blob: 2e978852ea7d379c4ec408f00cdfeb177144bbae [file] [log] [blame]
//===-- tsan_rtl_mutex.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_deadlock_detector_interface.h>
#include <sanitizer_common/sanitizer_stackdepot.h>
#include "tsan_rtl.h"
#include "tsan_flags.h"
#include "tsan_sync.h"
#include "tsan_report.h"
#include "tsan_symbolize.h"
#include "tsan_platform.h"
namespace __tsan {
void ReportDeadlock(ThreadState *thr, uptr pc, DDReport *r);
void ReportDestroyLocked(ThreadState *thr, uptr pc, uptr addr,
FastState last_lock, StackID creation_stack_id);
struct Callback final : public DDCallback {
ThreadState *thr;
uptr pc;
Callback(ThreadState *thr, uptr pc)
: thr(thr)
, pc(pc) {
DDCallback::pt = thr->proc()->dd_pt;
DDCallback::lt = thr->dd_lt;
}
StackID Unwind() override { return CurrentStackId(thr, pc); }
int UniqueTid() override { return thr->tid; }
};
void DDMutexInit(ThreadState *thr, uptr pc, SyncVar *s) {
Callback cb(thr, pc);
ctx->dd->MutexInit(&cb, &s->dd);
s->dd.ctx = s->addr;
}
static void ReportMutexMisuse(ThreadState *thr, uptr pc, ReportType typ,
uptr addr, StackID creation_stack_id) {
// In Go, these misuses are either impossible, or detected by std lib,
// or false positives (e.g. unlock in a different thread).
if (SANITIZER_GO)
return;
if (!ShouldReport(thr, typ))
return;
ThreadRegistryLock l(&ctx->thread_registry);
ScopedReport rep(typ);
rep.AddMutex(addr, creation_stack_id);
VarSizeStackTrace trace;
ObtainCurrentStack(thr, pc, &trace);
rep.AddStack(trace, true);
rep.AddLocation(addr, 1);
OutputReport(thr, rep);
}
static void RecordMutexLock(ThreadState *thr, uptr pc, uptr addr,
StackID stack_id, bool write) {
auto typ = write ? EventType::kLock : EventType::kRLock;
// Note: it's important to trace before modifying mutex set
// because tracing can switch trace part and we write the current
// mutex set in the beginning of each part.
// If we do it in the opposite order, we will write already reduced
// mutex set in the beginning of the part and then trace unlock again.
TraceMutexLock(thr, typ, pc, addr, stack_id);
thr->mset.AddAddr(addr, stack_id, write);
}
static void RecordMutexUnlock(ThreadState *thr, uptr addr) {
// See the comment in RecordMutexLock re order of operations.
TraceMutexUnlock(thr, addr);
thr->mset.DelAddr(addr);
}
void MutexCreate(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
DPrintf("#%d: MutexCreate %zx flagz=0x%x\n", thr->tid, addr, flagz);
if (!(flagz & MutexFlagLinkerInit) && pc && IsAppMem(addr))
MemoryAccess(thr, pc, addr, 1, kAccessWrite);
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
s->SetFlags(flagz & MutexCreationFlagMask);
// Save stack in the case the sync object was created before as atomic.
if (!SANITIZER_GO && s->creation_stack_id == kInvalidStackID)
s->creation_stack_id = CurrentStackId(thr, pc);
}
void MutexDestroy(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
DPrintf("#%d: MutexDestroy %zx\n", thr->tid, addr);
bool unlock_locked = false;
StackID creation_stack_id;
FastState last_lock;
{
auto s = ctx->metamap.GetSyncIfExists(addr);
if (!s)
return;
SlotLocker locker(thr);
{
Lock lock(&s->mtx);
creation_stack_id = s->creation_stack_id;
last_lock = s->last_lock;
if ((flagz & MutexFlagLinkerInit) || s->IsFlagSet(MutexFlagLinkerInit) ||
((flagz & MutexFlagNotStatic) && !s->IsFlagSet(MutexFlagNotStatic))) {
// Destroy is no-op for linker-initialized mutexes.
return;
}
if (common_flags()->detect_deadlocks) {
Callback cb(thr, pc);
ctx->dd->MutexDestroy(&cb, &s->dd);
ctx->dd->MutexInit(&cb, &s->dd);
}
if (flags()->report_destroy_locked && s->owner_tid != kInvalidTid &&
!s->IsFlagSet(MutexFlagBroken)) {
s->SetFlags(MutexFlagBroken);
unlock_locked = true;
}
s->Reset();
}
// Imitate a memory write to catch unlock-destroy races.
if (pc && IsAppMem(addr))
MemoryAccess(thr, pc, addr, 1,
kAccessWrite | kAccessFree | kAccessSlotLocked);
}
if (unlock_locked && ShouldReport(thr, ReportTypeMutexDestroyLocked))
ReportDestroyLocked(thr, pc, addr, last_lock, creation_stack_id);
thr->mset.DelAddr(addr, true);
// s will be destroyed and freed in MetaMap::FreeBlock.
}
void MutexPreLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
DPrintf("#%d: MutexPreLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
if (flagz & MutexFlagTryLock)
return;
if (!common_flags()->detect_deadlocks)
return;
Callback cb(thr, pc);
{
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
ReadLock lock(&s->mtx);
s->UpdateFlags(flagz);
if (s->owner_tid != thr->tid)
ctx->dd->MutexBeforeLock(&cb, &s->dd, true);
}
ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
}
void MutexPostLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz, int rec) {
DPrintf("#%d: MutexPostLock %zx flag=0x%x rec=%d\n",
thr->tid, addr, flagz, rec);
if (flagz & MutexFlagRecursiveLock)
CHECK_GT(rec, 0);
else
rec = 1;
if (pc && IsAppMem(addr))
MemoryAccess(thr, pc, addr, 1, kAccessRead | kAccessAtomic);
bool report_double_lock = false;
bool pre_lock = false;
bool first = false;
StackID creation_stack_id = kInvalidStackID;
{
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
creation_stack_id = s->creation_stack_id;
RecordMutexLock(thr, pc, addr, creation_stack_id, true);
{
Lock lock(&s->mtx);
first = s->recursion == 0;
s->UpdateFlags(flagz);
if (s->owner_tid == kInvalidTid) {
CHECK_EQ(s->recursion, 0);
s->owner_tid = thr->tid;
s->last_lock = thr->fast_state;
} else if (s->owner_tid == thr->tid) {
CHECK_GT(s->recursion, 0);
} else if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
s->SetFlags(MutexFlagBroken);
report_double_lock = true;
}
s->recursion += rec;
if (first) {
if (!thr->ignore_sync) {
thr->clock.Acquire(s->clock);
thr->clock.Acquire(s->read_clock);
}
}
if (first && common_flags()->detect_deadlocks) {
pre_lock = (flagz & MutexFlagDoPreLockOnPostLock) &&
!(flagz & MutexFlagTryLock);
Callback cb(thr, pc);
if (pre_lock)
ctx->dd->MutexBeforeLock(&cb, &s->dd, true);
ctx->dd->MutexAfterLock(&cb, &s->dd, true, flagz & MutexFlagTryLock);
}
}
}
if (report_double_lock)
ReportMutexMisuse(thr, pc, ReportTypeMutexDoubleLock, addr,
creation_stack_id);
if (first && pre_lock && common_flags()->detect_deadlocks) {
Callback cb(thr, pc);
ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
}
}
int MutexUnlock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
DPrintf("#%d: MutexUnlock %zx flagz=0x%x\n", thr->tid, addr, flagz);
if (pc && IsAppMem(addr))
MemoryAccess(thr, pc, addr, 1, kAccessRead | kAccessAtomic);
StackID creation_stack_id;
RecordMutexUnlock(thr, addr);
bool report_bad_unlock = false;
int rec = 0;
{
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
bool released = false;
{
Lock lock(&s->mtx);
creation_stack_id = s->creation_stack_id;
if (!SANITIZER_GO && (s->recursion == 0 || s->owner_tid != thr->tid)) {
if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
s->SetFlags(MutexFlagBroken);
report_bad_unlock = true;
}
} else {
rec = (flagz & MutexFlagRecursiveUnlock) ? s->recursion : 1;
s->recursion -= rec;
if (s->recursion == 0) {
s->owner_tid = kInvalidTid;
if (!thr->ignore_sync) {
thr->clock.ReleaseStore(&s->clock);
released = true;
}
}
}
if (common_flags()->detect_deadlocks && s->recursion == 0 &&
!report_bad_unlock) {
Callback cb(thr, pc);
ctx->dd->MutexBeforeUnlock(&cb, &s->dd, true);
}
}
if (released)
IncrementEpoch(thr);
}
if (report_bad_unlock)
ReportMutexMisuse(thr, pc, ReportTypeMutexBadUnlock, addr,
creation_stack_id);
if (common_flags()->detect_deadlocks && !report_bad_unlock) {
Callback cb(thr, pc);
ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
}
return rec;
}
void MutexPreReadLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
DPrintf("#%d: MutexPreReadLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
if ((flagz & MutexFlagTryLock) || !common_flags()->detect_deadlocks)
return;
Callback cb(thr, pc);
{
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
ReadLock lock(&s->mtx);
s->UpdateFlags(flagz);
ctx->dd->MutexBeforeLock(&cb, &s->dd, false);
}
ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
}
void MutexPostReadLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
DPrintf("#%d: MutexPostReadLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
if (pc && IsAppMem(addr))
MemoryAccess(thr, pc, addr, 1, kAccessRead | kAccessAtomic);
bool report_bad_lock = false;
bool pre_lock = false;
StackID creation_stack_id = kInvalidStackID;
{
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
creation_stack_id = s->creation_stack_id;
RecordMutexLock(thr, pc, addr, creation_stack_id, false);
{
ReadLock lock(&s->mtx);
s->UpdateFlags(flagz);
if (s->owner_tid != kInvalidTid) {
if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
s->SetFlags(MutexFlagBroken);
report_bad_lock = true;
}
}
if (!thr->ignore_sync)
thr->clock.Acquire(s->clock);
s->last_lock = thr->fast_state;
if (common_flags()->detect_deadlocks) {
pre_lock = (flagz & MutexFlagDoPreLockOnPostLock) &&
!(flagz & MutexFlagTryLock);
Callback cb(thr, pc);
if (pre_lock)
ctx->dd->MutexBeforeLock(&cb, &s->dd, false);
ctx->dd->MutexAfterLock(&cb, &s->dd, false, flagz & MutexFlagTryLock);
}
}
}
if (report_bad_lock)
ReportMutexMisuse(thr, pc, ReportTypeMutexBadReadLock, addr,
creation_stack_id);
if (pre_lock && common_flags()->detect_deadlocks) {
Callback cb(thr, pc);
ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
}
}
void MutexReadUnlock(ThreadState *thr, uptr pc, uptr addr) {
DPrintf("#%d: MutexReadUnlock %zx\n", thr->tid, addr);
if (pc && IsAppMem(addr))
MemoryAccess(thr, pc, addr, 1, kAccessRead | kAccessAtomic);
RecordMutexUnlock(thr, addr);
StackID creation_stack_id;
bool report_bad_unlock = false;
{
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
bool released = false;
{
Lock lock(&s->mtx);
creation_stack_id = s->creation_stack_id;
if (s->owner_tid != kInvalidTid) {
if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
s->SetFlags(MutexFlagBroken);
report_bad_unlock = true;
}
}
if (!thr->ignore_sync) {
thr->clock.Release(&s->read_clock);
released = true;
}
if (common_flags()->detect_deadlocks && s->recursion == 0) {
Callback cb(thr, pc);
ctx->dd->MutexBeforeUnlock(&cb, &s->dd, false);
}
}
if (released)
IncrementEpoch(thr);
}
if (report_bad_unlock)
ReportMutexMisuse(thr, pc, ReportTypeMutexBadReadUnlock, addr,
creation_stack_id);
if (common_flags()->detect_deadlocks) {
Callback cb(thr, pc);
ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
}
}
void MutexReadOrWriteUnlock(ThreadState *thr, uptr pc, uptr addr) {
DPrintf("#%d: MutexReadOrWriteUnlock %zx\n", thr->tid, addr);
if (pc && IsAppMem(addr))
MemoryAccess(thr, pc, addr, 1, kAccessRead | kAccessAtomic);
RecordMutexUnlock(thr, addr);
StackID creation_stack_id;
bool report_bad_unlock = false;
bool write = true;
{
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
bool released = false;
{
Lock lock(&s->mtx);
creation_stack_id = s->creation_stack_id;
if (s->owner_tid == kInvalidTid) {
// Seems to be read unlock.
write = false;
if (!thr->ignore_sync) {
thr->clock.Release(&s->read_clock);
released = true;
}
} else if (s->owner_tid == thr->tid) {
// Seems to be write unlock.
CHECK_GT(s->recursion, 0);
s->recursion--;
if (s->recursion == 0) {
s->owner_tid = kInvalidTid;
if (!thr->ignore_sync) {
thr->clock.ReleaseStore(&s->clock);
released = true;
}
}
} else if (!s->IsFlagSet(MutexFlagBroken)) {
s->SetFlags(MutexFlagBroken);
report_bad_unlock = true;
}
if (common_flags()->detect_deadlocks && s->recursion == 0) {
Callback cb(thr, pc);
ctx->dd->MutexBeforeUnlock(&cb, &s->dd, write);
}
}
if (released)
IncrementEpoch(thr);
}
if (report_bad_unlock)
ReportMutexMisuse(thr, pc, ReportTypeMutexBadUnlock, addr,
creation_stack_id);
if (common_flags()->detect_deadlocks) {
Callback cb(thr, pc);
ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
}
}
void MutexRepair(ThreadState *thr, uptr pc, uptr addr) {
DPrintf("#%d: MutexRepair %zx\n", thr->tid, addr);
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
Lock lock(&s->mtx);
s->owner_tid = kInvalidTid;
s->recursion = 0;
}
void MutexInvalidAccess(ThreadState *thr, uptr pc, uptr addr) {
DPrintf("#%d: MutexInvalidAccess %zx\n", thr->tid, addr);
StackID creation_stack_id = kInvalidStackID;
{
SlotLocker locker(thr);
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
if (s)
creation_stack_id = s->creation_stack_id;
}
ReportMutexMisuse(thr, pc, ReportTypeMutexInvalidAccess, addr,
creation_stack_id);
}
void Acquire(ThreadState *thr, uptr pc, uptr addr) {
DPrintf("#%d: Acquire %zx\n", thr->tid, addr);
if (thr->ignore_sync)
return;
auto s = ctx->metamap.GetSyncIfExists(addr);
if (!s)
return;
SlotLocker locker(thr);
if (!s->clock)
return;
ReadLock lock(&s->mtx);
thr->clock.Acquire(s->clock);
}
void AcquireGlobal(ThreadState *thr) {
DPrintf("#%d: AcquireGlobal\n", thr->tid);
if (thr->ignore_sync)
return;
SlotLocker locker(thr);
for (auto &slot : ctx->slots) thr->clock.Set(slot.sid, slot.epoch());
}
void Release(ThreadState *thr, uptr pc, uptr addr) {
DPrintf("#%d: Release %zx\n", thr->tid, addr);
if (thr->ignore_sync)
return;
SlotLocker locker(thr);
{
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, false);
Lock lock(&s->mtx);
thr->clock.Release(&s->clock);
}
IncrementEpoch(thr);
}
void ReleaseStore(ThreadState *thr, uptr pc, uptr addr) {
DPrintf("#%d: ReleaseStore %zx\n", thr->tid, addr);
if (thr->ignore_sync)
return;
SlotLocker locker(thr);
{
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, false);
Lock lock(&s->mtx);
thr->clock.ReleaseStore(&s->clock);
}
IncrementEpoch(thr);
}
void ReleaseStoreAcquire(ThreadState *thr, uptr pc, uptr addr) {
DPrintf("#%d: ReleaseStoreAcquire %zx\n", thr->tid, addr);
if (thr->ignore_sync)
return;
SlotLocker locker(thr);
{
auto s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, false);
Lock lock(&s->mtx);
thr->clock.ReleaseStoreAcquire(&s->clock);
}
IncrementEpoch(thr);
}
void IncrementEpoch(ThreadState *thr) {
DCHECK(!thr->ignore_sync);
DCHECK(thr->slot_locked);
Epoch epoch = EpochInc(thr->fast_state.epoch());
if (!EpochOverflow(epoch)) {
Sid sid = thr->fast_state.sid();
thr->clock.Set(sid, epoch);
thr->fast_state.SetEpoch(epoch);
thr->slot->SetEpoch(epoch);
TraceTime(thr);
}
}
#if !SANITIZER_GO
void AfterSleep(ThreadState *thr, uptr pc) {
DPrintf("#%d: AfterSleep\n", thr->tid);
if (thr->ignore_sync)
return;
thr->last_sleep_stack_id = CurrentStackId(thr, pc);
thr->last_sleep_clock.Reset();
SlotLocker locker(thr);
for (auto &slot : ctx->slots)
thr->last_sleep_clock.Set(slot.sid, slot.epoch());
}
#endif
void ReportDeadlock(ThreadState *thr, uptr pc, DDReport *r) {
if (r == 0 || !ShouldReport(thr, ReportTypeDeadlock))
return;
ThreadRegistryLock l(&ctx->thread_registry);
ScopedReport rep(ReportTypeDeadlock);
for (int i = 0; i < r->n; i++) {
rep.AddMutex(r->loop[i].mtx_ctx0, r->loop[i].stk[0]);
rep.AddUniqueTid((int)r->loop[i].thr_ctx);
rep.AddThread((int)r->loop[i].thr_ctx);
}
uptr dummy_pc = 0x42;
for (int i = 0; i < r->n; i++) {
for (int j = 0; j < (flags()->second_deadlock_stack ? 2 : 1); j++) {
u32 stk = r->loop[i].stk[j];
if (stk && stk != kInvalidStackID) {
rep.AddStack(StackDepotGet(stk), true);
} else {
// Sometimes we fail to extract the stack trace (FIXME: investigate),
// but we should still produce some stack trace in the report.
rep.AddStack(StackTrace(&dummy_pc, 1), true);
}
}
}
OutputReport(thr, rep);
}
void ReportDestroyLocked(ThreadState *thr, uptr pc, uptr addr,
FastState last_lock, StackID creation_stack_id) {
// We need to lock the slot during RestoreStack because it protects
// the slot journal.
Lock slot_lock(&ctx->slots[static_cast<uptr>(last_lock.sid())].mtx);
ThreadRegistryLock l0(&ctx->thread_registry);
Lock slots_lock(&ctx->slot_mtx);
ScopedReport rep(ReportTypeMutexDestroyLocked);
rep.AddMutex(addr, creation_stack_id);
VarSizeStackTrace trace;
ObtainCurrentStack(thr, pc, &trace);
rep.AddStack(trace, true);
Tid tid;
DynamicMutexSet mset;
uptr tag;
if (!RestoreStack(EventType::kLock, last_lock.sid(), last_lock.epoch(), addr,
0, kAccessWrite, &tid, &trace, mset, &tag))
return;
rep.AddStack(trace, true);
rep.AddLocation(addr, 1);
OutputReport(thr, rep);
}
} // namespace __tsan