gcc/libsanitizer/tsan/tsan_rtl.cc

643 lines
18 KiB
C++

//===-- tsan_rtl.cc -------------------------------------------------------===//
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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_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"
volatile int __tsan_resumed = 0;
extern "C" void __tsan_resume() {
__tsan_resumed = 1;
}
namespace __tsan {
#ifndef TSAN_GO
THREADLOCAL char cur_thread_placeholder[sizeof(ThreadState)] ALIGNED(64);
#endif
static char ctx_placeholder[sizeof(Context)] ALIGNED(64);
// Can be overriden by a front-end.
bool CPP_WEAK OnFinalize(bool failed) {
return failed;
}
static Context *ctx;
Context *CTX() {
return ctx;
}
Context::Context()
: initialized()
, report_mtx(MutexTypeReport, StatMtxReport)
, nreported()
, nmissed_expected()
, thread_mtx(MutexTypeThreads, StatMtxThreads)
, racy_stacks(MBlockRacyStacks)
, racy_addresses(MBlockRacyAddresses)
, fired_suppressions(MBlockRacyAddresses) {
}
// The objects are allocated in TLS, so one may rely on zero-initialization.
ThreadState::ThreadState(Context *ctx, int tid, int unique_id, u64 epoch,
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.
// , fast_ignore_reads()
// , fast_ignore_writes()
// , in_rtl()
, shadow_stack_pos(&shadow_stack[0])
, tid(tid)
, unique_id(unique_id)
, stk_addr(stk_addr)
, stk_size(stk_size)
, tls_addr(tls_addr)
, tls_size(tls_size) {
}
ThreadContext::ThreadContext(int tid)
: tid(tid)
, unique_id()
, os_id()
, user_id()
, thr()
, status(ThreadStatusInvalid)
, detached()
, reuse_count()
, epoch0()
, epoch1()
, dead_info()
, dead_next()
, name() {
}
static void WriteMemoryProfile(char *buf, uptr buf_size, int num) {
uptr shadow = GetShadowMemoryConsumption();
int nthread = 0;
int nlivethread = 0;
uptr threadmem = 0;
{
Lock l(&ctx->thread_mtx);
for (unsigned i = 0; i < kMaxTid; i++) {
ThreadContext *tctx = ctx->threads[i];
if (tctx == 0)
continue;
nthread += 1;
threadmem += sizeof(ThreadContext);
if (tctx->status != ThreadStatusRunning)
continue;
nlivethread += 1;
threadmem += sizeof(ThreadState);
}
}
uptr nsync = 0;
uptr syncmem = CTX()->synctab.GetMemoryConsumption(&nsync);
internal_snprintf(buf, buf_size, "%d: shadow=%zuMB"
" thread=%zuMB(total=%d/live=%d)"
" sync=%zuMB(cnt=%zu)\n",
num,
shadow >> 20,
threadmem >> 20, nthread, nlivethread,
syncmem >> 20, nsync);
}
static void MemoryProfileThread(void *arg) {
ScopedInRtl in_rtl;
fd_t fd = (fd_t)(uptr)arg;
for (int i = 0; ; i++) {
InternalScopedBuffer<char> buf(4096);
WriteMemoryProfile(buf.data(), buf.size(), i);
internal_write(fd, buf.data(), internal_strlen(buf.data()));
SleepForSeconds(1);
}
}
static void InitializeMemoryProfile() {
if (flags()->profile_memory == 0 || flags()->profile_memory[0] == 0)
return;
InternalScopedBuffer<char> filename(4096);
internal_snprintf(filename.data(), filename.size(), "%s.%d",
flags()->profile_memory, GetPid());
fd_t fd = OpenFile(filename.data(), true);
if (fd == kInvalidFd) {
Printf("Failed to open memory profile file '%s'\n", &filename[0]);
Die();
}
internal_start_thread(&MemoryProfileThread, (void*)(uptr)fd);
}
static void MemoryFlushThread(void *arg) {
ScopedInRtl in_rtl;
for (int i = 0; ; i++) {
SleepForMillis(flags()->flush_memory_ms);
FlushShadowMemory();
}
}
static void InitializeMemoryFlush() {
if (flags()->flush_memory_ms == 0)
return;
if (flags()->flush_memory_ms < 100)
flags()->flush_memory_ms = 100;
internal_start_thread(&MemoryFlushThread, 0);
}
void MapShadow(uptr addr, uptr size) {
MmapFixedNoReserve(MemToShadow(addr), size * kShadowMultiplier);
}
void MapThreadTrace(uptr addr, uptr size) {
DPrintf("#0: Mapping trace at %p-%p(0x%zx)\n", addr, addr + size, size);
CHECK_GE(addr, kTraceMemBegin);
CHECK_LE(addr + size, kTraceMemBegin + kTraceMemSize);
if (addr != (uptr)MmapFixedNoReserve(addr, size)) {
Printf("FATAL: ThreadSanitizer can not mmap thread trace\n");
Die();
}
}
void Initialize(ThreadState *thr) {
// Thread safe because done before all threads exist.
static bool is_initialized = false;
if (is_initialized)
return;
is_initialized = true;
SanitizerToolName = "ThreadSanitizer";
// Install tool-specific callbacks in sanitizer_common.
SetCheckFailedCallback(TsanCheckFailed);
ScopedInRtl in_rtl;
#ifndef TSAN_GO
InitializeAllocator();
#endif
InitializeInterceptors();
const char *env = InitializePlatform();
InitializeMutex();
InitializeDynamicAnnotations();
ctx = new(ctx_placeholder) Context;
#ifndef TSAN_GO
InitializeShadowMemory();
#endif
ctx->dead_list_size = 0;
ctx->dead_list_head = 0;
ctx->dead_list_tail = 0;
InitializeFlags(&ctx->flags, env);
// Setup correct file descriptor for error reports.
if (internal_strcmp(flags()->log_path, "stdout") == 0)
__sanitizer_set_report_fd(kStdoutFd);
else if (internal_strcmp(flags()->log_path, "stderr") == 0)
__sanitizer_set_report_fd(kStderrFd);
else
__sanitizer_set_report_path(flags()->log_path);
InitializeSuppressions();
#ifndef TSAN_GO
// Initialize external symbolizer before internal threads are started.
const char *external_symbolizer = flags()->external_symbolizer_path;
if (external_symbolizer != 0 && external_symbolizer[0] != '\0') {
if (!InitializeExternalSymbolizer(external_symbolizer)) {
Printf("Failed to start external symbolizer: '%s'\n",
external_symbolizer);
Die();
}
}
#endif
InitializeMemoryProfile();
InitializeMemoryFlush();
if (ctx->flags.verbosity)
Printf("***** Running under ThreadSanitizer v2 (pid %d) *****\n",
GetPid());
// Initialize thread 0.
ctx->thread_seq = 0;
int tid = ThreadCreate(thr, 0, 0, true);
CHECK_EQ(tid, 0);
ThreadStart(thr, tid, GetPid());
CHECK_EQ(thr->in_rtl, 1);
ctx->initialized = true;
if (flags()->stop_on_start) {
Printf("ThreadSanitizer is suspended at startup (pid %d)."
" Call __tsan_resume().\n",
GetPid());
while (__tsan_resumed == 0) {}
}
}
int Finalize(ThreadState *thr) {
ScopedInRtl in_rtl;
Context *ctx = __tsan::ctx;
bool failed = false;
if (flags()->atexit_sleep_ms > 0 && ThreadCount(thr) > 1)
SleepForMillis(flags()->atexit_sleep_ms);
// Wait for pending reports.
ctx->report_mtx.Lock();
ctx->report_mtx.Unlock();
#ifndef TSAN_GO
if (ctx->flags.verbosity)
AllocatorPrintStats();
#endif
ThreadFinalize(thr);
if (ctx->nreported) {
failed = true;
#ifndef TSAN_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);
}
failed = OnFinalize(failed);
StatAggregate(ctx->stat, thr->stat);
StatOutput(ctx->stat);
return failed ? flags()->exitcode : 0;
}
#ifndef TSAN_GO
u32 CurrentStackId(ThreadState *thr, uptr pc) {
if (thr->shadow_stack_pos == 0) // May happen during bootstrap.
return 0;
if (pc) {
thr->shadow_stack_pos[0] = pc;
thr->shadow_stack_pos++;
}
u32 id = StackDepotPut(thr->shadow_stack,
thr->shadow_stack_pos - thr->shadow_stack);
if (pc)
thr->shadow_stack_pos--;
return id;
}
#endif
void TraceSwitch(ThreadState *thr) {
thr->nomalloc++;
ScopedInRtl in_rtl;
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();
hdr->stack0.ObtainCurrent(thr, 0);
hdr->mset0 = thr->mset;
thr->nomalloc--;
}
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;
}
#ifndef TSAN_GO
extern "C" void __tsan_trace_switch() {
TraceSwitch(cur_thread());
}
extern "C" void __tsan_report_race() {
ReportRace(cur_thread());
}
#endif
ALWAYS_INLINE
static Shadow LoadShadow(u64 *p) {
u64 raw = atomic_load((atomic_uint64_t*)p, memory_order_relaxed);
return Shadow(raw);
}
ALWAYS_INLINE
static void StoreShadow(u64 *sp, u64 s) {
atomic_store((atomic_uint64_t*)sp, s, memory_order_relaxed);
}
ALWAYS_INLINE
static void StoreIfNotYetStored(u64 *sp, u64 *s) {
StoreShadow(sp, *s);
*s = 0;
}
static 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;
#ifndef TSAN_GO
HACKY_CALL(__tsan_report_race);
#else
ReportRace(thr);
#endif
}
static inline bool OldIsInSameSynchEpoch(Shadow old, ThreadState *thr) {
return old.epoch() >= thr->fast_synch_epoch;
}
static inline bool HappensBefore(Shadow old, ThreadState *thr) {
return thr->clock.get(old.TidWithIgnore()) >= old.epoch();
}
ALWAYS_INLINE
void MemoryAccessImpl(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();
// 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);
if (kShadowCnt == 1) {
int idx = 0;
#include "tsan_update_shadow_word_inl.h"
} else if (kShadowCnt == 2) {
int idx = 0;
#include "tsan_update_shadow_word_inl.h"
idx = 1;
#include "tsan_update_shadow_word_inl.h"
} else if (kShadowCnt == 4) {
int idx = 0;
#include "tsan_update_shadow_word_inl.h"
idx = 1;
#include "tsan_update_shadow_word_inl.h"
idx = 2;
#include "tsan_update_shadow_word_inl.h"
idx = 3;
#include "tsan_update_shadow_word_inl.h"
} else if (kShadowCnt == 8) {
int idx = 0;
#include "tsan_update_shadow_word_inl.h"
idx = 1;
#include "tsan_update_shadow_word_inl.h"
idx = 2;
#include "tsan_update_shadow_word_inl.h"
idx = 3;
#include "tsan_update_shadow_word_inl.h"
idx = 4;
#include "tsan_update_shadow_word_inl.h"
idx = 5;
#include "tsan_update_shadow_word_inl.h"
idx = 6;
#include "tsan_update_shadow_word_inl.h"
idx = 7;
#include "tsan_update_shadow_word_inl.h"
} else {
CHECK(false);
}
// we did not find any races and had already stored
// the current access info, so we are done
if (LIKELY(store_word == 0))
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;
}
ALWAYS_INLINE
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 TSAN_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
FastState fast_state = thr->fast_state;
if (fast_state.GetIgnoreBit())
return;
fast_state.IncrementEpoch();
thr->fast_state = fast_state;
Shadow cur(fast_state);
cur.SetAddr0AndSizeLog(addr & 7, kAccessSizeLog);
cur.SetWrite(kAccessIsWrite);
cur.SetAtomic(kIsAtomic);
// We must not store to the trace if we do not store to the shadow.
// That is, this call must be moved somewhere below.
TraceAddEvent(thr, fast_state, EventTypeMop, pc);
MemoryAccessImpl(thr, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic,
shadow_mem, cur);
}
static void MemoryRangeSet(ThreadState *thr, uptr pc, uptr addr, uptr size,
u64 val) {
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;
(void)thr;
(void)pc;
// Some programs mmap like hundreds of GBs but actually used a small part.
// So, it's better to report a false positive on the memory
// then to hang here senselessly.
const uptr kMaxResetSize = 4ull*1024*1024*1024;
if (size > kMaxResetSize)
size = kMaxResetSize;
size = (size + (kShadowCell - 1)) & ~(kShadowCell - 1);
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 * kShadowCnt / kShadowCell;) {
p[i++] = val;
for (uptr j = 1; j < kShadowCnt; j++)
p[i++] = 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) {
CHECK_EQ(thr->is_freeing, false);
thr->is_freeing = true;
MemoryAccessRange(thr, pc, addr, size, true);
thr->is_freeing = false;
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) {
Shadow s(thr->fast_state);
s.ClearIgnoreBit();
s.SetWrite(true);
s.SetAddr0AndSizeLog(0, 3);
MemoryRangeSet(thr, pc, addr, size, s.raw());
}
ALWAYS_INLINE
void FuncEntry(ThreadState *thr, uptr pc) {
DCHECK_EQ(thr->in_rtl, 0);
StatInc(thr, StatFuncEnter);
DPrintf2("#%d: FuncEntry %p\n", (int)thr->fast_state.tid(), (void*)pc);
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[0]);
#ifndef TSAN_GO
DCHECK_LT(thr->shadow_stack_pos, &thr->shadow_stack[kShadowStackSize]);
#else
if (thr->shadow_stack_pos == thr->shadow_stack_end) {
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
thr->shadow_stack_pos[0] = pc;
thr->shadow_stack_pos++;
}
ALWAYS_INLINE
void FuncExit(ThreadState *thr) {
DCHECK_EQ(thr->in_rtl, 0);
StatInc(thr, StatFuncExit);
DPrintf2("#%d: FuncExit\n", (int)thr->fast_state.tid());
thr->fast_state.IncrementEpoch();
TraceAddEvent(thr, thr->fast_state, EventTypeFuncExit, 0);
DCHECK_GT(thr->shadow_stack_pos, &thr->shadow_stack[0]);
#ifndef TSAN_GO
DCHECK_LT(thr->shadow_stack_pos, &thr->shadow_stack[kShadowStackSize]);
#endif
thr->shadow_stack_pos--;
}
void IgnoreCtl(ThreadState *thr, bool write, bool begin) {
DPrintf("#%d: IgnoreCtl(%d, %d)\n", thr->tid, write, begin);
thr->ignore_reads_and_writes += begin ? 1 : -1;
CHECK_GE(thr->ignore_reads_and_writes, 0);
if (thr->ignore_reads_and_writes)
thr->fast_state.SetIgnoreBit();
else
thr->fast_state.ClearIgnoreBit();
}
bool MD5Hash::operator==(const MD5Hash &other) const {
return hash[0] == other.hash[0] && hash[1] == other.hash[1];
}
#if TSAN_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
#if TSAN_SHADOW_COUNT == 1
void build_consistency_shadow1() {}
#elif TSAN_SHADOW_COUNT == 2
void build_consistency_shadow2() {}
#elif TSAN_SHADOW_COUNT == 4
void build_consistency_shadow4() {}
#else
void build_consistency_shadow8() {}
#endif
} // namespace __tsan
#ifndef TSAN_GO
// Must be included in this file to make sure everything is inlined.
#include "tsan_interface_inl.h"
#endif