zig/lib/tsan/tsan_rtl_thread.cpp

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//===-- tsan_rtl_thread.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_placement_new.h"
#include "tsan_rtl.h"
#include "tsan_mman.h"
#include "tsan_platform.h"
#include "tsan_report.h"
#include "tsan_sync.h"
namespace __tsan {
// ThreadContext implementation.
ThreadContext::ThreadContext(int tid)
: ThreadContextBase(tid)
, thr()
, sync()
, epoch0()
, epoch1() {
}
#if !SANITIZER_GO
ThreadContext::~ThreadContext() {
}
#endif
void ThreadContext::OnDead() {
CHECK_EQ(sync.size(), 0);
}
void ThreadContext::OnJoined(void *arg) {
ThreadState *caller_thr = static_cast<ThreadState *>(arg);
AcquireImpl(caller_thr, 0, &sync);
sync.Reset(&caller_thr->proc()->clock_cache);
}
struct OnCreatedArgs {
ThreadState *thr;
uptr pc;
};
void ThreadContext::OnCreated(void *arg) {
thr = 0;
if (tid == kMainTid)
return;
OnCreatedArgs *args = static_cast<OnCreatedArgs *>(arg);
if (!args->thr) // GCD workers don't have a parent thread.
return;
args->thr->fast_state.IncrementEpoch();
// Can't increment epoch w/o writing to the trace as well.
TraceAddEvent(args->thr, args->thr->fast_state, EventTypeMop, 0);
ReleaseImpl(args->thr, 0, &sync);
creation_stack_id = CurrentStackId(args->thr, args->pc);
}
void ThreadContext::OnReset() {
CHECK_EQ(sync.size(), 0);
uptr trace_p = GetThreadTrace(tid);
ReleaseMemoryPagesToOS(trace_p, trace_p + TraceSize() * sizeof(Event));
//!!! ReleaseMemoryToOS(GetThreadTraceHeader(tid), sizeof(Trace));
}
void ThreadContext::OnDetached(void *arg) {
ThreadState *thr1 = static_cast<ThreadState*>(arg);
sync.Reset(&thr1->proc()->clock_cache);
}
struct OnStartedArgs {
ThreadState *thr;
uptr stk_addr;
uptr stk_size;
uptr tls_addr;
uptr tls_size;
};
void ThreadContext::OnStarted(void *arg) {
OnStartedArgs *args = static_cast<OnStartedArgs*>(arg);
thr = args->thr;
// RoundUp so that one trace part does not contain events
// from different threads.
epoch0 = RoundUp(epoch1 + 1, kTracePartSize);
epoch1 = (u64)-1;
new(thr) ThreadState(ctx, tid, unique_id, epoch0, reuse_count,
args->stk_addr, args->stk_size, args->tls_addr, args->tls_size);
#if !SANITIZER_GO
thr->shadow_stack = &ThreadTrace(thr->tid)->shadow_stack[0];
thr->shadow_stack_pos = thr->shadow_stack;
thr->shadow_stack_end = thr->shadow_stack + kShadowStackSize;
#else
// Setup dynamic shadow stack.
const int kInitStackSize = 8;
thr->shadow_stack = (uptr*)internal_alloc(MBlockShadowStack,
kInitStackSize * sizeof(uptr));
thr->shadow_stack_pos = thr->shadow_stack;
thr->shadow_stack_end = thr->shadow_stack + kInitStackSize;
#endif
if (common_flags()->detect_deadlocks)
thr->dd_lt = ctx->dd->CreateLogicalThread(unique_id);
thr->fast_state.SetHistorySize(flags()->history_size);
// Commit switch to the new part of the trace.
// TraceAddEvent will reset stack0/mset0 in the new part for us.
TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
thr->fast_synch_epoch = epoch0;
AcquireImpl(thr, 0, &sync);
sync.Reset(&thr->proc()->clock_cache);
thr->is_inited = true;
DPrintf("#%d: ThreadStart epoch=%zu stk_addr=%zx stk_size=%zx "
"tls_addr=%zx tls_size=%zx\n",
tid, (uptr)epoch0, args->stk_addr, args->stk_size,
args->tls_addr, args->tls_size);
}
void ThreadContext::OnFinished() {
#if SANITIZER_GO
internal_free(thr->shadow_stack);
thr->shadow_stack = nullptr;
thr->shadow_stack_pos = nullptr;
thr->shadow_stack_end = nullptr;
#endif
if (!detached) {
thr->fast_state.IncrementEpoch();
// Can't increment epoch w/o writing to the trace as well.
TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
ReleaseImpl(thr, 0, &sync);
}
epoch1 = thr->fast_state.epoch();
if (common_flags()->detect_deadlocks)
ctx->dd->DestroyLogicalThread(thr->dd_lt);
thr->clock.ResetCached(&thr->proc()->clock_cache);
#if !SANITIZER_GO
thr->last_sleep_clock.ResetCached(&thr->proc()->clock_cache);
#endif
#if !SANITIZER_GO
PlatformCleanUpThreadState(thr);
#endif
thr->~ThreadState();
thr = 0;
}
#if !SANITIZER_GO
struct ThreadLeak {
ThreadContext *tctx;
int count;
};
static void MaybeReportThreadLeak(ThreadContextBase *tctx_base, void *arg) {
Vector<ThreadLeak> &leaks = *(Vector<ThreadLeak>*)arg;
ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
if (tctx->detached || tctx->status != ThreadStatusFinished)
return;
for (uptr i = 0; i < leaks.Size(); i++) {
if (leaks[i].tctx->creation_stack_id == tctx->creation_stack_id) {
leaks[i].count++;
return;
}
}
ThreadLeak leak = {tctx, 1};
leaks.PushBack(leak);
}
#endif
#if !SANITIZER_GO
static void ReportIgnoresEnabled(ThreadContext *tctx, IgnoreSet *set) {
if (tctx->tid == kMainTid) {
Printf("ThreadSanitizer: main thread finished with ignores enabled\n");
} else {
Printf("ThreadSanitizer: thread T%d %s finished with ignores enabled,"
" created at:\n", tctx->tid, tctx->name);
PrintStack(SymbolizeStackId(tctx->creation_stack_id));
}
Printf(" One of the following ignores was not ended"
" (in order of probability)\n");
for (uptr i = 0; i < set->Size(); i++) {
Printf(" Ignore was enabled at:\n");
PrintStack(SymbolizeStackId(set->At(i)));
}
Die();
}
static void ThreadCheckIgnore(ThreadState *thr) {
if (ctx->after_multithreaded_fork)
return;
if (thr->ignore_reads_and_writes)
ReportIgnoresEnabled(thr->tctx, &thr->mop_ignore_set);
if (thr->ignore_sync)
ReportIgnoresEnabled(thr->tctx, &thr->sync_ignore_set);
}
#else
static void ThreadCheckIgnore(ThreadState *thr) {}
#endif
void ThreadFinalize(ThreadState *thr) {
ThreadCheckIgnore(thr);
#if !SANITIZER_GO
if (!ShouldReport(thr, ReportTypeThreadLeak))
return;
ThreadRegistryLock l(ctx->thread_registry);
Vector<ThreadLeak> leaks;
ctx->thread_registry->RunCallbackForEachThreadLocked(
MaybeReportThreadLeak, &leaks);
for (uptr i = 0; i < leaks.Size(); i++) {
ScopedReport rep(ReportTypeThreadLeak);
rep.AddThread(leaks[i].tctx, true);
rep.SetCount(leaks[i].count);
OutputReport(thr, rep);
}
#endif
}
int ThreadCount(ThreadState *thr) {
uptr result;
ctx->thread_registry->GetNumberOfThreads(0, 0, &result);
return (int)result;
}
int ThreadCreate(ThreadState *thr, uptr pc, uptr uid, bool detached) {
OnCreatedArgs args = { thr, pc };
u32 parent_tid = thr ? thr->tid : kInvalidTid; // No parent for GCD workers.
int tid =
ctx->thread_registry->CreateThread(uid, detached, parent_tid, &args);
DPrintf("#%d: ThreadCreate tid=%d uid=%zu\n", parent_tid, tid, uid);
return tid;
}
void ThreadStart(ThreadState *thr, int tid, tid_t os_id,
ThreadType thread_type) {
uptr stk_addr = 0;
uptr stk_size = 0;
uptr tls_addr = 0;
uptr tls_size = 0;
#if !SANITIZER_GO
if (thread_type != ThreadType::Fiber)
GetThreadStackAndTls(tid == kMainTid, &stk_addr, &stk_size, &tls_addr,
&tls_size);
if (tid != kMainTid) {
if (stk_addr && stk_size)
MemoryRangeImitateWrite(thr, /*pc=*/ 1, stk_addr, stk_size);
if (tls_addr && tls_size) ImitateTlsWrite(thr, tls_addr, tls_size);
}
#endif
ThreadRegistry *tr = ctx->thread_registry;
OnStartedArgs args = { thr, stk_addr, stk_size, tls_addr, tls_size };
tr->StartThread(tid, os_id, thread_type, &args);
tr->Lock();
thr->tctx = (ThreadContext*)tr->GetThreadLocked(tid);
tr->Unlock();
#if !SANITIZER_GO
if (ctx->after_multithreaded_fork) {
thr->ignore_interceptors++;
ThreadIgnoreBegin(thr, 0);
ThreadIgnoreSyncBegin(thr, 0);
}
#endif
}
void ThreadFinish(ThreadState *thr) {
ThreadCheckIgnore(thr);
if (thr->stk_addr && thr->stk_size)
DontNeedShadowFor(thr->stk_addr, thr->stk_size);
if (thr->tls_addr && thr->tls_size)
DontNeedShadowFor(thr->tls_addr, thr->tls_size);
thr->is_dead = true;
ctx->thread_registry->FinishThread(thr->tid);
}
struct ConsumeThreadContext {
uptr uid;
ThreadContextBase *tctx;
};
static bool ConsumeThreadByUid(ThreadContextBase *tctx, void *arg) {
ConsumeThreadContext *findCtx = (ConsumeThreadContext *)arg;
if (tctx->user_id == findCtx->uid && tctx->status != ThreadStatusInvalid) {
if (findCtx->tctx) {
// Ensure that user_id is unique. If it's not the case we are screwed.
// Something went wrong before, but now there is no way to recover.
// Returning a wrong thread is not an option, it may lead to very hard
// to debug false positives (e.g. if we join a wrong thread).
Report("ThreadSanitizer: dup thread with used id 0x%zx\n", findCtx->uid);
Die();
}
findCtx->tctx = tctx;
tctx->user_id = 0;
}
return false;
}
int ThreadConsumeTid(ThreadState *thr, uptr pc, uptr uid) {
ConsumeThreadContext findCtx = {uid, nullptr};
ctx->thread_registry->FindThread(ConsumeThreadByUid, &findCtx);
int tid = findCtx.tctx ? findCtx.tctx->tid : kInvalidTid;
DPrintf("#%d: ThreadTid uid=%zu tid=%d\n", thr->tid, uid, tid);
return tid;
}
void ThreadJoin(ThreadState *thr, uptr pc, int tid) {
CHECK_GT(tid, 0);
CHECK_LT(tid, kMaxTid);
DPrintf("#%d: ThreadJoin tid=%d\n", thr->tid, tid);
ctx->thread_registry->JoinThread(tid, thr);
}
void ThreadDetach(ThreadState *thr, uptr pc, int tid) {
CHECK_GT(tid, 0);
CHECK_LT(tid, kMaxTid);
ctx->thread_registry->DetachThread(tid, thr);
}
void ThreadNotJoined(ThreadState *thr, uptr pc, int tid, uptr uid) {
CHECK_GT(tid, 0);
CHECK_LT(tid, kMaxTid);
ctx->thread_registry->SetThreadUserId(tid, uid);
}
void ThreadSetName(ThreadState *thr, const char *name) {
ctx->thread_registry->SetThreadName(thr->tid, name);
}
void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr,
uptr size, bool is_write) {
if (size == 0)
return;
u64 *shadow_mem = (u64*)MemToShadow(addr);
DPrintf2("#%d: MemoryAccessRange: @%p %p size=%d is_write=%d\n",
thr->tid, (void*)pc, (void*)addr,
(int)size, is_write);
#if SANITIZER_DEBUG
if (!IsAppMem(addr)) {
Printf("Access to non app mem %zx\n", addr);
DCHECK(IsAppMem(addr));
}
if (!IsAppMem(addr + size - 1)) {
Printf("Access to non app mem %zx\n", addr + size - 1);
DCHECK(IsAppMem(addr + size - 1));
}
if (!IsShadowMem((uptr)shadow_mem)) {
Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
DCHECK(IsShadowMem((uptr)shadow_mem));
}
if (!IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))) {
Printf("Bad shadow addr %p (%zx)\n",
shadow_mem + size * kShadowCnt / 8 - 1, addr + size - 1);
DCHECK(IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1)));
}
#endif
if (*shadow_mem == kShadowRodata) {
DCHECK(!is_write);
// 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 (fast_state.GetIgnoreBit())
return;
fast_state.IncrementEpoch();
thr->fast_state = fast_state;
TraceAddEvent(thr, fast_state, EventTypeMop, pc);
bool unaligned = (addr % kShadowCell) != 0;
// Handle unaligned beginning, if any.
for (; addr % kShadowCell && size; addr++, size--) {
int const kAccessSizeLog = 0;
Shadow cur(fast_state);
cur.SetWrite(is_write);
cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
shadow_mem, cur);
}
if (unaligned)
shadow_mem += kShadowCnt;
// Handle middle part, if any.
for (; size >= kShadowCell; addr += kShadowCell, size -= kShadowCell) {
int const kAccessSizeLog = 3;
Shadow cur(fast_state);
cur.SetWrite(is_write);
cur.SetAddr0AndSizeLog(0, kAccessSizeLog);
MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
shadow_mem, cur);
shadow_mem += kShadowCnt;
}
// Handle ending, if any.
for (; size; addr++, size--) {
int const kAccessSizeLog = 0;
Shadow cur(fast_state);
cur.SetWrite(is_write);
cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
shadow_mem, cur);
}
}
#if !SANITIZER_GO
void FiberSwitchImpl(ThreadState *from, ThreadState *to) {
Processor *proc = from->proc();
ProcUnwire(proc, from);
ProcWire(proc, to);
set_cur_thread(to);
}
ThreadState *FiberCreate(ThreadState *thr, uptr pc, unsigned flags) {
void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadState));
ThreadState *fiber = static_cast<ThreadState *>(mem);
internal_memset(fiber, 0, sizeof(*fiber));
int tid = ThreadCreate(thr, pc, 0, true);
FiberSwitchImpl(thr, fiber);
ThreadStart(fiber, tid, 0, ThreadType::Fiber);
FiberSwitchImpl(fiber, thr);
return fiber;
}
void FiberDestroy(ThreadState *thr, uptr pc, ThreadState *fiber) {
FiberSwitchImpl(thr, fiber);
ThreadFinish(fiber);
FiberSwitchImpl(fiber, thr);
internal_free(fiber);
}
void FiberSwitch(ThreadState *thr, uptr pc,
ThreadState *fiber, unsigned flags) {
if (!(flags & FiberSwitchFlagNoSync))
Release(thr, pc, (uptr)fiber);
FiberSwitchImpl(thr, fiber);
if (!(flags & FiberSwitchFlagNoSync))
Acquire(fiber, pc, (uptr)fiber);
}
#endif
} // namespace __tsan