//===-- tsan_interceptors.cc ----------------------------------------------===// // // The LLVM Compiler Infrastructure // // 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. // // FIXME: move as many interceptors as possible into // sanitizer_common/sanitizer_common_interceptors.inc //===----------------------------------------------------------------------===// #include "sanitizer_common/sanitizer_atomic.h" #include "sanitizer_common/sanitizer_libc.h" #include "sanitizer_common/sanitizer_linux.h" #include "sanitizer_common/sanitizer_platform_limits_posix.h" #include "sanitizer_common/sanitizer_placement_new.h" #include "sanitizer_common/sanitizer_stacktrace.h" #include "sanitizer_common/sanitizer_tls_get_addr.h" #include "interception/interception.h" #include "tsan_interceptors.h" #include "tsan_interface.h" #include "tsan_platform.h" #include "tsan_suppressions.h" #include "tsan_rtl.h" #include "tsan_mman.h" #include "tsan_fd.h" #if SANITIZER_POSIX #include "sanitizer_common/sanitizer_posix.h" #endif using namespace __tsan; // NOLINT #if SANITIZER_FREEBSD || SANITIZER_MAC #define __errno_location __error #define stdout __stdoutp #define stderr __stderrp #endif #if SANITIZER_ANDROID #define __errno_location __errno #define mallopt(a, b) #endif #if SANITIZER_LINUX || SANITIZER_FREEBSD #define PTHREAD_CREATE_DETACHED 1 #elif SANITIZER_MAC #define PTHREAD_CREATE_DETACHED 2 #endif #ifdef __mips__ const int kSigCount = 129; #else const int kSigCount = 65; #endif struct my_siginfo_t { // The size is determined by looking at sizeof of real siginfo_t on linux. u64 opaque[128 / sizeof(u64)]; }; #ifdef __mips__ struct ucontext_t { u64 opaque[768 / sizeof(u64) + 1]; }; #else struct ucontext_t { // The size is determined by looking at sizeof of real ucontext_t on linux. u64 opaque[936 / sizeof(u64) + 1]; }; #endif #if defined(__x86_64__) || defined(__mips__) || SANITIZER_PPC64V1 #define PTHREAD_ABI_BASE "GLIBC_2.3.2" #elif defined(__aarch64__) || SANITIZER_PPC64V2 #define PTHREAD_ABI_BASE "GLIBC_2.17" #endif extern "C" int pthread_attr_init(void *attr); extern "C" int pthread_attr_destroy(void *attr); DECLARE_REAL(int, pthread_attr_getdetachstate, void *, void *) extern "C" int pthread_attr_setstacksize(void *attr, uptr stacksize); extern "C" int pthread_key_create(unsigned *key, void (*destructor)(void* v)); extern "C" int pthread_setspecific(unsigned key, const void *v); DECLARE_REAL(int, pthread_mutexattr_gettype, void *, void *) extern "C" int pthread_sigmask(int how, const __sanitizer_sigset_t *set, __sanitizer_sigset_t *oldset); DECLARE_REAL(int, fflush, __sanitizer_FILE *fp) DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr size) DECLARE_REAL_AND_INTERCEPTOR(void, free, void *ptr) extern "C" void *pthread_self(); extern "C" void _exit(int status); extern "C" int *__errno_location(); extern "C" int fileno_unlocked(void *stream); extern "C" int dirfd(void *dirp); #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID extern "C" int mallopt(int param, int value); #endif extern __sanitizer_FILE *stdout, *stderr; #if !SANITIZER_FREEBSD && !SANITIZER_MAC const int PTHREAD_MUTEX_RECURSIVE = 1; const int PTHREAD_MUTEX_RECURSIVE_NP = 1; #else const int PTHREAD_MUTEX_RECURSIVE = 2; const int PTHREAD_MUTEX_RECURSIVE_NP = 2; #endif const int EINVAL = 22; const int EBUSY = 16; const int EOWNERDEAD = 130; #if !SANITIZER_FREEBSD && !SANITIZER_MAC const int EPOLL_CTL_ADD = 1; #endif const int SIGILL = 4; const int SIGABRT = 6; const int SIGFPE = 8; const int SIGSEGV = 11; const int SIGPIPE = 13; const int SIGTERM = 15; #if defined(__mips__) || SANITIZER_FREEBSD || SANITIZER_MAC const int SIGBUS = 10; const int SIGSYS = 12; #else const int SIGBUS = 7; const int SIGSYS = 31; #endif void *const MAP_FAILED = (void*)-1; #if !SANITIZER_MAC const int PTHREAD_BARRIER_SERIAL_THREAD = -1; #endif const int MAP_FIXED = 0x10; typedef long long_t; // NOLINT // From /usr/include/unistd.h # define F_ULOCK 0 /* Unlock a previously locked region. */ # define F_LOCK 1 /* Lock a region for exclusive use. */ # define F_TLOCK 2 /* Test and lock a region for exclusive use. */ # define F_TEST 3 /* Test a region for other processes locks. */ #define errno (*__errno_location()) typedef void (*sighandler_t)(int sig); typedef void (*sigactionhandler_t)(int sig, my_siginfo_t *siginfo, void *uctx); #if SANITIZER_ANDROID struct sigaction_t { u32 sa_flags; union { sighandler_t sa_handler; sigactionhandler_t sa_sigaction; }; __sanitizer_sigset_t sa_mask; void (*sa_restorer)(); }; #else struct sigaction_t { #ifdef __mips__ u32 sa_flags; #endif union { sighandler_t sa_handler; sigactionhandler_t sa_sigaction; }; #if SANITIZER_FREEBSD int sa_flags; __sanitizer_sigset_t sa_mask; #elif SANITIZER_MAC __sanitizer_sigset_t sa_mask; int sa_flags; #else __sanitizer_sigset_t sa_mask; #ifndef __mips__ int sa_flags; #endif void (*sa_restorer)(); #endif }; #endif const sighandler_t SIG_DFL = (sighandler_t)0; const sighandler_t SIG_IGN = (sighandler_t)1; const sighandler_t SIG_ERR = (sighandler_t)-1; #if SANITIZER_FREEBSD || SANITIZER_MAC const int SA_SIGINFO = 0x40; const int SIG_SETMASK = 3; #elif defined(__mips__) const int SA_SIGINFO = 8; const int SIG_SETMASK = 3; #else const int SA_SIGINFO = 4; const int SIG_SETMASK = 2; #endif #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED \ (!cur_thread()->is_inited) static sigaction_t sigactions[kSigCount]; namespace __tsan { struct SignalDesc { bool armed; bool sigaction; my_siginfo_t siginfo; ucontext_t ctx; }; struct ThreadSignalContext { int int_signal_send; atomic_uintptr_t in_blocking_func; atomic_uintptr_t have_pending_signals; SignalDesc pending_signals[kSigCount]; // emptyset and oldset are too big for stack. __sanitizer_sigset_t emptyset; __sanitizer_sigset_t oldset; }; // The object is 64-byte aligned, because we want hot data to be located in // a single cache line if possible (it's accessed in every interceptor). static ALIGNED(64) char libignore_placeholder[sizeof(LibIgnore)]; static LibIgnore *libignore() { return reinterpret_cast<LibIgnore*>(&libignore_placeholder[0]); } void InitializeLibIgnore() { const SuppressionContext &supp = *Suppressions(); const uptr n = supp.SuppressionCount(); for (uptr i = 0; i < n; i++) { const Suppression *s = supp.SuppressionAt(i); if (0 == internal_strcmp(s->type, kSuppressionLib)) libignore()->AddIgnoredLibrary(s->templ); } libignore()->OnLibraryLoaded(0); } } // namespace __tsan static ThreadSignalContext *SigCtx(ThreadState *thr) { ThreadSignalContext *ctx = (ThreadSignalContext*)thr->signal_ctx; if (ctx == 0 && !thr->is_dead) { ctx = (ThreadSignalContext*)MmapOrDie(sizeof(*ctx), "ThreadSignalContext"); MemoryResetRange(thr, (uptr)&SigCtx, (uptr)ctx, sizeof(*ctx)); thr->signal_ctx = ctx; } return ctx; } #if !SANITIZER_MAC static unsigned g_thread_finalize_key; #endif ScopedInterceptor::ScopedInterceptor(ThreadState *thr, const char *fname, uptr pc) : thr_(thr) , pc_(pc) , in_ignored_lib_(false) { Initialize(thr); if (!thr_->is_inited) return; if (!thr_->ignore_interceptors) FuncEntry(thr, pc); DPrintf("#%d: intercept %s()\n", thr_->tid, fname); if (!thr_->in_ignored_lib && libignore()->IsIgnored(pc)) { in_ignored_lib_ = true; thr_->in_ignored_lib = true; ThreadIgnoreBegin(thr_, pc_); } if (flags()->ignore_interceptors_accesses) ThreadIgnoreBegin(thr_, pc_); } ScopedInterceptor::~ScopedInterceptor() { if (!thr_->is_inited) return; if (flags()->ignore_interceptors_accesses) ThreadIgnoreEnd(thr_, pc_); if (in_ignored_lib_) { thr_->in_ignored_lib = false; ThreadIgnoreEnd(thr_, pc_); } if (!thr_->ignore_interceptors) { ProcessPendingSignals(thr_); FuncExit(thr_); CheckNoLocks(thr_); } } void ScopedInterceptor::UserCallbackStart() { if (flags()->ignore_interceptors_accesses) ThreadIgnoreEnd(thr_, pc_); if (in_ignored_lib_) { thr_->in_ignored_lib = false; ThreadIgnoreEnd(thr_, pc_); } } void ScopedInterceptor::UserCallbackEnd() { if (in_ignored_lib_) { thr_->in_ignored_lib = true; ThreadIgnoreBegin(thr_, pc_); } if (flags()->ignore_interceptors_accesses) ThreadIgnoreBegin(thr_, pc_); } #define TSAN_INTERCEPT(func) INTERCEPT_FUNCTION(func) #if SANITIZER_FREEBSD # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION(func) #else # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION_VER(func, ver) #endif #define READ_STRING_OF_LEN(thr, pc, s, len, n) \ MemoryAccessRange((thr), (pc), (uptr)(s), \ common_flags()->strict_string_checks ? (len) + 1 : (n), false) #define READ_STRING(thr, pc, s, n) \ READ_STRING_OF_LEN((thr), (pc), (s), internal_strlen(s), (n)) #define BLOCK_REAL(name) (BlockingCall(thr), REAL(name)) struct BlockingCall { explicit BlockingCall(ThreadState *thr) : thr(thr) , ctx(SigCtx(thr)) { for (;;) { atomic_store(&ctx->in_blocking_func, 1, memory_order_relaxed); if (atomic_load(&ctx->have_pending_signals, memory_order_relaxed) == 0) break; atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed); ProcessPendingSignals(thr); } // When we are in a "blocking call", we process signals asynchronously // (right when they arrive). In this context we do not expect to be // executing any user/runtime code. The known interceptor sequence when // this is not true is: pthread_join -> munmap(stack). It's fine // to ignore munmap in this case -- we handle stack shadow separately. thr->ignore_interceptors++; } ~BlockingCall() { thr->ignore_interceptors--; atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed); } ThreadState *thr; ThreadSignalContext *ctx; }; TSAN_INTERCEPTOR(unsigned, sleep, unsigned sec) { SCOPED_TSAN_INTERCEPTOR(sleep, sec); unsigned res = BLOCK_REAL(sleep)(sec); AfterSleep(thr, pc); return res; } TSAN_INTERCEPTOR(int, usleep, long_t usec) { SCOPED_TSAN_INTERCEPTOR(usleep, usec); int res = BLOCK_REAL(usleep)(usec); AfterSleep(thr, pc); return res; } TSAN_INTERCEPTOR(int, nanosleep, void *req, void *rem) { SCOPED_TSAN_INTERCEPTOR(nanosleep, req, rem); int res = BLOCK_REAL(nanosleep)(req, rem); AfterSleep(thr, pc); return res; } // The sole reason tsan wraps atexit callbacks is to establish synchronization // between callback setup and callback execution. struct AtExitCtx { void (*f)(); void *arg; }; static void at_exit_wrapper(void *arg) { ThreadState *thr = cur_thread(); uptr pc = 0; Acquire(thr, pc, (uptr)arg); AtExitCtx *ctx = (AtExitCtx*)arg; ((void(*)(void *arg))ctx->f)(ctx->arg); InternalFree(ctx); } static int setup_at_exit_wrapper(ThreadState *thr, uptr pc, void(*f)(), void *arg, void *dso); #if !SANITIZER_ANDROID TSAN_INTERCEPTOR(int, atexit, void (*f)()) { if (cur_thread()->in_symbolizer) return 0; // We want to setup the atexit callback even if we are in ignored lib // or after fork. SCOPED_INTERCEPTOR_RAW(atexit, f); return setup_at_exit_wrapper(thr, pc, (void(*)())f, 0, 0); } #endif TSAN_INTERCEPTOR(int, __cxa_atexit, void (*f)(void *a), void *arg, void *dso) { if (cur_thread()->in_symbolizer) return 0; SCOPED_TSAN_INTERCEPTOR(__cxa_atexit, f, arg, dso); return setup_at_exit_wrapper(thr, pc, (void(*)())f, arg, dso); } static int setup_at_exit_wrapper(ThreadState *thr, uptr pc, void(*f)(), void *arg, void *dso) { AtExitCtx *ctx = (AtExitCtx*)InternalAlloc(sizeof(AtExitCtx)); ctx->f = f; ctx->arg = arg; Release(thr, pc, (uptr)ctx); // Memory allocation in __cxa_atexit will race with free during exit, // because we do not see synchronization around atexit callback list. ThreadIgnoreBegin(thr, pc); int res = REAL(__cxa_atexit)(at_exit_wrapper, ctx, dso); ThreadIgnoreEnd(thr, pc); return res; } #if !SANITIZER_MAC static void on_exit_wrapper(int status, void *arg) { ThreadState *thr = cur_thread(); uptr pc = 0; Acquire(thr, pc, (uptr)arg); AtExitCtx *ctx = (AtExitCtx*)arg; ((void(*)(int status, void *arg))ctx->f)(status, ctx->arg); InternalFree(ctx); } TSAN_INTERCEPTOR(int, on_exit, void(*f)(int, void*), void *arg) { if (cur_thread()->in_symbolizer) return 0; SCOPED_TSAN_INTERCEPTOR(on_exit, f, arg); AtExitCtx *ctx = (AtExitCtx*)InternalAlloc(sizeof(AtExitCtx)); ctx->f = (void(*)())f; ctx->arg = arg; Release(thr, pc, (uptr)ctx); // Memory allocation in __cxa_atexit will race with free during exit, // because we do not see synchronization around atexit callback list. ThreadIgnoreBegin(thr, pc); int res = REAL(on_exit)(on_exit_wrapper, ctx); ThreadIgnoreEnd(thr, pc); return res; } #endif // Cleanup old bufs. static void JmpBufGarbageCollect(ThreadState *thr, uptr sp) { for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) { JmpBuf *buf = &thr->jmp_bufs[i]; if (buf->sp <= sp) { uptr sz = thr->jmp_bufs.Size(); internal_memcpy(buf, &thr->jmp_bufs[sz - 1], sizeof(*buf)); thr->jmp_bufs.PopBack(); i--; } } } static void SetJmp(ThreadState *thr, uptr sp, uptr mangled_sp) { if (!thr->is_inited) // called from libc guts during bootstrap return; // Cleanup old bufs. JmpBufGarbageCollect(thr, sp); // Remember the buf. JmpBuf *buf = thr->jmp_bufs.PushBack(); buf->sp = sp; buf->mangled_sp = mangled_sp; buf->shadow_stack_pos = thr->shadow_stack_pos; ThreadSignalContext *sctx = SigCtx(thr); buf->int_signal_send = sctx ? sctx->int_signal_send : 0; buf->in_blocking_func = sctx ? atomic_load(&sctx->in_blocking_func, memory_order_relaxed) : false; buf->in_signal_handler = atomic_load(&thr->in_signal_handler, memory_order_relaxed); } static void LongJmp(ThreadState *thr, uptr *env) { #ifdef __powerpc__ uptr mangled_sp = env[0]; #elif SANITIZER_FREEBSD || SANITIZER_MAC uptr mangled_sp = env[2]; #elif defined(SANITIZER_LINUX) # ifdef __aarch64__ uptr mangled_sp = env[13]; # else uptr mangled_sp = env[6]; # endif #endif // Find the saved buf by mangled_sp. for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) { JmpBuf *buf = &thr->jmp_bufs[i]; if (buf->mangled_sp == mangled_sp) { CHECK_GE(thr->shadow_stack_pos, buf->shadow_stack_pos); // Unwind the stack. while (thr->shadow_stack_pos > buf->shadow_stack_pos) FuncExit(thr); ThreadSignalContext *sctx = SigCtx(thr); if (sctx) { sctx->int_signal_send = buf->int_signal_send; atomic_store(&sctx->in_blocking_func, buf->in_blocking_func, memory_order_relaxed); } atomic_store(&thr->in_signal_handler, buf->in_signal_handler, memory_order_relaxed); JmpBufGarbageCollect(thr, buf->sp - 1); // do not collect buf->sp return; } } Printf("ThreadSanitizer: can't find longjmp buf\n"); CHECK(0); } // FIXME: put everything below into a common extern "C" block? extern "C" void __tsan_setjmp(uptr sp, uptr mangled_sp) { SetJmp(cur_thread(), sp, mangled_sp); } #if SANITIZER_MAC TSAN_INTERCEPTOR(int, setjmp, void *env); TSAN_INTERCEPTOR(int, _setjmp, void *env); TSAN_INTERCEPTOR(int, sigsetjmp, void *env); #else // SANITIZER_MAC // Not called. Merely to satisfy TSAN_INTERCEPT(). extern "C" SANITIZER_INTERFACE_ATTRIBUTE int __interceptor_setjmp(void *env); extern "C" int __interceptor_setjmp(void *env) { CHECK(0); return 0; } // FIXME: any reason to have a separate declaration? extern "C" SANITIZER_INTERFACE_ATTRIBUTE int __interceptor__setjmp(void *env); extern "C" int __interceptor__setjmp(void *env) { CHECK(0); return 0; } extern "C" SANITIZER_INTERFACE_ATTRIBUTE int __interceptor_sigsetjmp(void *env); extern "C" int __interceptor_sigsetjmp(void *env) { CHECK(0); return 0; } extern "C" SANITIZER_INTERFACE_ATTRIBUTE int __interceptor___sigsetjmp(void *env); extern "C" int __interceptor___sigsetjmp(void *env) { CHECK(0); return 0; } extern "C" int setjmp(void *env); extern "C" int _setjmp(void *env); extern "C" int sigsetjmp(void *env); extern "C" int __sigsetjmp(void *env); DEFINE_REAL(int, setjmp, void *env) DEFINE_REAL(int, _setjmp, void *env) DEFINE_REAL(int, sigsetjmp, void *env) DEFINE_REAL(int, __sigsetjmp, void *env) #endif // SANITIZER_MAC TSAN_INTERCEPTOR(void, longjmp, uptr *env, int val) { // Note: if we call REAL(longjmp) in the context of ScopedInterceptor, // bad things will happen. We will jump over ScopedInterceptor dtor and can // leave thr->in_ignored_lib set. { SCOPED_INTERCEPTOR_RAW(longjmp, env, val); } LongJmp(cur_thread(), env); REAL(longjmp)(env, val); } TSAN_INTERCEPTOR(void, siglongjmp, uptr *env, int val) { { SCOPED_INTERCEPTOR_RAW(siglongjmp, env, val); } LongJmp(cur_thread(), env); REAL(siglongjmp)(env, val); } #if !SANITIZER_MAC TSAN_INTERCEPTOR(void*, malloc, uptr size) { if (cur_thread()->in_symbolizer) return InternalAlloc(size); void *p = 0; { SCOPED_INTERCEPTOR_RAW(malloc, size); p = user_alloc(thr, pc, size); } invoke_malloc_hook(p, size); return p; } TSAN_INTERCEPTOR(void*, __libc_memalign, uptr align, uptr sz) { SCOPED_TSAN_INTERCEPTOR(__libc_memalign, align, sz); return user_alloc(thr, pc, sz, align); } TSAN_INTERCEPTOR(void*, calloc, uptr size, uptr n) { if (cur_thread()->in_symbolizer) return InternalCalloc(size, n); void *p = 0; { SCOPED_INTERCEPTOR_RAW(calloc, size, n); p = user_calloc(thr, pc, size, n); } invoke_malloc_hook(p, n * size); return p; } TSAN_INTERCEPTOR(void*, realloc, void *p, uptr size) { if (cur_thread()->in_symbolizer) return InternalRealloc(p, size); if (p) invoke_free_hook(p); { SCOPED_INTERCEPTOR_RAW(realloc, p, size); p = user_realloc(thr, pc, p, size); } invoke_malloc_hook(p, size); return p; } TSAN_INTERCEPTOR(void, free, void *p) { if (p == 0) return; if (cur_thread()->in_symbolizer) return InternalFree(p); invoke_free_hook(p); SCOPED_INTERCEPTOR_RAW(free, p); user_free(thr, pc, p); } TSAN_INTERCEPTOR(void, cfree, void *p) { if (p == 0) return; if (cur_thread()->in_symbolizer) return InternalFree(p); invoke_free_hook(p); SCOPED_INTERCEPTOR_RAW(cfree, p); user_free(thr, pc, p); } TSAN_INTERCEPTOR(uptr, malloc_usable_size, void *p) { SCOPED_INTERCEPTOR_RAW(malloc_usable_size, p); return user_alloc_usable_size(p); } #endif TSAN_INTERCEPTOR(char*, strcpy, char *dst, const char *src) { // NOLINT SCOPED_TSAN_INTERCEPTOR(strcpy, dst, src); // NOLINT uptr srclen = internal_strlen(src); MemoryAccessRange(thr, pc, (uptr)dst, srclen + 1, true); MemoryAccessRange(thr, pc, (uptr)src, srclen + 1, false); return REAL(strcpy)(dst, src); // NOLINT } TSAN_INTERCEPTOR(char*, strncpy, char *dst, char *src, uptr n) { SCOPED_TSAN_INTERCEPTOR(strncpy, dst, src, n); uptr srclen = internal_strnlen(src, n); MemoryAccessRange(thr, pc, (uptr)dst, n, true); MemoryAccessRange(thr, pc, (uptr)src, min(srclen + 1, n), false); return REAL(strncpy)(dst, src, n); } TSAN_INTERCEPTOR(char*, strdup, const char *str) { SCOPED_TSAN_INTERCEPTOR(strdup, str); // strdup will call malloc, so no instrumentation is required here. return REAL(strdup)(str); } static bool fix_mmap_addr(void **addr, long_t sz, int flags) { if (*addr) { if (!IsAppMem((uptr)*addr) || !IsAppMem((uptr)*addr + sz - 1)) { if (flags & MAP_FIXED) { errno = EINVAL; return false; } else { *addr = 0; } } } return true; } TSAN_INTERCEPTOR(void *, mmap, void *addr, SIZE_T sz, int prot, int flags, int fd, OFF_T off) { SCOPED_TSAN_INTERCEPTOR(mmap, addr, sz, prot, flags, fd, off); if (!fix_mmap_addr(&addr, sz, flags)) return MAP_FAILED; void *res = REAL(mmap)(addr, sz, prot, flags, fd, off); if (res != MAP_FAILED) { if (fd > 0) FdAccess(thr, pc, fd); if (thr->ignore_reads_and_writes == 0) MemoryRangeImitateWrite(thr, pc, (uptr)res, sz); else MemoryResetRange(thr, pc, (uptr)res, sz); } return res; } #if SANITIZER_LINUX TSAN_INTERCEPTOR(void *, mmap64, void *addr, SIZE_T sz, int prot, int flags, int fd, OFF64_T off) { SCOPED_TSAN_INTERCEPTOR(mmap64, addr, sz, prot, flags, fd, off); if (!fix_mmap_addr(&addr, sz, flags)) return MAP_FAILED; void *res = REAL(mmap64)(addr, sz, prot, flags, fd, off); if (res != MAP_FAILED) { if (fd > 0) FdAccess(thr, pc, fd); if (thr->ignore_reads_and_writes == 0) MemoryRangeImitateWrite(thr, pc, (uptr)res, sz); else MemoryResetRange(thr, pc, (uptr)res, sz); } return res; } #define TSAN_MAYBE_INTERCEPT_MMAP64 TSAN_INTERCEPT(mmap64) #else #define TSAN_MAYBE_INTERCEPT_MMAP64 #endif TSAN_INTERCEPTOR(int, munmap, void *addr, long_t sz) { SCOPED_TSAN_INTERCEPTOR(munmap, addr, sz); if (sz != 0) { // If sz == 0, munmap will return EINVAL and don't unmap any memory. DontNeedShadowFor((uptr)addr, sz); ScopedGlobalProcessor sgp; ctx->metamap.ResetRange(thr->proc(), (uptr)addr, (uptr)sz); } int res = REAL(munmap)(addr, sz); return res; } #if SANITIZER_LINUX TSAN_INTERCEPTOR(void*, memalign, uptr align, uptr sz) { SCOPED_INTERCEPTOR_RAW(memalign, align, sz); return user_alloc(thr, pc, sz, align); } #define TSAN_MAYBE_INTERCEPT_MEMALIGN TSAN_INTERCEPT(memalign) #else #define TSAN_MAYBE_INTERCEPT_MEMALIGN #endif #if !SANITIZER_MAC TSAN_INTERCEPTOR(void*, aligned_alloc, uptr align, uptr sz) { SCOPED_INTERCEPTOR_RAW(memalign, align, sz); return user_alloc(thr, pc, sz, align); } TSAN_INTERCEPTOR(void*, valloc, uptr sz) { SCOPED_INTERCEPTOR_RAW(valloc, sz); return user_alloc(thr, pc, sz, GetPageSizeCached()); } #endif #if SANITIZER_LINUX TSAN_INTERCEPTOR(void*, pvalloc, uptr sz) { SCOPED_INTERCEPTOR_RAW(pvalloc, sz); sz = RoundUp(sz, GetPageSizeCached()); return user_alloc(thr, pc, sz, GetPageSizeCached()); } #define TSAN_MAYBE_INTERCEPT_PVALLOC TSAN_INTERCEPT(pvalloc) #else #define TSAN_MAYBE_INTERCEPT_PVALLOC #endif #if !SANITIZER_MAC TSAN_INTERCEPTOR(int, posix_memalign, void **memptr, uptr align, uptr sz) { SCOPED_INTERCEPTOR_RAW(posix_memalign, memptr, align, sz); *memptr = user_alloc(thr, pc, sz, align); return 0; } #endif // __cxa_guard_acquire and friends need to be intercepted in a special way - // regular interceptors will break statically-linked libstdc++. Linux // interceptors are especially defined as weak functions (so that they don't // cause link errors when user defines them as well). So they silently // auto-disable themselves when such symbol is already present in the binary. If // we link libstdc++ statically, it will bring own __cxa_guard_acquire which // will silently replace our interceptor. That's why on Linux we simply export // these interceptors with INTERFACE_ATTRIBUTE. // On OS X, we don't support statically linking, so we just use a regular // interceptor. #if SANITIZER_MAC #define STDCXX_INTERCEPTOR TSAN_INTERCEPTOR #else #define STDCXX_INTERCEPTOR(rettype, name, ...) \ extern "C" rettype INTERFACE_ATTRIBUTE name(__VA_ARGS__) #endif // Used in thread-safe function static initialization. STDCXX_INTERCEPTOR(int, __cxa_guard_acquire, atomic_uint32_t *g) { SCOPED_INTERCEPTOR_RAW(__cxa_guard_acquire, g); for (;;) { u32 cmp = atomic_load(g, memory_order_acquire); if (cmp == 0) { if (atomic_compare_exchange_strong(g, &cmp, 1<<16, memory_order_relaxed)) return 1; } else if (cmp == 1) { Acquire(thr, pc, (uptr)g); return 0; } else { internal_sched_yield(); } } } STDCXX_INTERCEPTOR(void, __cxa_guard_release, atomic_uint32_t *g) { SCOPED_INTERCEPTOR_RAW(__cxa_guard_release, g); Release(thr, pc, (uptr)g); atomic_store(g, 1, memory_order_release); } STDCXX_INTERCEPTOR(void, __cxa_guard_abort, atomic_uint32_t *g) { SCOPED_INTERCEPTOR_RAW(__cxa_guard_abort, g); atomic_store(g, 0, memory_order_relaxed); } namespace __tsan { void DestroyThreadState() { ThreadState *thr = cur_thread(); Processor *proc = thr->proc(); ThreadFinish(thr); ProcUnwire(proc, thr); ProcDestroy(proc); ThreadSignalContext *sctx = thr->signal_ctx; if (sctx) { thr->signal_ctx = 0; UnmapOrDie(sctx, sizeof(*sctx)); } DTLS_Destroy(); cur_thread_finalize(); } } // namespace __tsan #if !SANITIZER_MAC static void thread_finalize(void *v) { uptr iter = (uptr)v; if (iter > 1) { if (pthread_setspecific(g_thread_finalize_key, (void*)(iter - 1))) { Printf("ThreadSanitizer: failed to set thread key\n"); Die(); } return; } DestroyThreadState(); } #endif struct ThreadParam { void* (*callback)(void *arg); void *param; atomic_uintptr_t tid; }; extern "C" void *__tsan_thread_start_func(void *arg) { ThreadParam *p = (ThreadParam*)arg; void* (*callback)(void *arg) = p->callback; void *param = p->param; int tid = 0; { ThreadState *thr = cur_thread(); // Thread-local state is not initialized yet. ScopedIgnoreInterceptors ignore; #if !SANITIZER_MAC ThreadIgnoreBegin(thr, 0); if (pthread_setspecific(g_thread_finalize_key, (void *)GetPthreadDestructorIterations())) { Printf("ThreadSanitizer: failed to set thread key\n"); Die(); } ThreadIgnoreEnd(thr, 0); #endif while ((tid = atomic_load(&p->tid, memory_order_acquire)) == 0) internal_sched_yield(); Processor *proc = ProcCreate(); ProcWire(proc, thr); ThreadStart(thr, tid, GetTid()); atomic_store(&p->tid, 0, memory_order_release); } void *res = callback(param); // Prevent the callback from being tail called, // it mixes up stack traces. volatile int foo = 42; foo++; return res; } TSAN_INTERCEPTOR(int, pthread_create, void *th, void *attr, void *(*callback)(void*), void * param) { SCOPED_INTERCEPTOR_RAW(pthread_create, th, attr, callback, param); if (ctx->after_multithreaded_fork) { if (flags()->die_after_fork) { Report("ThreadSanitizer: starting new threads after multi-threaded " "fork is not supported. Dying (set die_after_fork=0 to override)\n"); Die(); } else { VPrintf(1, "ThreadSanitizer: starting new threads after multi-threaded " "fork is not supported (pid %d). Continuing because of " "die_after_fork=0, but you are on your own\n", internal_getpid()); } } __sanitizer_pthread_attr_t myattr; if (attr == 0) { pthread_attr_init(&myattr); attr = &myattr; } int detached = 0; REAL(pthread_attr_getdetachstate)(attr, &detached); AdjustStackSize(attr); ThreadParam p; p.callback = callback; p.param = param; atomic_store(&p.tid, 0, memory_order_relaxed); int res = -1; { // Otherwise we see false positives in pthread stack manipulation. ScopedIgnoreInterceptors ignore; ThreadIgnoreBegin(thr, pc); res = REAL(pthread_create)(th, attr, __tsan_thread_start_func, &p); ThreadIgnoreEnd(thr, pc); } if (res == 0) { int tid = ThreadCreate(thr, pc, *(uptr*)th, detached == PTHREAD_CREATE_DETACHED); CHECK_NE(tid, 0); // Synchronization on p.tid serves two purposes: // 1. ThreadCreate must finish before the new thread starts. // Otherwise the new thread can call pthread_detach, but the pthread_t // identifier is not yet registered in ThreadRegistry by ThreadCreate. // 2. ThreadStart must finish before this thread continues. // Otherwise, this thread can call pthread_detach and reset thr->sync // before the new thread got a chance to acquire from it in ThreadStart. atomic_store(&p.tid, tid, memory_order_release); while (atomic_load(&p.tid, memory_order_acquire) != 0) internal_sched_yield(); } if (attr == &myattr) pthread_attr_destroy(&myattr); return res; } TSAN_INTERCEPTOR(int, pthread_join, void *th, void **ret) { SCOPED_INTERCEPTOR_RAW(pthread_join, th, ret); int tid = ThreadTid(thr, pc, (uptr)th); ThreadIgnoreBegin(thr, pc); int res = BLOCK_REAL(pthread_join)(th, ret); ThreadIgnoreEnd(thr, pc); if (res == 0) { ThreadJoin(thr, pc, tid); } return res; } DEFINE_REAL_PTHREAD_FUNCTIONS TSAN_INTERCEPTOR(int, pthread_detach, void *th) { SCOPED_TSAN_INTERCEPTOR(pthread_detach, th); int tid = ThreadTid(thr, pc, (uptr)th); int res = REAL(pthread_detach)(th); if (res == 0) { ThreadDetach(thr, pc, tid); } return res; } // Problem: // NPTL implementation of pthread_cond has 2 versions (2.2.5 and 2.3.2). // pthread_cond_t has different size in the different versions. // If call new REAL functions for old pthread_cond_t, they will corrupt memory // after pthread_cond_t (old cond is smaller). // If we call old REAL functions for new pthread_cond_t, we will lose some // functionality (e.g. old functions do not support waiting against // CLOCK_REALTIME). // Proper handling would require to have 2 versions of interceptors as well. // But this is messy, in particular requires linker scripts when sanitizer // runtime is linked into a shared library. // Instead we assume we don't have dynamic libraries built against old // pthread (2.2.5 is dated by 2002). And provide legacy_pthread_cond flag // that allows to work with old libraries (but this mode does not support // some features, e.g. pthread_condattr_getpshared). static void *init_cond(void *c, bool force = false) { // sizeof(pthread_cond_t) >= sizeof(uptr) in both versions. // So we allocate additional memory on the side large enough to hold // any pthread_cond_t object. Always call new REAL functions, but pass // the aux object to them. // Note: the code assumes that PTHREAD_COND_INITIALIZER initializes // first word of pthread_cond_t to zero. // It's all relevant only for linux. if (!common_flags()->legacy_pthread_cond) return c; atomic_uintptr_t *p = (atomic_uintptr_t*)c; uptr cond = atomic_load(p, memory_order_acquire); if (!force && cond != 0) return (void*)cond; void *newcond = WRAP(malloc)(pthread_cond_t_sz); internal_memset(newcond, 0, pthread_cond_t_sz); if (atomic_compare_exchange_strong(p, &cond, (uptr)newcond, memory_order_acq_rel)) return newcond; WRAP(free)(newcond); return (void*)cond; } struct CondMutexUnlockCtx { ScopedInterceptor *si; ThreadState *thr; uptr pc; void *m; }; static void cond_mutex_unlock(CondMutexUnlockCtx *arg) { // pthread_cond_wait interceptor has enabled async signal delivery // (see BlockingCall below). Disable async signals since we are running // tsan code. Also ScopedInterceptor and BlockingCall destructors won't run // since the thread is cancelled, so we have to manually execute them // (the thread still can run some user code due to pthread_cleanup_push). ThreadSignalContext *ctx = SigCtx(arg->thr); CHECK_EQ(atomic_load(&ctx->in_blocking_func, memory_order_relaxed), 1); atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed); MutexLock(arg->thr, arg->pc, (uptr)arg->m); // Undo BlockingCall ctor effects. arg->thr->ignore_interceptors--; arg->si->~ScopedInterceptor(); } INTERCEPTOR(int, pthread_cond_init, void *c, void *a) { void *cond = init_cond(c, true); SCOPED_TSAN_INTERCEPTOR(pthread_cond_init, cond, a); MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), true); return REAL(pthread_cond_init)(cond, a); } static int cond_wait(ThreadState *thr, uptr pc, ScopedInterceptor *si, int (*fn)(void *c, void *m, void *abstime), void *c, void *m, void *t) { MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false); MutexUnlock(thr, pc, (uptr)m); CondMutexUnlockCtx arg = {si, thr, pc, m}; int res = 0; // This ensures that we handle mutex lock even in case of pthread_cancel. // See test/tsan/cond_cancel.cc. { // Enable signal delivery while the thread is blocked. BlockingCall bc(thr); res = call_pthread_cancel_with_cleanup( fn, c, m, t, (void (*)(void *arg))cond_mutex_unlock, &arg); } if (res == errno_EOWNERDEAD) MutexRepair(thr, pc, (uptr)m); MutexLock(thr, pc, (uptr)m); return res; } INTERCEPTOR(int, pthread_cond_wait, void *c, void *m) { void *cond = init_cond(c); SCOPED_TSAN_INTERCEPTOR(pthread_cond_wait, cond, m); return cond_wait(thr, pc, &si, (int (*)(void *c, void *m, void *abstime))REAL( pthread_cond_wait), cond, m, 0); } INTERCEPTOR(int, pthread_cond_timedwait, void *c, void *m, void *abstime) { void *cond = init_cond(c); SCOPED_TSAN_INTERCEPTOR(pthread_cond_timedwait, cond, m, abstime); return cond_wait(thr, pc, &si, REAL(pthread_cond_timedwait), cond, m, abstime); } #if SANITIZER_MAC INTERCEPTOR(int, pthread_cond_timedwait_relative_np, void *c, void *m, void *reltime) { void *cond = init_cond(c); SCOPED_TSAN_INTERCEPTOR(pthread_cond_timedwait_relative_np, cond, m, reltime); return cond_wait(thr, pc, &si, REAL(pthread_cond_timedwait_relative_np), cond, m, reltime); } #endif INTERCEPTOR(int, pthread_cond_signal, void *c) { void *cond = init_cond(c); SCOPED_TSAN_INTERCEPTOR(pthread_cond_signal, cond); MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false); return REAL(pthread_cond_signal)(cond); } INTERCEPTOR(int, pthread_cond_broadcast, void *c) { void *cond = init_cond(c); SCOPED_TSAN_INTERCEPTOR(pthread_cond_broadcast, cond); MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false); return REAL(pthread_cond_broadcast)(cond); } INTERCEPTOR(int, pthread_cond_destroy, void *c) { void *cond = init_cond(c); SCOPED_TSAN_INTERCEPTOR(pthread_cond_destroy, cond); MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), true); int res = REAL(pthread_cond_destroy)(cond); if (common_flags()->legacy_pthread_cond) { // Free our aux cond and zero the pointer to not leave dangling pointers. WRAP(free)(cond); atomic_store((atomic_uintptr_t*)c, 0, memory_order_relaxed); } return res; } TSAN_INTERCEPTOR(int, pthread_mutex_init, void *m, void *a) { SCOPED_TSAN_INTERCEPTOR(pthread_mutex_init, m, a); int res = REAL(pthread_mutex_init)(m, a); if (res == 0) { bool recursive = false; if (a) { int type = 0; if (REAL(pthread_mutexattr_gettype)(a, &type) == 0) recursive = (type == PTHREAD_MUTEX_RECURSIVE || type == PTHREAD_MUTEX_RECURSIVE_NP); } MutexCreate(thr, pc, (uptr)m, false, recursive, false); } return res; } TSAN_INTERCEPTOR(int, pthread_mutex_destroy, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_mutex_destroy, m); int res = REAL(pthread_mutex_destroy)(m); if (res == 0 || res == EBUSY) { MutexDestroy(thr, pc, (uptr)m); } return res; } TSAN_INTERCEPTOR(int, pthread_mutex_trylock, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_mutex_trylock, m); int res = REAL(pthread_mutex_trylock)(m); if (res == EOWNERDEAD) MutexRepair(thr, pc, (uptr)m); if (res == 0 || res == EOWNERDEAD) MutexLock(thr, pc, (uptr)m, /*rec=*/1, /*try_lock=*/true); return res; } #if !SANITIZER_MAC TSAN_INTERCEPTOR(int, pthread_mutex_timedlock, void *m, void *abstime) { SCOPED_TSAN_INTERCEPTOR(pthread_mutex_timedlock, m, abstime); int res = REAL(pthread_mutex_timedlock)(m, abstime); if (res == 0) { MutexLock(thr, pc, (uptr)m); } return res; } #endif #if !SANITIZER_MAC TSAN_INTERCEPTOR(int, pthread_spin_init, void *m, int pshared) { SCOPED_TSAN_INTERCEPTOR(pthread_spin_init, m, pshared); int res = REAL(pthread_spin_init)(m, pshared); if (res == 0) { MutexCreate(thr, pc, (uptr)m, false, false, false); } return res; } TSAN_INTERCEPTOR(int, pthread_spin_destroy, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_spin_destroy, m); int res = REAL(pthread_spin_destroy)(m); if (res == 0) { MutexDestroy(thr, pc, (uptr)m); } return res; } TSAN_INTERCEPTOR(int, pthread_spin_lock, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_spin_lock, m); int res = REAL(pthread_spin_lock)(m); if (res == 0) { MutexLock(thr, pc, (uptr)m); } return res; } TSAN_INTERCEPTOR(int, pthread_spin_trylock, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_spin_trylock, m); int res = REAL(pthread_spin_trylock)(m); if (res == 0) { MutexLock(thr, pc, (uptr)m, /*rec=*/1, /*try_lock=*/true); } return res; } TSAN_INTERCEPTOR(int, pthread_spin_unlock, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_spin_unlock, m); MutexUnlock(thr, pc, (uptr)m); int res = REAL(pthread_spin_unlock)(m); return res; } #endif TSAN_INTERCEPTOR(int, pthread_rwlock_init, void *m, void *a) { SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_init, m, a); int res = REAL(pthread_rwlock_init)(m, a); if (res == 0) { MutexCreate(thr, pc, (uptr)m, true, false, false); } return res; } TSAN_INTERCEPTOR(int, pthread_rwlock_destroy, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_destroy, m); int res = REAL(pthread_rwlock_destroy)(m); if (res == 0) { MutexDestroy(thr, pc, (uptr)m); } return res; } TSAN_INTERCEPTOR(int, pthread_rwlock_rdlock, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_rdlock, m); int res = REAL(pthread_rwlock_rdlock)(m); if (res == 0) { MutexReadLock(thr, pc, (uptr)m); } return res; } TSAN_INTERCEPTOR(int, pthread_rwlock_tryrdlock, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_tryrdlock, m); int res = REAL(pthread_rwlock_tryrdlock)(m); if (res == 0) { MutexReadLock(thr, pc, (uptr)m, /*try_lock=*/true); } return res; } #if !SANITIZER_MAC TSAN_INTERCEPTOR(int, pthread_rwlock_timedrdlock, void *m, void *abstime) { SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedrdlock, m, abstime); int res = REAL(pthread_rwlock_timedrdlock)(m, abstime); if (res == 0) { MutexReadLock(thr, pc, (uptr)m); } return res; } #endif TSAN_INTERCEPTOR(int, pthread_rwlock_wrlock, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_wrlock, m); int res = REAL(pthread_rwlock_wrlock)(m); if (res == 0) { MutexLock(thr, pc, (uptr)m); } return res; } TSAN_INTERCEPTOR(int, pthread_rwlock_trywrlock, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_trywrlock, m); int res = REAL(pthread_rwlock_trywrlock)(m); if (res == 0) { MutexLock(thr, pc, (uptr)m, /*rec=*/1, /*try_lock=*/true); } return res; } #if !SANITIZER_MAC TSAN_INTERCEPTOR(int, pthread_rwlock_timedwrlock, void *m, void *abstime) { SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedwrlock, m, abstime); int res = REAL(pthread_rwlock_timedwrlock)(m, abstime); if (res == 0) { MutexLock(thr, pc, (uptr)m); } return res; } #endif TSAN_INTERCEPTOR(int, pthread_rwlock_unlock, void *m) { SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_unlock, m); MutexReadOrWriteUnlock(thr, pc, (uptr)m); int res = REAL(pthread_rwlock_unlock)(m); return res; } #if !SANITIZER_MAC TSAN_INTERCEPTOR(int, pthread_barrier_init, void *b, void *a, unsigned count) { SCOPED_TSAN_INTERCEPTOR(pthread_barrier_init, b, a, count); MemoryWrite(thr, pc, (uptr)b, kSizeLog1); int res = REAL(pthread_barrier_init)(b, a, count); return res; } TSAN_INTERCEPTOR(int, pthread_barrier_destroy, void *b) { SCOPED_TSAN_INTERCEPTOR(pthread_barrier_destroy, b); MemoryWrite(thr, pc, (uptr)b, kSizeLog1); int res = REAL(pthread_barrier_destroy)(b); return res; } TSAN_INTERCEPTOR(int, pthread_barrier_wait, void *b) { SCOPED_TSAN_INTERCEPTOR(pthread_barrier_wait, b); Release(thr, pc, (uptr)b); MemoryRead(thr, pc, (uptr)b, kSizeLog1); int res = REAL(pthread_barrier_wait)(b); MemoryRead(thr, pc, (uptr)b, kSizeLog1); if (res == 0 || res == PTHREAD_BARRIER_SERIAL_THREAD) { Acquire(thr, pc, (uptr)b); } return res; } #endif TSAN_INTERCEPTOR(int, pthread_once, void *o, void (*f)()) { SCOPED_INTERCEPTOR_RAW(pthread_once, o, f); if (o == 0 || f == 0) return EINVAL; atomic_uint32_t *a; if (!SANITIZER_MAC) a = static_cast<atomic_uint32_t*>(o); else // On OS X, pthread_once_t has a header with a long-sized signature. a = static_cast<atomic_uint32_t*>((void *)((char *)o + sizeof(long_t))); u32 v = atomic_load(a, memory_order_acquire); if (v == 0 && atomic_compare_exchange_strong(a, &v, 1, memory_order_relaxed)) { (*f)(); if (!thr->in_ignored_lib) Release(thr, pc, (uptr)o); atomic_store(a, 2, memory_order_release); } else { while (v != 2) { internal_sched_yield(); v = atomic_load(a, memory_order_acquire); } if (!thr->in_ignored_lib) Acquire(thr, pc, (uptr)o); } return 0; } #if SANITIZER_LINUX && !SANITIZER_ANDROID TSAN_INTERCEPTOR(int, __fxstat, int version, int fd, void *buf) { SCOPED_TSAN_INTERCEPTOR(__fxstat, version, fd, buf); if (fd > 0) FdAccess(thr, pc, fd); return REAL(__fxstat)(version, fd, buf); } #define TSAN_MAYBE_INTERCEPT___FXSTAT TSAN_INTERCEPT(__fxstat) #else #define TSAN_MAYBE_INTERCEPT___FXSTAT #endif TSAN_INTERCEPTOR(int, fstat, int fd, void *buf) { #if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_ANDROID SCOPED_TSAN_INTERCEPTOR(fstat, fd, buf); if (fd > 0) FdAccess(thr, pc, fd); return REAL(fstat)(fd, buf); #else SCOPED_TSAN_INTERCEPTOR(__fxstat, 0, fd, buf); if (fd > 0) FdAccess(thr, pc, fd); return REAL(__fxstat)(0, fd, buf); #endif } #if SANITIZER_LINUX && !SANITIZER_ANDROID TSAN_INTERCEPTOR(int, __fxstat64, int version, int fd, void *buf) { SCOPED_TSAN_INTERCEPTOR(__fxstat64, version, fd, buf); if (fd > 0) FdAccess(thr, pc, fd); return REAL(__fxstat64)(version, fd, buf); } #define TSAN_MAYBE_INTERCEPT___FXSTAT64 TSAN_INTERCEPT(__fxstat64) #else #define TSAN_MAYBE_INTERCEPT___FXSTAT64 #endif #if SANITIZER_LINUX && !SANITIZER_ANDROID TSAN_INTERCEPTOR(int, fstat64, int fd, void *buf) { SCOPED_TSAN_INTERCEPTOR(__fxstat64, 0, fd, buf); if (fd > 0) FdAccess(thr, pc, fd); return REAL(__fxstat64)(0, fd, buf); } #define TSAN_MAYBE_INTERCEPT_FSTAT64 TSAN_INTERCEPT(fstat64) #else #define TSAN_MAYBE_INTERCEPT_FSTAT64 #endif TSAN_INTERCEPTOR(int, open, const char *name, int flags, int mode) { SCOPED_TSAN_INTERCEPTOR(open, name, flags, mode); READ_STRING(thr, pc, name, 0); int fd = REAL(open)(name, flags, mode); if (fd >= 0) FdFileCreate(thr, pc, fd); return fd; } #if SANITIZER_LINUX TSAN_INTERCEPTOR(int, open64, const char *name, int flags, int mode) { SCOPED_TSAN_INTERCEPTOR(open64, name, flags, mode); READ_STRING(thr, pc, name, 0); int fd = REAL(open64)(name, flags, mode); if (fd >= 0) FdFileCreate(thr, pc, fd); return fd; } #define TSAN_MAYBE_INTERCEPT_OPEN64 TSAN_INTERCEPT(open64) #else #define TSAN_MAYBE_INTERCEPT_OPEN64 #endif TSAN_INTERCEPTOR(int, creat, const char *name, int mode) { SCOPED_TSAN_INTERCEPTOR(creat, name, mode); READ_STRING(thr, pc, name, 0); int fd = REAL(creat)(name, mode); if (fd >= 0) FdFileCreate(thr, pc, fd); return fd; } #if SANITIZER_LINUX TSAN_INTERCEPTOR(int, creat64, const char *name, int mode) { SCOPED_TSAN_INTERCEPTOR(creat64, name, mode); READ_STRING(thr, pc, name, 0); int fd = REAL(creat64)(name, mode); if (fd >= 0) FdFileCreate(thr, pc, fd); return fd; } #define TSAN_MAYBE_INTERCEPT_CREAT64 TSAN_INTERCEPT(creat64) #else #define TSAN_MAYBE_INTERCEPT_CREAT64 #endif TSAN_INTERCEPTOR(int, dup, int oldfd) { SCOPED_TSAN_INTERCEPTOR(dup, oldfd); int newfd = REAL(dup)(oldfd); if (oldfd >= 0 && newfd >= 0 && newfd != oldfd) FdDup(thr, pc, oldfd, newfd, true); return newfd; } TSAN_INTERCEPTOR(int, dup2, int oldfd, int newfd) { SCOPED_TSAN_INTERCEPTOR(dup2, oldfd, newfd); int newfd2 = REAL(dup2)(oldfd, newfd); if (oldfd >= 0 && newfd2 >= 0 && newfd2 != oldfd) FdDup(thr, pc, oldfd, newfd2, false); return newfd2; } #if !SANITIZER_MAC TSAN_INTERCEPTOR(int, dup3, int oldfd, int newfd, int flags) { SCOPED_TSAN_INTERCEPTOR(dup3, oldfd, newfd, flags); int newfd2 = REAL(dup3)(oldfd, newfd, flags); if (oldfd >= 0 && newfd2 >= 0 && newfd2 != oldfd) FdDup(thr, pc, oldfd, newfd2, false); return newfd2; } #endif #if SANITIZER_LINUX TSAN_INTERCEPTOR(int, eventfd, unsigned initval, int flags) { SCOPED_TSAN_INTERCEPTOR(eventfd, initval, flags); int fd = REAL(eventfd)(initval, flags); if (fd >= 0) FdEventCreate(thr, pc, fd); return fd; } #define TSAN_MAYBE_INTERCEPT_EVENTFD TSAN_INTERCEPT(eventfd) #else #define TSAN_MAYBE_INTERCEPT_EVENTFD #endif #if SANITIZER_LINUX TSAN_INTERCEPTOR(int, signalfd, int fd, void *mask, int flags) { SCOPED_TSAN_INTERCEPTOR(signalfd, fd, mask, flags); if (fd >= 0) FdClose(thr, pc, fd); fd = REAL(signalfd)(fd, mask, flags); if (fd >= 0) FdSignalCreate(thr, pc, fd); return fd; } #define TSAN_MAYBE_INTERCEPT_SIGNALFD TSAN_INTERCEPT(signalfd) #else #define TSAN_MAYBE_INTERCEPT_SIGNALFD #endif #if SANITIZER_LINUX TSAN_INTERCEPTOR(int, inotify_init, int fake) { SCOPED_TSAN_INTERCEPTOR(inotify_init, fake); int fd = REAL(inotify_init)(fake); if (fd >= 0) FdInotifyCreate(thr, pc, fd); return fd; } #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT TSAN_INTERCEPT(inotify_init) #else #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT #endif #if SANITIZER_LINUX TSAN_INTERCEPTOR(int, inotify_init1, int flags) { SCOPED_TSAN_INTERCEPTOR(inotify_init1, flags); int fd = REAL(inotify_init1)(flags); if (fd >= 0) FdInotifyCreate(thr, pc, fd); return fd; } #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1 TSAN_INTERCEPT(inotify_init1) #else #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1 #endif TSAN_INTERCEPTOR(int, socket, int domain, int type, int protocol) { SCOPED_TSAN_INTERCEPTOR(socket, domain, type, protocol); int fd = REAL(socket)(domain, type, protocol); if (fd >= 0) FdSocketCreate(thr, pc, fd); return fd; } TSAN_INTERCEPTOR(int, socketpair, int domain, int type, int protocol, int *fd) { SCOPED_TSAN_INTERCEPTOR(socketpair, domain, type, protocol, fd); int res = REAL(socketpair)(domain, type, protocol, fd); if (res == 0 && fd[0] >= 0 && fd[1] >= 0) FdPipeCreate(thr, pc, fd[0], fd[1]); return res; } TSAN_INTERCEPTOR(int, connect, int fd, void *addr, unsigned addrlen) { SCOPED_TSAN_INTERCEPTOR(connect, fd, addr, addrlen); FdSocketConnecting(thr, pc, fd); int res = REAL(connect)(fd, addr, addrlen); if (res == 0 && fd >= 0) FdSocketConnect(thr, pc, fd); return res; } TSAN_INTERCEPTOR(int, bind, int fd, void *addr, unsigned addrlen) { SCOPED_TSAN_INTERCEPTOR(bind, fd, addr, addrlen); int res = REAL(bind)(fd, addr, addrlen); if (fd > 0 && res == 0) FdAccess(thr, pc, fd); return res; } TSAN_INTERCEPTOR(int, listen, int fd, int backlog) { SCOPED_TSAN_INTERCEPTOR(listen, fd, backlog); int res = REAL(listen)(fd, backlog); if (fd > 0 && res == 0) FdAccess(thr, pc, fd); return res; } TSAN_INTERCEPTOR(int, close, int fd) { SCOPED_TSAN_INTERCEPTOR(close, fd); if (fd >= 0) FdClose(thr, pc, fd); return REAL(close)(fd); } #if SANITIZER_LINUX TSAN_INTERCEPTOR(int, __close, int fd) { SCOPED_TSAN_INTERCEPTOR(__close, fd); if (fd >= 0) FdClose(thr, pc, fd); return REAL(__close)(fd); } #define TSAN_MAYBE_INTERCEPT___CLOSE TSAN_INTERCEPT(__close) #else #define TSAN_MAYBE_INTERCEPT___CLOSE #endif // glibc guts #if SANITIZER_LINUX && !SANITIZER_ANDROID TSAN_INTERCEPTOR(void, __res_iclose, void *state, bool free_addr) { SCOPED_TSAN_INTERCEPTOR(__res_iclose, state, free_addr); int fds[64]; int cnt = ExtractResolvFDs(state, fds, ARRAY_SIZE(fds)); for (int i = 0; i < cnt; i++) { if (fds[i] > 0) FdClose(thr, pc, fds[i]); } REAL(__res_iclose)(state, free_addr); } #define TSAN_MAYBE_INTERCEPT___RES_ICLOSE TSAN_INTERCEPT(__res_iclose) #else #define TSAN_MAYBE_INTERCEPT___RES_ICLOSE #endif TSAN_INTERCEPTOR(int, pipe, int *pipefd) { SCOPED_TSAN_INTERCEPTOR(pipe, pipefd); int res = REAL(pipe)(pipefd); if (res == 0 && pipefd[0] >= 0 && pipefd[1] >= 0) FdPipeCreate(thr, pc, pipefd[0], pipefd[1]); return res; } #if !SANITIZER_MAC TSAN_INTERCEPTOR(int, pipe2, int *pipefd, int flags) { SCOPED_TSAN_INTERCEPTOR(pipe2, pipefd, flags); int res = REAL(pipe2)(pipefd, flags); if (res == 0 && pipefd[0] >= 0 && pipefd[1] >= 0) FdPipeCreate(thr, pc, pipefd[0], pipefd[1]); return res; } #endif TSAN_INTERCEPTOR(int, unlink, char *path) { SCOPED_TSAN_INTERCEPTOR(unlink, path); Release(thr, pc, File2addr(path)); int res = REAL(unlink)(path); return res; } TSAN_INTERCEPTOR(void*, tmpfile, int fake) { SCOPED_TSAN_INTERCEPTOR(tmpfile, fake); void *res = REAL(tmpfile)(fake); if (res) { int fd = fileno_unlocked(res); if (fd >= 0) FdFileCreate(thr, pc, fd); } return res; } #if SANITIZER_LINUX TSAN_INTERCEPTOR(void*, tmpfile64, int fake) { SCOPED_TSAN_INTERCEPTOR(tmpfile64, fake); void *res = REAL(tmpfile64)(fake); if (res) { int fd = fileno_unlocked(res); if (fd >= 0) FdFileCreate(thr, pc, fd); } return res; } #define TSAN_MAYBE_INTERCEPT_TMPFILE64 TSAN_INTERCEPT(tmpfile64) #else #define TSAN_MAYBE_INTERCEPT_TMPFILE64 #endif TSAN_INTERCEPTOR(uptr, fread, void *ptr, uptr size, uptr nmemb, void *f) { // libc file streams can call user-supplied functions, see fopencookie. { SCOPED_TSAN_INTERCEPTOR(fread, ptr, size, nmemb, f); MemoryAccessRange(thr, pc, (uptr)ptr, size * nmemb, true); } return REAL(fread)(ptr, size, nmemb, f); } TSAN_INTERCEPTOR(uptr, fwrite, const void *p, uptr size, uptr nmemb, void *f) { // libc file streams can call user-supplied functions, see fopencookie. { SCOPED_TSAN_INTERCEPTOR(fwrite, p, size, nmemb, f); MemoryAccessRange(thr, pc, (uptr)p, size * nmemb, false); } return REAL(fwrite)(p, size, nmemb, f); } static void FlushStreams() { // Flushing all the streams here may freeze the process if a child thread is // performing file stream operations at the same time. REAL(fflush)(stdout); REAL(fflush)(stderr); } TSAN_INTERCEPTOR(void, abort, int fake) { SCOPED_TSAN_INTERCEPTOR(abort, fake); FlushStreams(); REAL(abort)(fake); } TSAN_INTERCEPTOR(int, puts, const char *s) { SCOPED_TSAN_INTERCEPTOR(puts, s); MemoryAccessRange(thr, pc, (uptr)s, internal_strlen(s), false); return REAL(puts)(s); } TSAN_INTERCEPTOR(int, rmdir, char *path) { SCOPED_TSAN_INTERCEPTOR(rmdir, path); Release(thr, pc, Dir2addr(path)); int res = REAL(rmdir)(path); return res; } TSAN_INTERCEPTOR(int, closedir, void *dirp) { SCOPED_TSAN_INTERCEPTOR(closedir, dirp); if (dirp) { int fd = dirfd(dirp); FdClose(thr, pc, fd); } return REAL(closedir)(dirp); } #if SANITIZER_LINUX TSAN_INTERCEPTOR(int, epoll_create, int size) { SCOPED_TSAN_INTERCEPTOR(epoll_create, size); int fd = REAL(epoll_create)(size); if (fd >= 0) FdPollCreate(thr, pc, fd); return fd; } TSAN_INTERCEPTOR(int, epoll_create1, int flags) { SCOPED_TSAN_INTERCEPTOR(epoll_create1, flags); int fd = REAL(epoll_create1)(flags); if (fd >= 0) FdPollCreate(thr, pc, fd); return fd; } TSAN_INTERCEPTOR(int, epoll_ctl, int epfd, int op, int fd, void *ev) { SCOPED_TSAN_INTERCEPTOR(epoll_ctl, epfd, op, fd, ev); if (epfd >= 0) FdAccess(thr, pc, epfd); if (epfd >= 0 && fd >= 0) FdAccess(thr, pc, fd); if (op == EPOLL_CTL_ADD && epfd >= 0) FdRelease(thr, pc, epfd); int res = REAL(epoll_ctl)(epfd, op, fd, ev); return res; } TSAN_INTERCEPTOR(int, epoll_wait, int epfd, void *ev, int cnt, int timeout) { SCOPED_TSAN_INTERCEPTOR(epoll_wait, epfd, ev, cnt, timeout); if (epfd >= 0) FdAccess(thr, pc, epfd); int res = BLOCK_REAL(epoll_wait)(epfd, ev, cnt, timeout); if (res > 0 && epfd >= 0) FdAcquire(thr, pc, epfd); return res; } TSAN_INTERCEPTOR(int, epoll_pwait, int epfd, void *ev, int cnt, int timeout, void *sigmask) { SCOPED_TSAN_INTERCEPTOR(epoll_pwait, epfd, ev, cnt, timeout, sigmask); if (epfd >= 0) FdAccess(thr, pc, epfd); int res = BLOCK_REAL(epoll_pwait)(epfd, ev, cnt, timeout, sigmask); if (res > 0 && epfd >= 0) FdAcquire(thr, pc, epfd); return res; } #define TSAN_MAYBE_INTERCEPT_EPOLL \ TSAN_INTERCEPT(epoll_create); \ TSAN_INTERCEPT(epoll_create1); \ TSAN_INTERCEPT(epoll_ctl); \ TSAN_INTERCEPT(epoll_wait); \ TSAN_INTERCEPT(epoll_pwait) #else #define TSAN_MAYBE_INTERCEPT_EPOLL #endif namespace __tsan { static void CallUserSignalHandler(ThreadState *thr, bool sync, bool acquire, bool sigact, int sig, my_siginfo_t *info, void *uctx) { if (acquire) Acquire(thr, 0, (uptr)&sigactions[sig]); // Signals are generally asynchronous, so if we receive a signals when // ignores are enabled we should disable ignores. This is critical for sync // and interceptors, because otherwise we can miss syncronization and report // false races. int ignore_reads_and_writes = thr->ignore_reads_and_writes; int ignore_interceptors = thr->ignore_interceptors; int ignore_sync = thr->ignore_sync; if (!ctx->after_multithreaded_fork) { thr->ignore_reads_and_writes = 0; thr->fast_state.ClearIgnoreBit(); thr->ignore_interceptors = 0; thr->ignore_sync = 0; } // Ensure that the handler does not spoil errno. const int saved_errno = errno; errno = 99; // This code races with sigaction. Be careful to not read sa_sigaction twice. // Also need to remember pc for reporting before the call, // because the handler can reset it. volatile uptr pc = sigact ? (uptr)sigactions[sig].sa_sigaction : (uptr)sigactions[sig].sa_handler; if (pc != (uptr)SIG_DFL && pc != (uptr)SIG_IGN) { if (sigact) ((sigactionhandler_t)pc)(sig, info, uctx); else ((sighandler_t)pc)(sig); } if (!ctx->after_multithreaded_fork) { thr->ignore_reads_and_writes = ignore_reads_and_writes; if (ignore_reads_and_writes) thr->fast_state.SetIgnoreBit(); thr->ignore_interceptors = ignore_interceptors; thr->ignore_sync = ignore_sync; } // We do not detect errno spoiling for SIGTERM, // because some SIGTERM handlers do spoil errno but reraise SIGTERM, // tsan reports false positive in such case. // It's difficult to properly detect this situation (reraise), // because in async signal processing case (when handler is called directly // from rtl_generic_sighandler) we have not yet received the reraised // signal; and it looks too fragile to intercept all ways to reraise a signal. if (flags()->report_bugs && !sync && sig != SIGTERM && errno != 99) { VarSizeStackTrace stack; // StackTrace::GetNestInstructionPc(pc) is used because return address is // expected, OutputReport() will undo this. ObtainCurrentStack(thr, StackTrace::GetNextInstructionPc(pc), &stack); ThreadRegistryLock l(ctx->thread_registry); ScopedReport rep(ReportTypeErrnoInSignal); if (!IsFiredSuppression(ctx, ReportTypeErrnoInSignal, stack)) { rep.AddStack(stack, true); OutputReport(thr, rep); } } errno = saved_errno; } void ProcessPendingSignals(ThreadState *thr) { ThreadSignalContext *sctx = SigCtx(thr); if (sctx == 0 || atomic_load(&sctx->have_pending_signals, memory_order_relaxed) == 0) return; atomic_store(&sctx->have_pending_signals, 0, memory_order_relaxed); atomic_fetch_add(&thr->in_signal_handler, 1, memory_order_relaxed); internal_sigfillset(&sctx->emptyset); CHECK_EQ(0, pthread_sigmask(SIG_SETMASK, &sctx->emptyset, &sctx->oldset)); for (int sig = 0; sig < kSigCount; sig++) { SignalDesc *signal = &sctx->pending_signals[sig]; if (signal->armed) { signal->armed = false; CallUserSignalHandler(thr, false, true, signal->sigaction, sig, &signal->siginfo, &signal->ctx); } } CHECK_EQ(0, pthread_sigmask(SIG_SETMASK, &sctx->oldset, 0)); atomic_fetch_add(&thr->in_signal_handler, -1, memory_order_relaxed); } } // namespace __tsan static bool is_sync_signal(ThreadSignalContext *sctx, int sig) { return sig == SIGSEGV || sig == SIGBUS || sig == SIGILL || sig == SIGABRT || sig == SIGFPE || sig == SIGPIPE || sig == SIGSYS || // If we are sending signal to ourselves, we must process it now. (sctx && sig == sctx->int_signal_send); } void ALWAYS_INLINE rtl_generic_sighandler(bool sigact, int sig, my_siginfo_t *info, void *ctx) { ThreadState *thr = cur_thread(); ThreadSignalContext *sctx = SigCtx(thr); if (sig < 0 || sig >= kSigCount) { VPrintf(1, "ThreadSanitizer: ignoring signal %d\n", sig); return; } // Don't mess with synchronous signals. const bool sync = is_sync_signal(sctx, sig); if (sync || // If we are in blocking function, we can safely process it now // (but check if we are in a recursive interceptor, // i.e. pthread_join()->munmap()). (sctx && atomic_load(&sctx->in_blocking_func, memory_order_relaxed))) { atomic_fetch_add(&thr->in_signal_handler, 1, memory_order_relaxed); if (sctx && atomic_load(&sctx->in_blocking_func, memory_order_relaxed)) { atomic_store(&sctx->in_blocking_func, 0, memory_order_relaxed); CallUserSignalHandler(thr, sync, true, sigact, sig, info, ctx); atomic_store(&sctx->in_blocking_func, 1, memory_order_relaxed); } else { // Be very conservative with when we do acquire in this case. // It's unsafe to do acquire in async handlers, because ThreadState // can be in inconsistent state. // SIGSYS looks relatively safe -- it's synchronous and can actually // need some global state. bool acq = (sig == SIGSYS); CallUserSignalHandler(thr, sync, acq, sigact, sig, info, ctx); } atomic_fetch_add(&thr->in_signal_handler, -1, memory_order_relaxed); return; } if (sctx == 0) return; SignalDesc *signal = &sctx->pending_signals[sig]; if (signal->armed == false) { signal->armed = true; signal->sigaction = sigact; if (info) internal_memcpy(&signal->siginfo, info, sizeof(*info)); if (ctx) internal_memcpy(&signal->ctx, ctx, sizeof(signal->ctx)); atomic_store(&sctx->have_pending_signals, 1, memory_order_relaxed); } } static void rtl_sighandler(int sig) { rtl_generic_sighandler(false, sig, 0, 0); } static void rtl_sigaction(int sig, my_siginfo_t *info, void *ctx) { rtl_generic_sighandler(true, sig, info, ctx); } TSAN_INTERCEPTOR(int, sigaction, int sig, sigaction_t *act, sigaction_t *old) { // Note: if we call REAL(sigaction) directly for any reason without proxying // the signal handler through rtl_sigaction, very bad things will happen. // The handler will run synchronously and corrupt tsan per-thread state. SCOPED_INTERCEPTOR_RAW(sigaction, sig, act, old); if (old) internal_memcpy(old, &sigactions[sig], sizeof(*old)); if (act == 0) return 0; // Copy act into sigactions[sig]. // Can't use struct copy, because compiler can emit call to memcpy. // Can't use internal_memcpy, because it copies byte-by-byte, // and signal handler reads the sa_handler concurrently. It it can read // some bytes from old value and some bytes from new value. // Use volatile to prevent insertion of memcpy. sigactions[sig].sa_handler = *(volatile sighandler_t*)&act->sa_handler; sigactions[sig].sa_flags = *(volatile int*)&act->sa_flags; internal_memcpy(&sigactions[sig].sa_mask, &act->sa_mask, sizeof(sigactions[sig].sa_mask)); #if !SANITIZER_FREEBSD && !SANITIZER_MAC sigactions[sig].sa_restorer = act->sa_restorer; #endif sigaction_t newact; internal_memcpy(&newact, act, sizeof(newact)); internal_sigfillset(&newact.sa_mask); if (act->sa_handler != SIG_IGN && act->sa_handler != SIG_DFL) { if (newact.sa_flags & SA_SIGINFO) newact.sa_sigaction = rtl_sigaction; else newact.sa_handler = rtl_sighandler; } ReleaseStore(thr, pc, (uptr)&sigactions[sig]); int res = REAL(sigaction)(sig, &newact, 0); return res; } TSAN_INTERCEPTOR(sighandler_t, signal, int sig, sighandler_t h) { sigaction_t act; act.sa_handler = h; internal_memset(&act.sa_mask, -1, sizeof(act.sa_mask)); act.sa_flags = 0; sigaction_t old; int res = sigaction(sig, &act, &old); if (res) return SIG_ERR; return old.sa_handler; } TSAN_INTERCEPTOR(int, sigsuspend, const __sanitizer_sigset_t *mask) { SCOPED_TSAN_INTERCEPTOR(sigsuspend, mask); return REAL(sigsuspend)(mask); } TSAN_INTERCEPTOR(int, raise, int sig) { SCOPED_TSAN_INTERCEPTOR(raise, sig); ThreadSignalContext *sctx = SigCtx(thr); CHECK_NE(sctx, 0); int prev = sctx->int_signal_send; sctx->int_signal_send = sig; int res = REAL(raise)(sig); CHECK_EQ(sctx->int_signal_send, sig); sctx->int_signal_send = prev; return res; } TSAN_INTERCEPTOR(int, kill, int pid, int sig) { SCOPED_TSAN_INTERCEPTOR(kill, pid, sig); ThreadSignalContext *sctx = SigCtx(thr); CHECK_NE(sctx, 0); int prev = sctx->int_signal_send; if (pid == (int)internal_getpid()) { sctx->int_signal_send = sig; } int res = REAL(kill)(pid, sig); if (pid == (int)internal_getpid()) { CHECK_EQ(sctx->int_signal_send, sig); sctx->int_signal_send = prev; } return res; } TSAN_INTERCEPTOR(int, pthread_kill, void *tid, int sig) { SCOPED_TSAN_INTERCEPTOR(pthread_kill, tid, sig); ThreadSignalContext *sctx = SigCtx(thr); CHECK_NE(sctx, 0); int prev = sctx->int_signal_send; if (tid == pthread_self()) { sctx->int_signal_send = sig; } int res = REAL(pthread_kill)(tid, sig); if (tid == pthread_self()) { CHECK_EQ(sctx->int_signal_send, sig); sctx->int_signal_send = prev; } return res; } TSAN_INTERCEPTOR(int, gettimeofday, void *tv, void *tz) { SCOPED_TSAN_INTERCEPTOR(gettimeofday, tv, tz); // It's intercepted merely to process pending signals. return REAL(gettimeofday)(tv, tz); } TSAN_INTERCEPTOR(int, getaddrinfo, void *node, void *service, void *hints, void *rv) { SCOPED_TSAN_INTERCEPTOR(getaddrinfo, node, service, hints, rv); // We miss atomic synchronization in getaddrinfo, // and can report false race between malloc and free // inside of getaddrinfo. So ignore memory accesses. ThreadIgnoreBegin(thr, pc); int res = REAL(getaddrinfo)(node, service, hints, rv); ThreadIgnoreEnd(thr, pc); return res; } TSAN_INTERCEPTOR(int, fork, int fake) { if (cur_thread()->in_symbolizer) return REAL(fork)(fake); SCOPED_INTERCEPTOR_RAW(fork, fake); ForkBefore(thr, pc); int pid; { // On OS X, REAL(fork) can call intercepted functions (OSSpinLockLock), and // we'll assert in CheckNoLocks() unless we ignore interceptors. ScopedIgnoreInterceptors ignore; pid = REAL(fork)(fake); } if (pid == 0) { // child ForkChildAfter(thr, pc); FdOnFork(thr, pc); } else if (pid > 0) { // parent ForkParentAfter(thr, pc); } else { // error ForkParentAfter(thr, pc); } return pid; } TSAN_INTERCEPTOR(int, vfork, int fake) { // Some programs (e.g. openjdk) call close for all file descriptors // in the child process. Under tsan it leads to false positives, because // address space is shared, so the parent process also thinks that // the descriptors are closed (while they are actually not). // This leads to false positives due to missed synchronization. // Strictly saying this is undefined behavior, because vfork child is not // allowed to call any functions other than exec/exit. But this is what // openjdk does, so we want to handle it. // We could disable interceptors in the child process. But it's not possible // to simply intercept and wrap vfork, because vfork child is not allowed // to return from the function that calls vfork, and that's exactly what // we would do. So this would require some assembly trickery as well. // Instead we simply turn vfork into fork. return WRAP(fork)(fake); } #if !SANITIZER_MAC && !SANITIZER_ANDROID typedef int (*dl_iterate_phdr_cb_t)(__sanitizer_dl_phdr_info *info, SIZE_T size, void *data); struct dl_iterate_phdr_data { ThreadState *thr; uptr pc; dl_iterate_phdr_cb_t cb; void *data; }; static bool IsAppNotRodata(uptr addr) { return IsAppMem(addr) && *(u64*)MemToShadow(addr) != kShadowRodata; } static int dl_iterate_phdr_cb(__sanitizer_dl_phdr_info *info, SIZE_T size, void *data) { dl_iterate_phdr_data *cbdata = (dl_iterate_phdr_data *)data; // dlopen/dlclose allocate/free dynamic-linker-internal memory, which is later // accessible in dl_iterate_phdr callback. But we don't see synchronization // inside of dynamic linker, so we "unpoison" it here in order to not // produce false reports. Ignoring malloc/free in dlopen/dlclose is not enough // because some libc functions call __libc_dlopen. if (info && IsAppNotRodata((uptr)info->dlpi_name)) MemoryResetRange(cbdata->thr, cbdata->pc, (uptr)info->dlpi_name, internal_strlen(info->dlpi_name)); int res = cbdata->cb(info, size, cbdata->data); // Perform the check one more time in case info->dlpi_name was overwritten // by user callback. if (info && IsAppNotRodata((uptr)info->dlpi_name)) MemoryResetRange(cbdata->thr, cbdata->pc, (uptr)info->dlpi_name, internal_strlen(info->dlpi_name)); return res; } TSAN_INTERCEPTOR(int, dl_iterate_phdr, dl_iterate_phdr_cb_t cb, void *data) { SCOPED_TSAN_INTERCEPTOR(dl_iterate_phdr, cb, data); dl_iterate_phdr_data cbdata; cbdata.thr = thr; cbdata.pc = pc; cbdata.cb = cb; cbdata.data = data; int res = REAL(dl_iterate_phdr)(dl_iterate_phdr_cb, &cbdata); return res; } #endif static int OnExit(ThreadState *thr) { int status = Finalize(thr); FlushStreams(); return status; } struct TsanInterceptorContext { ThreadState *thr; const uptr caller_pc; const uptr pc; }; #if !SANITIZER_MAC static void HandleRecvmsg(ThreadState *thr, uptr pc, __sanitizer_msghdr *msg) { int fds[64]; int cnt = ExtractRecvmsgFDs(msg, fds, ARRAY_SIZE(fds)); for (int i = 0; i < cnt; i++) FdEventCreate(thr, pc, fds[i]); } #endif #include "sanitizer_common/sanitizer_platform_interceptors.h" // Causes interceptor recursion (getaddrinfo() and fopen()) #undef SANITIZER_INTERCEPT_GETADDRINFO // There interceptors do not seem to be strictly necessary for tsan. // But we see cases where the interceptors consume 70% of execution time. // Memory blocks passed to fgetgrent_r are "written to" by tsan several times. // First, there is some recursion (getgrnam_r calls fgetgrent_r), and each // function "writes to" the buffer. Then, the same memory is "written to" // twice, first as buf and then as pwbufp (both of them refer to the same // addresses). #undef SANITIZER_INTERCEPT_GETPWENT #undef SANITIZER_INTERCEPT_GETPWENT_R #undef SANITIZER_INTERCEPT_FGETPWENT #undef SANITIZER_INTERCEPT_GETPWNAM_AND_FRIENDS #undef SANITIZER_INTERCEPT_GETPWNAM_R_AND_FRIENDS // We define our own. #if SANITIZER_INTERCEPT_TLS_GET_ADDR #define NEED_TLS_GET_ADDR #endif #undef SANITIZER_INTERCEPT_TLS_GET_ADDR #define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name) #define COMMON_INTERCEPT_FUNCTION_VER(name, ver) \ INTERCEPT_FUNCTION_VER(name, ver) #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size) \ MemoryAccessRange(((TsanInterceptorContext *)ctx)->thr, \ ((TsanInterceptorContext *)ctx)->pc, (uptr)ptr, size, \ true) #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size) \ MemoryAccessRange(((TsanInterceptorContext *) ctx)->thr, \ ((TsanInterceptorContext *) ctx)->pc, (uptr) ptr, size, \ false) #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...) \ SCOPED_TSAN_INTERCEPTOR(func, __VA_ARGS__); \ TsanInterceptorContext _ctx = {thr, caller_pc, pc}; \ ctx = (void *)&_ctx; \ (void) ctx; #define COMMON_INTERCEPTOR_ENTER_NOIGNORE(ctx, func, ...) \ SCOPED_INTERCEPTOR_RAW(func, __VA_ARGS__); \ TsanInterceptorContext _ctx = {thr, caller_pc, pc}; \ ctx = (void *)&_ctx; \ (void) ctx; #define COMMON_INTERCEPTOR_FILE_OPEN(ctx, file, path) \ Acquire(thr, pc, File2addr(path)); \ if (file) { \ int fd = fileno_unlocked(file); \ if (fd >= 0) FdFileCreate(thr, pc, fd); \ } #define COMMON_INTERCEPTOR_FILE_CLOSE(ctx, file) \ if (file) { \ int fd = fileno_unlocked(file); \ if (fd >= 0) FdClose(thr, pc, fd); \ } #define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle) \ libignore()->OnLibraryLoaded(filename) #define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() \ libignore()->OnLibraryUnloaded() #define COMMON_INTERCEPTOR_ACQUIRE(ctx, u) \ Acquire(((TsanInterceptorContext *) ctx)->thr, pc, u) #define COMMON_INTERCEPTOR_RELEASE(ctx, u) \ Release(((TsanInterceptorContext *) ctx)->thr, pc, u) #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \ Acquire(((TsanInterceptorContext *) ctx)->thr, pc, Dir2addr(path)) #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \ FdAcquire(((TsanInterceptorContext *) ctx)->thr, pc, fd) #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \ FdRelease(((TsanInterceptorContext *) ctx)->thr, pc, fd) #define COMMON_INTERCEPTOR_FD_ACCESS(ctx, fd) \ FdAccess(((TsanInterceptorContext *) ctx)->thr, pc, fd) #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \ FdSocketAccept(((TsanInterceptorContext *) ctx)->thr, pc, fd, newfd) #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \ ThreadSetName(((TsanInterceptorContext *) ctx)->thr, name) #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \ __tsan::ctx->thread_registry->SetThreadNameByUserId(thread, name) #define COMMON_INTERCEPTOR_BLOCK_REAL(name) BLOCK_REAL(name) #define COMMON_INTERCEPTOR_ON_EXIT(ctx) \ OnExit(((TsanInterceptorContext *) ctx)->thr) #define COMMON_INTERCEPTOR_MUTEX_LOCK(ctx, m) \ MutexLock(((TsanInterceptorContext *)ctx)->thr, \ ((TsanInterceptorContext *)ctx)->pc, (uptr)m) #define COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m) \ MutexUnlock(((TsanInterceptorContext *)ctx)->thr, \ ((TsanInterceptorContext *)ctx)->pc, (uptr)m) #define COMMON_INTERCEPTOR_MUTEX_REPAIR(ctx, m) \ MutexRepair(((TsanInterceptorContext *)ctx)->thr, \ ((TsanInterceptorContext *)ctx)->pc, (uptr)m) #define COMMON_INTERCEPTOR_MUTEX_INVALID(ctx, m) \ MutexInvalidAccess(((TsanInterceptorContext *)ctx)->thr, \ ((TsanInterceptorContext *)ctx)->pc, (uptr)m) #if !SANITIZER_MAC #define COMMON_INTERCEPTOR_HANDLE_RECVMSG(ctx, msg) \ HandleRecvmsg(((TsanInterceptorContext *)ctx)->thr, \ ((TsanInterceptorContext *)ctx)->pc, msg) #endif #define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end) \ if (TsanThread *t = GetCurrentThread()) { \ *begin = t->tls_begin(); \ *end = t->tls_end(); \ } else { \ *begin = *end = 0; \ } #define COMMON_INTERCEPTOR_USER_CALLBACK_START() \ SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START() #define COMMON_INTERCEPTOR_USER_CALLBACK_END() \ SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END() #include "sanitizer_common/sanitizer_common_interceptors.inc" #define TSAN_SYSCALL() \ ThreadState *thr = cur_thread(); \ if (thr->ignore_interceptors) \ return; \ ScopedSyscall scoped_syscall(thr) \ /**/ struct ScopedSyscall { ThreadState *thr; explicit ScopedSyscall(ThreadState *thr) : thr(thr) { Initialize(thr); } ~ScopedSyscall() { ProcessPendingSignals(thr); } }; #if !SANITIZER_FREEBSD && !SANITIZER_MAC static void syscall_access_range(uptr pc, uptr p, uptr s, bool write) { TSAN_SYSCALL(); MemoryAccessRange(thr, pc, p, s, write); } static void syscall_acquire(uptr pc, uptr addr) { TSAN_SYSCALL(); Acquire(thr, pc, addr); DPrintf("syscall_acquire(%p)\n", addr); } static void syscall_release(uptr pc, uptr addr) { TSAN_SYSCALL(); DPrintf("syscall_release(%p)\n", addr); Release(thr, pc, addr); } static void syscall_fd_close(uptr pc, int fd) { TSAN_SYSCALL(); FdClose(thr, pc, fd); } static USED void syscall_fd_acquire(uptr pc, int fd) { TSAN_SYSCALL(); FdAcquire(thr, pc, fd); DPrintf("syscall_fd_acquire(%p)\n", fd); } static USED void syscall_fd_release(uptr pc, int fd) { TSAN_SYSCALL(); DPrintf("syscall_fd_release(%p)\n", fd); FdRelease(thr, pc, fd); } static void syscall_pre_fork(uptr pc) { TSAN_SYSCALL(); ForkBefore(thr, pc); } static void syscall_post_fork(uptr pc, int pid) { TSAN_SYSCALL(); if (pid == 0) { // child ForkChildAfter(thr, pc); FdOnFork(thr, pc); } else if (pid > 0) { // parent ForkParentAfter(thr, pc); } else { // error ForkParentAfter(thr, pc); } } #endif #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) \ syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), false) #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \ syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), true) #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \ do { \ (void)(p); \ (void)(s); \ } while (false) #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) \ do { \ (void)(p); \ (void)(s); \ } while (false) #define COMMON_SYSCALL_ACQUIRE(addr) \ syscall_acquire(GET_CALLER_PC(), (uptr)(addr)) #define COMMON_SYSCALL_RELEASE(addr) \ syscall_release(GET_CALLER_PC(), (uptr)(addr)) #define COMMON_SYSCALL_FD_CLOSE(fd) syscall_fd_close(GET_CALLER_PC(), fd) #define COMMON_SYSCALL_FD_ACQUIRE(fd) syscall_fd_acquire(GET_CALLER_PC(), fd) #define COMMON_SYSCALL_FD_RELEASE(fd) syscall_fd_release(GET_CALLER_PC(), fd) #define COMMON_SYSCALL_PRE_FORK() \ syscall_pre_fork(GET_CALLER_PC()) #define COMMON_SYSCALL_POST_FORK(res) \ syscall_post_fork(GET_CALLER_PC(), res) #include "sanitizer_common/sanitizer_common_syscalls.inc" #ifdef NEED_TLS_GET_ADDR // Define own interceptor instead of sanitizer_common's for three reasons: // 1. It must not process pending signals. // Signal handlers may contain MOVDQA instruction (see below). // 2. It must be as simple as possible to not contain MOVDQA. // 3. Sanitizer_common version uses COMMON_INTERCEPTOR_INITIALIZE_RANGE which // is empty for tsan (meant only for msan). // Note: __tls_get_addr can be called with mis-aligned stack due to: // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 // So the interceptor must work with mis-aligned stack, in particular, does not // execute MOVDQA with stack addresses. TSAN_INTERCEPTOR(void *, __tls_get_addr, void *arg) { void *res = REAL(__tls_get_addr)(arg); ThreadState *thr = cur_thread(); if (!thr) return res; DTLS::DTV *dtv = DTLS_on_tls_get_addr(arg, res, thr->tls_addr, thr->tls_size); if (!dtv) return res; // New DTLS block has been allocated. MemoryResetRange(thr, 0, dtv->beg, dtv->size); return res; } #endif namespace __tsan { static void finalize(void *arg) { ThreadState *thr = cur_thread(); int status = Finalize(thr); // Make sure the output is not lost. FlushStreams(); if (status) Die(); } #if !SANITIZER_MAC && !SANITIZER_ANDROID static void unreachable() { Report("FATAL: ThreadSanitizer: unreachable called\n"); Die(); } #endif void InitializeInterceptors() { #if !SANITIZER_MAC // We need to setup it early, because functions like dlsym() can call it. REAL(memset) = internal_memset; REAL(memcpy) = internal_memcpy; #endif // Instruct libc malloc to consume less memory. #if SANITIZER_LINUX mallopt(1, 0); // M_MXFAST mallopt(-3, 32*1024); // M_MMAP_THRESHOLD #endif InitializeCommonInterceptors(); #if !SANITIZER_MAC // We can not use TSAN_INTERCEPT to get setjmp addr, // because it does &setjmp and setjmp is not present in some versions of libc. using __interception::GetRealFunctionAddress; GetRealFunctionAddress("setjmp", (uptr*)&REAL(setjmp), 0, 0); GetRealFunctionAddress("_setjmp", (uptr*)&REAL(_setjmp), 0, 0); GetRealFunctionAddress("sigsetjmp", (uptr*)&REAL(sigsetjmp), 0, 0); GetRealFunctionAddress("__sigsetjmp", (uptr*)&REAL(__sigsetjmp), 0, 0); #endif TSAN_INTERCEPT(longjmp); TSAN_INTERCEPT(siglongjmp); TSAN_INTERCEPT(malloc); TSAN_INTERCEPT(__libc_memalign); TSAN_INTERCEPT(calloc); TSAN_INTERCEPT(realloc); TSAN_INTERCEPT(free); TSAN_INTERCEPT(cfree); TSAN_INTERCEPT(mmap); TSAN_MAYBE_INTERCEPT_MMAP64; TSAN_INTERCEPT(munmap); TSAN_MAYBE_INTERCEPT_MEMALIGN; TSAN_INTERCEPT(valloc); TSAN_MAYBE_INTERCEPT_PVALLOC; TSAN_INTERCEPT(posix_memalign); TSAN_INTERCEPT(strcpy); // NOLINT TSAN_INTERCEPT(strncpy); TSAN_INTERCEPT(strdup); TSAN_INTERCEPT(pthread_create); TSAN_INTERCEPT(pthread_join); TSAN_INTERCEPT(pthread_detach); TSAN_INTERCEPT_VER(pthread_cond_init, PTHREAD_ABI_BASE); TSAN_INTERCEPT_VER(pthread_cond_signal, PTHREAD_ABI_BASE); TSAN_INTERCEPT_VER(pthread_cond_broadcast, PTHREAD_ABI_BASE); TSAN_INTERCEPT_VER(pthread_cond_wait, PTHREAD_ABI_BASE); TSAN_INTERCEPT_VER(pthread_cond_timedwait, PTHREAD_ABI_BASE); TSAN_INTERCEPT_VER(pthread_cond_destroy, PTHREAD_ABI_BASE); TSAN_INTERCEPT(pthread_mutex_init); TSAN_INTERCEPT(pthread_mutex_destroy); TSAN_INTERCEPT(pthread_mutex_trylock); TSAN_INTERCEPT(pthread_mutex_timedlock); TSAN_INTERCEPT(pthread_spin_init); TSAN_INTERCEPT(pthread_spin_destroy); TSAN_INTERCEPT(pthread_spin_lock); TSAN_INTERCEPT(pthread_spin_trylock); TSAN_INTERCEPT(pthread_spin_unlock); TSAN_INTERCEPT(pthread_rwlock_init); TSAN_INTERCEPT(pthread_rwlock_destroy); TSAN_INTERCEPT(pthread_rwlock_rdlock); TSAN_INTERCEPT(pthread_rwlock_tryrdlock); TSAN_INTERCEPT(pthread_rwlock_timedrdlock); TSAN_INTERCEPT(pthread_rwlock_wrlock); TSAN_INTERCEPT(pthread_rwlock_trywrlock); TSAN_INTERCEPT(pthread_rwlock_timedwrlock); TSAN_INTERCEPT(pthread_rwlock_unlock); TSAN_INTERCEPT(pthread_barrier_init); TSAN_INTERCEPT(pthread_barrier_destroy); TSAN_INTERCEPT(pthread_barrier_wait); TSAN_INTERCEPT(pthread_once); TSAN_INTERCEPT(fstat); TSAN_MAYBE_INTERCEPT___FXSTAT; TSAN_MAYBE_INTERCEPT_FSTAT64; TSAN_MAYBE_INTERCEPT___FXSTAT64; TSAN_INTERCEPT(open); TSAN_MAYBE_INTERCEPT_OPEN64; TSAN_INTERCEPT(creat); TSAN_MAYBE_INTERCEPT_CREAT64; TSAN_INTERCEPT(dup); TSAN_INTERCEPT(dup2); TSAN_INTERCEPT(dup3); TSAN_MAYBE_INTERCEPT_EVENTFD; TSAN_MAYBE_INTERCEPT_SIGNALFD; TSAN_MAYBE_INTERCEPT_INOTIFY_INIT; TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1; TSAN_INTERCEPT(socket); TSAN_INTERCEPT(socketpair); TSAN_INTERCEPT(connect); TSAN_INTERCEPT(bind); TSAN_INTERCEPT(listen); TSAN_MAYBE_INTERCEPT_EPOLL; TSAN_INTERCEPT(close); TSAN_MAYBE_INTERCEPT___CLOSE; TSAN_MAYBE_INTERCEPT___RES_ICLOSE; TSAN_INTERCEPT(pipe); TSAN_INTERCEPT(pipe2); TSAN_INTERCEPT(unlink); TSAN_INTERCEPT(tmpfile); TSAN_MAYBE_INTERCEPT_TMPFILE64; TSAN_INTERCEPT(fread); TSAN_INTERCEPT(fwrite); TSAN_INTERCEPT(abort); TSAN_INTERCEPT(puts); TSAN_INTERCEPT(rmdir); TSAN_INTERCEPT(closedir); TSAN_INTERCEPT(sigaction); TSAN_INTERCEPT(signal); TSAN_INTERCEPT(sigsuspend); TSAN_INTERCEPT(raise); TSAN_INTERCEPT(kill); TSAN_INTERCEPT(pthread_kill); TSAN_INTERCEPT(sleep); TSAN_INTERCEPT(usleep); TSAN_INTERCEPT(nanosleep); TSAN_INTERCEPT(gettimeofday); TSAN_INTERCEPT(getaddrinfo); TSAN_INTERCEPT(fork); TSAN_INTERCEPT(vfork); #if !SANITIZER_ANDROID TSAN_INTERCEPT(dl_iterate_phdr); #endif TSAN_INTERCEPT(on_exit); TSAN_INTERCEPT(__cxa_atexit); TSAN_INTERCEPT(_exit); #ifdef NEED_TLS_GET_ADDR TSAN_INTERCEPT(__tls_get_addr); #endif #if !SANITIZER_MAC && !SANITIZER_ANDROID // Need to setup it, because interceptors check that the function is resolved. // But atexit is emitted directly into the module, so can't be resolved. REAL(atexit) = (int(*)(void(*)()))unreachable; #endif if (REAL(__cxa_atexit)(&finalize, 0, 0)) { Printf("ThreadSanitizer: failed to setup atexit callback\n"); Die(); } #if !SANITIZER_MAC if (pthread_key_create(&g_thread_finalize_key, &thread_finalize)) { Printf("ThreadSanitizer: failed to create thread key\n"); Die(); } #endif FdInit(); } } // namespace __tsan // Invisible barrier for tests. // There were several unsuccessful iterations for this functionality: // 1. Initially it was implemented in user code using // REAL(pthread_barrier_wait). But pthread_barrier_wait is not supported on // MacOS. Futexes are linux-specific for this matter. // 2. Then we switched to atomics+usleep(10). But usleep produced parasitic // "as-if synchronized via sleep" messages in reports which failed some // output tests. // 3. Then we switched to atomics+sched_yield. But this produced tons of tsan- // visible events, which lead to "failed to restore stack trace" failures. // Note that no_sanitize_thread attribute does not turn off atomic interception // so attaching it to the function defined in user code does not help. // That's why we now have what we have. extern "C" SANITIZER_INTERFACE_ATTRIBUTE void __tsan_testonly_barrier_init(u64 *barrier, u32 count) { if (count >= (1 << 8)) { Printf("barrier_init: count is too large (%d)\n", count); Die(); } // 8 lsb is thread count, the remaining are count of entered threads. *barrier = count; } extern "C" SANITIZER_INTERFACE_ATTRIBUTE void __tsan_testonly_barrier_wait(u64 *barrier) { unsigned old = __atomic_fetch_add(barrier, 1 << 8, __ATOMIC_RELAXED); unsigned old_epoch = (old >> 8) / (old & 0xff); for (;;) { unsigned cur = __atomic_load_n(barrier, __ATOMIC_RELAXED); unsigned cur_epoch = (cur >> 8) / (cur & 0xff); if (cur_epoch != old_epoch) return; internal_sched_yield(); } }