Files
AnyPS5/core/libs/prx/libSceAgcDriver/tests/WriteTracking.cpp
T
Dean Galvin 59db660f7b test(agc): reserve the arena host hole the write-tracking checks query
On Windows the guest arena is reserved while libc loads, around whatever
the process has already mapped in its interval. About one start in forty
has nothing mapped there, so the arena has no host hole:
agc_driver_graphics then fails with "write-watched arena contained no
host exclusion to test" and agc_write_tracking prints that its host-hole
checks were skipped.

agc_write_tracking now starts itself suspended, reserves one allocation
granule in the middle of the child's arena interval before the child's
loader runs, and the child runs the host-hole checks on that range. The
range is a host hole on every start, so the checks no longer depend on
the address layout. The four queries agc_driver_graphics made on an
enumerated hole are among them and are removed there.
2026-10-13 07:47:05 +13:00

445 lines
23 KiB
C++

#include "prx/libSceAgcDriver/Execution/include/GuestMemory.hpp"
#include "prx/libc/include/GuestArena.hpp"
#include "prx/libc/include/GuestWriteWatch.hpp"
#ifdef _WIN32
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <windows.h>
#else
#include <sys/mman.h>
#endif
#include <array>
#include <cstdint>
#include <cstring>
#include <iostream>
#include <stdexcept>
#include <string>
#include <string_view>
#include <thread>
#include <vector>
namespace {
using namespace AgcDriver::GuestMemory;
constexpr std::size_t Block = 65536;
#ifdef _WIN32
constexpr wchar_t HostHoleMode[] = L"--host-hole";
#endif
void Require(bool condition, const std::string& message) {
if (!condition) throw std::runtime_error(message);
}
void* AllocateWatched(std::size_t bytes, bool crossLeaf = false) {
#ifdef _WIN32
static_cast<void>(crossLeaf);
void* block = GuestArena::GuestArenaAllocate_nid_postfix(bytes, Block);
GuestArena::GuestArenaCommit_nid_postfix(block, bytes, PAGE_READWRITE, bytes);
#else
const std::size_t alignment = crossLeaf ? std::size_t{1} << 32 : Block;
const auto prefix = crossLeaf ? Block : 0;
void* raw = mmap(nullptr, bytes + alignment, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (raw == MAP_FAILED) throw std::runtime_error("cannot map the watched block");
const auto begin = reinterpret_cast<std::uintptr_t>(raw);
const auto aligned = ((begin + prefix + alignment - 1) & ~static_cast<std::uintptr_t>(alignment - 1)) - prefix;
if (aligned != begin) munmap(raw, aligned - begin);
if (aligned + bytes != begin + bytes + alignment) munmap(reinterpret_cast<void*>(aligned + bytes), begin + alignment - aligned);
void* block = reinterpret_cast<void*>(aligned);
GuestWriteWatch::GuestWriteWatchRegister_nid_postfix(block, bytes);
#endif
Require(Watched(reinterpret_cast<std::uint64_t>(block), bytes), "the test block is not watched");
return block;
}
void CheckSharedBlock() {
void* memory = AllocateWatched(3 * Block);
const auto base = reinterpret_cast<std::uint64_t>(memory);
const auto boundary = base + 2 * Block - 0xb800;
const auto firstBegin = base;
const auto secondEnd = base + 3 * Block;
const auto sharedFirst = boundary - (base + Block);
const auto sharedSecond = base + 2 * Block - boundary;
std::memset(memory, 0x11, 3 * Block);
const auto synced = CollectWrites(base, 3 * Block);
Require(synced != 0, "the test block is not collected");
Require(MarkWritten(firstBegin, static_cast<std::size_t>(boundary - firstBegin)) != 0, "a driver store into watched memory is not stamped");
std::array<std::uint64_t, 2> generations{synced, synced};
std::array<std::uint8_t, 2> changed{};
Require(ChangedBlocks(base + Block, 2 * Block, generations, changed) && changed[0] == BlockWritten && changed[1] == BlockUnchanged, "the shared block does not read as written");
Require(!StoredOver(boundary, static_cast<std::size_t>(sharedSecond), synced), "a store of the neighbour's bytes counts for the second surface's part of the shared block");
Require(StoredOver(base + Block, static_cast<std::size_t>(sharedFirst), synced), "the first surface's own store is not seen over its part of the shared block");
Require(!StoredOver(boundary, static_cast<std::size_t>(secondEnd - boundary), synced), "the second surface reads as stored over");
const auto touched = MarkWritten(boundary + 0x100, 4);
Require(StoredOver(boundary, static_cast<std::size_t>(sharedSecond), synced), "a store over the second surface's bytes is not seen");
Require(!StoredOver(boundary, static_cast<std::size_t>(sharedSecond), touched), "a store older than the generation is seen");
const auto whole = TrackerGeneration();
MarkWritten(base + Block, Block);
Require(StoredOver(boundary, static_cast<std::size_t>(sharedSecond), whole), "a store over the whole block is not seen");
const auto afterWhole = TrackerGeneration();
MarkWritten(base + Block, static_cast<std::size_t>(sharedFirst));
Require(!StoredOver(boundary, static_cast<std::size_t>(sharedSecond), afterWhole), "a partial store after a whole-block store is taken for the whole block");
const auto many = TrackerGeneration();
for (int store = 0; store < 6; ++store) MarkWritten(base + Block + static_cast<std::uint64_t>(store) * 64, 4);
Require(StoredOver(boundary, static_cast<std::size_t>(sharedSecond), many), "forgotten driver stores are taken as missing the range");
const auto beforeCpu = CollectWrites(base, 3 * Block);
static_cast<volatile std::uint8_t*>(memory)[Block + 8] = 0x22;
CollectWritesUncached(base, 3 * Block);
Require(!StoredOver(boundary, static_cast<std::size_t>(sharedSecond), beforeCpu), "a CPU store outside the shared range counts for it");
std::array<std::uint8_t, 64> unwatched{};
const auto outside = reinterpret_cast<std::uint64_t>(unwatched.data());
if (!Watched(outside, unwatched.size())) Require(StoredOver(outside, unwatched.size(), TrackerGeneration()), "an unwatched range reads as not stored over");
}
void CheckOwnStore() {
void* memory = AllocateWatched(2 * Block);
const auto base = reinterpret_cast<std::uint64_t>(memory);
const auto second = base + Block;
std::memset(memory, 0x11, 2 * Block);
const auto synced = CollectWrites(base, 2 * Block);
Require(synced != 0, "the own-store block is not collected");
std::array<std::byte, 8192> bytes{};
bytes.fill(std::byte{0x44});
Write(second, bytes);
const auto stored = TrackerGeneration();
Require(!UnchangedSince(second, bytes.size(), synced), "the driver store is not stamped");
CollectWritesUncached(base, 2 * Block);
Require(UnchangedSince(second, Block, stored), "a walk after a driver store reports the store again as a newer write");
Require(UnchangedSinceCollected(second, bytes.size(), synced), "the driver store's own page faults are stamped as a CPU write");
static_cast<volatile std::uint8_t*>(memory)[Block + 3 * 4096 + 8] = 0x22;
const std::array<std::byte, 64> label{};
Write(second + 3 * 4096 + 64, label);
Require(!UnchangedSinceCollected(second + 3 * 4096, 4096, stored), "a CPU write before a driver store in its page is not stamped as one");
const auto beforeCpu = TrackerGeneration();
static_cast<volatile std::uint8_t*>(memory)[16] = 0x33;
CollectWritesUncached(base, 2 * Block);
Require(!UnchangedSince(base, 64, beforeCpu), "a CPU write after the driver store is not seen");
}
void CheckUnwatch() {
void* memory = AllocateWatched(3 * Block);
const auto base = reinterpret_cast<std::uint64_t>(memory);
const auto imported = base + Block;
std::memset(memory, 0x11, 3 * Block);
BumpCollectEpoch();
const auto before = CollectWrites(base, 3 * Block);
Require(before != 0 && UnchangedSince(imported, Block, before), "the import range was not initially watched");
Unwatch(imported, Block);
Require(!Watched(imported, Block) && !UnchangedSince(imported, Block, before), "unwatch kept trusting import stamps");
Require(CollectWrites(base, 3 * Block) == 0 && CollectWritesUncached(imported, Block) == 0, "unwatch did not invalidate a cached collect");
Require(Watched(base, Block) && Watched(base + 2 * Block, Block), "unwatch disabled unrelated memory");
const auto beforeDriverWrite = TrackerGeneration();
Require(MarkWritten(imported, Block) == 0, "an unwatched import still produces trusted stamps");
Require(TrackerGeneration() > beforeDriverWrite, "an unwatched driver write did not invalidate byte comparisons");
const auto beforeOwnWrite = TrackerGeneration();
StoreOwnBytes(imported, 1, [&] { *reinterpret_cast<std::uint8_t*>(imported) = 0x42; });
Require(TrackerGeneration() > beforeOwnWrite, "an unwatched CPU store did not invalidate byte comparisons");
std::array<std::uint64_t, 1> generations{before};
std::array<std::uint8_t, 1> changed{};
Require(!ChangedBlocks(imported, Block, generations, changed), "an unwatched import still uses block stamps");
Unwatch(imported, Block);
const auto adjacent = CollectWrites(base, Block);
Require(adjacent != 0, "unwatch broke the adjacent block's collect");
static_cast<volatile std::uint8_t*>(memory)[0] = 0x33;
CollectWritesUncached(base, Block);
Require(!UnchangedSince(base, Block, adjacent), "unwatch hid a CPU edit in unrelated memory");
}
void CheckNewestStamp() {
void* memory = AllocateWatched(4 * Block);
const auto base = reinterpret_cast<std::uint64_t>(memory);
const auto first = base + Block;
const auto second = base + 2 * Block;
std::memset(memory, 0x11, 4 * Block);
BumpCollectEpoch();
CollectWrites(base, 4 * Block);
Unwatch(first, 2 * Block);
const auto firstBefore = NewestStamp(first, Block);
const auto secondBefore = NewestStamp(second, Block);
MarkWritten(second + 16, 4);
Require(NewestStamp(second, Block) > secondBefore, "a driver store into unwatched memory did not advance its stamp");
Require(NewestStamp(first, Block) == firstBefore, "a driver store advanced the stamp of other unwatched memory");
const auto generation = TrackerGeneration();
static_cast<volatile std::uint8_t*>(memory)[0] = 0x22;
CollectWritesUncached(base, Block);
Require(TrackerGeneration() > generation && NewestStamp(first, Block) == firstBefore, "a CPU store into watched memory advanced the stamp of unwatched memory");
StoreOwnBytes(first, 1, [&] { *reinterpret_cast<std::uint8_t*>(first) = 0x42; });
Require(NewestStamp(first, Block) > firstBefore, "an own store into unwatched memory did not advance its stamp");
const auto partial = NewestStamp(base + 3 * Block - 8, Block + 8);
static_cast<volatile std::uint8_t*>(memory)[3 * Block] = 0x33;
CollectWritesUncached(base + 3 * Block, Block);
Require(NewestStamp(base + 3 * Block - 8, Block + 8) > partial, "a CPU store into the watched part of a partly watched range did not advance its stamp");
}
#ifdef _WIN32
void CheckPrivateMappingReuse() {
void* memory = AllocateWatched(3 * Block);
const auto base = reinterpret_cast<std::uint64_t>(memory);
std::memset(memory, 0x11, 3 * Block);
BumpCollectEpoch();
const auto before = CollectWrites(base, 3 * Block);
Require(before != 0, "the original backing was not collected");
Unwatch(base + Block, Block);
Require(!Watched(base + Block, Block), "the imported block stayed watched");
GuestArena::GuestArenaCommit_nid_postfix(memory, 3 * Block, PAGE_READWRITE, 3 * Block);
Require(!Watched(base + Block, Block), "a protection-only commit restored an imported block");
const auto neighbour = CollectWrites(base, Block);
Require(neighbour != 0, "the neighbouring block was not collected before remapping");
GuestArena::GuestArenaReset_nid_postfix(memory, 3 * Block);
GuestArena::GuestArenaRelease_nid_postfix(memory, 3 * Block);
auto* replacement = GuestArena::GuestArenaAllocateAtOrAbove_nid_postfix(base, 3 * Block, Block);
Require(replacement == memory, "the released arena address was not reused");
GuestArena::GuestArenaCommit_nid_postfix(replacement, 3 * Block, PAGE_READWRITE, 3 * Block);
Require(Watched(base, 3 * Block), "fresh backing at an excluded address is not watched");
Require(!UnchangedSince(base + Block, Block, before), "fresh backing reused an old import generation");
Require(!UnchangedSince(base, Block, neighbour), "fresh backing reused an adjacent block's old generation");
const auto after = CollectWrites(base, 3 * Block);
Require(after > before && UnchangedSince(base, 3 * Block, after), "fresh backing was not collected");
static_cast<volatile std::uint8_t*>(replacement)[Block + 8] = 0x22;
CollectWritesUncached(base, 3 * Block);
Require(!UnchangedSince(base + Block, Block, after), "a CPU edit in fresh backing was missed");
Unwatch(base + Block, Block);
Require(!Watched(base + Block, Block) && CollectWrites(base + Block, Block) == 0, "a second import of fresh backing stayed watched");
GuestArena::GuestArenaReset_nid_postfix(replacement, 3 * Block);
GuestArena::GuestArenaRelease_nid_postfix(replacement, 3 * Block);
}
std::uint64_t ChildHostHole() {
std::uintptr_t arena = 0;
std::size_t arenaBytes = 0;
GuestArena::GuestArenaRange_nid_postfix(&arena, &arenaBytes);
return (arena + arenaBytes / 2) & ~(std::uint64_t{Block} - 1);
}
void CheckHostHoleInChild() {
std::array<wchar_t, 32768> executable{};
const DWORD length = GetModuleFileNameW(nullptr, executable.data(), static_cast<DWORD>(executable.size()));
Require(length != 0 && length < executable.size(), "cannot name the test executable");
const std::wstring command = L"\"" + std::wstring(executable.data(), length) + L"\" " + HostHoleMode;
std::vector<wchar_t> commandLine(command.begin(), command.end());
commandLine.push_back(L'\0');
STARTUPINFOW startup{};
startup.cb = sizeof(startup);
startup.dwFlags = STARTF_USESTDHANDLES;
startup.hStdInput = GetStdHandle(STD_INPUT_HANDLE);
startup.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
startup.hStdError = GetStdHandle(STD_ERROR_HANDLE);
PROCESS_INFORMATION process{};
Require(CreateProcessW(executable.data(), commandLine.data(), nullptr, nullptr, TRUE, CREATE_NO_WINDOW | CREATE_SUSPENDED, nullptr, nullptr, &startup, &process) != 0, "cannot create the host-hole child");
const bool reserved = VirtualAllocEx(process.hProcess, reinterpret_cast<void*>(ChildHostHole()), Block, MEM_RESERVE, PAGE_NOACCESS) != nullptr;
const bool resumed = reserved && ResumeThread(process.hThread) != static_cast<DWORD>(-1);
const bool exited = resumed && WaitForSingleObject(process.hProcess, 60000) == WAIT_OBJECT_0;
if (!exited) {
TerminateProcess(process.hProcess, 1);
WaitForSingleObject(process.hProcess, INFINITE);
}
DWORD exitCode = 1;
const bool reported = GetExitCodeProcess(process.hProcess, &exitCode) != 0;
CloseHandle(process.hThread);
CloseHandle(process.hProcess);
Require(reserved, "cannot reserve a host range in the child's arena interval");
Require(resumed, "cannot resume the host-hole child");
Require(exited, "the host-hole child did not exit");
Require(reported && exitCode == 0, "the host-hole child failed");
}
void CheckHostHole() {
constexpr std::size_t bytes = 64;
const auto hole = ChildHostHole();
Require(GuestArena::GuestArenaHostRegionOverlaps_nid_postfix(hole, bytes), "the range reserved before the arena is not an arena host region");
const auto before = TrackerGeneration();
Require(!Watched(hole, bytes), "an arena host hole reads as watched");
Require(CollectWrites(hole, bytes) == 0 && CollectWritesUncached(hole, bytes) == 0, "an arena host hole was collected");
auto* watched = static_cast<std::uint8_t*>(AllocateWatched(Block, true));
struct Cleanup {
void* memory;
~Cleanup() { GuestArena::GuestArenaRelease_nid_postfix(memory, Block); }
} cleanup{watched};
const auto base = reinterpret_cast<std::uint64_t>(watched);
for (unsigned epoch = 0; epoch < 2; ++epoch) {
BumpCollectEpoch();
watched[7] ^= 1;
Require(CollectWrites(base + 7, 1) != 0, "a warm host-hole check could not collect its watched range");
for (unsigned repeat = 0; repeat < 3; ++repeat) {
Require(CollectWrites(base + 7, 1) != 0, "a warm host-hole check lost its watched range");
Require(CollectWrites(hole, bytes) == 0, "a repeated host-hole query hit a collect memo");
Require(CollectWrites(hole + 7, 1) == 0, "a page-rounded host-hole query hit a collect memo");
}
}
Require(StoredOver(hole, bytes, before), "an arena host hole reads as not stored over");
Require(!UnchangedSince(hole, bytes, before), "an arena host hole reads as unchanged");
const std::array queries{UnchangedQuery{hole, bytes, before}};
Require(!UnchangedSinceAll(queries), "an arena host hole reads as unchanged in a batch");
Require(!UnchangedSinceCollected(hole, bytes, before), "an arena host hole reads as unchanged since a collect");
Require(MarkWritten(hole, bytes) == 0, "a driver store into an arena host hole is stamped");
Require(StoreOwnBytes(hole, bytes, [] {}) == 0, "an own store into an arena host hole is stamped");
Require(!WrittenSince(hole, bytes, before), "an arena host hole reads its stamps as written");
std::array<std::uint64_t, 1> generations{before};
std::array<std::uint8_t, 1> changed{};
std::array<std::uint8_t, 1> cpu{};
Require(!ChangedBlocks(hole, bytes, generations, changed, cpu) && changed[0] == BlockWritten && cpu[0] == 1, "an arena host hole uses block stamps");
bool imported = false;
Require(ImportWatched(hole, bytes, [&] {
imported = true;
return true;
}) && imported, "an import into an arena host hole did not run");
Require(!Watched(hole, bytes), "an import made an arena host hole watched");
}
#endif
void CheckVersionRanges() {
constexpr std::size_t count = 80;
constexpr auto bytes = count * Block;
auto* memory = static_cast<std::uint8_t*>(AllocateWatched(bytes, true));
struct Cleanup {
void* memory;
~Cleanup() {
#ifdef _WIN32
GuestArena::GuestArenaRelease_nid_postfix(memory, bytes);
#else
GuestWriteWatch::GuestWriteWatchUnregister_nid_postfix(memory, bytes);
munmap(memory, bytes);
#endif
}
} cleanup{memory};
const auto base = reinterpret_cast<std::uint64_t>(memory);
Require(UnchangedSince(base, bytes, TrackerGeneration()), "a new range has newer version stamps");
std::memset(memory, 17, bytes);
const auto initial = CollectWritesUncached(base, bytes);
Require(initial != 0, "version ranges could not be collected");
struct Write { std::size_t block; std::uint64_t generation; };
std::vector<Write> history;
std::vector<std::uint64_t> checkpoints{initial};
std::uint32_t random = 0x61387a29;
const auto next = [&] { random = random * 1664525u + 1013904223u; return random; };
const auto expected = [&](const UnchangedQuery& query) {
if (query.generation == 0) return false;
for (const auto& write : history) {
const auto begin = base + write.block * Block;
if (write.generation > query.generation && begin < query.address + query.bytes && query.address < begin + Block) return false;
}
return true;
};
for (unsigned step = 0; step < 512; ++step) {
const auto block = step < 3 ? step : next() % count;
std::uint64_t generation;
if (step % 3 == 0) {
memory[block * Block + 9] ^= 1;
generation = CollectWritesUncached(base + block * Block, Block);
} else generation = MarkWritten(base + block * Block + 13, 4);
Require(generation > checkpoints.back(), "version range write did not advance the tracker");
history.push_back({block, generation});
checkpoints.push_back(generation);
for (unsigned check = 0; check < 16; ++check) {
std::array<UnchangedQuery, 3> queries;
bool all = true;
for (auto& query : queries) {
const auto offset = next() % bytes;
query = {base + offset, 1 + next() % (bytes - offset), checkpoints[next() % checkpoints.size()]};
const auto same = expected(query);
Require(UnchangedSince(query.address, query.bytes, query.generation) == same, "version range disagrees with write history");
all = all && same;
}
Require(UnchangedSinceAll(queries) == all, "batched version ranges disagree with write history");
}
}
Require(!UnchangedSince(base, bytes, 0), "an unknown generation was accepted");
Require(UnchangedSince(base, bytes, checkpoints.back()), "the latest checkpoint was rejected");
}
void CheckCollectBoundaries() {
constexpr std::size_t bytes = 3 * Block;
auto* memory = static_cast<std::uint8_t*>(AllocateWatched(bytes));
struct Cleanup {
void* memory;
~Cleanup() {
#ifdef _WIN32
GuestArena::GuestArenaRelease_nid_postfix(memory, bytes);
#else
Unwatch(reinterpret_cast<std::uint64_t>(memory), bytes);
munmap(memory, bytes);
#endif
}
} cleanup{memory};
const auto base = reinterpret_cast<std::uint64_t>(memory);
std::memset(memory, 17, bytes);
bool unboundedObserved = false;
std::thread observer([&] {
const auto before = CollectWrites(base + 7, 1);
memory[7] = 19;
const auto after = CollectWrites(base + 7, 1);
unboundedObserved = before != 0 && after > before && !UnchangedSince(base + 7, 1, before);
});
observer.join();
Require(unboundedObserved, "a thread without collect epochs reused a stale observation");
for (const auto offset : {7u, 4096u + 3u, static_cast<unsigned>(Block - 8), static_cast<unsigned>(Block + 3)}) {
BumpCollectEpoch();
const auto before = CollectWrites(base + offset, 16);
Require(before != 0, "an epoch lost watched coverage");
memory[offset] ^= 1;
BumpCollectEpoch();
Require(CollectWrites(base + offset, 16) > before && !UnchangedSince(base + offset, 16, before), "a new epoch missed a CPU write");
const auto observed = TrackerGeneration();
memory[offset + 1] ^= 1;
Require(CollectWritesUncached(base + offset, 16) > observed && !UnchangedSince(base + offset, 16, observed), "an uncached observation reused an epoch result");
const auto stored = MarkWritten(base + offset + 2, 1);
Require(CollectWrites(base + offset, 16) >= stored && !UnchangedSince(base + offset, 16, observed), "a memoized observation hid a driver write");
}
#ifndef _WIN32
BumpCollectEpoch();
Require(CollectWrites(base, 1) != 0, "initial partial-block observation failed");
Unwatch(base + 4096, 4096);
Require(CollectWrites(base + 4096, 1) == 0, "an unwatched neighbor retained an epoch observation");
BumpCollectEpoch();
const auto before = CollectWrites(base, 16);
Require(before != 0, "an unwatched neighbor prevented collecting a watched prefix");
memory[0] ^= 1;
BumpCollectEpoch();
Require(CollectWrites(base, 16) > before && !UnchangedSince(base, 16, before), "partial-block collection missed a CPU write");
GuestWriteWatch::GuestWriteWatchRegister_nid_postfix(memory + 4096, 4096);
Require(CollectWrites(base + 4096, 1) != 0, "a re-registered neighbor stayed unwatched");
#endif
}
}
int main() {
try {
if (!WriteWatched()) {
std::cout << "no write watching: skipped\n";
return 77;
}
#ifdef _WIN32
if (std::wstring_view(GetCommandLineW()).ends_with(HostHoleMode)) {
CheckHostHole();
return 0;
}
#endif
CheckSharedBlock();
CheckOwnStore();
CheckUnwatch();
CheckNewestStamp();
#ifdef _WIN32
CheckPrivateMappingReuse();
CheckHostHoleInChild();
#endif
CheckVersionRanges();
CheckCollectBoundaries();
} catch (const std::exception& error) {
std::cerr << "write tracking test failed: " << error.what() << "\n";
return 1;
}
std::cout << "write tracking tests passed\n";
return 0;
}