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gcc/libsanitizer/tsan/tsan_rtl.cpp
Martin Liska 98f792ff53 libsanitizer: merge from master.
2020-11-13 17:28:49 +01:00

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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 "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_stackdepot.h"
#include "sanitizer_common/sanitizer_placement_new.h"
#include "sanitizer_common/sanitizer_symbolizer.h"
#include "tsan_defs.h"
#include "tsan_platform.h"
#include "tsan_rtl.h"
#include "tsan_mman.h"
#include "tsan_suppressions.h"
#include "tsan_symbolize.h"
#include "ubsan/ubsan_init.h"
#ifdef __SSE3__
// <emmintrin.h> transitively includes <stdlib.h>,
// and it's prohibited to include std headers into tsan runtime.
// So we do this dirty trick.
#define _MM_MALLOC_H_INCLUDED
#define __MM_MALLOC_H
#include <emmintrin.h>
typedef __m128i m128;
#endif
volatile int __tsan_resumed = 0;
extern "C" void __tsan_resume() {
__tsan_resumed = 1;
}
namespace __tsan {
#if !SANITIZER_GO && !SANITIZER_MAC
__attribute__((tls_model("initial-exec")))
THREADLOCAL char cur_thread_placeholder[sizeof(ThreadState)] ALIGNED(64);
#endif
static char ctx_placeholder[sizeof(Context)] ALIGNED(64);
Context *ctx;
// Can be overriden by a front-end.
#ifdef TSAN_EXTERNAL_HOOKS
bool OnFinalize(bool failed);
void OnInitialize();
#else
SANITIZER_WEAK_CXX_DEFAULT_IMPL
bool OnFinalize(bool failed) {
return failed;
}
SANITIZER_WEAK_CXX_DEFAULT_IMPL
void OnInitialize() {}
#endif
static char thread_registry_placeholder[sizeof(ThreadRegistry)];
static ThreadContextBase *CreateThreadContext(u32 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.
// Unmap 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))
UnmapOrDie((void*)hdr_end, hdr + sizeof(Trace) - hdr_end);
void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadContext));
return new(mem) ThreadContext(tid);
}
#if !SANITIZER_GO
static const u32 kThreadQuarantineSize = 16;
#else
static const u32 kThreadQuarantineSize = 64;
#endif
Context::Context()
: initialized()
, report_mtx(MutexTypeReport, StatMtxReport)
, nreported()
, nmissed_expected()
, thread_registry(new(thread_registry_placeholder) ThreadRegistry(
CreateThreadContext, kMaxTid, kThreadQuarantineSize, kMaxTidReuse))
, racy_mtx(MutexTypeRacy, StatMtxRacy)
, racy_stacks()
, racy_addresses()
, fired_suppressions_mtx(MutexTypeFired, StatMtxFired)
, clock_alloc("clock allocator") {
fired_suppressions.reserve(8);
}
// The objects are allocated in TLS, so one may rely on zero-initialization.
ThreadState::ThreadState(Context *ctx, int 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
{
}
#if !SANITIZER_GO
static void MemoryProfiler(Context *ctx, fd_t fd, int i) {
uptr n_threads;
uptr n_running_threads;
ctx->thread_registry->GetNumberOfThreads(&n_threads, &n_running_threads);
InternalMmapVector<char> buf(4096);
WriteMemoryProfile(buf.data(), buf.size(), n_threads, n_running_threads);
WriteToFile(fd, buf.data(), internal_strlen(buf.data()));
}
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();
cur_thread()->ignore_interceptors++;
const u64 kMs2Ns = 1000 * 1000;
fd_t mprof_fd = kInvalidFd;
if (flags()->profile_memory && flags()->profile_memory[0]) {
if (internal_strcmp(flags()->profile_memory, "stdout") == 0) {
mprof_fd = 1;
} else if (internal_strcmp(flags()->profile_memory, "stderr") == 0) {
mprof_fd = 2;
} else {
InternalScopedString filename(kMaxPathLength);
filename.append("%s.%d", flags()->profile_memory, (int)internal_getpid());
fd_t fd = OpenFile(filename.data(), WrOnly);
if (fd == kInvalidFd) {
Printf("ThreadSanitizer: failed to open memory profile file '%s'\n",
&filename[0]);
} else {
mprof_fd = fd;
}
}
}
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();
}
}
// GetRSS can be expensive on huge programs, so don't do it every 100ms.
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;
}
// Write memory profile if requested.
if (mprof_fd != kInvalidFd)
MemoryProfiler(ctx, mprof_fd, i);
// 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(MemToShadow(addr), 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 continous 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 (%p-%p) at (%p-%p)\n",
addr, addr+size, meta_begin, meta_end);
}
void MapThreadTrace(uptr addr, uptr size, const char *name) {
DPrintf("#0: Mapping trace at %p-%p(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 (%p/%p)\n",
addr, size);
Die();
}
}
static void CheckShadowMapping() {
uptr beg, end;
for (int i = 0; GetUserRegion(i, &beg, &end); i++) {
// Skip cases for empty regions (heap definition for architectures that
// do not use 64-bit allocator).
if (beg == end)
continue;
VPrintf(3, "checking shadow region %p-%p\n", beg, end);
uptr prev = 0;
for (uptr p0 = beg; p0 <= end; p0 += (end - beg) / 4) {
for (int x = -(int)kShadowCell; x <= (int)kShadowCell; x += kShadowCell) {
const uptr p = RoundDown(p0 + x, kShadowCell);
if (p < beg || p >= end)
continue;
const uptr s = MemToShadow(p);
const uptr m = (uptr)MemToMeta(p);
VPrintf(3, " checking pointer %p: shadow=%p meta=%p\n", p, s, m);
CHECK(IsAppMem(p));
CHECK(IsShadowMem(s));
CHECK_EQ(p, ShadowToMem(s));
CHECK(IsMetaMem(m));
if (prev) {
// Ensure that shadow and meta mappings are linear within a single
// user range. Lots of code that processes memory ranges assumes it.
const uptr prev_s = MemToShadow(prev);
const uptr prev_m = (uptr)MemToMeta(prev);
CHECK_EQ(s - prev_s, (p - prev) * kShadowMultiplier);
CHECK_EQ((m - prev_m) / kMetaShadowSize,
(p - prev) / kMetaShadowCell);
}
prev = p;
}
}
}
}
#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 Initialize(ThreadState *thr) {
// Thread safe because done before all threads exist.
static bool is_initialized = false;
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.
SetCheckFailedCallback(TsanCheckFailed);
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();
CheckShadowMapping();
InitializePlatform();
InitializeMutex();
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.
int tid = ThreadCreate(thr, 0, 0, true);
CHECK_EQ(tid, 0);
ThreadStart(thr, tid, GetTid(), ThreadType::Regular);
#if TSAN_CONTAINS_UBSAN
__ubsan::InitAsPlugin();
#endif
ctx->initialized = true;
#if !SANITIZER_GO
Symbolizer::LateInitialize();
#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 (ctx->nmissed_expected) {
failed = true;
Printf("ThreadSanitizer: missed %d expected races\n",
ctx->nmissed_expected);
}
if (common_flags()->print_suppressions)
PrintMatchedSuppressions();
#if !SANITIZER_GO
if (flags()->print_benign)
PrintMatchedBenignRaces();
#endif
failed = OnFinalize(failed);
#if TSAN_COLLECT_STATS
StatAggregate(ctx->stat, thr->stat);
StatOutput(ctx->stat);
#endif
return failed ? common_flags()->exitcode : 0;
}
#if !SANITIZER_GO
void ForkBefore(ThreadState *thr, uptr pc) {
ctx->thread_registry->Lock();
ctx->report_mtx.Lock();
// Ignore memory accesses in the pthread_atfork callbacks.
// If any of them triggers a data race we will deadlock
// on the report_mtx.
// We could ignore interceptors and 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.
ThreadIgnoreBegin(thr, pc);
}
void ForkParentAfter(ThreadState *thr, uptr pc) {
ThreadIgnoreEnd(thr, pc); // Begin is in ForkBefore.
ctx->report_mtx.Unlock();
ctx->thread_registry->Unlock();
}
void ForkChildAfter(ThreadState *thr, uptr pc) {
ThreadIgnoreEnd(thr, pc); // Begin is in ForkBefore.
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;
uptr *newstack = (uptr*)internal_alloc(MBlockShadowStack,
newsz * sizeof(uptr));
internal_memcpy(newstack, thr->shadow_stack, sz * sizeof(uptr));
internal_free(thr->shadow_stack);
thr->shadow_stack = newstack;
thr->shadow_stack_pos = newstack + sz;
thr->shadow_stack_end = newstack + newsz;
}
#endif
u32 CurrentStackId(ThreadState *thr, uptr pc) {
if (!thr->is_inited) // May happen during bootstrap.
return 0;
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++;
}
u32 id = StackDepotPut(
StackTrace(thr->shadow_stack, thr->shadow_stack_pos - thr->shadow_stack));
if (pc != 0)
thr->shadow_stack_pos--;
return id;
}
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(int 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) {
StatInc(thr, StatMop);
StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
// 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_inl.h"
}
#else
int idx = 0;
#include "tsan_update_shadow_word_inl.h"
idx = 1;
if (stored) {
#include "tsan_update_shadow_word_inl.h"
} else {
#include "tsan_update_shadow_word_inl.h"
}
idx = 2;
if (stored) {
#include "tsan_update_shadow_word_inl.h"
} else {
#include "tsan_update_shadow_word_inl.h"
}
idx = 3;
if (stored) {
#include "tsan_update_shadow_word_inl.h"
} else {
#include "tsan_update_shadow_word_inl.h"
}
#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);
StatInc(thr, StatShadowReplace);
return;
RACE:
HandleRace(thr, shadow_mem, cur, old);
return;
}
void UnalignedMemoryAccess(ThreadState *thr, uptr pc, uptr addr,
int size, bool kAccessIsWrite, bool kIsAtomic) {
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 defined(__SSE3__)
#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 defined(__SSE3__)
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) {
u64 *shadow_mem = (u64*)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((uptr)shadow_mem)) {
Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
DCHECK(IsShadowMem((uptr)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.
StatInc(thr, StatMop);
StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
StatInc(thr, StatMopRodata);
return;
}
FastState fast_state = thr->fast_state;
if (UNLIKELY(fast_state.GetIgnoreBit())) {
StatInc(thr, StatMop);
StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
StatInc(thr, StatMopIgnored);
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))) {
StatInc(thr, StatMop);
StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
StatInc(thr, StatMopSame);
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))) {
StatInc(thr, StatMop);
StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
StatInc(thr, StatMopSame);
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) {
u64 *p = (u64*)MemToShadow(addr);
CHECK(IsShadowMem((uptr)p));
CHECK(IsShadowMem((uptr)(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();
u64 *begin = (u64*)MemToShadow(addr);
u64 *end = begin + size / kShadowCell * kShadowCnt;
u64 *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.
u64 *p1 = p;
p = RoundDown(end, kPageSize);
UnmapOrDie((void*)p1, (uptr)p - (uptr)p1);
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) {
StatInc(thr, StatFuncEnter);
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) {
StatInc(thr, StatFuncExit);
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, bool save_stack) {
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 (save_stack && !ctx->after_multithreaded_fork)
thr->mop_ignore_set.Add(CurrentStackId(thr, pc));
#endif
}
void ThreadIgnoreEnd(ThreadState *thr, uptr pc) {
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, bool save_stack) {
DPrintf("#%d: ThreadIgnoreSyncBegin\n", thr->tid);
thr->ignore_sync++;
CHECK_GT(thr->ignore_sync, 0);
#if !SANITIZER_GO
if (save_stack && !ctx->after_multithreaded_fork)
thr->sync_ignore_set.Add(CurrentStackId(thr, pc));
#endif
}
void ThreadIgnoreSyncEnd(ThreadState *thr, uptr pc) {
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
#if TSAN_COLLECT_STATS
void build_consistency_stats() {}
#else
void build_consistency_nostats() {}
#endif
} // namespace __tsan
#if !SANITIZER_GO
// Must be included in this file to make sure everything is inlined.
#include "tsan_interface_inl.h"
#endif
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