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//===-- tsan_rtl.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.
//
// Main file (entry points) for the TSan run-time.
//===----------------------------------------------------------------------===//
#include "tsan_rtl.h"
#include "sanitizer_common/sanitizer_atomic.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_file.h"
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_placement_new.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
#include "sanitizer_common/sanitizer_symbolizer.h"
#include "tsan_defs.h"
#include "tsan_interface.h"
#include "tsan_mman.h"
#include "tsan_platform.h"
#include "tsan_suppressions.h"
#include "tsan_symbolize.h"
#include "ubsan/ubsan_init.h"
volatile int __tsan_resumed = 0;
extern "C" void __tsan_resume() {
__tsan_resumed = 1;
}
namespace __tsan {
#if !SANITIZER_GO
void (*on_initialize)(void);
int (*on_finalize)(int);
#endif
#if !SANITIZER_GO && !SANITIZER_MAC
__attribute__((tls_model("initial-exec")))
THREADLOCAL char cur_thread_placeholder[sizeof(ThreadState)] ALIGNED(
SANITIZER_CACHE_LINE_SIZE);
#endif
static char ctx_placeholder[sizeof(Context)] ALIGNED(SANITIZER_CACHE_LINE_SIZE);
Context *ctx;
// Can be overriden by a front-end.
#ifdef TSAN_EXTERNAL_HOOKS
bool OnFinalize(bool failed);
void OnInitialize();
#else
#include <dlfcn.h>
SANITIZER_WEAK_CXX_DEFAULT_IMPL
bool OnFinalize(bool failed) {
#if !SANITIZER_GO
if (on_finalize)
return on_finalize(failed);
#endif
return failed;
}
SANITIZER_WEAK_CXX_DEFAULT_IMPL
void OnInitialize() {
#if !SANITIZER_GO
if (on_initialize)
on_initialize();
#endif
}
#endif
static ThreadContextBase *CreateThreadContext(Tid tid) {
// Map thread trace when context is created.
char name[50];
internal_snprintf(name, sizeof(name), "trace %u", tid);
MapThreadTrace(GetThreadTrace(tid), TraceSize() * sizeof(Event), name);
const uptr hdr = GetThreadTraceHeader(tid);
internal_snprintf(name, sizeof(name), "trace header %u", tid);
MapThreadTrace(hdr, sizeof(Trace), name);
new((void*)hdr) Trace();
// We are going to use only a small part of the trace with the default
// value of history_size. However, the constructor writes to the whole trace.
// Release the unused part.
uptr hdr_end = hdr + sizeof(Trace);
hdr_end -= sizeof(TraceHeader) * (kTraceParts - TraceParts());
hdr_end = RoundUp(hdr_end, GetPageSizeCached());
if (hdr_end < hdr + sizeof(Trace)) {
ReleaseMemoryPagesToOS(hdr_end, hdr + sizeof(Trace));
uptr unused = hdr + sizeof(Trace) - hdr_end;
if (hdr_end != (uptr)MmapFixedNoAccess(hdr_end, unused)) {
Report("ThreadSanitizer: failed to mprotect [0x%zx-0x%zx) \n", hdr_end,
unused);
CHECK("unable to mprotect" && 0);
}
}
return New<ThreadContext>(tid);
}
#if !SANITIZER_GO
static const u32 kThreadQuarantineSize = 16;
#else
static const u32 kThreadQuarantineSize = 64;
#endif
Context::Context()
: initialized(),
report_mtx(MutexTypeReport),
nreported(),
thread_registry(CreateThreadContext, kMaxTid, kThreadQuarantineSize,
kMaxTidReuse),
racy_mtx(MutexTypeRacy),
racy_stacks(),
racy_addresses(),
fired_suppressions_mtx(MutexTypeFired),
clock_alloc(LINKER_INITIALIZED, "clock allocator") {
fired_suppressions.reserve(8);
}
// The objects are allocated in TLS, so one may rely on zero-initialization.
ThreadState::ThreadState(Context *ctx, Tid tid, int unique_id, u64 epoch,
unsigned reuse_count, uptr stk_addr, uptr stk_size,
uptr tls_addr, uptr tls_size)
: fast_state(tid, epoch)
// Do not touch these, rely on zero initialization,
// they may be accessed before the ctor.
// , ignore_reads_and_writes()
// , ignore_interceptors()
,
clock(tid, reuse_count)
#if !SANITIZER_GO
,
jmp_bufs()
#endif
,
tid(tid),
unique_id(unique_id),
stk_addr(stk_addr),
stk_size(stk_size),
tls_addr(tls_addr),
tls_size(tls_size)
#if !SANITIZER_GO
,
last_sleep_clock(tid)
#endif
{
CHECK_EQ(reinterpret_cast<uptr>(this) % SANITIZER_CACHE_LINE_SIZE, 0);
#if !SANITIZER_GO
shadow_stack_pos = shadow_stack;
shadow_stack_end = shadow_stack + kShadowStackSize;
#else
// Setup dynamic shadow stack.
const int kInitStackSize = 8;
shadow_stack = (uptr *)Alloc(kInitStackSize * sizeof(uptr));
shadow_stack_pos = shadow_stack;
shadow_stack_end = shadow_stack + kInitStackSize;
#endif
}
#if !SANITIZER_GO
void MemoryProfiler(u64 uptime) {
if (ctx->memprof_fd == kInvalidFd)
return;
InternalMmapVector<char> buf(4096);
WriteMemoryProfile(buf.data(), buf.size(), uptime);
WriteToFile(ctx->memprof_fd, buf.data(), internal_strlen(buf.data()));
}
void InitializeMemoryProfiler() {
ctx->memprof_fd = kInvalidFd;
const char *fname = flags()->profile_memory;
if (!fname || !fname[0])
return;
if (internal_strcmp(fname, "stdout") == 0) {
ctx->memprof_fd = 1;
} else if (internal_strcmp(fname, "stderr") == 0) {
ctx->memprof_fd = 2;
} else {
InternalScopedString filename;
filename.append("%s.%d", fname, (int)internal_getpid());
ctx->memprof_fd = OpenFile(filename.data(), WrOnly);
if (ctx->memprof_fd == kInvalidFd) {
Printf("ThreadSanitizer: failed to open memory profile file '%s'\n",
filename.data());
return;
}
}
MemoryProfiler(0);
MaybeSpawnBackgroundThread();
}
static void *BackgroundThread(void *arg) {
// This is a non-initialized non-user thread, nothing to see here.
// We don't use ScopedIgnoreInterceptors, because we want ignores to be
// enabled even when the thread function exits (e.g. during pthread thread
// shutdown code).
cur_thread_init()->ignore_interceptors++;
const u64 kMs2Ns = 1000 * 1000;
const u64 start = NanoTime();
u64 last_flush = NanoTime();
uptr last_rss = 0;
for (int i = 0;
atomic_load(&ctx->stop_background_thread, memory_order_relaxed) == 0;
i++) {
SleepForMillis(100);
u64 now = NanoTime();
// Flush memory if requested.
if (flags()->flush_memory_ms > 0) {
if (last_flush + flags()->flush_memory_ms * kMs2Ns < now) {
VPrintf(1, "ThreadSanitizer: periodic memory flush\n");
FlushShadowMemory();
last_flush = NanoTime();
}
}
if (flags()->memory_limit_mb > 0) {
uptr rss = GetRSS();
uptr limit = uptr(flags()->memory_limit_mb) << 20;
VPrintf(1, "ThreadSanitizer: memory flush check"
" RSS=%llu LAST=%llu LIMIT=%llu\n",
(u64)rss >> 20, (u64)last_rss >> 20, (u64)limit >> 20);
if (2 * rss > limit + last_rss) {
VPrintf(1, "ThreadSanitizer: flushing memory due to RSS\n");
FlushShadowMemory();
rss = GetRSS();
VPrintf(1, "ThreadSanitizer: memory flushed RSS=%llu\n", (u64)rss>>20);
}
last_rss = rss;
}
MemoryProfiler(now - start);
// Flush symbolizer cache if requested.
if (flags()->flush_symbolizer_ms > 0) {
u64 last = atomic_load(&ctx->last_symbolize_time_ns,
memory_order_relaxed);
if (last != 0 && last + flags()->flush_symbolizer_ms * kMs2Ns < now) {
Lock l(&ctx->report_mtx);
ScopedErrorReportLock l2;
SymbolizeFlush();
atomic_store(&ctx->last_symbolize_time_ns, 0, memory_order_relaxed);
}
}
}
return nullptr;
}
static void StartBackgroundThread() {
ctx->background_thread = internal_start_thread(&BackgroundThread, 0);
}
#ifndef __mips__
static void StopBackgroundThread() {
atomic_store(&ctx->stop_background_thread, 1, memory_order_relaxed);
internal_join_thread(ctx->background_thread);
ctx->background_thread = 0;
}
#endif
#endif
void DontNeedShadowFor(uptr addr, uptr size) {
ReleaseMemoryPagesToOS(reinterpret_cast<uptr>(MemToShadow(addr)),
reinterpret_cast<uptr>(MemToShadow(addr + size)));
}
#if !SANITIZER_GO
void UnmapShadow(ThreadState *thr, uptr addr, uptr size) {
if (size == 0) return;
DontNeedShadowFor(addr, size);
ScopedGlobalProcessor sgp;
ctx->metamap.ResetRange(thr->proc(), addr, size);
}
#endif
void MapShadow(uptr addr, uptr size) {
// Global data is not 64K aligned, but there are no adjacent mappings,
// so we can get away with unaligned mapping.
// CHECK_EQ(addr, addr & ~((64 << 10) - 1)); // windows wants 64K alignment
const uptr kPageSize = GetPageSizeCached();
uptr shadow_begin = RoundDownTo((uptr)MemToShadow(addr), kPageSize);
uptr shadow_end = RoundUpTo((uptr)MemToShadow(addr + size), kPageSize);
if (!MmapFixedSuperNoReserve(shadow_begin, shadow_end - shadow_begin,
"shadow"))
Die();
// Meta shadow is 2:1, so tread carefully.
static bool data_mapped = false;
static uptr mapped_meta_end = 0;
uptr meta_begin = (uptr)MemToMeta(addr);
uptr meta_end = (uptr)MemToMeta(addr + size);
meta_begin = RoundDownTo(meta_begin, 64 << 10);
meta_end = RoundUpTo(meta_end, 64 << 10);
if (!data_mapped) {
// First call maps data+bss.
data_mapped = true;
if (!MmapFixedSuperNoReserve(meta_begin, meta_end - meta_begin,
"meta shadow"))
Die();
} else {
// Mapping continuous heap.
// Windows wants 64K alignment.
meta_begin = RoundDownTo(meta_begin, 64 << 10);
meta_end = RoundUpTo(meta_end, 64 << 10);
if (meta_end <= mapped_meta_end)
return;
if (meta_begin < mapped_meta_end)
meta_begin = mapped_meta_end;
if (!MmapFixedSuperNoReserve(meta_begin, meta_end - meta_begin,
"meta shadow"))
Die();
mapped_meta_end = meta_end;
}
VPrintf(2, "mapped meta shadow for (0x%zx-0x%zx) at (0x%zx-0x%zx)\n", addr,
addr + size, meta_begin, meta_end);
}
void MapThreadTrace(uptr addr, uptr size, const char *name) {
DPrintf("#0: Mapping trace at 0x%zx-0x%zx(0x%zx)\n", addr, addr + size, size);
CHECK_GE(addr, TraceMemBeg());
CHECK_LE(addr + size, TraceMemEnd());
CHECK_EQ(addr, addr & ~((64 << 10) - 1)); // windows wants 64K alignment
if (!MmapFixedSuperNoReserve(addr, size, name)) {
Printf("FATAL: ThreadSanitizer can not mmap thread trace (0x%zx/0x%zx)\n",
addr, size);
Die();
}
}
#if !SANITIZER_GO
static void OnStackUnwind(const SignalContext &sig, const void *,
BufferedStackTrace *stack) {
stack->Unwind(StackTrace::GetNextInstructionPc(sig.pc), sig.bp, sig.context,
common_flags()->fast_unwind_on_fatal);
}
static void TsanOnDeadlySignal(int signo, void *siginfo, void *context) {
HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
}
#endif
void CheckUnwind() {
// There is high probability that interceptors will check-fail as well,
// on the other hand there is no sense in processing interceptors
// since we are going to die soon.
ScopedIgnoreInterceptors ignore;
#if !SANITIZER_GO
cur_thread()->ignore_sync++;
cur_thread()->ignore_reads_and_writes++;
#endif
PrintCurrentStackSlow(StackTrace::GetCurrentPc());
}
bool is_initialized;
void Initialize(ThreadState *thr) {
// Thread safe because done before all threads exist.
if (is_initialized)
return;
is_initialized = true;
// We are not ready to handle interceptors yet.
ScopedIgnoreInterceptors ignore;
SanitizerToolName = "ThreadSanitizer";
// Install tool-specific callbacks in sanitizer_common.
SetCheckUnwindCallback(CheckUnwind);
ctx = new(ctx_placeholder) Context;
const char *env_name = SANITIZER_GO ? "GORACE" : "TSAN_OPTIONS";
const char *options = GetEnv(env_name);
CacheBinaryName();
CheckASLR();
InitializeFlags(&ctx->flags, options, env_name);
AvoidCVE_2016_2143();
__sanitizer::InitializePlatformEarly();
__tsan::InitializePlatformEarly();
#if !SANITIZER_GO
// Re-exec ourselves if we need to set additional env or command line args.
MaybeReexec();
InitializeAllocator();
ReplaceSystemMalloc();
#endif
if (common_flags()->detect_deadlocks)
ctx->dd = DDetector::Create(flags());
Processor *proc = ProcCreate();
ProcWire(proc, thr);
InitializeInterceptors();
InitializePlatform();
InitializeDynamicAnnotations();
#if !SANITIZER_GO
InitializeShadowMemory();
InitializeAllocatorLate();
InstallDeadlySignalHandlers(TsanOnDeadlySignal);
#endif
// Setup correct file descriptor for error reports.
__sanitizer_set_report_path(common_flags()->log_path);
InitializeSuppressions();
#if !SANITIZER_GO
InitializeLibIgnore();
Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer, ExitSymbolizer);
#endif
VPrintf(1, "***** Running under ThreadSanitizer v2 (pid %d) *****\n",
(int)internal_getpid());
// Initialize thread 0.
Tid tid = ThreadCreate(thr, 0, 0, true);
CHECK_EQ(tid, kMainTid);
ThreadStart(thr, tid, GetTid(), ThreadType::Regular);
#if TSAN_CONTAINS_UBSAN
__ubsan::InitAsPlugin();
#endif
ctx->initialized = true;
#if !SANITIZER_GO
Symbolizer::LateInitialize();
InitializeMemoryProfiler();
#endif
if (flags()->stop_on_start) {
Printf("ThreadSanitizer is suspended at startup (pid %d)."
" Call __tsan_resume().\n",
(int)internal_getpid());
while (__tsan_resumed == 0) {}
}
OnInitialize();
}
void MaybeSpawnBackgroundThread() {
// On MIPS, TSan initialization is run before
// __pthread_initialize_minimal_internal() is finished, so we can not spawn
// new threads.
#if !SANITIZER_GO && !defined(__mips__)
static atomic_uint32_t bg_thread = {};
if (atomic_load(&bg_thread, memory_order_relaxed) == 0 &&
atomic_exchange(&bg_thread, 1, memory_order_relaxed) == 0) {
StartBackgroundThread();
SetSandboxingCallback(StopBackgroundThread);
}
#endif
}
int Finalize(ThreadState *thr) {
bool failed = false;
if (common_flags()->print_module_map == 1)
DumpProcessMap();
if (flags()->atexit_sleep_ms > 0 && ThreadCount(thr) > 1)
SleepForMillis(flags()->atexit_sleep_ms);
// Wait for pending reports.
ctx->report_mtx.Lock();
{ ScopedErrorReportLock l; }
ctx->report_mtx.Unlock();
#if !SANITIZER_GO
if (Verbosity()) AllocatorPrintStats();
#endif
ThreadFinalize(thr);
if (ctx->nreported) {
failed = true;
#if !SANITIZER_GO
Printf("ThreadSanitizer: reported %d warnings\n", ctx->nreported);
#else
Printf("Found %d data race(s)\n", ctx->nreported);
#endif
}
if (common_flags()->print_suppressions)
PrintMatchedSuppressions();
failed = OnFinalize(failed);
return failed ? common_flags()->exitcode : 0;
}
#if !SANITIZER_GO
void ForkBefore(ThreadState *thr, uptr pc) NO_THREAD_SAFETY_ANALYSIS {
ctx->thread_registry.Lock();
ctx->report_mtx.Lock();
ScopedErrorReportLock::Lock();
// Suppress all reports in the pthread_atfork callbacks.
// Reports will deadlock on the report_mtx.
// We could ignore sync operations as well,
// but so far it's unclear if it will do more good or harm.
// Unnecessarily ignoring things can lead to false positives later.
thr->suppress_reports++;
// On OS X, REAL(fork) can call intercepted functions (OSSpinLockLock), and
// we'll assert in CheckNoLocks() unless we ignore interceptors.
thr->ignore_interceptors++;
}
void ForkParentAfter(ThreadState *thr, uptr pc) NO_THREAD_SAFETY_ANALYSIS {
thr->suppress_reports--; // Enabled in ForkBefore.
thr->ignore_interceptors--;
ScopedErrorReportLock::Unlock();
ctx->report_mtx.Unlock();
ctx->thread_registry.Unlock();
}
void ForkChildAfter(ThreadState *thr, uptr pc) NO_THREAD_SAFETY_ANALYSIS {
thr->suppress_reports--; // Enabled in ForkBefore.
thr->ignore_interceptors--;
ScopedErrorReportLock::Unlock();
ctx->report_mtx.Unlock();
ctx->thread_registry.Unlock();
uptr nthread = 0;
ctx->thread_registry.GetNumberOfThreads(0, 0, &nthread /* alive threads */);
VPrintf(1, "ThreadSanitizer: forked new process with pid %d,"
" parent had %d threads\n", (int)internal_getpid(), (int)nthread);
if (nthread == 1) {
StartBackgroundThread();
} else {
// We've just forked a multi-threaded process. We cannot reasonably function
// after that (some mutexes may be locked before fork). So just enable
// ignores for everything in the hope that we will exec soon.
ctx->after_multithreaded_fork = true;
thr->ignore_interceptors++;
ThreadIgnoreBegin(thr, pc);
ThreadIgnoreSyncBegin(thr, pc);
}
}
#endif
#if SANITIZER_GO
NOINLINE
void GrowShadowStack(ThreadState *thr) {
const int sz = thr->shadow_stack_end - thr->shadow_stack;
const int newsz = 2 * sz;
auto *newstack = (uptr *)Alloc(newsz * sizeof(uptr));
internal_memcpy(newstack, thr->shadow_stack, sz * sizeof(uptr));
Free(thr->shadow_stack);
thr->shadow_stack = newstack;
thr->shadow_stack_pos = newstack + sz;
thr->shadow_stack_end = newstack + newsz;
}
#endif
StackID CurrentStackId(ThreadState *thr, uptr pc) {
if (!thr->is_inited) // May happen during bootstrap.
return kInvalidStackID;
if (pc != 0) {
#if !SANITIZER_GO
DCHECK_LT(thr->shadow_stack_pos, thr->shadow_stack_end);
#else
if (thr->shadow_stack_pos == thr->shadow_stack_end)
GrowShadowStack(thr);
#endif
thr->shadow_stack_pos[0] = pc;
thr->shadow_stack_pos++;
}
StackID id = StackDepotPut(
StackTrace(thr->shadow_stack, thr->shadow_stack_pos - thr->shadow_stack));
if (pc != 0)
thr->shadow_stack_pos--;
return id;
}
namespace v3 {
ALWAYS_INLINE USED bool TryTraceMemoryAccess(ThreadState *thr, uptr pc,
uptr addr, uptr size,
AccessType typ) {
DCHECK(size == 1 || size == 2 || size == 4 || size == 8);
if (!kCollectHistory)
return true;
EventAccess *ev;
if (UNLIKELY(!TraceAcquire(thr, &ev)))
return false;
u64 size_log = size == 1 ? 0 : size == 2 ? 1 : size == 4 ? 2 : 3;
uptr pc_delta = pc - thr->trace_prev_pc + (1 << (EventAccess::kPCBits - 1));
thr->trace_prev_pc = pc;
if (LIKELY(pc_delta < (1 << EventAccess::kPCBits))) {
ev->is_access = 1;
ev->is_read = !!(typ & kAccessRead);
ev->is_atomic = !!(typ & kAccessAtomic);
ev->size_log = size_log;
ev->pc_delta = pc_delta;
DCHECK_EQ(ev->pc_delta, pc_delta);
ev->addr = CompressAddr(addr);
TraceRelease(thr, ev);
return true;
}
auto *evex = reinterpret_cast<EventAccessExt *>(ev);
evex->is_access = 0;
evex->is_func = 0;
evex->type = EventType::kAccessExt;
evex->is_read = !!(typ & kAccessRead);
evex->is_atomic = !!(typ & kAccessAtomic);
evex->size_log = size_log;
evex->addr = CompressAddr(addr);
evex->pc = pc;
TraceRelease(thr, evex);
return true;
}
ALWAYS_INLINE USED bool TryTraceMemoryAccessRange(ThreadState *thr, uptr pc,
uptr addr, uptr size,
AccessType typ) {
if (!kCollectHistory)
return true;
EventAccessRange *ev;
if (UNLIKELY(!TraceAcquire(thr, &ev)))
return false;
thr->trace_prev_pc = pc;
ev->is_access = 0;
ev->is_func = 0;
ev->type = EventType::kAccessRange;
ev->is_read = !!(typ & kAccessRead);
ev->is_free = !!(typ & kAccessFree);
ev->size_lo = size;
ev->pc = CompressAddr(pc);
ev->addr = CompressAddr(addr);
ev->size_hi = size >> EventAccessRange::kSizeLoBits;
TraceRelease(thr, ev);
return true;
}
void TraceMemoryAccessRange(ThreadState *thr, uptr pc, uptr addr, uptr size,
AccessType typ) {
if (LIKELY(TryTraceMemoryAccessRange(thr, pc, addr, size, typ)))
return;
TraceSwitchPart(thr);
UNUSED bool res = TryTraceMemoryAccessRange(thr, pc, addr, size, typ);
DCHECK(res);
}
void TraceFunc(ThreadState *thr, uptr pc) {
if (LIKELY(TryTraceFunc(thr, pc)))
return;
TraceSwitchPart(thr);
UNUSED bool res = TryTraceFunc(thr, pc);
DCHECK(res);
}
void TraceMutexLock(ThreadState *thr, EventType type, uptr pc, uptr addr,
StackID stk) {
DCHECK(type == EventType::kLock || type == EventType::kRLock);
if (!kCollectHistory)
return;
EventLock ev;
ev.is_access = 0;
ev.is_func = 0;
ev.type = type;
ev.pc = CompressAddr(pc);
ev.stack_lo = stk;
ev.stack_hi = stk >> EventLock::kStackIDLoBits;
ev._ = 0;
ev.addr = CompressAddr(addr);
TraceEvent(thr, ev);
}
void TraceMutexUnlock(ThreadState *thr, uptr addr) {
if (!kCollectHistory)
return;
EventUnlock ev;
ev.is_access = 0;
ev.is_func = 0;
ev.type = EventType::kUnlock;
ev._ = 0;
ev.addr = CompressAddr(addr);
TraceEvent(thr, ev);
}
void TraceTime(ThreadState *thr) {
if (!kCollectHistory)
return;
EventTime ev;
ev.is_access = 0;
ev.is_func = 0;
ev.type = EventType::kTime;
ev.sid = static_cast<u64>(thr->sid);
ev.epoch = static_cast<u64>(thr->epoch);
ev._ = 0;
TraceEvent(thr, ev);
}
NOINLINE
void TraceSwitchPart(ThreadState *thr) {
Trace *trace = &thr->tctx->trace;
Event *pos = reinterpret_cast<Event *>(atomic_load_relaxed(&thr->trace_pos));
DCHECK_EQ(reinterpret_cast<uptr>(pos + 1) & TracePart::kAlignment, 0);
auto *part = trace->parts.Back();
DPrintf("TraceSwitchPart part=%p pos=%p\n", part, pos);
if (part) {
// We can get here when we still have space in the current trace part.
// The fast-path check in TraceAcquire has false positives in the middle of
// the part. Check if we are indeed at the end of the current part or not,
// and fill any gaps with NopEvent's.
Event *end = &part->events[TracePart::kSize];
DCHECK_GE(pos, &part->events[0]);
DCHECK_LE(pos, end);
if (pos + 1 < end) {
if ((reinterpret_cast<uptr>(pos) & TracePart::kAlignment) ==
TracePart::kAlignment)
*pos++ = NopEvent;
*pos++ = NopEvent;
DCHECK_LE(pos + 2, end);
atomic_store_relaxed(&thr->trace_pos, reinterpret_cast<uptr>(pos));
// Ensure we setup trace so that the next TraceAcquire
// won't detect trace part end.
Event *ev;
CHECK(TraceAcquire(thr, &ev));
return;
}
// We are indeed at the end.
for (; pos < end; pos++) *pos = NopEvent;
}
#if !SANITIZER_GO
if (ctx->after_multithreaded_fork) {
// We just need to survive till exec.
CHECK(part);
atomic_store_relaxed(&thr->trace_pos,
reinterpret_cast<uptr>(&part->events[0]));
return;
}
#endif
part = new (MmapOrDie(sizeof(TracePart), "TracePart")) TracePart();
part->trace = trace;
thr->trace_prev_pc = 0;
{
Lock lock(&trace->mtx);
trace->parts.PushBack(part);
atomic_store_relaxed(&thr->trace_pos,
reinterpret_cast<uptr>(&part->events[0]));
}
// Make this part self-sufficient by restoring the current stack
// and mutex set in the beginning of the trace.
TraceTime(thr);
for (uptr *pos = &thr->shadow_stack[0]; pos < thr->shadow_stack_pos; pos++)
CHECK(TryTraceFunc(thr, *pos));
for (uptr i = 0; i < thr->mset.Size(); i++) {
MutexSet::Desc d = thr->mset.Get(i);
TraceMutexLock(thr, d.write ? EventType::kLock : EventType::kRLock, 0,
d.addr, d.stack_id);
}
}
} // namespace v3
void TraceSwitch(ThreadState *thr) {
#if !SANITIZER_GO
if (ctx->after_multithreaded_fork)
return;
#endif
thr->nomalloc++;
Trace *thr_trace = ThreadTrace(thr->tid);
Lock l(&thr_trace->mtx);
unsigned trace = (thr->fast_state.epoch() / kTracePartSize) % TraceParts();
TraceHeader *hdr = &thr_trace->headers[trace];
hdr->epoch0 = thr->fast_state.epoch();
ObtainCurrentStack(thr, 0, &hdr->stack0);
hdr->mset0 = thr->mset;
thr->nomalloc--;
}
Trace *ThreadTrace(Tid tid) { return (Trace *)GetThreadTraceHeader(tid); }
uptr TraceTopPC(ThreadState *thr) {
Event *events = (Event*)GetThreadTrace(thr->tid);
uptr pc = events[thr->fast_state.GetTracePos()];
return pc;
}
uptr TraceSize() {
return (uptr)(1ull << (kTracePartSizeBits + flags()->history_size + 1));
}
uptr TraceParts() {
return TraceSize() / kTracePartSize;
}
#if !SANITIZER_GO
extern "C" void __tsan_trace_switch() {
TraceSwitch(cur_thread());
}
extern "C" void __tsan_report_race() {
ReportRace(cur_thread());
}
#endif
ALWAYS_INLINE
Shadow LoadShadow(u64 *p) {
u64 raw = atomic_load((atomic_uint64_t*)p, memory_order_relaxed);
return Shadow(raw);
}
ALWAYS_INLINE
void StoreShadow(u64 *sp, u64 s) {
atomic_store((atomic_uint64_t*)sp, s, memory_order_relaxed);
}
ALWAYS_INLINE
void StoreIfNotYetStored(u64 *sp, u64 *s) {
StoreShadow(sp, *s);
*s = 0;
}
ALWAYS_INLINE
void HandleRace(ThreadState *thr, u64 *shadow_mem,
Shadow cur, Shadow old) {
thr->racy_state[0] = cur.raw();
thr->racy_state[1] = old.raw();
thr->racy_shadow_addr = shadow_mem;
#if !SANITIZER_GO
HACKY_CALL(__tsan_report_race);
#else
ReportRace(thr);
#endif
}
static inline bool HappensBefore(Shadow old, ThreadState *thr) {
return thr->clock.get(old.TidWithIgnore()) >= old.epoch();
}
ALWAYS_INLINE
void MemoryAccessImpl1(ThreadState *thr, uptr addr,
int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic,
u64 *shadow_mem, Shadow cur) {
// This potentially can live in an MMX/SSE scratch register.
// The required intrinsics are:
// __m128i _mm_move_epi64(__m128i*);
// _mm_storel_epi64(u64*, __m128i);
u64 store_word = cur.raw();
bool stored = false;
// scan all the shadow values and dispatch to 4 categories:
// same, replace, candidate and race (see comments below).
// we consider only 3 cases regarding access sizes:
// equal, intersect and not intersect. initially I considered
// larger and smaller as well, it allowed to replace some
// 'candidates' with 'same' or 'replace', but I think
// it's just not worth it (performance- and complexity-wise).
Shadow old(0);
// It release mode we manually unroll the loop,
// because empirically gcc generates better code this way.
// However, we can't afford unrolling in debug mode, because the function
// consumes almost 4K of stack. Gtest gives only 4K of stack to death test
// threads, which is not enough for the unrolled loop.
#if SANITIZER_DEBUG
for (int idx = 0; idx < 4; idx++) {
# include "tsan_update_shadow_word.inc"
}
#else
int idx = 0;
# include "tsan_update_shadow_word.inc"
idx = 1;
if (stored) {
# include "tsan_update_shadow_word.inc"
} else {
# include "tsan_update_shadow_word.inc"
}
idx = 2;
if (stored) {
# include "tsan_update_shadow_word.inc"
} else {
# include "tsan_update_shadow_word.inc"
}
idx = 3;
if (stored) {
# include "tsan_update_shadow_word.inc"
} else {
# include "tsan_update_shadow_word.inc"
}
#endif
// we did not find any races and had already stored
// the current access info, so we are done
if (LIKELY(stored))
return;
// choose a random candidate slot and replace it
StoreShadow(shadow_mem + (cur.epoch() % kShadowCnt), store_word);
return;
RACE:
HandleRace(thr, shadow_mem, cur, old);
return;
}
void UnalignedMemoryAccess(ThreadState *thr, uptr pc, uptr addr, uptr size,
AccessType typ) {
DCHECK(!(typ & kAccessAtomic));
const bool kAccessIsWrite = !(typ & kAccessRead);
const bool kIsAtomic = false;
while (size) {
int size1 = 1;
int kAccessSizeLog = kSizeLog1;
if (size >= 8 && (addr & ~7) == ((addr + 7) & ~7)) {
size1 = 8;
kAccessSizeLog = kSizeLog8;
} else if (size >= 4 && (addr & ~7) == ((addr + 3) & ~7)) {
size1 = 4;
kAccessSizeLog = kSizeLog4;
} else if (size >= 2 && (addr & ~7) == ((addr + 1) & ~7)) {
size1 = 2;
kAccessSizeLog = kSizeLog2;
}
MemoryAccess(thr, pc, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic);
addr += size1;
size -= size1;
}
}
ALWAYS_INLINE
bool ContainsSameAccessSlow(u64 *s, u64 a, u64 sync_epoch, bool is_write) {
Shadow cur(a);
for (uptr i = 0; i < kShadowCnt; i++) {
Shadow old(LoadShadow(&s[i]));
if (Shadow::Addr0AndSizeAreEqual(cur, old) &&
old.TidWithIgnore() == cur.TidWithIgnore() &&
old.epoch() > sync_epoch &&
old.IsAtomic() == cur.IsAtomic() &&
old.IsRead() <= cur.IsRead())
return true;
}
return false;
}
#if TSAN_VECTORIZE
# define SHUF(v0, v1, i0, i1, i2, i3) \
_mm_castps_si128(_mm_shuffle_ps(_mm_castsi128_ps(v0), \
_mm_castsi128_ps(v1), \
(i0)*1 + (i1)*4 + (i2)*16 + (i3)*64))
ALWAYS_INLINE
bool ContainsSameAccessFast(u64 *s, u64 a, u64 sync_epoch, bool is_write) {
// This is an optimized version of ContainsSameAccessSlow.
// load current access into access[0:63]
const m128 access = _mm_cvtsi64_si128(a);
// duplicate high part of access in addr0:
// addr0[0:31] = access[32:63]
// addr0[32:63] = access[32:63]
// addr0[64:95] = access[32:63]
// addr0[96:127] = access[32:63]
const m128 addr0 = SHUF(access, access, 1, 1, 1, 1);
// load 4 shadow slots
const m128 shadow0 = _mm_load_si128((__m128i*)s);
const m128 shadow1 = _mm_load_si128((__m128i*)s + 1);
// load high parts of 4 shadow slots into addr_vect:
// addr_vect[0:31] = shadow0[32:63]
// addr_vect[32:63] = shadow0[96:127]
// addr_vect[64:95] = shadow1[32:63]
// addr_vect[96:127] = shadow1[96:127]
m128 addr_vect = SHUF(shadow0, shadow1, 1, 3, 1, 3);
if (!is_write) {
// set IsRead bit in addr_vect
const m128 rw_mask1 = _mm_cvtsi64_si128(1<<15);
const m128 rw_mask = SHUF(rw_mask1, rw_mask1, 0, 0, 0, 0);
addr_vect = _mm_or_si128(addr_vect, rw_mask);
}
// addr0 == addr_vect?
const m128 addr_res = _mm_cmpeq_epi32(addr0, addr_vect);
// epoch1[0:63] = sync_epoch
const m128 epoch1 = _mm_cvtsi64_si128(sync_epoch);
// epoch[0:31] = sync_epoch[0:31]
// epoch[32:63] = sync_epoch[0:31]
// epoch[64:95] = sync_epoch[0:31]
// epoch[96:127] = sync_epoch[0:31]
const m128 epoch = SHUF(epoch1, epoch1, 0, 0, 0, 0);
// load low parts of shadow cell epochs into epoch_vect:
// epoch_vect[0:31] = shadow0[0:31]
// epoch_vect[32:63] = shadow0[64:95]
// epoch_vect[64:95] = shadow1[0:31]
// epoch_vect[96:127] = shadow1[64:95]
const m128 epoch_vect = SHUF(shadow0, shadow1, 0, 2, 0, 2);
// epoch_vect >= sync_epoch?
const m128 epoch_res = _mm_cmpgt_epi32(epoch_vect, epoch);
// addr_res & epoch_res
const m128 res = _mm_and_si128(addr_res, epoch_res);
// mask[0] = res[7]
// mask[1] = res[15]
// ...
// mask[15] = res[127]
const int mask = _mm_movemask_epi8(res);
return mask != 0;
}
#endif
ALWAYS_INLINE
bool ContainsSameAccess(u64 *s, u64 a, u64 sync_epoch, bool is_write) {
#if TSAN_VECTORIZE
bool res = ContainsSameAccessFast(s, a, sync_epoch, is_write);
// NOTE: this check can fail if the shadow is concurrently mutated
// by other threads. But it still can be useful if you modify
// ContainsSameAccessFast and want to ensure that it's not completely broken.
// DCHECK_EQ(res, ContainsSameAccessSlow(s, a, sync_epoch, is_write));
return res;
#else
return ContainsSameAccessSlow(s, a, sync_epoch, is_write);
#endif
}
ALWAYS_INLINE USED
void MemoryAccess(ThreadState *thr, uptr pc, uptr addr,
int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic) {
RawShadow *shadow_mem = MemToShadow(addr);
DPrintf2("#%d: MemoryAccess: @%p %p size=%d"
" is_write=%d shadow_mem=%p {%zx, %zx, %zx, %zx}\n",
(int)thr->fast_state.tid(), (void*)pc, (void*)addr,
(int)(1 << kAccessSizeLog), kAccessIsWrite, shadow_mem,
(uptr)shadow_mem[0], (uptr)shadow_mem[1],
(uptr)shadow_mem[2], (uptr)shadow_mem[3]);
#if SANITIZER_DEBUG
if (!IsAppMem(addr)) {
Printf("Access to non app mem %zx\n", addr);
DCHECK(IsAppMem(addr));
}
if (!IsShadowMem(shadow_mem)) {
Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
DCHECK(IsShadowMem(shadow_mem));
}
#endif
if (!SANITIZER_GO && !kAccessIsWrite && *shadow_mem == kShadowRodata) {
// Access to .rodata section, no races here.
// Measurements show that it can be 10-20% of all memory accesses.
return;
}
FastState fast_state = thr->fast_state;
if (UNLIKELY(fast_state.GetIgnoreBit())) {
return;
}
Shadow cur(fast_state);
cur.SetAddr0AndSizeLog(addr & 7, kAccessSizeLog);
cur.SetWrite(kAccessIsWrite);
cur.SetAtomic(kIsAtomic);
if (LIKELY(ContainsSameAccess(shadow_mem, cur.raw(),
thr->fast_synch_epoch, kAccessIsWrite))) {
return;
}
if (kCollectHistory) {
fast_state.IncrementEpoch();
thr->fast_state = fast_state;
TraceAddEvent(thr, fast_state, EventTypeMop, pc);
cur.IncrementEpoch();
}
MemoryAccessImpl1(thr, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic,
shadow_mem, cur);
}
// Called by MemoryAccessRange in tsan_rtl_thread.cpp
ALWAYS_INLINE USED
void MemoryAccessImpl(ThreadState *thr, uptr addr,
int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic,
u64 *shadow_mem, Shadow cur) {
if (LIKELY(ContainsSameAccess(shadow_mem, cur.raw(),
thr->fast_synch_epoch, kAccessIsWrite))) {
return;
}
MemoryAccessImpl1(thr, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic,
shadow_mem, cur);
}
static void MemoryRangeSet(ThreadState *thr, uptr pc, uptr addr, uptr size,
u64 val) {
(void)thr;
(void)pc;
if (size == 0)
return;
// FIXME: fix me.
uptr offset = addr % kShadowCell;
if (offset) {
offset = kShadowCell - offset;
if (size <= offset)
return;
addr += offset;
size -= offset;
}
DCHECK_EQ(addr % 8, 0);
// If a user passes some insane arguments (memset(0)),
// let it just crash as usual.
if (!IsAppMem(addr) || !IsAppMem(addr + size - 1))
return;
// Don't want to touch lots of shadow memory.
// If a program maps 10MB stack, there is no need reset the whole range.
size = (size + (kShadowCell - 1)) & ~(kShadowCell - 1);
// UnmapOrDie/MmapFixedNoReserve does not work on Windows.
if (SANITIZER_WINDOWS || size < common_flags()->clear_shadow_mmap_threshold) {
RawShadow *p = MemToShadow(addr);
CHECK(IsShadowMem(p));
CHECK(IsShadowMem(p + size * kShadowCnt / kShadowCell - 1));
// FIXME: may overwrite a part outside the region
for (uptr i = 0; i < size / kShadowCell * kShadowCnt;) {
p[i++] = val;
for (uptr j = 1; j < kShadowCnt; j++)
p[i++] = 0;
}
} else {
// The region is big, reset only beginning and end.
const uptr kPageSize = GetPageSizeCached();
RawShadow *begin = MemToShadow(addr);
RawShadow *end = begin + size / kShadowCell * kShadowCnt;
RawShadow *p = begin;
// Set at least first kPageSize/2 to page boundary.
while ((p < begin + kPageSize / kShadowSize / 2) || ((uptr)p % kPageSize)) {
*p++ = val;
for (uptr j = 1; j < kShadowCnt; j++)
*p++ = 0;
}
// Reset middle part.
RawShadow *p1 = p;
p = RoundDown(end, kPageSize);
if (!MmapFixedSuperNoReserve((uptr)p1, (uptr)p - (uptr)p1))
Die();
// Set the ending.
while (p < end) {
*p++ = val;
for (uptr j = 1; j < kShadowCnt; j++)
*p++ = 0;
}
}
}
void MemoryResetRange(ThreadState *thr, uptr pc, uptr addr, uptr size) {
MemoryRangeSet(thr, pc, addr, size, 0);
}
void MemoryRangeFreed(ThreadState *thr, uptr pc, uptr addr, uptr size) {
// Processing more than 1k (4k of shadow) is expensive,
// can cause excessive memory consumption (user does not necessary touch
// the whole range) and most likely unnecessary.
if (size > 1024)
size = 1024;
CHECK_EQ(thr->is_freeing, false);
thr->is_freeing = true;
MemoryAccessRange(thr, pc, addr, size, true);
thr->is_freeing = false;
if (kCollectHistory) {
thr->fast_state.IncrementEpoch();
TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
}
Shadow s(thr->fast_state);
s.ClearIgnoreBit();
s.MarkAsFreed();
s.SetWrite(true);
s.SetAddr0AndSizeLog(0, 3);
MemoryRangeSet(thr, pc, addr, size, s.raw());
}
void MemoryRangeImitateWrite(ThreadState *thr, uptr pc, uptr addr, uptr size) {
if (kCollectHistory) {
thr->fast_state.IncrementEpoch();
TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
}
Shadow s(thr->fast_state);
s.ClearIgnoreBit();
s.SetWrite(true);
s.SetAddr0AndSizeLog(0, 3);
MemoryRangeSet(thr, pc, addr, size, s.raw());
}
void MemoryRangeImitateWriteOrResetRange(ThreadState *thr, uptr pc, uptr addr,
uptr size) {
if (thr->ignore_reads_and_writes == 0)
MemoryRangeImitateWrite(thr, pc, addr, size);
else
MemoryResetRange(thr, pc, addr, size);
}
ALWAYS_INLINE USED
void FuncEntry(ThreadState *thr, uptr pc) {
DPrintf2("#%d: FuncEntry %p\n", (int)thr->fast_state.tid(), (void*)pc);
if (kCollectHistory) {
thr->fast_state.IncrementEpoch();
TraceAddEvent(thr, thr->fast_state, EventTypeFuncEnter, pc);
}
// Shadow stack maintenance can be replaced with
// stack unwinding during trace switch (which presumably must be faster).
DCHECK_GE(thr->shadow_stack_pos, thr->shadow_stack);
#if !SANITIZER_GO
DCHECK_LT(thr->shadow_stack_pos, thr->shadow_stack_end);
#else
if (thr->shadow_stack_pos == thr->shadow_stack_end)
GrowShadowStack(thr);
#endif
thr->shadow_stack_pos[0] = pc;
thr->shadow_stack_pos++;
}
ALWAYS_INLINE USED
void FuncExit(ThreadState *thr) {
DPrintf2("#%d: FuncExit\n", (int)thr->fast_state.tid());
if (kCollectHistory) {
thr->fast_state.IncrementEpoch();
TraceAddEvent(thr, thr->fast_state, EventTypeFuncExit, 0);
}
DCHECK_GT(thr->shadow_stack_pos, thr->shadow_stack);
#if !SANITIZER_GO
DCHECK_LT(thr->shadow_stack_pos, thr->shadow_stack_end);
#endif
thr->shadow_stack_pos--;
}
void ThreadIgnoreBegin(ThreadState *thr, uptr pc) {
DPrintf("#%d: ThreadIgnoreBegin\n", thr->tid);
thr->ignore_reads_and_writes++;
CHECK_GT(thr->ignore_reads_and_writes, 0);
thr->fast_state.SetIgnoreBit();
#if !SANITIZER_GO
if (pc && !ctx->after_multithreaded_fork)
thr->mop_ignore_set.Add(CurrentStackId(thr, pc));
#endif
}
void ThreadIgnoreEnd(ThreadState *thr) {
DPrintf("#%d: ThreadIgnoreEnd\n", thr->tid);
CHECK_GT(thr->ignore_reads_and_writes, 0);
thr->ignore_reads_and_writes--;
if (thr->ignore_reads_and_writes == 0) {
thr->fast_state.ClearIgnoreBit();
#if !SANITIZER_GO
thr->mop_ignore_set.Reset();
#endif
}
}
#if !SANITIZER_GO
extern "C" SANITIZER_INTERFACE_ATTRIBUTE
uptr __tsan_testonly_shadow_stack_current_size() {
ThreadState *thr = cur_thread();
return thr->shadow_stack_pos - thr->shadow_stack;
}
#endif
void ThreadIgnoreSyncBegin(ThreadState *thr, uptr pc) {
DPrintf("#%d: ThreadIgnoreSyncBegin\n", thr->tid);
thr->ignore_sync++;
CHECK_GT(thr->ignore_sync, 0);
#if !SANITIZER_GO
if (pc && !ctx->after_multithreaded_fork)
thr->sync_ignore_set.Add(CurrentStackId(thr, pc));
#endif
}
void ThreadIgnoreSyncEnd(ThreadState *thr) {
DPrintf("#%d: ThreadIgnoreSyncEnd\n", thr->tid);
CHECK_GT(thr->ignore_sync, 0);
thr->ignore_sync--;
#if !SANITIZER_GO
if (thr->ignore_sync == 0)
thr->sync_ignore_set.Reset();
#endif
}
bool MD5Hash::operator==(const MD5Hash &other) const {
return hash[0] == other.hash[0] && hash[1] == other.hash[1];
}
#if SANITIZER_DEBUG
void build_consistency_debug() {}
#else
void build_consistency_release() {}
#endif
} // namespace __tsan
#if SANITIZER_CHECK_DEADLOCKS
namespace __sanitizer {
using namespace __tsan;
MutexMeta mutex_meta[] = {
{MutexInvalid, "Invalid", {}},
{MutexThreadRegistry, "ThreadRegistry", {}},
{MutexTypeTrace, "Trace", {MutexLeaf}},
{MutexTypeReport, "Report", {MutexTypeSyncVar}},
{MutexTypeSyncVar, "SyncVar", {}},
{MutexTypeAnnotations, "Annotations", {}},
{MutexTypeAtExit, "AtExit", {MutexTypeSyncVar}},
{MutexTypeFired, "Fired", {MutexLeaf}},
{MutexTypeRacy, "Racy", {MutexLeaf}},
{MutexTypeGlobalProc, "GlobalProc", {}},
{},
};
void PrintMutexPC(uptr pc) { StackTrace(&pc, 1).Print(); }
} // namespace __sanitizer
#endif
#if !SANITIZER_GO
// Must be included in this file to make sure everything is inlined.
# include "tsan_interface.inc"
#endif