Merge pull request #2533 from DarkLordZach/memory-frozen

memory: Add class to manage and enforce memory freezing
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bunnei 2019-06-28 14:03:38 -04:00 committed by GitHub
commit bb4a1e059c
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4 changed files with 274 additions and 0 deletions

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@ -476,6 +476,8 @@ add_library(core STATIC
settings.h
telemetry_session.cpp
telemetry_session.h
tools/freezer.cpp
tools/freezer.h
)
create_target_directory_groups(core)

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@ -33,6 +33,7 @@
#include "core/reporter.h"
#include "core/settings.h"
#include "core/telemetry_session.h"
#include "core/tools/freezer.h"
#include "file_sys/cheat_engine.h"
#include "file_sys/patch_manager.h"
#include "video_core/debug_utils/debug_utils.h"
@ -300,6 +301,7 @@ struct System::Impl {
bool is_powered_on = false;
std::unique_ptr<FileSys::CheatEngine> cheat_engine;
std::unique_ptr<Tools::Freezer> memory_freezer;
/// Frontend applets
Service::AM::Applets::AppletManager applet_manager;

188
src/core/tools/freezer.cpp Normal file
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@ -0,0 +1,188 @@
// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include "common/assert.h"
#include "common/logging/log.h"
#include "core/core.h"
#include "core/core_timing.h"
#include "core/core_timing_util.h"
#include "core/memory.h"
#include "core/tools/freezer.h"
namespace Tools {
namespace {
constexpr s64 MEMORY_FREEZER_TICKS = static_cast<s64>(Core::Timing::BASE_CLOCK_RATE / 60);
u64 MemoryReadWidth(u32 width, VAddr addr) {
switch (width) {
case 1:
return Memory::Read8(addr);
case 2:
return Memory::Read16(addr);
case 4:
return Memory::Read32(addr);
case 8:
return Memory::Read64(addr);
default:
UNREACHABLE();
return 0;
}
}
void MemoryWriteWidth(u32 width, VAddr addr, u64 value) {
switch (width) {
case 1:
Memory::Write8(addr, static_cast<u8>(value));
break;
case 2:
Memory::Write16(addr, static_cast<u16>(value));
break;
case 4:
Memory::Write32(addr, static_cast<u32>(value));
break;
case 8:
Memory::Write64(addr, value);
break;
default:
UNREACHABLE();
}
}
} // Anonymous namespace
Freezer::Freezer(Core::Timing::CoreTiming& core_timing) : core_timing(core_timing) {
event = core_timing.RegisterEvent(
"MemoryFreezer::FrameCallback",
[this](u64 userdata, s64 cycles_late) { FrameCallback(userdata, cycles_late); });
core_timing.ScheduleEvent(MEMORY_FREEZER_TICKS, event);
}
Freezer::~Freezer() {
core_timing.UnscheduleEvent(event, 0);
}
void Freezer::SetActive(bool active) {
if (!this->active.exchange(active)) {
FillEntryReads();
core_timing.ScheduleEvent(MEMORY_FREEZER_TICKS, event);
LOG_DEBUG(Common_Memory, "Memory freezer activated!");
} else {
LOG_DEBUG(Common_Memory, "Memory freezer deactivated!");
}
}
bool Freezer::IsActive() const {
return active.load(std::memory_order_relaxed);
}
void Freezer::Clear() {
std::lock_guard lock{entries_mutex};
LOG_DEBUG(Common_Memory, "Clearing all frozen memory values.");
entries.clear();
}
u64 Freezer::Freeze(VAddr address, u32 width) {
std::lock_guard lock{entries_mutex};
const auto current_value = MemoryReadWidth(width, address);
entries.push_back({address, width, current_value});
LOG_DEBUG(Common_Memory,
"Freezing memory for address={:016X}, width={:02X}, current_value={:016X}", address,
width, current_value);
return current_value;
}
void Freezer::Unfreeze(VAddr address) {
std::lock_guard lock{entries_mutex};
LOG_DEBUG(Common_Memory, "Unfreezing memory for address={:016X}", address);
entries.erase(
std::remove_if(entries.begin(), entries.end(),
[&address](const Entry& entry) { return entry.address == address; }),
entries.end());
}
bool Freezer::IsFrozen(VAddr address) const {
std::lock_guard lock{entries_mutex};
return std::find_if(entries.begin(), entries.end(), [&address](const Entry& entry) {
return entry.address == address;
}) != entries.end();
}
void Freezer::SetFrozenValue(VAddr address, u64 value) {
std::lock_guard lock{entries_mutex};
const auto iter = std::find_if(entries.begin(), entries.end(), [&address](const Entry& entry) {
return entry.address == address;
});
if (iter == entries.end()) {
LOG_ERROR(Common_Memory,
"Tried to set freeze value for address={:016X} that is not frozen!", address);
return;
}
LOG_DEBUG(Common_Memory,
"Manually overridden freeze value for address={:016X}, width={:02X} to value={:016X}",
iter->address, iter->width, value);
iter->value = value;
}
std::optional<Freezer::Entry> Freezer::GetEntry(VAddr address) const {
std::lock_guard lock{entries_mutex};
const auto iter = std::find_if(entries.begin(), entries.end(), [&address](const Entry& entry) {
return entry.address == address;
});
if (iter == entries.end()) {
return std::nullopt;
}
return *iter;
}
std::vector<Freezer::Entry> Freezer::GetEntries() const {
std::lock_guard lock{entries_mutex};
return entries;
}
void Freezer::FrameCallback(u64 userdata, s64 cycles_late) {
if (!IsActive()) {
LOG_DEBUG(Common_Memory, "Memory freezer has been deactivated, ending callback events.");
return;
}
std::lock_guard lock{entries_mutex};
for (const auto& entry : entries) {
LOG_DEBUG(Common_Memory,
"Enforcing memory freeze at address={:016X}, value={:016X}, width={:02X}",
entry.address, entry.value, entry.width);
MemoryWriteWidth(entry.width, entry.address, entry.value);
}
core_timing.ScheduleEvent(MEMORY_FREEZER_TICKS - cycles_late, event);
}
void Freezer::FillEntryReads() {
std::lock_guard lock{entries_mutex};
LOG_DEBUG(Common_Memory, "Updating memory freeze entries to current values.");
for (auto& entry : entries) {
entry.value = MemoryReadWidth(entry.width, entry.address);
}
}
} // namespace Tools

82
src/core/tools/freezer.h Normal file
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@ -0,0 +1,82 @@
// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <atomic>
#include <mutex>
#include <optional>
#include <vector>
#include "common/common_types.h"
namespace Core::Timing {
class CoreTiming;
struct EventType;
} // namespace Core::Timing
namespace Tools {
/**
* This class allows the user to prevent an application from writing new values to certain memory
* locations. This has a variety of uses when attempting to reverse a game.
*
* One example could be a cheat to prevent Mario from taking damage in SMO. One could freeze the
* memory address that the game uses to store Mario's health so when he takes damage (and the game
* tries to write the new health value to memory), the value won't change.
*/
class Freezer {
public:
struct Entry {
VAddr address;
u32 width;
u64 value;
};
explicit Freezer(Core::Timing::CoreTiming& core_timing);
~Freezer();
// Enables or disables the entire memory freezer.
void SetActive(bool active);
// Returns whether or not the freezer is active.
bool IsActive() const;
// Removes all entries from the freezer.
void Clear();
// Freezes a value to its current memory address. The value the memory is kept at will be the
// value that is read during this function. Width can be 1, 2, 4, or 8 (in bytes).
u64 Freeze(VAddr address, u32 width);
// Unfreezes the memory value at address. If the address isn't frozen, this is a no-op.
void Unfreeze(VAddr address);
// Returns whether or not the address is frozen.
bool IsFrozen(VAddr address) const;
// Sets the value that address should be frozen to. This doesn't change the width set by using
// Freeze(). If the value isn't frozen, this will not freeze it and is thus a no-op.
void SetFrozenValue(VAddr address, u64 value);
// Returns the entry corresponding to the address if the address is frozen, otherwise
// std::nullopt.
std::optional<Entry> GetEntry(VAddr address) const;
// Returns all the entries in the freezer, an empty vector means nothing is frozen.
std::vector<Entry> GetEntries() const;
private:
void FrameCallback(u64 userdata, s64 cycles_late);
void FillEntryReads();
std::atomic_bool active{false};
mutable std::mutex entries_mutex;
std::vector<Entry> entries;
Core::Timing::EventType* event;
Core::Timing::CoreTiming& core_timing;
};
} // namespace Tools