Files
clang-p2996/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cpp
Kenny Yu 1146d96096 [TSAN] Add __tsan_check_no_mutexes_held helper (#71568)
This adds a new helper that can be called from application code to
ensure that no mutexes are held on specific code paths. This is useful
for multiple scenarios, including ensuring no locks are held:

- at thread exit
- in peformance-critical code
- when a coroutine is suspended (can cause deadlocks)

See this discourse thread for more discussion:

https://discourse.llvm.org/t/add-threadsanitizer-check-to-prevent-coroutine-suspending-while-holding-a-lock-potential-deadlock/74051

This resubmits and fixes #69372 (was reverted because of build
breakage).
This also includes the followup change #71471 (to fix a land race).
2023-11-08 08:02:14 +01:00

461 lines
13 KiB
C++

//===-- tsan_interface_ann.cpp --------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer (TSan), a race detector.
//
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_internal_defs.h"
#include "sanitizer_common/sanitizer_placement_new.h"
#include "sanitizer_common/sanitizer_stacktrace.h"
#include "sanitizer_common/sanitizer_vector.h"
#include "tsan_interface_ann.h"
#include "tsan_report.h"
#include "tsan_rtl.h"
#include "tsan_mman.h"
#include "tsan_flags.h"
#include "tsan_platform.h"
#define CALLERPC ((uptr)__builtin_return_address(0))
using namespace __tsan;
namespace __tsan {
class ScopedAnnotation {
public:
ScopedAnnotation(ThreadState *thr, const char *aname, uptr pc)
: thr_(thr) {
FuncEntry(thr_, pc);
DPrintf("#%d: annotation %s()\n", thr_->tid, aname);
}
~ScopedAnnotation() {
FuncExit(thr_);
CheckedMutex::CheckNoLocks();
}
private:
ThreadState *const thr_;
};
#define SCOPED_ANNOTATION_RET(typ, ret) \
if (!flags()->enable_annotations) \
return ret; \
ThreadState *thr = cur_thread(); \
const uptr caller_pc = (uptr)__builtin_return_address(0); \
ScopedAnnotation sa(thr, __func__, caller_pc); \
const uptr pc = StackTrace::GetCurrentPc(); \
(void)pc;
#define SCOPED_ANNOTATION(typ) SCOPED_ANNOTATION_RET(typ, )
static const int kMaxDescLen = 128;
struct ExpectRace {
ExpectRace *next;
ExpectRace *prev;
atomic_uintptr_t hitcount;
atomic_uintptr_t addcount;
uptr addr;
uptr size;
char *file;
int line;
char desc[kMaxDescLen];
};
struct DynamicAnnContext {
Mutex mtx;
ExpectRace benign;
DynamicAnnContext() : mtx(MutexTypeAnnotations) {}
};
static DynamicAnnContext *dyn_ann_ctx;
static char dyn_ann_ctx_placeholder[sizeof(DynamicAnnContext)] ALIGNED(64);
static void AddExpectRace(ExpectRace *list,
char *f, int l, uptr addr, uptr size, char *desc) {
ExpectRace *race = list->next;
for (; race != list; race = race->next) {
if (race->addr == addr && race->size == size) {
atomic_store_relaxed(&race->addcount,
atomic_load_relaxed(&race->addcount) + 1);
return;
}
}
race = static_cast<ExpectRace *>(Alloc(sizeof(ExpectRace)));
race->addr = addr;
race->size = size;
race->file = f;
race->line = l;
race->desc[0] = 0;
atomic_store_relaxed(&race->hitcount, 0);
atomic_store_relaxed(&race->addcount, 1);
if (desc) {
int i = 0;
for (; i < kMaxDescLen - 1 && desc[i]; i++)
race->desc[i] = desc[i];
race->desc[i] = 0;
}
race->prev = list;
race->next = list->next;
race->next->prev = race;
list->next = race;
}
static ExpectRace *FindRace(ExpectRace *list, uptr addr, uptr size) {
for (ExpectRace *race = list->next; race != list; race = race->next) {
uptr maxbegin = max(race->addr, addr);
uptr minend = min(race->addr + race->size, addr + size);
if (maxbegin < minend)
return race;
}
return 0;
}
static bool CheckContains(ExpectRace *list, uptr addr, uptr size) {
ExpectRace *race = FindRace(list, addr, size);
if (race == 0)
return false;
DPrintf("Hit expected/benign race: %s addr=%zx:%d %s:%d\n",
race->desc, race->addr, (int)race->size, race->file, race->line);
atomic_fetch_add(&race->hitcount, 1, memory_order_relaxed);
return true;
}
static void InitList(ExpectRace *list) {
list->next = list;
list->prev = list;
}
void InitializeDynamicAnnotations() {
dyn_ann_ctx = new(dyn_ann_ctx_placeholder) DynamicAnnContext;
InitList(&dyn_ann_ctx->benign);
}
bool IsExpectedReport(uptr addr, uptr size) {
ReadLock lock(&dyn_ann_ctx->mtx);
return CheckContains(&dyn_ann_ctx->benign, addr, size);
}
} // namespace __tsan
using namespace __tsan;
extern "C" {
void INTERFACE_ATTRIBUTE AnnotateHappensBefore(char *f, int l, uptr addr) {
SCOPED_ANNOTATION(AnnotateHappensBefore);
Release(thr, pc, addr);
}
void INTERFACE_ATTRIBUTE AnnotateHappensAfter(char *f, int l, uptr addr) {
SCOPED_ANNOTATION(AnnotateHappensAfter);
Acquire(thr, pc, addr);
}
void INTERFACE_ATTRIBUTE AnnotateCondVarSignal(char *f, int l, uptr cv) {
}
void INTERFACE_ATTRIBUTE AnnotateCondVarSignalAll(char *f, int l, uptr cv) {
}
void INTERFACE_ATTRIBUTE AnnotateMutexIsNotPHB(char *f, int l, uptr mu) {
}
void INTERFACE_ATTRIBUTE AnnotateCondVarWait(char *f, int l, uptr cv,
uptr lock) {
}
void INTERFACE_ATTRIBUTE AnnotateRWLockCreate(char *f, int l, uptr m) {
SCOPED_ANNOTATION(AnnotateRWLockCreate);
MutexCreate(thr, pc, m, MutexFlagWriteReentrant);
}
void INTERFACE_ATTRIBUTE AnnotateRWLockCreateStatic(char *f, int l, uptr m) {
SCOPED_ANNOTATION(AnnotateRWLockCreateStatic);
MutexCreate(thr, pc, m, MutexFlagWriteReentrant | MutexFlagLinkerInit);
}
void INTERFACE_ATTRIBUTE AnnotateRWLockDestroy(char *f, int l, uptr m) {
SCOPED_ANNOTATION(AnnotateRWLockDestroy);
MutexDestroy(thr, pc, m);
}
void INTERFACE_ATTRIBUTE AnnotateRWLockAcquired(char *f, int l, uptr m,
uptr is_w) {
SCOPED_ANNOTATION(AnnotateRWLockAcquired);
if (is_w)
MutexPostLock(thr, pc, m, MutexFlagDoPreLockOnPostLock);
else
MutexPostReadLock(thr, pc, m, MutexFlagDoPreLockOnPostLock);
}
void INTERFACE_ATTRIBUTE AnnotateRWLockReleased(char *f, int l, uptr m,
uptr is_w) {
SCOPED_ANNOTATION(AnnotateRWLockReleased);
if (is_w)
MutexUnlock(thr, pc, m);
else
MutexReadUnlock(thr, pc, m);
}
void INTERFACE_ATTRIBUTE AnnotateTraceMemory(char *f, int l, uptr mem) {
}
void INTERFACE_ATTRIBUTE AnnotateFlushState(char *f, int l) {
}
void INTERFACE_ATTRIBUTE AnnotateNewMemory(char *f, int l, uptr mem,
uptr size) {
}
void INTERFACE_ATTRIBUTE AnnotateNoOp(char *f, int l, uptr mem) {
}
void INTERFACE_ATTRIBUTE AnnotateFlushExpectedRaces(char *f, int l) {
}
void INTERFACE_ATTRIBUTE AnnotateEnableRaceDetection(
char *f, int l, int enable) {
}
void INTERFACE_ATTRIBUTE AnnotateMutexIsUsedAsCondVar(
char *f, int l, uptr mu) {
}
void INTERFACE_ATTRIBUTE AnnotatePCQGet(
char *f, int l, uptr pcq) {
}
void INTERFACE_ATTRIBUTE AnnotatePCQPut(
char *f, int l, uptr pcq) {
}
void INTERFACE_ATTRIBUTE AnnotatePCQDestroy(
char *f, int l, uptr pcq) {
}
void INTERFACE_ATTRIBUTE AnnotatePCQCreate(
char *f, int l, uptr pcq) {
}
void INTERFACE_ATTRIBUTE AnnotateExpectRace(
char *f, int l, uptr mem, char *desc) {
}
static void BenignRaceImpl(char *f, int l, uptr mem, uptr size, char *desc) {
Lock lock(&dyn_ann_ctx->mtx);
AddExpectRace(&dyn_ann_ctx->benign,
f, l, mem, size, desc);
DPrintf("Add benign race: %s addr=%zx %s:%d\n", desc, mem, f, l);
}
void INTERFACE_ATTRIBUTE AnnotateBenignRaceSized(
char *f, int l, uptr mem, uptr size, char *desc) {
SCOPED_ANNOTATION(AnnotateBenignRaceSized);
BenignRaceImpl(f, l, mem, size, desc);
}
void INTERFACE_ATTRIBUTE AnnotateBenignRace(
char *f, int l, uptr mem, char *desc) {
SCOPED_ANNOTATION(AnnotateBenignRace);
BenignRaceImpl(f, l, mem, 1, desc);
}
void INTERFACE_ATTRIBUTE AnnotateIgnoreReadsBegin(char *f, int l) {
SCOPED_ANNOTATION(AnnotateIgnoreReadsBegin);
ThreadIgnoreBegin(thr, pc);
}
void INTERFACE_ATTRIBUTE AnnotateIgnoreReadsEnd(char *f, int l) {
SCOPED_ANNOTATION(AnnotateIgnoreReadsEnd);
ThreadIgnoreEnd(thr);
}
void INTERFACE_ATTRIBUTE AnnotateIgnoreWritesBegin(char *f, int l) {
SCOPED_ANNOTATION(AnnotateIgnoreWritesBegin);
ThreadIgnoreBegin(thr, pc);
}
void INTERFACE_ATTRIBUTE AnnotateIgnoreWritesEnd(char *f, int l) {
SCOPED_ANNOTATION(AnnotateIgnoreWritesEnd);
ThreadIgnoreEnd(thr);
}
void INTERFACE_ATTRIBUTE AnnotateIgnoreSyncBegin(char *f, int l) {
SCOPED_ANNOTATION(AnnotateIgnoreSyncBegin);
ThreadIgnoreSyncBegin(thr, pc);
}
void INTERFACE_ATTRIBUTE AnnotateIgnoreSyncEnd(char *f, int l) {
SCOPED_ANNOTATION(AnnotateIgnoreSyncEnd);
ThreadIgnoreSyncEnd(thr);
}
void INTERFACE_ATTRIBUTE AnnotatePublishMemoryRange(
char *f, int l, uptr addr, uptr size) {
}
void INTERFACE_ATTRIBUTE AnnotateUnpublishMemoryRange(
char *f, int l, uptr addr, uptr size) {
}
void INTERFACE_ATTRIBUTE AnnotateThreadName(
char *f, int l, char *name) {
SCOPED_ANNOTATION(AnnotateThreadName);
ThreadSetName(thr, name);
}
// We deliberately omit the implementation of WTFAnnotateHappensBefore() and
// WTFAnnotateHappensAfter(). Those are being used by Webkit to annotate
// atomic operations, which should be handled by ThreadSanitizer correctly.
void INTERFACE_ATTRIBUTE WTFAnnotateHappensBefore(char *f, int l, uptr addr) {
}
void INTERFACE_ATTRIBUTE WTFAnnotateHappensAfter(char *f, int l, uptr addr) {
}
void INTERFACE_ATTRIBUTE WTFAnnotateBenignRaceSized(
char *f, int l, uptr mem, uptr sz, char *desc) {
SCOPED_ANNOTATION(AnnotateBenignRaceSized);
BenignRaceImpl(f, l, mem, sz, desc);
}
int INTERFACE_ATTRIBUTE RunningOnValgrind() {
return flags()->running_on_valgrind;
}
double __attribute__((weak)) INTERFACE_ATTRIBUTE ValgrindSlowdown(void) {
return 10.0;
}
const char INTERFACE_ATTRIBUTE* ThreadSanitizerQuery(const char *query) {
if (internal_strcmp(query, "pure_happens_before") == 0)
return "1";
else
return "0";
}
void INTERFACE_ATTRIBUTE
AnnotateMemoryIsInitialized(char *f, int l, uptr mem, uptr sz) {}
void INTERFACE_ATTRIBUTE
AnnotateMemoryIsUninitialized(char *f, int l, uptr mem, uptr sz) {}
// Note: the parameter is called flagz, because flags is already taken
// by the global function that returns flags.
INTERFACE_ATTRIBUTE
void __tsan_mutex_create(void *m, unsigned flagz) {
SCOPED_ANNOTATION(__tsan_mutex_create);
MutexCreate(thr, pc, (uptr)m, flagz & MutexCreationFlagMask);
}
INTERFACE_ATTRIBUTE
void __tsan_mutex_destroy(void *m, unsigned flagz) {
SCOPED_ANNOTATION(__tsan_mutex_destroy);
MutexDestroy(thr, pc, (uptr)m, flagz);
}
INTERFACE_ATTRIBUTE
void __tsan_mutex_pre_lock(void *m, unsigned flagz) {
SCOPED_ANNOTATION(__tsan_mutex_pre_lock);
if (!(flagz & MutexFlagTryLock)) {
if (flagz & MutexFlagReadLock)
MutexPreReadLock(thr, pc, (uptr)m);
else
MutexPreLock(thr, pc, (uptr)m);
}
ThreadIgnoreBegin(thr, 0);
ThreadIgnoreSyncBegin(thr, 0);
}
INTERFACE_ATTRIBUTE
void __tsan_mutex_post_lock(void *m, unsigned flagz, int rec) {
SCOPED_ANNOTATION(__tsan_mutex_post_lock);
ThreadIgnoreSyncEnd(thr);
ThreadIgnoreEnd(thr);
if (!(flagz & MutexFlagTryLockFailed)) {
if (flagz & MutexFlagReadLock)
MutexPostReadLock(thr, pc, (uptr)m, flagz);
else
MutexPostLock(thr, pc, (uptr)m, flagz, rec);
}
}
INTERFACE_ATTRIBUTE
int __tsan_mutex_pre_unlock(void *m, unsigned flagz) {
SCOPED_ANNOTATION_RET(__tsan_mutex_pre_unlock, 0);
int ret = 0;
if (flagz & MutexFlagReadLock) {
CHECK(!(flagz & MutexFlagRecursiveUnlock));
MutexReadUnlock(thr, pc, (uptr)m);
} else {
ret = MutexUnlock(thr, pc, (uptr)m, flagz);
}
ThreadIgnoreBegin(thr, 0);
ThreadIgnoreSyncBegin(thr, 0);
return ret;
}
INTERFACE_ATTRIBUTE
void __tsan_mutex_post_unlock(void *m, unsigned flagz) {
SCOPED_ANNOTATION(__tsan_mutex_post_unlock);
ThreadIgnoreSyncEnd(thr);
ThreadIgnoreEnd(thr);
}
INTERFACE_ATTRIBUTE
void __tsan_mutex_pre_signal(void *addr, unsigned flagz) {
SCOPED_ANNOTATION(__tsan_mutex_pre_signal);
ThreadIgnoreBegin(thr, 0);
ThreadIgnoreSyncBegin(thr, 0);
}
INTERFACE_ATTRIBUTE
void __tsan_mutex_post_signal(void *addr, unsigned flagz) {
SCOPED_ANNOTATION(__tsan_mutex_post_signal);
ThreadIgnoreSyncEnd(thr);
ThreadIgnoreEnd(thr);
}
INTERFACE_ATTRIBUTE
void __tsan_mutex_pre_divert(void *addr, unsigned flagz) {
SCOPED_ANNOTATION(__tsan_mutex_pre_divert);
// Exit from ignore region started in __tsan_mutex_pre_lock/unlock/signal.
ThreadIgnoreSyncEnd(thr);
ThreadIgnoreEnd(thr);
}
INTERFACE_ATTRIBUTE
void __tsan_mutex_post_divert(void *addr, unsigned flagz) {
SCOPED_ANNOTATION(__tsan_mutex_post_divert);
ThreadIgnoreBegin(thr, 0);
ThreadIgnoreSyncBegin(thr, 0);
}
static void ReportMutexHeldWrongContext(ThreadState *thr, uptr pc) {
ThreadRegistryLock l(&ctx->thread_registry);
ScopedReport rep(ReportTypeMutexHeldWrongContext);
for (uptr i = 0; i < thr->mset.Size(); ++i) {
MutexSet::Desc desc = thr->mset.Get(i);
rep.AddMutex(desc.addr, desc.stack_id);
}
VarSizeStackTrace trace;
ObtainCurrentStack(thr, pc, &trace);
rep.AddStack(trace, true);
OutputReport(thr, rep);
}
INTERFACE_ATTRIBUTE
void __tsan_check_no_mutexes_held() {
SCOPED_ANNOTATION(__tsan_check_no_mutexes_held);
if (thr->mset.Size() == 0) {
return;
}
ReportMutexHeldWrongContext(thr, pc);
}
} // extern "C"