blob: 3385aa73df2b3ba182b89e67609e36890a772c79 [file] [log] [blame]
// Copyright 2019 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/diagnostics/unwinding-info-win64.h"
#if defined(V8_OS_WIN_X64)
#include "src/codegen/macro-assembler.h"
#include "src/codegen/x64/assembler-x64.h"
#include "src/utils/allocation.h"
namespace v8 {
namespace internal {
namespace win64_unwindinfo {
bool CanEmitUnwindInfoForBuiltins() { return FLAG_win64_unwinding_info; }
bool CanRegisterUnwindInfoForNonABICompliantCodeRange() {
return !FLAG_jitless;
}
bool RegisterUnwindInfoForExceptionHandlingOnly() {
DCHECK(CanRegisterUnwindInfoForNonABICompliantCodeRange());
#if !defined(DISABLE_WASM_COMPILER_ISSUE_STARBOARD)
return !IsWindows8OrGreater() || !FLAG_win64_unwinding_info;
#else
return false;
#endif
}
#pragma pack(push, 1)
/*
* From Windows SDK ehdata.h, which does not compile with Clang.
* See https://msdn.microsoft.com/en-us/library/ddssxxy8.aspx.
*/
union UNWIND_CODE {
struct {
unsigned char CodeOffset;
unsigned char UnwindOp : 4;
unsigned char OpInfo : 4;
};
uint16_t FrameOffset;
};
struct UNWIND_INFO {
unsigned char Version : 3;
unsigned char Flags : 5;
unsigned char SizeOfProlog;
unsigned char CountOfCodes;
unsigned char FrameRegister : 4;
unsigned char FrameOffset : 4;
};
struct V8UnwindData {
UNWIND_INFO unwind_info;
UNWIND_CODE unwind_codes[2];
V8UnwindData() {
static constexpr int kOpPushNonvol = 0;
static constexpr int kOpSetFPReg = 3;
unwind_info.Version = 1;
unwind_info.Flags = UNW_FLAG_EHANDLER;
unwind_info.SizeOfProlog = kRbpPrefixLength;
unwind_info.CountOfCodes = kRbpPrefixCodes;
unwind_info.FrameRegister = rbp.code();
unwind_info.FrameOffset = 0;
unwind_codes[0].CodeOffset = kRbpPrefixLength; // movq rbp, rsp
unwind_codes[0].UnwindOp = kOpSetFPReg;
unwind_codes[0].OpInfo = 0;
unwind_codes[1].CodeOffset = kPushRbpInstructionLength; // push rbp
unwind_codes[1].UnwindOp = kOpPushNonvol;
unwind_codes[1].OpInfo = rbp.code();
}
};
struct ExceptionHandlerUnwindData {
UNWIND_INFO unwind_info;
ExceptionHandlerUnwindData() {
unwind_info.Version = 1;
unwind_info.Flags = UNW_FLAG_EHANDLER;
unwind_info.SizeOfProlog = 0;
unwind_info.CountOfCodes = 0;
unwind_info.FrameRegister = 0;
unwind_info.FrameOffset = 0;
}
};
#pragma pack(pop)
v8::UnhandledExceptionCallback unhandled_exception_callback_g = nullptr;
void SetUnhandledExceptionCallback(
v8::UnhandledExceptionCallback unhandled_exception_callback) {
unhandled_exception_callback_g = unhandled_exception_callback;
}
// This function is registered as exception handler for V8-generated code as
// part of the registration of unwinding info. It is referenced by
// RegisterNonABICompliantCodeRange(), below, and by the unwinding info for
// builtins declared in the embedded blob.
extern "C" __declspec(dllexport) int CRASH_HANDLER_FUNCTION_NAME(
PEXCEPTION_RECORD ExceptionRecord, ULONG64 EstablisherFrame,
PCONTEXT ContextRecord, PDISPATCHER_CONTEXT DispatcherContext) {
if (unhandled_exception_callback_g != nullptr) {
EXCEPTION_POINTERS info = {ExceptionRecord, ContextRecord};
return unhandled_exception_callback_g(&info);
}
return ExceptionContinueSearch;
}
static constexpr int kMaxExceptionThunkSize = 12;
struct CodeRangeUnwindingRecord {
RUNTIME_FUNCTION runtime_function;
V8UnwindData unwind_info;
uint32_t exception_handler;
uint8_t exception_thunk[kMaxExceptionThunkSize];
void* dynamic_table;
};
struct ExceptionHandlerRecord {
RUNTIME_FUNCTION runtime_function;
ExceptionHandlerUnwindData unwind_info;
uint32_t exception_handler;
uint8_t exception_thunk[kMaxExceptionThunkSize];
};
namespace {
// Many codes here are disabled because Cobalt's Windows host build does not
// support RtlAddGrowableFunctionTable and RtlDeleteGrowableFunctionTable yet
// and Cobalt doesn't need them unwinding data.
#if !defined(DISABLE_UNWIND_STARBOARD)
V8_DECLARE_ONCE(load_ntdll_unwinding_functions_once);
static decltype(
&::RtlAddGrowableFunctionTable) add_growable_function_table_func = nullptr;
static decltype(
&::RtlDeleteGrowableFunctionTable) delete_growable_function_table_func =
nullptr;
#endif
void LoadNtdllUnwindingFunctions() {
#if !defined(DISABLE_UNWIND_STARBOARD)
base::CallOnce(&load_ntdll_unwinding_functions_once, []() {
// Load functions from the ntdll.dll module.
HMODULE ntdll_module =
LoadLibraryEx(L"ntdll.dll", nullptr, LOAD_LIBRARY_SEARCH_SYSTEM32);
DCHECK_NOT_NULL(ntdll_module);
// This fails on Windows 7.
add_growable_function_table_func =
reinterpret_cast<decltype(&::RtlAddGrowableFunctionTable)>(
::GetProcAddress(ntdll_module, "RtlAddGrowableFunctionTable"));
DCHECK_IMPLIES(IsWindows8OrGreater(), add_growable_function_table_func);
delete_growable_function_table_func =
reinterpret_cast<decltype(&::RtlDeleteGrowableFunctionTable)>(
::GetProcAddress(ntdll_module, "RtlDeleteGrowableFunctionTable"));
DCHECK_IMPLIES(IsWindows8OrGreater(), delete_growable_function_table_func);
});
#endif
}
bool AddGrowableFunctionTable(PVOID* DynamicTable,
PRUNTIME_FUNCTION FunctionTable, DWORD EntryCount,
DWORD MaximumEntryCount, ULONG_PTR RangeBase,
ULONG_PTR RangeEnd) {
#if !defined(DISABLE_UNWIND_STARBOARD)
DCHECK(::IsWindows8OrGreater());
LoadNtdllUnwindingFunctions();
DCHECK_NOT_NULL(add_growable_function_table_func);
*DynamicTable = nullptr;
DWORD status =
add_growable_function_table_func(DynamicTable, FunctionTable, EntryCount,
MaximumEntryCount, RangeBase, RangeEnd);
DCHECK((status == 0 && *DynamicTable != nullptr) ||
status == 0xC000009A); // STATUS_INSUFFICIENT_RESOURCES
return (status == 0);
#else
return false;
#endif
}
void DeleteGrowableFunctionTable(PVOID dynamic_table) {
#if !defined(DISABLE_UNWIND_STARBOARD)
DCHECK(::IsWindows8OrGreater());
LoadNtdllUnwindingFunctions();
DCHECK_NOT_NULL(delete_growable_function_table_func);
delete_growable_function_table_func(dynamic_table);
#endif
}
} // namespace
std::vector<uint8_t> GetUnwindInfoForBuiltinFunctions() {
V8UnwindData xdata;
return std::vector<uint8_t>(
reinterpret_cast<uint8_t*>(&xdata),
reinterpret_cast<uint8_t*>(&xdata) + sizeof(xdata));
}
template <typename Record>
void InitUnwindingRecord(Record* record, size_t code_size_in_bytes) {
// We assume that the first page of the code range is executable and
// committed and reserved to contain PDATA/XDATA.
// All addresses are 32bit relative offsets to start.
#if !defined(DISABLE_UNWIND_STARBOARD)
record->runtime_function.BeginAddress = 0;
record->runtime_function.EndAddress = static_cast<DWORD>(code_size_in_bytes);
record->runtime_function.UnwindData = offsetof(Record, unwind_info);
record->exception_handler = offsetof(Record, exception_thunk);
// Hardcoded thunk.
AssemblerOptions options;
options.record_reloc_info_for_serialization = false;
MacroAssembler masm(nullptr, options, CodeObjectRequired::kNo,
NewAssemblerBuffer(64));
masm.movq(rax, reinterpret_cast<uint64_t>(&CRASH_HANDLER_FUNCTION_NAME));
masm.jmp(rax);
DCHECK_LE(masm.instruction_size(), sizeof(record->exception_thunk));
memcpy(&record->exception_thunk[0], masm.buffer_start(),
masm.instruction_size());
#endif
}
void RegisterNonABICompliantCodeRange(void* start, size_t size_in_bytes) {
#if !defined(DISABLE_UNWIND_STARBOARD)
DCHECK(CanRegisterUnwindInfoForNonABICompliantCodeRange());
// When the --win64-unwinding-info flag is set, we call
// RtlAddGrowableFunctionTable to register unwinding info for the whole code
// range of an isolate or WASM module. This enables the Windows OS stack
// unwinder to work correctly with V8-generated code, enabling stack walking
// in Windows debuggers and performance tools. However, the
// RtlAddGrowableFunctionTable API is only supported on Windows 8 and above.
//
// On Windows 7, or when --win64-unwinding-info is not set, we may still need
// to call RtlAddFunctionTable to register a custom exception handler passed
// by the embedder (like Crashpad).
if (RegisterUnwindInfoForExceptionHandlingOnly()) {
if (unhandled_exception_callback_g) {
ExceptionHandlerRecord* record = new (start) ExceptionHandlerRecord();
InitUnwindingRecord(record, size_in_bytes);
CHECK(::RtlAddFunctionTable(&record->runtime_function, 1,
reinterpret_cast<DWORD64>(start)));
// Protect reserved page against modifications.
DWORD old_protect;
CHECK(VirtualProtect(start, sizeof(CodeRangeUnwindingRecord),
PAGE_EXECUTE_READ, &old_protect));
}
} else {
CodeRangeUnwindingRecord* record = new (start) CodeRangeUnwindingRecord();
InitUnwindingRecord(record, size_in_bytes);
CHECK(AddGrowableFunctionTable(
&record->dynamic_table, &record->runtime_function, 1, 1,
reinterpret_cast<DWORD64>(start),
reinterpret_cast<DWORD64>(reinterpret_cast<uint8_t*>(start) +
size_in_bytes)));
// Protect reserved page against modifications.
DWORD old_protect;
CHECK(VirtualProtect(start, sizeof(CodeRangeUnwindingRecord),
PAGE_EXECUTE_READ, &old_protect));
}
#endif
}
void UnregisterNonABICompliantCodeRange(void* start) {
#if !defined(DISABLE_UNWIND_STARBOARD)
DCHECK(CanRegisterUnwindInfoForNonABICompliantCodeRange());
if (RegisterUnwindInfoForExceptionHandlingOnly()) {
if (unhandled_exception_callback_g) {
ExceptionHandlerRecord* record =
reinterpret_cast<ExceptionHandlerRecord*>(start);
CHECK(::RtlDeleteFunctionTable(&record->runtime_function));
}
} else {
CodeRangeUnwindingRecord* record =
reinterpret_cast<CodeRangeUnwindingRecord*>(start);
if (record->dynamic_table) {
DeleteGrowableFunctionTable(record->dynamic_table);
}
}
#endif
}
void XdataEncoder::onPushRbp() {
current_push_rbp_offset_ = assembler_.pc_offset() - kPushRbpInstructionLength;
}
void XdataEncoder::onMovRbpRsp() {
if (current_push_rbp_offset_ >= 0 &&
current_push_rbp_offset_ == assembler_.pc_offset() - kRbpPrefixLength) {
fp_offsets_.push_back(current_push_rbp_offset_);
}
}
} // namespace win64_unwindinfo
} // namespace internal
} // namespace v8
#endif // defined(V8_OS_WIN_X64)