoidNoDebug(step_out_avoids_code_without_debug_info);
m_step_from_insn = m_thread.GetRegisterContext()->GetPC(0);
StackFrameSP return_frame_sp(m_thread.GetStackFrameAtIndex(frame_idx + 1));
StackFrameSP immediate_return_from_sp(
m_thread.GetStackFrameAtIndex(frame_idx));
if (!return_frame_sp || !immediate_return_from_sp)
return; // we can't do anything here. ValidatePlan() will return false.
m_step_out_to_id = return_frame_sp->GetStackID();
m_immediate_step_from_id = immediate_return_from_sp->GetStackID();
// If the frame directly below the one we are returning to is inlined, we have
// to be
// a little more careful. It is non-trivial to determine the real "return
// code address" for
// an inlined frame, so we have to work our way to that frame and then step
// out.
if (immediate_return_from_sp && immediate_return_from_sp->IsInlined()) {
if (frame_idx > 0) {
// First queue a plan that gets us to this inlined frame, and when we get
// there we'll queue a second
// plan that walks us out of this frame.
m_step_out_to_inline_plan_sp.reset(new ThreadPlanStepOut(
m_thread, nullptr, false, stop_others, eVoteNoOpinion, eVoteNoOpinion,
frame_idx - 1, eLazyBoolNo, continue_to_next_branch));
static_cast<ThreadPlanStepOut *>(m_step_out_to_inline_plan_sp.get())
->SetShouldStopHereCallbacks(nullptr, nullptr);
m_step_out_to_inline_plan_sp->SetPrivate(true);
} else {
// If we're already at the inlined frame we're stepping through, then just
// do that now.
QueueInlinedStepPlan(false);
}
} else if (return_frame_sp) {
// Find the return address and set a breakpoint there:
// FIXME - can we do this more securely if we know first_insn?
Address return_address(return_frame_sp->GetFrameCodeAddress());
if (continue_to_next_branch) {
SymbolContext return_address_sc;
AddressRange range;
Address return_address_decr_pc = return_address;
if (return_address_decr_pc.GetOffset() > 0)
return_address_decr_pc.Slide(-1);
return_address_decr_pc.CalculateSymbolContext(
&return_address_sc, lldb::eSymbolContextLineEntry);
if (return_address_sc.line_entry.IsValid()) {
range =
return_address_sc.line_entry.GetSameLineContiguousAddressRange();
if (range.GetByteSize() > 0) {
return_address =
m_thread.GetProcess()->AdvanceAddressToNextBranchInstruction(
return_address, range);
}
}
}
m_return_addr =
return_address.GetLoadAddress(&m_thread.GetProcess()->GetTarget());
if (m_return_addr == LLDB_INVALID_ADDRESS)
return;
Breakpoint *return_bp = m_thread.CalculateTarget()
->CreateBreakpoint(m_return_addr, true, false)
.get();
if (return_bp != nullptr) {
return_bp->SetThreadID(m_thread.GetID());
m_return_bp_id = return_bp->GetID();
return_bp->SetBreakpointKind("step-out");
}
if (immediate_return_from_sp) {
const SymbolContext &sc =
immediate_return_from_sp->GetSymbolContext(eSymbolContextFunction);
if (sc.function) {
m_immediate_step_from_function = sc.function;
}
}
}
}
bool
CommandObjectDisassemble::Execute
(
CommandInterpreter &interpreter,
Args& command,
CommandReturnObject &result
)
{
Target *target = interpreter.GetDebugger().GetCurrentTarget().get();
if (target == NULL)
{
result.AppendError ("invalid target, set executable file using 'file' command");
result.SetStatus (eReturnStatusFailed);
return false;
}
ArchSpec arch(target->GetArchitecture());
if (!arch.IsValid())
{
result.AppendError ("target needs valid architecure in order to be able to disassemble");
result.SetStatus (eReturnStatusFailed);
return false;
}
Disassembler *disassembler = Disassembler::FindPlugin(arch);
if (disassembler == NULL)
{
result.AppendErrorWithFormat ("Unable to find Disassembler plug-in for %s architecture.\n", arch.AsCString());
result.SetStatus (eReturnStatusFailed);
return false;
}
result.SetStatus (eReturnStatusSuccessFinishResult);
if (command.GetArgumentCount() != 0)
{
result.AppendErrorWithFormat ("\"disassemble\" doesn't take any arguments.\n");
result.SetStatus (eReturnStatusFailed);
return false;
}
ExecutionContext exe_ctx(interpreter.GetDebugger().GetExecutionContext());
if (m_options.show_mixed && m_options.num_lines_context == 0)
m_options.num_lines_context = 3;
if (!m_options.m_func_name.empty())
{
ConstString name(m_options.m_func_name.c_str());
if (Disassembler::Disassemble (interpreter.GetDebugger(),
arch,
exe_ctx,
name,
NULL, // Module *
m_options.show_mixed ? m_options.num_lines_context : 0,
m_options.show_bytes,
result.GetOutputStream()))
{
result.SetStatus (eReturnStatusSuccessFinishResult);
}
else
{
result.AppendErrorWithFormat ("Unable to find symbol with name '%s'.\n", name.GetCString());
result.SetStatus (eReturnStatusFailed);
}
}
else
{
AddressRange range;
if (m_options.m_start_addr != LLDB_INVALID_ADDRESS)
{
range.GetBaseAddress().SetOffset (m_options.m_start_addr);
if (m_options.m_end_addr != LLDB_INVALID_ADDRESS)
{
if (m_options.m_end_addr < m_options.m_start_addr)
{
result.AppendErrorWithFormat ("End address before start address.\n");
result.SetStatus (eReturnStatusFailed);
return false;
}
range.SetByteSize (m_options.m_end_addr - m_options.m_start_addr);
}
else
range.SetByteSize (DEFAULT_DISASM_BYTE_SIZE);
}
else
{
if (exe_ctx.frame)
{
SymbolContext sc(exe_ctx.frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol));
if (sc.function)
range = sc.function->GetAddressRange();
else if (sc.symbol && sc.symbol->GetAddressRangePtr())
range = *sc.symbol->GetAddressRangePtr();
else
range.GetBaseAddress() = exe_ctx.frame->GetPC();
}
else
{
result.AppendError ("invalid frame");
result.SetStatus (eReturnStatusFailed);
return false;
}
}
if (range.GetByteSize() == 0)
range.SetByteSize(DEFAULT_DISASM_BYTE_SIZE);
if (Disassembler::Disassemble (interpreter.GetDebugger(),
arch,
exe_ctx,
range,
m_options.show_mixed ? m_options.num_lines_context : 0,
m_options.show_bytes,
result.GetOutputStream()))
{
result.SetStatus (eReturnStatusSuccessFinishResult);
}
else
{
result.AppendErrorWithFormat ("Failed to disassemble memory at 0x%8.8llx.\n", m_options.m_start_addr);
result.SetStatus (eReturnStatusFailed);
}
}
return result.Succeeded();
}
bool
CommandObjectDisassemble::DoExecute (Args& command, CommandReturnObject &result)
{
Target *target = m_interpreter.GetDebugger().GetSelectedTarget().get();
if (target == NULL)
{
result.AppendError ("invalid target, create a debug target using the 'target create' command");
result.SetStatus (eReturnStatusFailed);
return false;
}
if (!m_options.arch.IsValid())
m_options.arch = target->GetArchitecture();
if (!m_options.arch.IsValid())
{
result.AppendError ("use the --arch option or set the target architecure to disassemble");
result.SetStatus (eReturnStatusFailed);
return false;
}
const char *plugin_name = m_options.GetPluginName ();
const char *flavor_string = m_options.GetFlavorString();
DisassemblerSP disassembler = Disassembler::FindPlugin(m_options.arch, flavor_string, plugin_name);
if (!disassembler)
{
if (plugin_name)
{
result.AppendErrorWithFormat ("Unable to find Disassembler plug-in named '%s' that supports the '%s' architecture.\n",
plugin_name,
m_options.arch.GetArchitectureName());
}
else
result.AppendErrorWithFormat ("Unable to find Disassembler plug-in for the '%s' architecture.\n",
m_options.arch.GetArchitectureName());
result.SetStatus (eReturnStatusFailed);
return false;
}
else if (flavor_string != NULL && !disassembler->FlavorValidForArchSpec(m_options.arch, flavor_string))
result.AppendWarningWithFormat("invalid disassembler flavor \"%s\", using default.\n", flavor_string);
result.SetStatus (eReturnStatusSuccessFinishResult);
if (command.GetArgumentCount() != 0)
{
result.AppendErrorWithFormat ("\"disassemble\" arguments are specified as options.\n");
GetOptions()->GenerateOptionUsage (result.GetErrorStream(), this);
result.SetStatus (eReturnStatusFailed);
return false;
}
if (m_options.show_mixed && m_options.num_lines_context == 0)
m_options.num_lines_context = 1;
// Always show the PC in the disassembly
uint32_t options = Disassembler::eOptionMarkPCAddress;
// Mark the source line for the current PC only if we are doing mixed source and assembly
if (m_options.show_mixed)
options |= Disassembler::eOptionMarkPCSourceLine;
if (m_options.show_bytes)
options |= Disassembler::eOptionShowBytes;
if (m_options.raw)
options |= Disassembler::eOptionRawOuput;
if (!m_options.func_name.empty())
{
ConstString name(m_options.func_name.c_str());
if (Disassembler::Disassemble (m_interpreter.GetDebugger(),
m_options.arch,
plugin_name,
flavor_string,
m_exe_ctx,
name,
NULL, // Module *
m_options.num_instructions,
m_options.show_mixed ? m_options.num_lines_context : 0,
options,
result.GetOutputStream()))
{
result.SetStatus (eReturnStatusSuccessFinishResult);
}
else
{
result.AppendErrorWithFormat ("Unable to find symbol with name '%s'.\n", name.GetCString());
result.SetStatus (eReturnStatusFailed);
}
}
else
{
std::vector<AddressRange> ranges;
AddressRange range;
StackFrame *frame = m_exe_ctx.GetFramePtr();
if (m_options.frame_line)
{
if (frame == NULL)
{
result.AppendError ("Cannot disassemble around the current line without a selected frame.\n");
result.SetStatus (eReturnStatusFailed);
return false;
}
LineEntry pc_line_entry (frame->GetSymbolContext(eSymbolContextLineEntry).line_entry);
if (pc_line_entry.IsValid())
{
range = pc_line_entry.range;
}
else
{
m_options.at_pc = true; // No line entry, so just disassemble around the current pc
m_options.show_mixed = false;
}
}
else if (m_options.current_function)
{
if (frame == NULL)
{
result.AppendError ("Cannot disassemble around the current function without a selected frame.\n");
result.SetStatus (eReturnStatusFailed);
return false;
}
Symbol *symbol = frame->GetSymbolContext(eSymbolContextSymbol).symbol;
if (symbol)
{
range.GetBaseAddress() = symbol->GetAddress();
range.SetByteSize(symbol->GetByteSize());
}
}
// Did the "m_options.frame_line" find a valid range already? If so
// skip the rest...
if (range.GetByteSize() == 0)
{
if (m_options.at_pc)
{
if (frame == NULL)
{
result.AppendError ("Cannot disassemble around the current PC without a selected frame.\n");
result.SetStatus (eReturnStatusFailed);
return false;
}
range.GetBaseAddress() = frame->GetFrameCodeAddress();
if (m_options.num_instructions == 0)
{
// Disassembling at the PC always disassembles some number of instructions (not the whole function).
m_options.num_instructions = DEFAULT_DISASM_NUM_INS;
}
ranges.push_back(range);
}
else
{
range.GetBaseAddress().SetOffset (m_options.start_addr);
if (range.GetBaseAddress().IsValid())
{
if (m_options.end_addr != LLDB_INVALID_ADDRESS)
{
if (m_options.end_addr <= m_options.start_addr)
{
result.AppendErrorWithFormat ("End address before start address.\n");
result.SetStatus (eReturnStatusFailed);
return false;
}
range.SetByteSize (m_options.end_addr - m_options.start_addr);
}
ranges.push_back(range);
}
else
{
if (m_options.symbol_containing_addr != LLDB_INVALID_ADDRESS
&& target)
{
if (!target->GetSectionLoadList().IsEmpty())
{
bool failed = false;
Address symbol_containing_address;
if (target->GetSectionLoadList().ResolveLoadAddress (m_options.symbol_containing_addr, symbol_containing_address))
{
ModuleSP module_sp (symbol_containing_address.GetModule());
SymbolContext sc;
bool resolve_tail_call_address = true; // PC can be one past the address range of the function.
module_sp->ResolveSymbolContextForAddress (symbol_containing_address, eSymbolContextEverything, sc,
resolve_tail_call_address);
if (sc.function || sc.symbol)
{
sc.GetAddressRange (eSymbolContextFunction | eSymbolContextSymbol, 0, false, range);
}
else
{
failed = true;
}
}
else
{
failed = true;
}
if (failed)
{
result.AppendErrorWithFormat ("Could not find function bounds for address 0x%" PRIx64 "\n", m_options.symbol_containing_addr);
result.SetStatus (eReturnStatusFailed);
return false;
}
ranges.push_back(range);
}
else
{
for (lldb::ModuleSP module_sp : target->GetImages().Modules())
{
lldb::addr_t file_addr = m_options.symbol_containing_addr;
Address file_address;
if (module_sp->ResolveFileAddress(file_addr, file_address))
{
SymbolContext sc;
bool resolve_tail_call_address = true; // PC can be one past the address range of the function.
module_sp->ResolveSymbolContextForAddress (file_address, eSymbolContextEverything, sc, resolve_tail_call_address);
if (sc.function || sc.symbol)
{
sc.GetAddressRange (eSymbolContextFunction | eSymbolContextSymbol, 0, false, range);
ranges.push_back(range);
}
}
}
}
}
}
}
}
else
ranges.push_back(range);
if (m_options.num_instructions != 0)
{
if (ranges.size() == 0)
{
// The default action is to disassemble the current frame function.
if (frame)
{
SymbolContext sc(frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol));
if (sc.function)
range.GetBaseAddress() = sc.function->GetAddressRange().GetBaseAddress();
else if (sc.symbol && sc.symbol->ValueIsAddress())
range.GetBaseAddress() = sc.symbol->GetAddress();
else
range.GetBaseAddress() = frame->GetFrameCodeAddress();
}
if (!range.GetBaseAddress().IsValid())
{
result.AppendError ("invalid frame");
result.SetStatus (eReturnStatusFailed);
return false;
}
}
bool print_sc_header = ranges.size() > 1;
for (AddressRange cur_range : ranges)
{
if (Disassembler::Disassemble (m_interpreter.GetDebugger(),
m_options.arch,
plugin_name,
flavor_string,
m_exe_ctx,
cur_range.GetBaseAddress(),
m_options.num_instructions,
m_options.show_mixed ? m_options.num_lines_context : 0,
options,
result.GetOutputStream()))
{
result.SetStatus (eReturnStatusSuccessFinishResult);
}
else
{
if (m_options.start_addr != LLDB_INVALID_ADDRESS)
result.AppendErrorWithFormat ("Failed to disassemble memory at 0x%8.8" PRIx64 ".\n", m_options.start_addr);
else if (m_options.symbol_containing_addr != LLDB_INVALID_ADDRESS)
result.AppendErrorWithFormat ("Failed to disassemble memory in function at 0x%8.8" PRIx64 ".\n", m_options.symbol_containing_addr);
result.SetStatus (eReturnStatusFailed);
}
}
if (print_sc_header)
result.AppendMessage("\n");
}
else
{
if (ranges.size() == 0)
{
// The default action is to disassemble the current frame function.
if (frame)
{
SymbolContext sc(frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol));
if (sc.function)
range = sc.function->GetAddressRange();
else if (sc.symbol && sc.symbol->ValueIsAddress())
{
range.GetBaseAddress() = sc.symbol->GetAddress();
range.SetByteSize (sc.symbol->GetByteSize());
}
else
range.GetBaseAddress() = frame->GetFrameCodeAddress();
}
else
{
result.AppendError ("invalid frame");
result.SetStatus (eReturnStatusFailed);
return false;
}
ranges.push_back(range);
}
bool print_sc_header = ranges.size() > 1;
for (AddressRange cur_range : ranges)
{
if (cur_range.GetByteSize() == 0)
cur_range.SetByteSize(DEFAULT_DISASM_BYTE_SIZE);
if (Disassembler::Disassemble (m_interpreter.GetDebugger(),
m_options.arch,
plugin_name,
flavor_string,
m_exe_ctx,
cur_range,
m_options.num_instructions,
m_options.show_mixed ? m_options.num_lines_context : 0,
options,
result.GetOutputStream()))
{
result.SetStatus (eReturnStatusSuccessFinishResult);
}
else
{
result.AppendErrorWithFormat ("Failed to disassemble memory at 0x%8.8" PRIx64 ".\n", m_options.start_addr);
result.SetStatus (eReturnStatusFailed);
}
if (print_sc_header)
result.AppendMessage("\n");
}
}
}
return result.Succeeded();
}
bool
UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly (AddressRange& range,
Thread& thread,
UnwindPlan& unwind_plan)
{
if (range.GetByteSize() > 0 &&
range.GetBaseAddress().IsValid() &&
m_inst_emulator_ap.get())
{
// The instruction emulation subclass setup the unwind plan for the
// first instruction.
m_inst_emulator_ap->CreateFunctionEntryUnwind (unwind_plan);
// CreateFunctionEntryUnwind should have created the first row. If it
// doesn't, then we are done.
if (unwind_plan.GetRowCount() == 0)
return false;
ExecutionContext exe_ctx;
thread.CalculateExecutionContext(exe_ctx);
const bool prefer_file_cache = true;
DisassemblerSP disasm_sp (Disassembler::DisassembleRange (m_arch,
NULL,
NULL,
exe_ctx,
range,
prefer_file_cache));
Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
if (disasm_sp)
{
m_range_ptr = ⦥
m_thread_ptr = &thread;
m_unwind_plan_ptr = &unwind_plan;
const uint32_t addr_byte_size = m_arch.GetAddressByteSize();
const bool show_address = true;
const bool show_bytes = true;
m_inst_emulator_ap->GetRegisterInfo (unwind_plan.GetRegisterKind(),
unwind_plan.GetInitialCFARegister(),
m_cfa_reg_info);
m_fp_is_cfa = false;
m_register_values.clear();
m_pushed_regs.clear();
// Initialize the CFA with a known value. In the 32 bit case
// it will be 0x80000000, and in the 64 bit case 0x8000000000000000.
// We use the address byte size to be safe for any future address sizes
m_initial_sp = (1ull << ((addr_byte_size * 8) - 1));
RegisterValue cfa_reg_value;
cfa_reg_value.SetUInt (m_initial_sp, m_cfa_reg_info.byte_size);
SetRegisterValue (m_cfa_reg_info, cfa_reg_value);
const InstructionList &inst_list = disasm_sp->GetInstructionList ();
const size_t num_instructions = inst_list.GetSize();
if (num_instructions > 0)
{
Instruction *inst = inst_list.GetInstructionAtIndex (0).get();
const lldb::addr_t base_addr = inst->GetAddress().GetFileAddress();
// Map for storing the unwind plan row and the value of the registers at a given offset.
// When we see a forward branch we add a new entry to this map with the actual unwind plan
// row and register context for the target address of the branch as the current data have
// to be valid for the target address of the branch too if we are in the same function.
std::map<lldb::addr_t, std::pair<UnwindPlan::RowSP, RegisterValueMap>> saved_unwind_states;
// Make a copy of the current instruction Row and save it in m_curr_row
// so we can add updates as we process the instructions.
UnwindPlan::RowSP last_row = unwind_plan.GetLastRow();
UnwindPlan::Row *newrow = new UnwindPlan::Row;
if (last_row.get())
*newrow = *last_row.get();
m_curr_row.reset(newrow);
// Add the initial state to the save list with offset 0.
saved_unwind_states.insert({0, {last_row, m_register_values}});
// cache the pc register number (in whatever register numbering this UnwindPlan uses) for
// quick reference during instruction parsing.
uint32_t pc_reg_num = LLDB_INVALID_REGNUM;
RegisterInfo pc_reg_info;
if (m_inst_emulator_ap->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, pc_reg_info))
pc_reg_num = pc_reg_info.kinds[unwind_plan.GetRegisterKind()];
else
pc_reg_num = LLDB_INVALID_REGNUM;
// cache the return address register number (in whatever register numbering this UnwindPlan uses) for
// quick reference during instruction parsing.
uint32_t ra_reg_num = LLDB_INVALID_REGNUM;
RegisterInfo ra_reg_info;
if (m_inst_emulator_ap->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA, ra_reg_info))
ra_reg_num = ra_reg_info.kinds[unwind_plan.GetRegisterKind()];
else
ra_reg_num = LLDB_INVALID_REGNUM;
for (size_t idx=0; idx<num_instructions; ++idx)
{
m_curr_row_modified = false;
m_forward_branch_offset = 0;
inst = inst_list.GetInstructionAtIndex (idx).get();
if (inst)
{
lldb::addr_t current_offset = inst->GetAddress().GetFileAddress() - base_addr;
auto it = saved_unwind_states.upper_bound(current_offset);
assert(it != saved_unwind_states.begin() && "Unwind row for the function entry missing");
--it; // Move it to the row corresponding to the current offset
// If the offset of m_curr_row don't match with the offset we see in saved_unwind_states
// then we have to update m_curr_row and m_register_values based on the saved values. It
// is happenning after we processed an epilogue and a return to caller instruction.
if (it->second.first->GetOffset() != m_curr_row->GetOffset())
{
UnwindPlan::Row *newrow = new UnwindPlan::Row;
*newrow = *it->second.first;
m_curr_row.reset(newrow);
m_register_values = it->second.second;;
}
if (log && log->GetVerbose ())
{
StreamString strm;
lldb_private::FormatEntity::Entry format;
FormatEntity::Parse("${frame.pc}: ", format);
inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize (), show_address, show_bytes, NULL, NULL, NULL, &format, 0);
log->PutCString (strm.GetData());
}
m_inst_emulator_ap->SetInstruction (inst->GetOpcode(),
inst->GetAddress(),
exe_ctx.GetTargetPtr());
m_inst_emulator_ap->EvaluateInstruction (eEmulateInstructionOptionIgnoreConditions);
// If the current instruction is a branch forward then save the current CFI information
// for the offset where we are branching.
if (m_forward_branch_offset != 0 && range.ContainsFileAddress(inst->GetAddress().GetFileAddress() + m_forward_branch_offset))
{
auto newrow = std::make_shared<UnwindPlan::Row>(*m_curr_row.get());
newrow->SetOffset(current_offset + m_forward_branch_offset);
saved_unwind_states.insert({current_offset + m_forward_branch_offset, {newrow, m_register_values}});
unwind_plan.InsertRow(newrow);
}
// Were there any changes to the CFI while evaluating this instruction?
if (m_curr_row_modified)
{
// Save the modified row if we don't already have a CFI row in the currennt address
if (saved_unwind_states.count(current_offset + inst->GetOpcode().GetByteSize()) == 0)
{
m_curr_row->SetOffset (current_offset + inst->GetOpcode().GetByteSize());
unwind_plan.InsertRow (m_curr_row);
saved_unwind_states.insert({current_offset + inst->GetOpcode().GetByteSize(), {m_curr_row, m_register_values}});
// Allocate a new Row for m_curr_row, copy the current state into it
UnwindPlan::Row *newrow = new UnwindPlan::Row;
*newrow = *m_curr_row.get();
m_curr_row.reset(newrow);
}
}
}
}
}
// FIXME: The DisassemblerLLVMC has a reference cycle and won't go away if it has any active instructions.
// I'll fix that but for now, just clear the list and it will go away nicely.
disasm_sp->GetInstructionList().Clear();
}
if (log && log->GetVerbose ())
{
StreamString strm;
lldb::addr_t base_addr = range.GetBaseAddress().GetLoadAddress(thread.CalculateTarget().get());
strm.Printf ("Resulting unwind rows for [0x%" PRIx64 " - 0x%" PRIx64 "):", base_addr, base_addr + range.GetByteSize());
unwind_plan.Dump(strm, &thread, base_addr);
log->PutCString (strm.GetData());
}
return unwind_plan.GetRowCount() > 0;
}
return false;
}
bool UnwindAssembly_x86::AugmentUnwindPlanFromCallSite(
AddressRange &func, Thread &thread, UnwindPlan &unwind_plan) {
bool do_augment_unwindplan = true;
UnwindPlan::RowSP first_row = unwind_plan.GetRowForFunctionOffset(0);
UnwindPlan::RowSP last_row = unwind_plan.GetRowForFunctionOffset(-1);
int wordsize = 8;
ProcessSP process_sp(thread.GetProcess());
if (process_sp.get() == nullptr)
return false;
wordsize = process_sp->GetTarget().GetArchitecture().GetAddressByteSize();
RegisterNumber sp_regnum(thread, eRegisterKindGeneric,
LLDB_REGNUM_GENERIC_SP);
RegisterNumber pc_regnum(thread, eRegisterKindGeneric,
LLDB_REGNUM_GENERIC_PC);
// Does this UnwindPlan describe the prologue? I want to see that the CFA is
// set in terms of the stack pointer plus an offset, and I want to see that
// rip is retrieved at the CFA-wordsize. If there is no description of the
// prologue, don't try to augment this eh_frame unwinder code, fall back to
// assembly parsing instead.
if (first_row->GetCFAValue().GetValueType() !=
UnwindPlan::Row::FAValue::isRegisterPlusOffset ||
RegisterNumber(thread, unwind_plan.GetRegisterKind(),
first_row->GetCFAValue().GetRegisterNumber()) !=
sp_regnum ||
first_row->GetCFAValue().GetOffset() != wordsize) {
return false;
}
UnwindPlan::Row::RegisterLocation first_row_pc_loc;
if (!first_row->GetRegisterInfo(
pc_regnum.GetAsKind(unwind_plan.GetRegisterKind()),
first_row_pc_loc) ||
!first_row_pc_loc.IsAtCFAPlusOffset() ||
first_row_pc_loc.GetOffset() != -wordsize) {
return false;
}
// It looks like the prologue is described. Is the epilogue described? If it
// is, no need to do any augmentation.
if (first_row != last_row &&
first_row->GetOffset() != last_row->GetOffset()) {
// The first & last row have the same CFA register and the same CFA offset
// value and the CFA register is esp/rsp (the stack pointer).
// We're checking that both of them have an unwind rule like "CFA=esp+4" or
// CFA+rsp+8".
if (first_row->GetCFAValue().GetValueType() ==
last_row->GetCFAValue().GetValueType() &&
first_row->GetCFAValue().GetRegisterNumber() ==
last_row->GetCFAValue().GetRegisterNumber() &&
first_row->GetCFAValue().GetOffset() ==
last_row->GetCFAValue().GetOffset()) {
// Get the register locations for eip/rip from the first & last rows. Are
// they both CFA plus an offset? Is it the same offset?
UnwindPlan::Row::RegisterLocation last_row_pc_loc;
if (last_row->GetRegisterInfo(
pc_regnum.GetAsKind(unwind_plan.GetRegisterKind()),
last_row_pc_loc)) {
if (last_row_pc_loc.IsAtCFAPlusOffset() &&
first_row_pc_loc.GetOffset() == last_row_pc_loc.GetOffset()) {
// One last sanity check: Is the unwind rule for getting the caller
// pc value "deref the CFA-4" or "deref the CFA-8"?
// If so, we have an UnwindPlan that already describes the epilogue
// and we don't need to modify it at all.
if (first_row_pc_loc.GetOffset() == -wordsize) {
do_augment_unwindplan = false;
}
}
}
}
}
if (do_augment_unwindplan) {
if (!func.GetBaseAddress().IsValid() || func.GetByteSize() == 0)
return false;
if (m_assembly_inspection_engine == nullptr)
return false;
const bool prefer_file_cache = true;
std::vector<uint8_t> function_text(func.GetByteSize());
Status error;
if (process_sp->GetTarget().ReadMemory(
func.GetBaseAddress(), prefer_file_cache, function_text.data(),
func.GetByteSize(), error) == func.GetByteSize()) {
RegisterContextSP reg_ctx(thread.GetRegisterContext());
m_assembly_inspection_engine->Initialize(reg_ctx);
return m_assembly_inspection_engine->AugmentUnwindPlanFromCallSite(
function_text.data(), func.GetByteSize(), func, unwind_plan, reg_ctx);
}
}
return false;
}
bool UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly(
AddressRange &range, uint8_t *opcode_data, size_t opcode_size,
UnwindPlan &unwind_plan) {
if (opcode_data == nullptr || opcode_size == 0)
return false;
if (range.GetByteSize() > 0 && range.GetBaseAddress().IsValid() &&
m_inst_emulator_ap.get()) {
// The instruction emulation subclass setup the unwind plan for the
// first instruction.
m_inst_emulator_ap->CreateFunctionEntryUnwind(unwind_plan);
// CreateFunctionEntryUnwind should have created the first row. If it
// doesn't, then we are done.
if (unwind_plan.GetRowCount() == 0)
return false;
const bool prefer_file_cache = true;
DisassemblerSP disasm_sp(Disassembler::DisassembleBytes(
m_arch, NULL, NULL, range.GetBaseAddress(), opcode_data, opcode_size,
99999, prefer_file_cache));
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
if (disasm_sp) {
m_range_ptr = ⦥
m_unwind_plan_ptr = &unwind_plan;
const uint32_t addr_byte_size = m_arch.GetAddressByteSize();
const bool show_address = true;
const bool show_bytes = true;
m_inst_emulator_ap->GetRegisterInfo(unwind_plan.GetRegisterKind(),
unwind_plan.GetInitialCFARegister(),
m_cfa_reg_info);
m_fp_is_cfa = false;
m_register_values.clear();
m_pushed_regs.clear();
// Initialize the CFA with a known value. In the 32 bit case
// it will be 0x80000000, and in the 64 bit case 0x8000000000000000.
// We use the address byte size to be safe for any future address sizes
m_initial_sp = (1ull << ((addr_byte_size * 8) - 1));
RegisterValue cfa_reg_value;
cfa_reg_value.SetUInt(m_initial_sp, m_cfa_reg_info.byte_size);
SetRegisterValue(m_cfa_reg_info, cfa_reg_value);
const InstructionList &inst_list = disasm_sp->GetInstructionList();
const size_t num_instructions = inst_list.GetSize();
if (num_instructions > 0) {
Instruction *inst = inst_list.GetInstructionAtIndex(0).get();
const lldb::addr_t base_addr = inst->GetAddress().GetFileAddress();
// Map for storing the unwind plan row and the value of the registers at
// a given offset.
// When we see a forward branch we add a new entry to this map with the
// actual unwind plan
// row and register context for the target address of the branch as the
// current data have
// to be valid for the target address of the branch too if we are in the
// same function.
std::map<lldb::addr_t, std::pair<UnwindPlan::RowSP, RegisterValueMap>>
saved_unwind_states;
// Make a copy of the current instruction Row and save it in m_curr_row
// so we can add updates as we process the instructions.
UnwindPlan::RowSP last_row = unwind_plan.GetLastRow();
UnwindPlan::Row *newrow = new UnwindPlan::Row;
if (last_row.get())
*newrow = *last_row.get();
m_curr_row.reset(newrow);
// Add the initial state to the save list with offset 0.
saved_unwind_states.insert({0, {last_row, m_register_values}});
// cache the pc register number (in whatever register numbering this
// UnwindPlan uses) for
// quick reference during instruction parsing.
RegisterInfo pc_reg_info;
m_inst_emulator_ap->GetRegisterInfo(
eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, pc_reg_info);
// cache the return address register number (in whatever register
// numbering this UnwindPlan uses) for
// quick reference during instruction parsing.
RegisterInfo ra_reg_info;
m_inst_emulator_ap->GetRegisterInfo(
eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA, ra_reg_info);
// The architecture dependent condition code of the last processed
// instruction.
EmulateInstruction::InstructionCondition last_condition =
EmulateInstruction::UnconditionalCondition;
lldb::addr_t condition_block_start_offset = 0;
for (size_t idx = 0; idx < num_instructions; ++idx) {
m_curr_row_modified = false;
m_forward_branch_offset = 0;
inst = inst_list.GetInstructionAtIndex(idx).get();
if (inst) {
lldb::addr_t current_offset =
inst->GetAddress().GetFileAddress() - base_addr;
auto it = saved_unwind_states.upper_bound(current_offset);
assert(it != saved_unwind_states.begin() &&
"Unwind row for the function entry missing");
--it; // Move it to the row corresponding to the current offset
// If the offset of m_curr_row don't match with the offset we see in
// saved_unwind_states
// then we have to update m_curr_row and m_register_values based on
// the saved values. It
// is happenning after we processed an epilogue and a return to
// caller instruction.
if (it->second.first->GetOffset() != m_curr_row->GetOffset()) {
UnwindPlan::Row *newrow = new UnwindPlan::Row;
*newrow = *it->second.first;
m_curr_row.reset(newrow);
m_register_values = it->second.second;
}
m_inst_emulator_ap->SetInstruction(inst->GetOpcode(),
inst->GetAddress(), nullptr);
if (last_condition !=
m_inst_emulator_ap->GetInstructionCondition()) {
if (m_inst_emulator_ap->GetInstructionCondition() !=
EmulateInstruction::UnconditionalCondition &&
saved_unwind_states.count(current_offset) == 0) {
// If we don't have a saved row for the current offset then save
// our
// current state because we will have to restore it after the
// conditional block.
auto new_row =
std::make_shared<UnwindPlan::Row>(*m_curr_row.get());
saved_unwind_states.insert(
{current_offset, {new_row, m_register_values}});
}
// If the last instruction was conditional with a different
// condition
// then the then current condition then restore the condition.
if (last_condition !=
EmulateInstruction::UnconditionalCondition) {
const auto &saved_state =
saved_unwind_states.at(condition_block_start_offset);
m_curr_row =
std::make_shared<UnwindPlan::Row>(*saved_state.first);
m_curr_row->SetOffset(current_offset);
m_register_values = saved_state.second;
bool replace_existing =
true; // The last instruction might already
// created a row for this offset and
// we want to overwrite it.
unwind_plan.InsertRow(
std::make_shared<UnwindPlan::Row>(*m_curr_row),
replace_existing);
}
// We are starting a new conditional block at the catual offset
condition_block_start_offset = current_offset;
}
if (log && log->GetVerbose()) {
StreamString strm;
lldb_private::FormatEntity::Entry format;
FormatEntity::Parse("${frame.pc}: ", format);
inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize(), show_address,
show_bytes, NULL, NULL, NULL, &format, 0);
log->PutString(strm.GetString());
}
last_condition = m_inst_emulator_ap->GetInstructionCondition();
m_inst_emulator_ap->EvaluateInstruction(
eEmulateInstructionOptionIgnoreConditions);
// If the current instruction is a branch forward then save the
// current CFI information
// for the offset where we are branching.
if (m_forward_branch_offset != 0 &&
range.ContainsFileAddress(inst->GetAddress().GetFileAddress() +
m_forward_branch_offset)) {
auto newrow =
std::make_shared<UnwindPlan::Row>(*m_curr_row.get());
newrow->SetOffset(current_offset + m_forward_branch_offset);
saved_unwind_states.insert(
{current_offset + m_forward_branch_offset,
{newrow, m_register_values}});
unwind_plan.InsertRow(newrow);
}
// Were there any changes to the CFI while evaluating this
// instruction?
if (m_curr_row_modified) {
// Save the modified row if we don't already have a CFI row in the
// currennt address
if (saved_unwind_states.count(
current_offset + inst->GetOpcode().GetByteSize()) == 0) {
m_curr_row->SetOffset(current_offset +
inst->GetOpcode().GetByteSize());
unwind_plan.InsertRow(m_curr_row);
saved_unwind_states.insert(
{current_offset + inst->GetOpcode().GetByteSize(),
{m_curr_row, m_register_values}});
// Allocate a new Row for m_curr_row, copy the current state
// into it
UnwindPlan::Row *newrow = new UnwindPlan::Row;
*newrow = *m_curr_row.get();
m_curr_row.reset(newrow);
}
}
}
}
}
}
if (log && log->GetVerbose()) {
StreamString strm;
lldb::addr_t base_addr = range.GetBaseAddress().GetFileAddress();
strm.Printf("Resulting unwind rows for [0x%" PRIx64 " - 0x%" PRIx64 "):",
base_addr, base_addr + range.GetByteSize());
unwind_plan.Dump(strm, nullptr, base_addr);
log->PutString(strm.GetString());
}
return unwind_plan.GetRowCount() > 0;
}
return false;
}
bool
Disassembler::Disassemble
(
Debugger &debugger,
const ArchSpec &arch,
const ExecutionContext &exe_ctx,
const AddressRange &disasm_range,
uint32_t num_mixed_context_lines,
bool show_bytes,
Stream &strm
)
{
if (disasm_range.GetByteSize())
{
Disassembler *disassembler = Disassembler::FindPlugin(arch);
if (disassembler)
{
AddressRange range(disasm_range);
Process *process = exe_ctx.process;
// If we weren't passed in a section offset address range,
// try and resolve it to something
if (range.GetBaseAddress().IsSectionOffset() == false)
{
if (process && process->IsAlive())
{
process->ResolveLoadAddress (range.GetBaseAddress().GetOffset(), range.GetBaseAddress());
}
else if (exe_ctx.target)
{
exe_ctx.target->GetImages().ResolveFileAddress (range.GetBaseAddress().GetOffset(), range.GetBaseAddress());
}
}
DataExtractor data;
size_t bytes_disassembled = disassembler->ParseInstructions (&exe_ctx, range, data);
if (bytes_disassembled == 0)
{
return false;
}
else
{
// We got some things disassembled...
size_t num_instructions = disassembler->GetInstructionList().GetSize();
uint32_t offset = 0;
SymbolContext sc;
SymbolContext prev_sc;
AddressRange sc_range;
if (num_mixed_context_lines)
strm.IndentMore ();
Address addr(range.GetBaseAddress());
// We extract the section to make sure we don't transition out
// of the current section when disassembling
const Section *addr_section = addr.GetSection();
Module *range_module = range.GetBaseAddress().GetModule();
for (size_t i=0; i<num_instructions; ++i)
{
Disassembler::Instruction *inst = disassembler->GetInstructionList().GetInstructionAtIndex (i);
if (inst)
{
addr_t file_addr = addr.GetFileAddress();
if (addr_section == NULL || addr_section->ContainsFileAddress (file_addr) == false)
{
if (range_module)
range_module->ResolveFileAddress (file_addr, addr);
else if (exe_ctx.target)
exe_ctx.target->GetImages().ResolveFileAddress (file_addr, addr);
addr_section = addr.GetSection();
}
prev_sc = sc;
if (addr_section)
{
Module *module = addr_section->GetModule();
uint32_t resolved_mask = module->ResolveSymbolContextForAddress(addr, eSymbolContextEverything, sc);
if (resolved_mask)
{
if (prev_sc.function != sc.function || prev_sc.symbol != sc.symbol)
{
if (prev_sc.function || prev_sc.symbol)
strm.EOL();
strm << sc.module_sp->GetFileSpec().GetFilename();
if (sc.function)
strm << '`' << sc.function->GetMangled().GetName();
else if (sc.symbol)
strm << '`' << sc.symbol->GetMangled().GetName();
strm << ":\n";
}
if (num_mixed_context_lines && !sc_range.ContainsFileAddress (addr))
{
sc.GetAddressRange (eSymbolContextEverything, sc_range);
if (sc != prev_sc)
{
if (offset != 0)
strm.EOL();
sc.DumpStopContext(&strm, process, addr);
if (sc.comp_unit && sc.line_entry.IsValid())
{
debugger.GetSourceManager().DisplaySourceLinesWithLineNumbers (sc.line_entry.file,
sc.line_entry.line,
num_mixed_context_lines,
num_mixed_context_lines,
num_mixed_context_lines ? "->" : "",
&strm);
}
}
}
}
else
{
sc.Clear();
}
}
if (num_mixed_context_lines)
strm.IndentMore ();
strm.Indent();
size_t inst_byte_size = inst->GetByteSize();
inst->Dump(&strm, &addr, show_bytes ? &data : NULL, offset, exe_ctx, show_bytes);
strm.EOL();
offset += inst_byte_size;
addr.SetOffset (addr.GetOffset() + inst_byte_size);
if (num_mixed_context_lines)
strm.IndentLess ();
}
else
{
break;
}
}
if (num_mixed_context_lines)
strm.IndentLess ();
}
}
return true;
}
return false;
}
bool
UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly (AddressRange& range,
Thread& thread,
UnwindPlan& unwind_plan)
{
if (range.GetByteSize() > 0 &&
range.GetBaseAddress().IsValid() &&
m_inst_emulator_ap.get())
{
// The the instruction emulation subclass setup the unwind plan for the
// first instruction.
m_inst_emulator_ap->CreateFunctionEntryUnwind (unwind_plan);
// CreateFunctionEntryUnwind should have created the first row. If it
// doesn't, then we are done.
if (unwind_plan.GetRowCount() == 0)
return false;
ExecutionContext exe_ctx;
thread.CalculateExecutionContext(exe_ctx);
DisassemblerSP disasm_sp (Disassembler::DisassembleRange (m_arch,
NULL,
exe_ctx,
range));
LogSP log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
if (disasm_sp)
{
m_range_ptr = ⦥
m_thread_ptr = &thread;
m_unwind_plan_ptr = &unwind_plan;
const uint32_t addr_byte_size = m_arch.GetAddressByteSize();
const bool show_address = true;
const bool show_bytes = true;
const bool raw = false;
// Initialize the CFA with a known value. In the 32 bit case
// it will be 0x80000000, and in the 64 bit case 0x8000000000000000.
// We use the address byte size to be safe for any future addresss sizes
m_inst_emulator_ap->GetRegisterInfo (unwind_plan.GetRegisterKind(),
unwind_plan.GetInitialCFARegister(),
m_cfa_reg_info);
m_fp_is_cfa = false;
m_register_values.clear();
m_pushed_regs.clear();
m_initial_sp = (1ull << ((addr_byte_size * 8) - 1));
RegisterValue cfa_reg_value;
cfa_reg_value.SetUInt (m_initial_sp, m_cfa_reg_info.byte_size);
SetRegisterValue (m_cfa_reg_info, cfa_reg_value);
const InstructionList &inst_list = disasm_sp->GetInstructionList ();
const size_t num_instructions = inst_list.GetSize();
if (num_instructions > 0)
{
Instruction *inst = inst_list.GetInstructionAtIndex (0).get();
const addr_t base_addr = inst->GetAddress().GetFileAddress();
// Initialize the current row with the one row that was created
// from the CreateFunctionEntryUnwind call above...
m_curr_row = unwind_plan.GetLastRow();
for (size_t idx=0; idx<num_instructions; ++idx)
{
inst = inst_list.GetInstructionAtIndex (idx).get();
if (inst)
{
if (log && log->GetVerbose ())
{
StreamString strm;
inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize (), show_address, show_bytes, &exe_ctx, raw);
log->PutCString (strm.GetData());
}
m_inst_emulator_ap->SetInstruction (inst->GetOpcode(),
inst->GetAddress(),
exe_ctx.GetTargetPtr());
m_inst_emulator_ap->EvaluateInstruction (eEmulateInstructionOptionIgnoreConditions);
if (unwind_plan.GetLastRow() != m_curr_row)
{
// Be sure to not edit the offset unless our row has changed
// so that the "!=" call above doesn't trigger every time
m_curr_row.SetOffset (inst->GetAddress().GetFileAddress() + inst->GetOpcode().GetByteSize() - base_addr);
// Append the new row
unwind_plan.AppendRow (m_curr_row);
}
}
}
}
}
if (log && log->GetVerbose ())
{
StreamString strm;
lldb::addr_t base_addr = range.GetBaseAddress().GetLoadAddress(&thread.GetProcess().GetTarget());
strm.Printf ("Resulting unwind rows for [0x%llx - 0x%llx):", base_addr, base_addr + range.GetByteSize());
unwind_plan.Dump(strm, &thread, base_addr);
log->PutCString (strm.GetData());
}
return unwind_plan.GetRowCount() > 0;
}
return false;
}
bool
UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly (AddressRange& range,
Thread& thread,
UnwindPlan& unwind_plan)
{
if (range.GetByteSize() > 0 &&
range.GetBaseAddress().IsValid() &&
m_inst_emulator_ap.get())
{
// The instruction emulation subclass setup the unwind plan for the
// first instruction.
m_inst_emulator_ap->CreateFunctionEntryUnwind (unwind_plan);
// CreateFunctionEntryUnwind should have created the first row. If it
// doesn't, then we are done.
if (unwind_plan.GetRowCount() == 0)
return false;
ExecutionContext exe_ctx;
thread.CalculateExecutionContext(exe_ctx);
const bool prefer_file_cache = true;
DisassemblerSP disasm_sp (Disassembler::DisassembleRange (m_arch,
NULL,
NULL,
exe_ctx,
range,
prefer_file_cache));
Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
if (disasm_sp)
{
m_range_ptr = ⦥
m_thread_ptr = &thread;
m_unwind_plan_ptr = &unwind_plan;
const uint32_t addr_byte_size = m_arch.GetAddressByteSize();
const bool show_address = true;
const bool show_bytes = true;
m_inst_emulator_ap->GetRegisterInfo (unwind_plan.GetRegisterKind(),
unwind_plan.GetInitialCFARegister(),
m_cfa_reg_info);
m_fp_is_cfa = false;
m_register_values.clear();
m_pushed_regs.clear();
// Initialize the CFA with a known value. In the 32 bit case
// it will be 0x80000000, and in the 64 bit case 0x8000000000000000.
// We use the address byte size to be safe for any future address sizes
m_initial_sp = (1ull << ((addr_byte_size * 8) - 1));
RegisterValue cfa_reg_value;
cfa_reg_value.SetUInt (m_initial_sp, m_cfa_reg_info.byte_size);
SetRegisterValue (m_cfa_reg_info, cfa_reg_value);
const InstructionList &inst_list = disasm_sp->GetInstructionList ();
const size_t num_instructions = inst_list.GetSize();
if (num_instructions > 0)
{
Instruction *inst = inst_list.GetInstructionAtIndex (0).get();
const addr_t base_addr = inst->GetAddress().GetFileAddress();
// Make a copy of the current instruction Row and save it in m_curr_row
// so we can add updates as we process the instructions.
UnwindPlan::RowSP last_row = unwind_plan.GetLastRow();
UnwindPlan::Row *newrow = new UnwindPlan::Row;
if (last_row.get())
*newrow = *last_row.get();
m_curr_row.reset(newrow);
// Once we've seen the initial prologue instructions complete, save a
// copy of the CFI at that point into prologue_completed_row for possible
// use later.
int instructions_since_last_prologue_insn = 0; // # of insns since last CFI was update
bool reinstate_prologue_next_instruction = false; // Next iteration, re-install the prologue row of CFI
bool last_instruction_restored_return_addr_reg = false; // re-install the prologue row of CFI if the next instruction is a branch immediate
bool return_address_register_has_been_saved = false; // if we've seen the ra register get saved yet
UnwindPlan::RowSP prologue_completed_row; // copy of prologue row of CFI
// cache the pc register number (in whatever register numbering this UnwindPlan uses) for
// quick reference during instruction parsing.
uint32_t pc_reg_num = LLDB_INVALID_REGNUM;
RegisterInfo pc_reg_info;
if (m_inst_emulator_ap->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, pc_reg_info))
pc_reg_num = pc_reg_info.kinds[unwind_plan.GetRegisterKind()];
else
pc_reg_num = LLDB_INVALID_REGNUM;
// cache the return address register number (in whatever register numbering this UnwindPlan uses) for
// quick reference during instruction parsing.
uint32_t ra_reg_num = LLDB_INVALID_REGNUM;
RegisterInfo ra_reg_info;
if (m_inst_emulator_ap->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA, ra_reg_info))
ra_reg_num = ra_reg_info.kinds[unwind_plan.GetRegisterKind()];
else
ra_reg_num = LLDB_INVALID_REGNUM;
for (size_t idx=0; idx<num_instructions; ++idx)
{
m_curr_row_modified = false;
m_curr_insn_restored_a_register = false;
inst = inst_list.GetInstructionAtIndex (idx).get();
if (inst)
{
if (log && log->GetVerbose ())
{
StreamString strm;
inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize (), show_address, show_bytes, NULL);
log->PutCString (strm.GetData());
}
m_inst_emulator_ap->SetInstruction (inst->GetOpcode(),
inst->GetAddress(),
exe_ctx.GetTargetPtr());
m_inst_emulator_ap->EvaluateInstruction (eEmulateInstructionOptionIgnoreConditions);
// Were there any changes to the CFI while evaluating this instruction?
if (m_curr_row_modified)
{
reinstate_prologue_next_instruction = false;
m_curr_row->SetOffset (inst->GetAddress().GetFileAddress() + inst->GetOpcode().GetByteSize() - base_addr);
// Append the new row
unwind_plan.AppendRow (m_curr_row);
// Allocate a new Row for m_curr_row, copy the current state into it
UnwindPlan::Row *newrow = new UnwindPlan::Row;
*newrow = *m_curr_row.get();
m_curr_row.reset(newrow);
// If m_curr_insn_restored_a_register == true, we're looking at an epilogue instruction.
// Set instructions_since_last_prologue_insn to a very high number so we don't append
// any of these epilogue instructions to our prologue_complete row.
if (m_curr_insn_restored_a_register == false && instructions_since_last_prologue_insn < 8)
instructions_since_last_prologue_insn = 0;
else
instructions_since_last_prologue_insn = 99;
UnwindPlan::Row::RegisterLocation pc_regloc;
UnwindPlan::Row::RegisterLocation ra_regloc;
// While parsing the instructions of this function, if we've ever
// seen the return address register (aka lr on arm) in a non-IsSame() state,
// it has been saved on the stack. If it's ever back to IsSame(), we've
// executed an epilogue.
if (ra_reg_num != LLDB_INVALID_REGNUM
&& m_curr_row->GetRegisterInfo (ra_reg_num, ra_regloc)
&& !ra_regloc.IsSame())
{
return_address_register_has_been_saved = true;
}
// If the caller's pc is "same", we've just executed an epilogue and we return to the caller
// after this instruction completes executing.
// If there are any instructions past this, there must have been flow control over this
// epilogue so we'll reinstate the original prologue setup instructions.
if (prologue_completed_row.get()
&& pc_reg_num != LLDB_INVALID_REGNUM
&& m_curr_row->GetRegisterInfo (pc_reg_num, pc_regloc)
&& pc_regloc.IsSame())
{
if (log && log->GetVerbose())
log->Printf("UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly -- pc is <same>, restore prologue instructions.");
reinstate_prologue_next_instruction = true;
}
else if (prologue_completed_row.get()
&& return_address_register_has_been_saved
&& ra_reg_num != LLDB_INVALID_REGNUM
&& m_curr_row->GetRegisterInfo (ra_reg_num, ra_regloc)
&& ra_regloc.IsSame())
{
if (log && log->GetVerbose())
log->Printf("UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly -- lr is <same>, restore prologue instruction if the next instruction is a branch immediate.");
last_instruction_restored_return_addr_reg = true;
}
}
else
{
// If the previous instruction was a return-to-caller (epilogue), and we're still executing
// instructions in this function, there must be a code path that jumps over that epilogue.
// Also detect the case where we epilogue & branch imm to another function (tail-call opt)
// instead of a normal pop lr-into-pc exit.
// Reinstate the frame setup from the prologue.
if (reinstate_prologue_next_instruction
|| (m_curr_insn_is_branch_immediate && last_instruction_restored_return_addr_reg))
{
if (log && log->GetVerbose())
log->Printf("UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly -- Reinstating prologue instruction set");
UnwindPlan::Row *newrow = new UnwindPlan::Row;
*newrow = *prologue_completed_row.get();
m_curr_row.reset(newrow);
m_curr_row->SetOffset (inst->GetAddress().GetFileAddress() + inst->GetOpcode().GetByteSize() - base_addr);
unwind_plan.AppendRow(m_curr_row);
newrow = new UnwindPlan::Row;
*newrow = *m_curr_row.get();
m_curr_row.reset(newrow);
reinstate_prologue_next_instruction = false;
last_instruction_restored_return_addr_reg = false;
m_curr_insn_is_branch_immediate = false;
}
// clear both of these if either one wasn't set
if (last_instruction_restored_return_addr_reg)
{
last_instruction_restored_return_addr_reg = false;
}
if (m_curr_insn_is_branch_immediate)
{
m_curr_insn_is_branch_immediate = false;
}
// Stop updating the prologue instructions if we've seen 8 non-prologue instructions
// in a row.
if (instructions_since_last_prologue_insn++ < 8)
{
UnwindPlan::Row *newrow = new UnwindPlan::Row;
*newrow = *m_curr_row.get();
prologue_completed_row.reset(newrow);
if (log && log->GetVerbose())
log->Printf("UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly -- saving a copy of the current row as the prologue row.");
}
}
}
}
}
// FIXME: The DisassemblerLLVMC has a reference cycle and won't go away if it has any active instructions.
// I'll fix that but for now, just clear the list and it will go away nicely.
disasm_sp->GetInstructionList().Clear();
}
if (log && log->GetVerbose ())
{
StreamString strm;
lldb::addr_t base_addr = range.GetBaseAddress().GetLoadAddress(thread.CalculateTarget().get());
strm.Printf ("Resulting unwind rows for [0x%" PRIx64 " - 0x%" PRIx64 "):", base_addr, base_addr + range.GetByteSize());
unwind_plan.Dump(strm, &thread, base_addr);
log->PutCString (strm.GetData());
}
return unwind_plan.GetRowCount() > 0;
}
return false;
}
