123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222 |
- //===-- tsan_trace.h --------------------------------------------*- C++ -*-===//
- //
- // 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.
- //
- //===----------------------------------------------------------------------===//
- #ifndef TSAN_TRACE_H
- #define TSAN_TRACE_H
- #include "tsan_defs.h"
- #include "tsan_ilist.h"
- #include "tsan_mutexset.h"
- #include "tsan_stack_trace.h"
- namespace __tsan {
- const int kTracePartSizeBits = 13;
- const int kTracePartSize = 1 << kTracePartSizeBits;
- const int kTraceParts = 2 * 1024 * 1024 / kTracePartSize;
- const int kTraceSize = kTracePartSize * kTraceParts;
- // Must fit into 3 bits.
- enum EventType {
- EventTypeMop,
- EventTypeFuncEnter,
- EventTypeFuncExit,
- EventTypeLock,
- EventTypeUnlock,
- EventTypeRLock,
- EventTypeRUnlock
- };
- // Represents a thread event (from most significant bit):
- // u64 typ : 3; // EventType.
- // u64 addr : 61; // Associated pc.
- typedef u64 Event;
- const uptr kEventPCBits = 61;
- struct TraceHeader {
- #if !SANITIZER_GO
- BufferedStackTrace stack0; // Start stack for the trace.
- #else
- VarSizeStackTrace stack0;
- #endif
- u64 epoch0; // Start epoch for the trace.
- MutexSet mset0;
- TraceHeader() : stack0(), epoch0() {}
- };
- struct Trace {
- Mutex mtx;
- #if !SANITIZER_GO
- // Must be last to catch overflow as paging fault.
- // Go shadow stack is dynamically allocated.
- uptr shadow_stack[kShadowStackSize];
- #endif
- // Must be the last field, because we unmap the unused part in
- // CreateThreadContext.
- TraceHeader headers[kTraceParts];
- Trace() : mtx(MutexTypeTrace) {}
- };
- namespace v3 {
- enum class EventType : u64 {
- kAccessExt,
- kAccessRange,
- kLock,
- kRLock,
- kUnlock,
- kTime,
- };
- // "Base" type for all events for type dispatch.
- struct Event {
- // We use variable-length type encoding to give more bits to some event
- // types that need them. If is_access is set, this is EventAccess.
- // Otherwise, if is_func is set, this is EventFunc.
- // Otherwise type denotes the type.
- u64 is_access : 1;
- u64 is_func : 1;
- EventType type : 3;
- u64 _ : 59;
- };
- static_assert(sizeof(Event) == 8, "bad Event size");
- // Nop event used as padding and does not affect state during replay.
- static constexpr Event NopEvent = {1, 0, EventType::kAccessExt, 0};
- // Compressed memory access can represent only some events with PCs
- // close enough to each other. Otherwise we fall back to EventAccessExt.
- struct EventAccess {
- static constexpr uptr kPCBits = 15;
- u64 is_access : 1; // = 1
- u64 is_read : 1;
- u64 is_atomic : 1;
- u64 size_log : 2;
- u64 pc_delta : kPCBits; // signed delta from the previous memory access PC
- u64 addr : kCompressedAddrBits;
- };
- static_assert(sizeof(EventAccess) == 8, "bad EventAccess size");
- // Function entry (pc != 0) or exit (pc == 0).
- struct EventFunc {
- u64 is_access : 1; // = 0
- u64 is_func : 1; // = 1
- u64 pc : 62;
- };
- static_assert(sizeof(EventFunc) == 8, "bad EventFunc size");
- // Extended memory access with full PC.
- struct EventAccessExt {
- u64 is_access : 1; // = 0
- u64 is_func : 1; // = 0
- EventType type : 3; // = EventType::kAccessExt
- u64 is_read : 1;
- u64 is_atomic : 1;
- u64 size_log : 2;
- u64 _ : 11;
- u64 addr : kCompressedAddrBits;
- u64 pc;
- };
- static_assert(sizeof(EventAccessExt) == 16, "bad EventAccessExt size");
- // Access to a memory range.
- struct EventAccessRange {
- static constexpr uptr kSizeLoBits = 13;
- u64 is_access : 1; // = 0
- u64 is_func : 1; // = 0
- EventType type : 3; // = EventType::kAccessRange
- u64 is_read : 1;
- u64 is_free : 1;
- u64 size_lo : kSizeLoBits;
- u64 pc : kCompressedAddrBits;
- u64 addr : kCompressedAddrBits;
- u64 size_hi : 64 - kCompressedAddrBits;
- };
- static_assert(sizeof(EventAccessRange) == 16, "bad EventAccessRange size");
- // Mutex lock.
- struct EventLock {
- static constexpr uptr kStackIDLoBits = 15;
- u64 is_access : 1; // = 0
- u64 is_func : 1; // = 0
- EventType type : 3; // = EventType::kLock or EventType::kRLock
- u64 pc : kCompressedAddrBits;
- u64 stack_lo : kStackIDLoBits;
- u64 stack_hi : sizeof(StackID) * kByteBits - kStackIDLoBits;
- u64 _ : 3;
- u64 addr : kCompressedAddrBits;
- };
- static_assert(sizeof(EventLock) == 16, "bad EventLock size");
- // Mutex unlock.
- struct EventUnlock {
- u64 is_access : 1; // = 0
- u64 is_func : 1; // = 0
- EventType type : 3; // = EventType::kUnlock
- u64 _ : 15;
- u64 addr : kCompressedAddrBits;
- };
- static_assert(sizeof(EventUnlock) == 8, "bad EventUnlock size");
- // Time change event.
- struct EventTime {
- u64 is_access : 1; // = 0
- u64 is_func : 1; // = 0
- EventType type : 3; // = EventType::kTime
- u64 sid : sizeof(Sid) * kByteBits;
- u64 epoch : kEpochBits;
- u64 _ : 64 - 5 - sizeof(Sid) * kByteBits - kEpochBits;
- };
- static_assert(sizeof(EventTime) == 8, "bad EventTime size");
- struct Trace;
- struct TraceHeader {
- Trace* trace = nullptr; // back-pointer to Trace containing this part
- INode trace_parts; // in Trace::parts
- };
- struct TracePart : TraceHeader {
- static constexpr uptr kByteSize = 256 << 10;
- static constexpr uptr kSize =
- (kByteSize - sizeof(TraceHeader)) / sizeof(Event);
- // TraceAcquire does a fast event pointer overflow check by comparing
- // pointer into TracePart::events with kAlignment mask. Since TracePart's
- // are allocated page-aligned, this check detects end of the array
- // (it also have false positives in the middle that are filtered separately).
- // This also requires events to be the last field.
- static constexpr uptr kAlignment = 0xff0;
- Event events[kSize];
- TracePart() {}
- };
- static_assert(sizeof(TracePart) == TracePart::kByteSize, "bad TracePart size");
- struct Trace {
- Mutex mtx;
- IList<TraceHeader, &TraceHeader::trace_parts, TracePart> parts;
- Event* final_pos =
- nullptr; // final position in the last part for finished threads
- Trace() : mtx(MutexTypeTrace) {}
- };
- } // namespace v3
- } // namespace __tsan
- #endif // TSAN_TRACE_H
|