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Cp/109185291 strip unaddressable bits from pc sp fp 59 #6993

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merged 2 commits into from
Jun 15, 2023
Merged

Cp/109185291 strip unaddressable bits from pc sp fp 59 #6993

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8031915
In InitializeZerothFrame check for a CFA/AFA or error out
jasonmolenda Feb 6, 2023
447cc61
Clear non-addressable bits from pc/fp/sp in unwinds
jasonmolenda Jun 14, 2023
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112 changes: 71 additions & 41 deletions lldb/source/Target/RegisterContextUnwind.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -37,6 +37,8 @@
#include "lldb/Utility/RegisterValue.h"
#include "lldb/Utility/VASPrintf.h"
#include "lldb/lldb-private.h"

#include <cassert>
#include <memory>

using namespace lldb;
Expand Down Expand Up @@ -135,9 +137,8 @@ void RegisterContextUnwind::InitializeZerothFrame() {
// (which would be a no-op in frame 0 where we get it from the register set,
// but still a good idea to make the call here for other ABIs that may
// exist.)
ABI *abi = process->GetABI().get();
if (abi)
current_pc = abi->FixCodeAddress(current_pc);
if (ABISP abi_sp = process->GetABI())
current_pc = abi_sp->FixCodeAddress(current_pc);

UnwindPlanSP lang_runtime_plan_sp = LanguageRuntime::GetRuntimeUnwindPlan(
m_thread, this, m_behaves_like_zeroth_frame);
Expand Down Expand Up @@ -289,6 +290,13 @@ void RegisterContextUnwind::InitializeZerothFrame() {
} else
ReadFrameAddress(row_register_kind, active_row->GetAFAValue(), m_afa);

if (m_cfa == LLDB_INVALID_ADDRESS && m_afa == LLDB_INVALID_ADDRESS) {
UnwindLogMsg(
"could not read CFA or AFA values for first frame, not valid.");
m_frame_type = eNotAValidFrame;
return;
}

UnwindLogMsg("initialized frame current pc is 0x%" PRIx64 " cfa is 0x%" PRIx64
" afa is 0x%" PRIx64 " using %s UnwindPlan",
(uint64_t)m_current_pc.GetLoadAddress(exe_ctx.GetTargetPtr()),
Expand Down Expand Up @@ -346,17 +354,23 @@ void RegisterContextUnwind::InitializeNonZerothFrame() {

// Let ABIs fixup code addresses to make sure they are valid. In ARM ABIs
// this will strip bit zero in case we read a PC from memory or from the LR.
ABI *abi = process->GetABI().get();
if (abi)
pc = abi->FixCodeAddress(pc);
ABISP abi_sp = process->GetABI();
if (abi_sp)
pc = abi_sp->FixCodeAddress(pc);

if (log) {
UnwindLogMsg("pc = 0x%" PRIx64, pc);
addr_t reg_val;
if (ReadGPRValue(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FP, reg_val))
if (ReadGPRValue(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FP, reg_val)) {
if (abi_sp)
reg_val = abi_sp->FixDataAddress(reg_val);
UnwindLogMsg("fp = 0x%" PRIx64, reg_val);
if (ReadGPRValue(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP, reg_val))
}
if (ReadGPRValue(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP, reg_val)) {
if (abi_sp)
reg_val = abi_sp->FixDataAddress(reg_val);
UnwindLogMsg("sp = 0x%" PRIx64, reg_val);
}
}

// A pc of 0x0 means it's the end of the stack crawl unless we're above a trap
Expand Down Expand Up @@ -415,11 +429,11 @@ void RegisterContextUnwind::InitializeNonZerothFrame() {
}
}

if (abi) {
if (abi_sp) {
m_fast_unwind_plan_sp.reset();
m_full_unwind_plan_sp =
std::make_shared<UnwindPlan>(lldb::eRegisterKindGeneric);
abi->CreateDefaultUnwindPlan(*m_full_unwind_plan_sp);
abi_sp->CreateDefaultUnwindPlan(*m_full_unwind_plan_sp);
if (m_frame_type != eSkipFrame) // don't override eSkipFrame
{
m_frame_type = eNormalFrame;
Expand Down Expand Up @@ -1742,8 +1756,8 @@ bool RegisterContextUnwind::TryFallbackUnwindPlan() {
if (ReadRegisterValueFromRegisterLocation(regloc, reg_info, reg_value)) {
old_caller_pc_value = reg_value.GetAsUInt64();
if (ProcessSP process_sp = m_thread.GetProcess()) {
if (ABISP abi = process_sp->GetABI())
old_caller_pc_value = abi->FixCodeAddress(old_caller_pc_value);
if (ABISP abi_sp = process_sp->GetABI())
old_caller_pc_value = abi_sp->FixCodeAddress(old_caller_pc_value);
}
}
}
Expand Down Expand Up @@ -1802,8 +1816,8 @@ bool RegisterContextUnwind::TryFallbackUnwindPlan() {
reg_value)) {
new_caller_pc_value = reg_value.GetAsUInt64();
if (ProcessSP process_sp = m_thread.GetProcess()) {
if (ABISP abi = process_sp->GetABI())
new_caller_pc_value = abi->FixCodeAddress(new_caller_pc_value);
if (ABISP abi_sp = process_sp->GetABI())
new_caller_pc_value = abi_sp->FixCodeAddress(new_caller_pc_value);
}
}
}
Expand Down Expand Up @@ -1944,6 +1958,7 @@ bool RegisterContextUnwind::ReadFrameAddress(

address = LLDB_INVALID_ADDRESS;
addr_t cfa_reg_contents;
ABISP abi_sp = m_thread.GetProcess()->GetABI();

switch (fa.GetValueType()) {
case UnwindPlan::Row::FAValue::isRegisterDereferenced: {
Expand All @@ -1954,11 +1969,13 @@ bool RegisterContextUnwind::ReadFrameAddress(
GetRegisterInfoAtIndex(cfa_reg.GetAsKind(eRegisterKindLLDB));
RegisterValue reg_value;
if (reg_info) {
if (abi_sp)
cfa_reg_contents = abi_sp->FixDataAddress(cfa_reg_contents);
Status error = ReadRegisterValueFromMemory(
reg_info, cfa_reg_contents, reg_info->byte_size, reg_value);
if (error.Success()) {
address = reg_value.GetAsUInt64();
if (ABISP abi_sp = m_thread.GetProcess()->GetABI())
if (abi_sp)
address = abi_sp->FixCodeAddress(address);
UnwindLogMsg(
"CFA value via dereferencing reg %s (%d): reg has val 0x%" PRIx64
Expand All @@ -1980,6 +1997,8 @@ bool RegisterContextUnwind::ReadFrameAddress(
RegisterNumber cfa_reg(m_thread, row_register_kind,
fa.GetRegisterNumber());
if (ReadGPRValue(cfa_reg, cfa_reg_contents)) {
if (abi_sp)
cfa_reg_contents = abi_sp->FixDataAddress(cfa_reg_contents);
if (cfa_reg_contents == LLDB_INVALID_ADDRESS || cfa_reg_contents == 0 ||
cfa_reg_contents == 1) {
UnwindLogMsg(
Expand Down Expand Up @@ -2067,6 +2086,8 @@ lldb::addr_t RegisterContextUnwind::GetReturnAddressHint(int32_t plan_offset) {
return LLDB_INVALID_ADDRESS;
if (!m_sym_ctx.module_sp || !m_sym_ctx.symbol)
return LLDB_INVALID_ADDRESS;
if (ABISP abi_sp = m_thread.GetProcess()->GetABI())
hint = abi_sp->FixCodeAddress(hint);

hint += plan_offset;

Expand Down Expand Up @@ -2116,28 +2137,46 @@ bool RegisterContextUnwind::ReadGPRValue(lldb::RegisterKind register_kind,
}

const RegisterInfo *reg_info = GetRegisterInfoAtIndex(lldb_regnum);
assert(reg_info);
if (!reg_info) {
UnwindLogMsg(
"Could not find RegisterInfo definition for lldb register number %d",
lldb_regnum);
return false;
}

uint32_t generic_regnum = LLDB_INVALID_REGNUM;
if (register_kind == eRegisterKindGeneric)
generic_regnum = regnum;
else
m_thread.GetRegisterContext()->ConvertBetweenRegisterKinds(
register_kind, regnum, eRegisterKindGeneric, generic_regnum);
ABISP abi_sp = m_thread.GetProcess()->GetABI();

RegisterValue reg_value;
// if this is frame 0 (currently executing frame), get the requested reg
// contents from the actual thread registers
if (IsFrameZero()) {
if (m_thread.GetRegisterContext()->ReadRegister(reg_info, reg_value)) {
value = reg_value.GetAsUInt64();
if (abi_sp && generic_regnum != LLDB_INVALID_REGNUM) {
if (generic_regnum == LLDB_REGNUM_GENERIC_PC ||
generic_regnum == LLDB_REGNUM_GENERIC_RA)
value = abi_sp->FixCodeAddress(value);
if (generic_regnum == LLDB_REGNUM_GENERIC_SP ||
generic_regnum == LLDB_REGNUM_GENERIC_FP)
value = abi_sp->FixDataAddress(value);
}
return true;
}
return false;
}

bool pc_register = false;
uint32_t generic_regnum;
if (register_kind == eRegisterKindGeneric &&
(regnum == LLDB_REGNUM_GENERIC_PC || regnum == LLDB_REGNUM_GENERIC_RA)) {
if (generic_regnum != LLDB_INVALID_REGNUM &&
(generic_regnum == LLDB_REGNUM_GENERIC_PC ||
generic_regnum == LLDB_REGNUM_GENERIC_RA))
pc_register = true;
} else if (m_thread.GetRegisterContext()->ConvertBetweenRegisterKinds(
register_kind, regnum, eRegisterKindGeneric, generic_regnum) &&
(generic_regnum == LLDB_REGNUM_GENERIC_PC ||
generic_regnum == LLDB_REGNUM_GENERIC_RA)) {
pc_register = true;
}

lldb_private::UnwindLLDB::RegisterLocation regloc;
if (!m_parent_unwind.SearchForSavedLocationForRegister(
Expand All @@ -2147,9 +2186,8 @@ bool RegisterContextUnwind::ReadGPRValue(lldb::RegisterKind register_kind,
if (ReadRegisterValueFromRegisterLocation(regloc, reg_info, reg_value)) {
value = reg_value.GetAsUInt64();
if (pc_register) {
if (ProcessSP process_sp = m_thread.GetProcess()) {
if (ABISP abi = process_sp->GetABI())
value = abi->FixCodeAddress(value);
if (ABISP abi_sp = m_thread.GetProcess()->GetABI()) {
value = abi_sp->FixCodeAddress(value);
}
}
return true;
Expand Down Expand Up @@ -2198,10 +2236,8 @@ bool RegisterContextUnwind::ReadRegister(const RegisterInfo *reg_info,
if (is_pc_regnum && value.GetType() == RegisterValue::eTypeUInt64) {
addr_t reg_value = value.GetAsUInt64(LLDB_INVALID_ADDRESS);
if (reg_value != LLDB_INVALID_ADDRESS) {
if(ProcessSP process_sp = m_thread.GetProcess()) {
if (ABISP abi = process_sp->GetABI())
value = abi->FixCodeAddress(reg_value);
}
if (ABISP abi_sp = m_thread.GetProcess()->GetABI())
value = abi_sp->FixCodeAddress(reg_value);
}
}
}
Expand Down Expand Up @@ -2283,9 +2319,8 @@ bool RegisterContextUnwind::GetStartPC(addr_t &start_pc) {
ProcessSP process_sp (m_thread.GetProcess());
if (process_sp)
{
ABI *abi = process_sp->GetABI().get();
if (abi)
start_pc = abi->FixCodeAddress(start_pc);
if (ABISP abi_sp = process_sp->GetABI())
start_pc = abi_sp->FixCodeAddress(start_pc);
}
}
return read_successfully;
Expand Down Expand Up @@ -2313,13 +2348,8 @@ bool RegisterContextUnwind::ReadPC(addr_t &pc) {
// through a NULL pointer -- we want to be able to unwind past that frame
// to help find the bug.

ProcessSP process_sp (m_thread.GetProcess());
if (process_sp)
{
ABI *abi = process_sp->GetABI().get();
if (abi)
pc = abi->FixCodeAddress(pc);
}
if (ABISP abi_sp = m_thread.GetProcess()->GetABI())
pc = abi_sp->FixCodeAddress(pc);

return !(m_all_registers_available == false &&
above_trap_handler == false && (pc == 0 || pc == 1));
Expand Down