[compiler-rt] [scudo] Add ScopedTSD to avoid releasing TSD manually (PR #72303)
via llvm-commits
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Tue Nov 14 11:40:45 PST 2023
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-compiler-rt-sanitizer
Author: None (ChiaHungDuan)
<details>
<summary>Changes</summary>
This makes the use of TSD be RAII style and avoid the exposing of the type of TSDs.
Also move some thread safety analyses from static to runtime because of its limitation. Even we mark some code path as NO_THREAD_SAFETY_ANALYSIS but we still have the `assertLocked()` cover the correctness.
---
Full diff: https://github.com/llvm/llvm-project/pull/72303.diff
5 Files Affected:
- (modified) compiler-rt/lib/scudo/standalone/combined.h (+7-17)
- (modified) compiler-rt/lib/scudo/standalone/tests/combined_test.cpp (+24-14)
- (modified) compiler-rt/lib/scudo/standalone/tests/tsd_test.cpp (+25-30)
- (modified) compiler-rt/lib/scudo/standalone/tsd_exclusive.h (+37-17)
- (modified) compiler-rt/lib/scudo/standalone/tsd_shared.h (+38-20)
``````````diff
diff --git a/compiler-rt/lib/scudo/standalone/combined.h b/compiler-rt/lib/scudo/standalone/combined.h
index b1700e5ecef7f5b..02cd5e80e873665 100644
--- a/compiler-rt/lib/scudo/standalone/combined.h
+++ b/compiler-rt/lib/scudo/standalone/combined.h
@@ -363,9 +363,7 @@ class Allocator {
if (LIKELY(PrimaryT::canAllocate(NeededSize))) {
ClassId = SizeClassMap::getClassIdBySize(NeededSize);
DCHECK_NE(ClassId, 0U);
- bool UnlockRequired;
- auto *TSD = TSDRegistry.getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
+ typename TSDRegistryT::ScopedTSD TSD(TSDRegistry);
Block = TSD->getCache().allocate(ClassId);
// If the allocation failed, retry in each successively larger class until
// it fits. If it fails to fit in the largest class, fallback to the
@@ -376,8 +374,6 @@ class Allocator {
if (!Block)
ClassId = 0;
}
- if (UnlockRequired)
- TSD->unlock();
}
if (UNLIKELY(ClassId == 0)) {
Block = Secondary.allocate(Options, Size, Alignment, &SecondaryBlockEnd,
@@ -1148,13 +1144,11 @@ class Allocator {
void *BlockBegin = getBlockBegin(Ptr, Header);
const uptr ClassId = Header->ClassId;
if (LIKELY(ClassId)) {
- bool UnlockRequired;
- auto *TSD = TSDRegistry.getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
- const bool CacheDrained =
- TSD->getCache().deallocate(ClassId, BlockBegin);
- if (UnlockRequired)
- TSD->unlock();
+ bool CacheDrained;
+ {
+ typename TSDRegistryT::ScopedTSD TSD(TSDRegistry);
+ CacheDrained = TSD->getCache().deallocate(ClassId, BlockBegin);
+ }
// When we have drained some blocks back to the Primary from TSD, that
// implies that we may have the chance to release some pages as well.
// Note that in order not to block other thread's accessing the TSD,
@@ -1168,13 +1162,9 @@ class Allocator {
Secondary.deallocate(Options, BlockBegin);
}
} else {
- bool UnlockRequired;
- auto *TSD = TSDRegistry.getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
+ typename TSDRegistryT::ScopedTSD TSD(TSDRegistry);
Quarantine.put(&TSD->getQuarantineCache(),
QuarantineCallback(*this, TSD->getCache()), Ptr, Size);
- if (UnlockRequired)
- TSD->unlock();
}
}
diff --git a/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp b/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
index 3dbd93cacefd684..a29463a0344739a 100644
--- a/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
@@ -229,11 +229,25 @@ struct TestConditionVariableConfig {
#define SCUDO_TYPED_TEST(FIXTURE, NAME) \
template <class TypeParam> \
struct FIXTURE##NAME : public FIXTURE<TypeParam> { \
+ using BaseT = FIXTURE<TypeParam>; \
void Run(); \
}; \
SCUDO_TYPED_TEST_ALL_TYPES(FIXTURE, NAME) \
template <class TypeParam> void FIXTURE##NAME<TypeParam>::Run()
+// Accessing `TSD->getCache()` requires `TSD::Mutex` and which doesn't have easy
+// way to test it by thread-safety analysis. Alternatively, we verify the thread
+// safety through runtime check in ScopedTSD and mark the test body with
+// NO_THREAD_SAFETY_ANALYSIS.
+#define SCUDO_TYPED_TEST_SKIP_THREAD_SAFETY(FIXTURE, NAME) \
+ template <class TypeParam> \
+ struct FIXTURE##NAME : public FIXTURE<TypeParam> { \
+ using BaseT = FIXTURE<TypeParam>; \
+ void Run() NO_THREAD_SAFETY_ANALYSIS; \
+ }; \
+ SCUDO_TYPED_TEST_ALL_TYPES(FIXTURE, NAME) \
+ template <class TypeParam> void FIXTURE##NAME<TypeParam>::Run()
+
SCUDO_TYPED_TEST(ScudoCombinedTest, IsOwned) {
auto *Allocator = this->Allocator.get();
static scudo::u8 StaticBuffer[scudo::Chunk::getHeaderSize() + 1];
@@ -547,7 +561,8 @@ SCUDO_TYPED_TEST(ScudoCombinedTest, Stats) {
EXPECT_NE(Stats.find("Stats: Quarantine"), std::string::npos);
}
-SCUDO_TYPED_TEST(ScudoCombinedTest, CacheDrain) NO_THREAD_SAFETY_ANALYSIS {
+SCUDO_TYPED_TEST_SKIP_THREAD_SAFETY(ScudoCombinedTest, CacheDrain) {
+ using AllocatorT = typename BaseT::AllocatorT;
auto *Allocator = this->Allocator.get();
std::vector<void *> V;
@@ -559,17 +574,15 @@ SCUDO_TYPED_TEST(ScudoCombinedTest, CacheDrain) NO_THREAD_SAFETY_ANALYSIS {
for (auto P : V)
Allocator->deallocate(P, Origin);
- bool UnlockRequired;
- auto *TSD = Allocator->getTSDRegistry()->getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
+ typename AllocatorT::TSDRegistryT::ScopedTSD TSD(
+ *Allocator->getTSDRegistry());
EXPECT_TRUE(!TSD->getCache().isEmpty());
TSD->getCache().drain();
EXPECT_TRUE(TSD->getCache().isEmpty());
- if (UnlockRequired)
- TSD->unlock();
}
-SCUDO_TYPED_TEST(ScudoCombinedTest, ForceCacheDrain) NO_THREAD_SAFETY_ANALYSIS {
+SCUDO_TYPED_TEST_SKIP_THREAD_SAFETY(ScudoCombinedTest, ForceCacheDrain) {
+ using AllocatorT = typename BaseT::AllocatorT;
auto *Allocator = this->Allocator.get();
std::vector<void *> V;
@@ -584,14 +597,11 @@ SCUDO_TYPED_TEST(ScudoCombinedTest, ForceCacheDrain) NO_THREAD_SAFETY_ANALYSIS {
// `ForceAll` will also drain the caches.
Allocator->releaseToOS(scudo::ReleaseToOS::ForceAll);
- bool UnlockRequired;
- auto *TSD = Allocator->getTSDRegistry()->getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
+ typename AllocatorT::TSDRegistryT::ScopedTSD TSD(
+ *Allocator->getTSDRegistry());
EXPECT_TRUE(TSD->getCache().isEmpty());
EXPECT_EQ(TSD->getQuarantineCache().getSize(), 0U);
EXPECT_TRUE(Allocator->getQuarantine()->isEmpty());
- if (UnlockRequired)
- TSD->unlock();
}
SCUDO_TYPED_TEST(ScudoCombinedTest, ThreadedCombined) {
@@ -892,8 +902,8 @@ TEST(ScudoCombinedTest, BasicTrustyConfig) {
}
bool UnlockRequired;
- auto *TSD = Allocator->getTSDRegistry()->getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
+ typename AllocatorT::TSDRegistryT::ScopedTSD TSD(
+ *Allocator->getTSDRegistry());
TSD->getCache().drain();
Allocator->releaseToOS(scudo::ReleaseToOS::Force);
diff --git a/compiler-rt/lib/scudo/standalone/tests/tsd_test.cpp b/compiler-rt/lib/scudo/standalone/tests/tsd_test.cpp
index fad8fcf90077116..432129c37d424f7 100644
--- a/compiler-rt/lib/scudo/standalone/tests/tsd_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/tsd_test.cpp
@@ -17,6 +17,7 @@
#include <mutex>
#include <set>
#include <thread>
+#include <type_traits>
// We mock out an allocator with a TSD registry, mostly using empty stubs. The
// cache contains a single volatile uptr, to be able to test that several
@@ -86,7 +87,8 @@ TEST(ScudoTSDTest, TSDRegistryInit) {
EXPECT_TRUE(Allocator->isInitialized());
}
-template <class AllocatorT> static void testRegistry() {
+template <class AllocatorT>
+static void testRegistry() NO_THREAD_SAFETY_ANALYSIS {
auto Deleter = [](AllocatorT *A) {
A->unmapTestOnly();
delete A;
@@ -99,22 +101,17 @@ template <class AllocatorT> static void testRegistry() {
Registry->initThreadMaybe(Allocator.get(), /*MinimalInit=*/true);
EXPECT_TRUE(Allocator->isInitialized());
- bool UnlockRequired;
- auto TSD = Registry->getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
- EXPECT_NE(TSD, nullptr);
- EXPECT_EQ(TSD->getCache().Canary, 0U);
- if (UnlockRequired)
- TSD->unlock();
+ {
+ typename AllocatorT::TSDRegistryT::ScopedTSD TSD(*Registry);
+ EXPECT_EQ(TSD->getCache().Canary, 0U);
+ }
Registry->initThreadMaybe(Allocator.get(), /*MinimalInit=*/false);
- TSD = Registry->getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
- EXPECT_NE(TSD, nullptr);
- EXPECT_EQ(TSD->getCache().Canary, 0U);
- memset(&TSD->getCache(), 0x42, sizeof(TSD->getCache()));
- if (UnlockRequired)
- TSD->unlock();
+ {
+ typename AllocatorT::TSDRegistryT::ScopedTSD TSD(*Registry);
+ EXPECT_EQ(TSD->getCache().Canary, 0U);
+ memset(&TSD->getCache(), 0x42, sizeof(TSD->getCache()));
+ }
}
TEST(ScudoTSDTest, TSDRegistryBasic) {
@@ -129,7 +126,12 @@ static std::mutex Mutex;
static std::condition_variable Cv;
static bool Ready;
-template <typename AllocatorT> static void stressCache(AllocatorT *Allocator) {
+// Accessing `TSD->getCache()` requires `TSD::Mutex` and which doesn't have easy
+// way to test it by thread-safety analysis. Alternatively, we verify the thread
+// safety through runtime check in ScopedTSD and mark it as
+// NO_THREAD_SAFETY_ANALYSIS here.
+template <typename AllocatorT>
+static void stressCache(AllocatorT *Allocator) NO_THREAD_SAFETY_ANALYSIS {
auto Registry = Allocator->getTSDRegistry();
{
std::unique_lock<std::mutex> Lock(Mutex);
@@ -137,14 +139,13 @@ template <typename AllocatorT> static void stressCache(AllocatorT *Allocator) {
Cv.wait(Lock);
}
Registry->initThreadMaybe(Allocator, /*MinimalInit=*/false);
- bool UnlockRequired;
- auto TSD = Registry->getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
- EXPECT_NE(TSD, nullptr);
+ typename AllocatorT::TSDRegistryT::ScopedTSD TSD(*Registry);
// For an exclusive TSD, the cache should be empty. We cannot guarantee the
// same for a shared TSD.
- if (!UnlockRequired)
+ if (std::is_same<typename AllocatorT::TSDRegistryT,
+ scudo::TSDRegistryExT<AllocatorT>>()) {
EXPECT_EQ(TSD->getCache().Canary, 0U);
+ }
// Transform the thread id to a uptr to use it as canary.
const scudo::uptr Canary = static_cast<scudo::uptr>(
std::hash<std::thread::id>{}(std::this_thread::get_id()));
@@ -152,8 +153,6 @@ template <typename AllocatorT> static void stressCache(AllocatorT *Allocator) {
// Loop a few times to make sure that a concurrent thread isn't modifying it.
for (scudo::uptr I = 0; I < 4096U; I++)
EXPECT_EQ(TSD->getCache().Canary, Canary);
- if (UnlockRequired)
- TSD->unlock();
}
template <class AllocatorT> static void testRegistryThreaded() {
@@ -195,14 +194,10 @@ static void stressSharedRegistry(MockAllocator<SharedCaches> *Allocator) {
Cv.wait(Lock);
}
Registry->initThreadMaybe(Allocator, /*MinimalInit=*/false);
- bool UnlockRequired;
for (scudo::uptr I = 0; I < 4096U; I++) {
- auto TSD = Registry->getTSDAndLock(&UnlockRequired);
- TSD->assertLocked(/*BypassCheck=*/!UnlockRequired);
- EXPECT_NE(TSD, nullptr);
- Set.insert(reinterpret_cast<void *>(TSD));
- if (UnlockRequired)
- TSD->unlock();
+ typename MockAllocator<SharedCaches>::TSDRegistryT::ScopedTSD TSD(
+ *Registry);
+ Set.insert(reinterpret_cast<void *>(&*TSD));
}
{
std::unique_lock<std::mutex> Lock(Mutex);
diff --git a/compiler-rt/lib/scudo/standalone/tsd_exclusive.h b/compiler-rt/lib/scudo/standalone/tsd_exclusive.h
index 238367420238dae..9a32d03b0613987 100644
--- a/compiler-rt/lib/scudo/standalone/tsd_exclusive.h
+++ b/compiler-rt/lib/scudo/standalone/tsd_exclusive.h
@@ -27,6 +27,31 @@ struct ThreadState {
template <class Allocator> void teardownThread(void *Ptr);
template <class Allocator> struct TSDRegistryExT {
+ using ThisT = TSDRegistryExT<Allocator>;
+
+ struct ScopedTSD {
+ ScopedTSD(ThisT &TSDRegistry) {
+ CurrentTSD = TSDRegistry.getTSDAndLock(&IsFallback);
+ DCHECK_NE(CurrentTSD, nullptr);
+ }
+
+ ~ScopedTSD() {
+ if (UNLIKELY(IsFallback))
+ CurrentTSD->unlock();
+ }
+
+ TSD<Allocator> &operator*() { return *CurrentTSD; }
+
+ TSD<Allocator> *operator->() {
+ CurrentTSD->assertLocked(/*BypassCheck=*/!IsFallback);
+ return CurrentTSD;
+ }
+
+ private:
+ TSD<Allocator> *CurrentTSD;
+ bool IsFallback;
+ };
+
void init(Allocator *Instance) REQUIRES(Mutex) {
DCHECK(!Initialized);
Instance->init();
@@ -74,23 +99,6 @@ template <class Allocator> struct TSDRegistryExT {
initThread(Instance, MinimalInit);
}
- // TODO(chiahungduan): Consider removing the argument `UnlockRequired` by
- // embedding the logic into TSD or always locking the TSD. It will enable us
- // to properly mark thread annotation here and adding proper runtime
- // assertions in the member functions of TSD. For example, assert the lock is
- // acquired before calling TSD::commitBack().
- ALWAYS_INLINE TSD<Allocator> *
- getTSDAndLock(bool *UnlockRequired) NO_THREAD_SAFETY_ANALYSIS {
- if (LIKELY(State.InitState == ThreadState::Initialized &&
- !atomic_load(&Disabled, memory_order_acquire))) {
- *UnlockRequired = false;
- return &ThreadTSD;
- }
- FallbackTSD.lock();
- *UnlockRequired = true;
- return &FallbackTSD;
- }
-
// To disable the exclusive TSD registry, we effectively lock the fallback TSD
// and force all threads to attempt to use it instead of their local one.
void disable() NO_THREAD_SAFETY_ANALYSIS {
@@ -123,6 +131,18 @@ template <class Allocator> struct TSDRegistryExT {
}
private:
+ ALWAYS_INLINE TSD<Allocator> *
+ getTSDAndLock(bool *UnlockRequired) NO_THREAD_SAFETY_ANALYSIS {
+ if (LIKELY(State.InitState == ThreadState::Initialized &&
+ !atomic_load(&Disabled, memory_order_acquire))) {
+ *UnlockRequired = false;
+ return &ThreadTSD;
+ }
+ FallbackTSD.lock();
+ *UnlockRequired = true;
+ return &FallbackTSD;
+ }
+
// Using minimal initialization allows for global initialization while keeping
// the thread specific structure untouched. The fallback structure will be
// used instead.
diff --git a/compiler-rt/lib/scudo/standalone/tsd_shared.h b/compiler-rt/lib/scudo/standalone/tsd_shared.h
index 1bca578ee14be4c..a2e9bb3d4a6632b 100644
--- a/compiler-rt/lib/scudo/standalone/tsd_shared.h
+++ b/compiler-rt/lib/scudo/standalone/tsd_shared.h
@@ -26,6 +26,27 @@ namespace scudo {
template <class Allocator, u32 TSDsArraySize, u32 DefaultTSDCount>
struct TSDRegistrySharedT {
+ using ThisT = TSDRegistrySharedT<Allocator, TSDsArraySize, DefaultTSDCount>;
+
+ struct ScopedTSD {
+ ScopedTSD(ThisT &TSDRegistry) {
+ CurrentTSD = TSDRegistry.getTSDAndLock();
+ DCHECK_NE(CurrentTSD, nullptr);
+ }
+
+ ~ScopedTSD() { CurrentTSD->unlock(); }
+
+ TSD<Allocator> &operator*() { return *CurrentTSD; }
+
+ TSD<Allocator> *operator->() {
+ CurrentTSD->assertLocked(/*BypassCheck=*/false);
+ return CurrentTSD;
+ }
+
+ private:
+ TSD<Allocator> *CurrentTSD;
+ };
+
void init(Allocator *Instance) REQUIRES(Mutex) {
DCHECK(!Initialized);
Instance->init();
@@ -70,26 +91,6 @@ struct TSDRegistrySharedT {
initThread(Instance);
}
- // TSDs is an array of locks and which is not supported for marking
- // thread-safety capability.
- ALWAYS_INLINE TSD<Allocator> *
- getTSDAndLock(bool *UnlockRequired) NO_THREAD_SAFETY_ANALYSIS {
- TSD<Allocator> *TSD = getCurrentTSD();
- DCHECK(TSD);
- *UnlockRequired = true;
- // Try to lock the currently associated context.
- if (TSD->tryLock())
- return TSD;
- // If that fails, go down the slow path.
- if (TSDsArraySize == 1U) {
- // Only 1 TSD, not need to go any further.
- // The compiler will optimize this one way or the other.
- TSD->lock();
- return TSD;
- }
- return getTSDAndLockSlow(TSD);
- }
-
void disable() NO_THREAD_SAFETY_ANALYSIS {
Mutex.lock();
for (u32 I = 0; I < TSDsArraySize; I++)
@@ -132,6 +133,23 @@ struct TSDRegistrySharedT {
}
private:
+ ALWAYS_INLINE TSD<Allocator> *
+ getTSDAndLock() NO_THREAD_SAFETY_ANALYSIS {
+ TSD<Allocator> *TSD = getCurrentTSD();
+ DCHECK(TSD);
+ // Try to lock the currently associated context.
+ if (TSD->tryLock())
+ return TSD;
+ // If that fails, go down the slow path.
+ if (TSDsArraySize == 1U) {
+ // Only 1 TSD, not need to go any further.
+ // The compiler will optimize this one way or the other.
+ TSD->lock();
+ return TSD;
+ }
+ return getTSDAndLockSlow(TSD);
+ }
+
ALWAYS_INLINE uptr *getTlsPtr() const {
#if SCUDO_HAS_PLATFORM_TLS_SLOT
return reinterpret_cast<uptr *>(getPlatformAllocatorTlsSlot());
``````````
</details>
https://github.com/llvm/llvm-project/pull/72303
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