13cab2bb3Spatrick //===-- sanitizer_deadlock_detector1.cpp ----------------------------------===//
23cab2bb3Spatrick //
33cab2bb3Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
43cab2bb3Spatrick // See https://llvm.org/LICENSE.txt for license information.
53cab2bb3Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
63cab2bb3Spatrick //
73cab2bb3Spatrick //===----------------------------------------------------------------------===//
83cab2bb3Spatrick //
93cab2bb3Spatrick // Deadlock detector implementation based on NxN adjacency bit matrix.
103cab2bb3Spatrick //
113cab2bb3Spatrick //===----------------------------------------------------------------------===//
123cab2bb3Spatrick
133cab2bb3Spatrick #include "sanitizer_deadlock_detector_interface.h"
143cab2bb3Spatrick #include "sanitizer_deadlock_detector.h"
153cab2bb3Spatrick #include "sanitizer_allocator_internal.h"
163cab2bb3Spatrick #include "sanitizer_placement_new.h"
173cab2bb3Spatrick #include "sanitizer_mutex.h"
183cab2bb3Spatrick
193cab2bb3Spatrick #if SANITIZER_DEADLOCK_DETECTOR_VERSION == 1
203cab2bb3Spatrick
213cab2bb3Spatrick namespace __sanitizer {
223cab2bb3Spatrick
233cab2bb3Spatrick typedef TwoLevelBitVector<> DDBV; // DeadlockDetector's bit vector.
243cab2bb3Spatrick
253cab2bb3Spatrick struct DDPhysicalThread {
263cab2bb3Spatrick };
273cab2bb3Spatrick
283cab2bb3Spatrick struct DDLogicalThread {
293cab2bb3Spatrick u64 ctx;
303cab2bb3Spatrick DeadlockDetectorTLS<DDBV> dd;
313cab2bb3Spatrick DDReport rep;
323cab2bb3Spatrick bool report_pending;
333cab2bb3Spatrick };
343cab2bb3Spatrick
35*d89ec533Spatrick struct DD final : public DDetector {
363cab2bb3Spatrick SpinMutex mtx;
373cab2bb3Spatrick DeadlockDetector<DDBV> dd;
383cab2bb3Spatrick DDFlags flags;
393cab2bb3Spatrick
403cab2bb3Spatrick explicit DD(const DDFlags *flags);
413cab2bb3Spatrick
423cab2bb3Spatrick DDPhysicalThread *CreatePhysicalThread() override;
433cab2bb3Spatrick void DestroyPhysicalThread(DDPhysicalThread *pt) override;
443cab2bb3Spatrick
453cab2bb3Spatrick DDLogicalThread *CreateLogicalThread(u64 ctx) override;
463cab2bb3Spatrick void DestroyLogicalThread(DDLogicalThread *lt) override;
473cab2bb3Spatrick
483cab2bb3Spatrick void MutexInit(DDCallback *cb, DDMutex *m) override;
493cab2bb3Spatrick void MutexBeforeLock(DDCallback *cb, DDMutex *m, bool wlock) override;
503cab2bb3Spatrick void MutexAfterLock(DDCallback *cb, DDMutex *m, bool wlock,
513cab2bb3Spatrick bool trylock) override;
523cab2bb3Spatrick void MutexBeforeUnlock(DDCallback *cb, DDMutex *m, bool wlock) override;
533cab2bb3Spatrick void MutexDestroy(DDCallback *cb, DDMutex *m) override;
543cab2bb3Spatrick
553cab2bb3Spatrick DDReport *GetReport(DDCallback *cb) override;
563cab2bb3Spatrick
573cab2bb3Spatrick void MutexEnsureID(DDLogicalThread *lt, DDMutex *m);
583cab2bb3Spatrick void ReportDeadlock(DDCallback *cb, DDMutex *m);
593cab2bb3Spatrick };
603cab2bb3Spatrick
Create(const DDFlags * flags)613cab2bb3Spatrick DDetector *DDetector::Create(const DDFlags *flags) {
623cab2bb3Spatrick (void)flags;
633cab2bb3Spatrick void *mem = MmapOrDie(sizeof(DD), "deadlock detector");
643cab2bb3Spatrick return new(mem) DD(flags);
653cab2bb3Spatrick }
663cab2bb3Spatrick
DD(const DDFlags * flags)673cab2bb3Spatrick DD::DD(const DDFlags *flags)
683cab2bb3Spatrick : flags(*flags) {
693cab2bb3Spatrick dd.clear();
703cab2bb3Spatrick }
713cab2bb3Spatrick
CreatePhysicalThread()723cab2bb3Spatrick DDPhysicalThread* DD::CreatePhysicalThread() {
733cab2bb3Spatrick return nullptr;
743cab2bb3Spatrick }
753cab2bb3Spatrick
DestroyPhysicalThread(DDPhysicalThread * pt)763cab2bb3Spatrick void DD::DestroyPhysicalThread(DDPhysicalThread *pt) {
773cab2bb3Spatrick }
783cab2bb3Spatrick
CreateLogicalThread(u64 ctx)793cab2bb3Spatrick DDLogicalThread* DD::CreateLogicalThread(u64 ctx) {
803cab2bb3Spatrick DDLogicalThread *lt = (DDLogicalThread*)InternalAlloc(sizeof(*lt));
813cab2bb3Spatrick lt->ctx = ctx;
823cab2bb3Spatrick lt->dd.clear();
833cab2bb3Spatrick lt->report_pending = false;
843cab2bb3Spatrick return lt;
853cab2bb3Spatrick }
863cab2bb3Spatrick
DestroyLogicalThread(DDLogicalThread * lt)873cab2bb3Spatrick void DD::DestroyLogicalThread(DDLogicalThread *lt) {
883cab2bb3Spatrick lt->~DDLogicalThread();
893cab2bb3Spatrick InternalFree(lt);
903cab2bb3Spatrick }
913cab2bb3Spatrick
MutexInit(DDCallback * cb,DDMutex * m)923cab2bb3Spatrick void DD::MutexInit(DDCallback *cb, DDMutex *m) {
933cab2bb3Spatrick m->id = 0;
943cab2bb3Spatrick m->stk = cb->Unwind();
953cab2bb3Spatrick }
963cab2bb3Spatrick
MutexEnsureID(DDLogicalThread * lt,DDMutex * m)973cab2bb3Spatrick void DD::MutexEnsureID(DDLogicalThread *lt, DDMutex *m) {
983cab2bb3Spatrick if (!dd.nodeBelongsToCurrentEpoch(m->id))
993cab2bb3Spatrick m->id = dd.newNode(reinterpret_cast<uptr>(m));
1003cab2bb3Spatrick dd.ensureCurrentEpoch(<->dd);
1013cab2bb3Spatrick }
1023cab2bb3Spatrick
MutexBeforeLock(DDCallback * cb,DDMutex * m,bool wlock)1033cab2bb3Spatrick void DD::MutexBeforeLock(DDCallback *cb,
1043cab2bb3Spatrick DDMutex *m, bool wlock) {
1053cab2bb3Spatrick DDLogicalThread *lt = cb->lt;
1063cab2bb3Spatrick if (lt->dd.empty()) return; // This will be the first lock held by lt.
1073cab2bb3Spatrick if (dd.hasAllEdges(<->dd, m->id)) return; // We already have all edges.
1083cab2bb3Spatrick SpinMutexLock lk(&mtx);
1093cab2bb3Spatrick MutexEnsureID(lt, m);
1103cab2bb3Spatrick if (dd.isHeld(<->dd, m->id))
1113cab2bb3Spatrick return; // FIXME: allow this only for recursive locks.
1123cab2bb3Spatrick if (dd.onLockBefore(<->dd, m->id)) {
1133cab2bb3Spatrick // Actually add this edge now so that we have all the stack traces.
1143cab2bb3Spatrick dd.addEdges(<->dd, m->id, cb->Unwind(), cb->UniqueTid());
1153cab2bb3Spatrick ReportDeadlock(cb, m);
1163cab2bb3Spatrick }
1173cab2bb3Spatrick }
1183cab2bb3Spatrick
ReportDeadlock(DDCallback * cb,DDMutex * m)1193cab2bb3Spatrick void DD::ReportDeadlock(DDCallback *cb, DDMutex *m) {
1203cab2bb3Spatrick DDLogicalThread *lt = cb->lt;
1213cab2bb3Spatrick uptr path[20];
1223cab2bb3Spatrick uptr len = dd.findPathToLock(<->dd, m->id, path, ARRAY_SIZE(path));
1233cab2bb3Spatrick if (len == 0U) {
1243cab2bb3Spatrick // A cycle of 20+ locks? Well, that's a bit odd...
1253cab2bb3Spatrick Printf("WARNING: too long mutex cycle found\n");
1263cab2bb3Spatrick return;
1273cab2bb3Spatrick }
1283cab2bb3Spatrick CHECK_EQ(m->id, path[0]);
1293cab2bb3Spatrick lt->report_pending = true;
1303cab2bb3Spatrick len = Min<uptr>(len, DDReport::kMaxLoopSize);
1313cab2bb3Spatrick DDReport *rep = <->rep;
1323cab2bb3Spatrick rep->n = len;
1333cab2bb3Spatrick for (uptr i = 0; i < len; i++) {
1343cab2bb3Spatrick uptr from = path[i];
1353cab2bb3Spatrick uptr to = path[(i + 1) % len];
1363cab2bb3Spatrick DDMutex *m0 = (DDMutex*)dd.getData(from);
1373cab2bb3Spatrick DDMutex *m1 = (DDMutex*)dd.getData(to);
1383cab2bb3Spatrick
139*d89ec533Spatrick u32 stk_from = 0, stk_to = 0;
1403cab2bb3Spatrick int unique_tid = 0;
1413cab2bb3Spatrick dd.findEdge(from, to, &stk_from, &stk_to, &unique_tid);
1423cab2bb3Spatrick // Printf("Edge: %zd=>%zd: %u/%u T%d\n", from, to, stk_from, stk_to,
1433cab2bb3Spatrick // unique_tid);
1443cab2bb3Spatrick rep->loop[i].thr_ctx = unique_tid;
1453cab2bb3Spatrick rep->loop[i].mtx_ctx0 = m0->ctx;
1463cab2bb3Spatrick rep->loop[i].mtx_ctx1 = m1->ctx;
1473cab2bb3Spatrick rep->loop[i].stk[0] = stk_to;
1483cab2bb3Spatrick rep->loop[i].stk[1] = stk_from;
1493cab2bb3Spatrick }
1503cab2bb3Spatrick }
1513cab2bb3Spatrick
MutexAfterLock(DDCallback * cb,DDMutex * m,bool wlock,bool trylock)1523cab2bb3Spatrick void DD::MutexAfterLock(DDCallback *cb, DDMutex *m, bool wlock, bool trylock) {
1533cab2bb3Spatrick DDLogicalThread *lt = cb->lt;
1543cab2bb3Spatrick u32 stk = 0;
1553cab2bb3Spatrick if (flags.second_deadlock_stack)
1563cab2bb3Spatrick stk = cb->Unwind();
1573cab2bb3Spatrick // Printf("T%p MutexLock: %zx stk %u\n", lt, m->id, stk);
1583cab2bb3Spatrick if (dd.onFirstLock(<->dd, m->id, stk))
1593cab2bb3Spatrick return;
1603cab2bb3Spatrick if (dd.onLockFast(<->dd, m->id, stk))
1613cab2bb3Spatrick return;
1623cab2bb3Spatrick
1633cab2bb3Spatrick SpinMutexLock lk(&mtx);
1643cab2bb3Spatrick MutexEnsureID(lt, m);
1653cab2bb3Spatrick if (wlock) // Only a recursive rlock may be held.
1663cab2bb3Spatrick CHECK(!dd.isHeld(<->dd, m->id));
1673cab2bb3Spatrick if (!trylock)
1683cab2bb3Spatrick dd.addEdges(<->dd, m->id, stk ? stk : cb->Unwind(), cb->UniqueTid());
1693cab2bb3Spatrick dd.onLockAfter(<->dd, m->id, stk);
1703cab2bb3Spatrick }
1713cab2bb3Spatrick
MutexBeforeUnlock(DDCallback * cb,DDMutex * m,bool wlock)1723cab2bb3Spatrick void DD::MutexBeforeUnlock(DDCallback *cb, DDMutex *m, bool wlock) {
1733cab2bb3Spatrick // Printf("T%p MutexUnLock: %zx\n", cb->lt, m->id);
1743cab2bb3Spatrick dd.onUnlock(&cb->lt->dd, m->id);
1753cab2bb3Spatrick }
1763cab2bb3Spatrick
MutexDestroy(DDCallback * cb,DDMutex * m)1773cab2bb3Spatrick void DD::MutexDestroy(DDCallback *cb,
1783cab2bb3Spatrick DDMutex *m) {
1793cab2bb3Spatrick if (!m->id) return;
1803cab2bb3Spatrick SpinMutexLock lk(&mtx);
1813cab2bb3Spatrick if (dd.nodeBelongsToCurrentEpoch(m->id))
1823cab2bb3Spatrick dd.removeNode(m->id);
1833cab2bb3Spatrick m->id = 0;
1843cab2bb3Spatrick }
1853cab2bb3Spatrick
GetReport(DDCallback * cb)1863cab2bb3Spatrick DDReport *DD::GetReport(DDCallback *cb) {
1873cab2bb3Spatrick if (!cb->lt->report_pending)
1883cab2bb3Spatrick return nullptr;
1893cab2bb3Spatrick cb->lt->report_pending = false;
1903cab2bb3Spatrick return &cb->lt->rep;
1913cab2bb3Spatrick }
1923cab2bb3Spatrick
1933cab2bb3Spatrick } // namespace __sanitizer
1943cab2bb3Spatrick #endif // #if SANITIZER_DEADLOCK_DETECTOR_VERSION == 1
195