tsan: add fiber support

This patch adds functions for managing fibers:

__tsan_get_current_fiber()
__tsan_create_fiber()
__tsan_destroy_fiber()
__tsan_switch_to_fiber()
__tsan_set_fiber_name()

See the added tests for use examples.

Author: yuri (Yuri Per)
Reviewed in: https://reviews.llvm.org/D54889

[The previous commit of this change was reverted,
this is a resubmit with a squashed fix for check_analyze.sh
and COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED]

llvm-svn: 353947

7 files changed, 100 insertions, 10 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_thread_registry.h b/compiler-rt/lib/sanitizer_common/sanitizer_thread_registry.h
index fc38d0f80d2..493aa988f7e 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_thread_registry.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_thread_registry.h
@@ -31,6 +31,7 @@ enum ThreadStatus {
 enum class ThreadType {
   Regular, // Normal thread
   Worker,  // macOS Grand Central Dispatch (GCD) worker thread
+  Fiber,   // Fiber
 };
 
 // Generic thread context. Specific sanitizer tools may inherit from it.
diff --git a/compiler-rt/lib/tsan/check_analyze.sh b/compiler-rt/lib/tsan/check_analyze.sh
index 5e7a9a96742..a2a7e82b47a 100755
--- a/compiler-rt/lib/tsan/check_analyze.sh
+++ b/compiler-rt/lib/tsan/check_analyze.sh
@@ -36,17 +36,11 @@ check() {
 
 for f in write1 write2 write4 write8; do
   check $f rsp 1
-  check $f push 1
-  check $f pop 8
-done
-
-for f in read1; do
-  check $f rsp 1
   check $f push 2
   check $f pop 16
 done
 
-for f in read2 read4 read8; do
+for f in read1 read2 read4 read8; do
   check $f rsp 1
   check $f push 3
   check $f pop 24
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
index b9f245e409b..e4b8def7831 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
@@ -153,7 +153,7 @@ const int SIG_SETMASK = 2;
 #endif
 
 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED \
-  (!cur_thread()->is_inited)
+  (cur_thread_init(), !cur_thread()->is_inited)
 
 namespace __tsan {
 struct SignalDesc {
@@ -554,6 +554,7 @@ static void LongJmp(ThreadState *thr, uptr *env) {
 
 // FIXME: put everything below into a common extern "C" block?
 extern "C" void __tsan_setjmp(uptr sp, uptr mangled_sp) {
+  cur_thread_init();
   SetJmp(cur_thread(), sp, mangled_sp);
 }
 
@@ -942,6 +943,7 @@ extern "C" void *__tsan_thread_start_func(void *arg) {
   void *param = p->param;
   int tid = 0;
   {
+    cur_thread_init();
     ThreadState *thr = cur_thread();
     // Thread-local state is not initialized yet.
     ScopedIgnoreInterceptors ignore;
@@ -1053,6 +1055,9 @@ TSAN_INTERCEPTOR(int, pthread_detach, void *th) {
 TSAN_INTERCEPTOR(void, pthread_exit, void *retval) {
   {
     SCOPED_INTERCEPTOR_RAW(pthread_exit, retval);
+#if !SANITIZER_MAC && !SANITIZER_ANDROID
+    CHECK_EQ(thr, &cur_thread_placeholder);
+#endif
   }
   REAL(pthread_exit)(retval);
 }
@@ -1981,6 +1986,7 @@ static bool is_sync_signal(ThreadSignalContext *sctx, int sig) {
 void ALWAYS_INLINE rtl_generic_sighandler(bool sigact, int sig,
                                           __sanitizer_siginfo *info,
                                           void *ctx) {
+  cur_thread_init();
   ThreadState *thr = cur_thread();
   ThreadSignalContext *sctx = SigCtx(thr);
   if (sig < 0 || sig >= kSigCount) {
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors.h b/compiler-rt/lib/tsan/rtl/tsan_interceptors.h
index 29b0f76f971..88d1edd775d 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors.h
@@ -23,6 +23,7 @@ LibIgnore *libignore();
 
 #if !SANITIZER_GO
 INLINE bool in_symbolizer() {
+  cur_thread_init();
   return UNLIKELY(cur_thread()->in_symbolizer);
 }
 #endif
@@ -30,6 +31,7 @@ INLINE bool in_symbolizer() {
 }  // namespace __tsan
 
 #define SCOPED_INTERCEPTOR_RAW(func, ...) \
+    cur_thread_init(); \
     ThreadState *thr = cur_thread(); \
     const uptr caller_pc = GET_CALLER_PC(); \
     ScopedInterceptor si(thr, #func, caller_pc); \
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interface.cc b/compiler-rt/lib/tsan/rtl/tsan_interface.cc
index 09a84015295..8101ba19382 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interface.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_interface.cc
@@ -24,6 +24,7 @@ typedef u32 uint32_t;
 typedef u64 uint64_t;
 
 void __tsan_init() {
+  cur_thread_init();
   Initialize(cur_thread());
 }
 
@@ -123,6 +124,33 @@ void __sanitizer_unaligned_store64(uu64 *addr, u64 v) {
   __tsan_unaligned_write8(addr);
   *addr = v;
 }
+
+#if !SANITIZER_MAC && !SANITIZER_ANDROID
+SANITIZER_INTERFACE_ATTRIBUTE
+void *__tsan_get_current_fiber() {
+  return cur_thread();
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void *__tsan_create_fiber(unsigned flags) {
+  return FiberCreate(cur_thread(), CALLERPC, flags);
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_destroy_fiber(void *fiber) {
+  FiberDestroy(cur_thread(), CALLERPC, static_cast<ThreadState *>(fiber));
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_switch_to_fiber(void *fiber, unsigned flags) {
+  FiberSwitch(cur_thread(), CALLERPC, static_cast<ThreadState *>(fiber), flags);
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_set_fiber_name(void *fiber, const char *name) {
+  ThreadSetName(static_cast<ThreadState *>(fiber), name);
+}
+#endif // !SANITIZER_MAC && !SANITIZER_ANDROID
 }  // extern "C"
 
 void __tsan_acquire(void *addr) {
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.h b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
index 37ca731e923..1804deaf56a 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
@@ -384,6 +384,9 @@ struct ThreadState {
   // taken by epoch between synchs.
   // This way we can save one load from tls.
   u64 fast_synch_epoch;
+  // Technically `current` should be a separate THREADLOCAL variable;
+  // but it is placed here in order to share cache line with previous fields.
+  ThreadState* current;
   // This is a slow path flag. On fast path, fast_state.GetIgnoreBit() is read.
   // We do not distinguish beteween ignoring reads and writes
   // for better performance.
@@ -462,11 +465,20 @@ struct ThreadState {
 #if SANITIZER_MAC || SANITIZER_ANDROID
 ThreadState *cur_thread();
 void cur_thread_finalize();
+INLINE void cur_thread_init() { }
 #else
 __attribute__((tls_model("initial-exec")))
 extern THREADLOCAL char cur_thread_placeholder[];
 INLINE ThreadState *cur_thread() {
-  return reinterpret_cast<ThreadState *>(&cur_thread_placeholder);
+  return reinterpret_cast<ThreadState *>(cur_thread_placeholder)->current;
+}
+INLINE void cur_thread_init() {
+  ThreadState *thr = reinterpret_cast<ThreadState *>(cur_thread_placeholder);
+  if (UNLIKELY(!thr->current))
+    thr->current = thr;
+}
+INLINE void set_cur_thread(ThreadState *thr) {
+  reinterpret_cast<ThreadState *>(cur_thread_placeholder)->current = thr;
 }
 INLINE void cur_thread_finalize() { }
 #endif  // SANITIZER_MAC || SANITIZER_ANDROID
@@ -868,6 +880,16 @@ uptr ALWAYS_INLINE HeapEnd() {
 }
 #endif
 
+ThreadState *FiberCreate(ThreadState *thr, uptr pc, unsigned flags);
+void FiberDestroy(ThreadState *thr, uptr pc, ThreadState *fiber);
+void FiberSwitch(ThreadState *thr, uptr pc, ThreadState *fiber, unsigned flags);
+
+// These need to match __tsan_switch_to_fiber_* flags defined in
+// tsan_interface.h. See documentation there as well.
+enum FiberSwitchFlags {
+  FiberSwitchFlagNoSync = 1 << 0, // __tsan_switch_to_fiber_no_sync
+};
+
 }  // namespace __tsan
 
 #endif  // TSAN_RTL_H
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc
index de429a553d1..60513489448 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc
@@ -246,7 +246,8 @@ void ThreadStart(ThreadState *thr, int tid, tid_t os_id,
   uptr tls_addr = 0;
   uptr tls_size = 0;
 #if !SANITIZER_GO
-  GetThreadStackAndTls(tid == 0, &stk_addr, &stk_size, &tls_addr, &tls_size);
+  if (thread_type != ThreadType::Fiber)
+    GetThreadStackAndTls(tid == 0, &stk_addr, &stk_size, &tls_addr, &tls_size);
 
   if (tid) {
     if (stk_addr && stk_size)
@@ -404,4 +405,40 @@ void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr,
   }
 }
 
+#if !SANITIZER_MAC && !SANITIZER_ANDROID && !SANITIZER_GO
+void FiberSwitchImpl(ThreadState *from, ThreadState *to) {
+  Processor *proc = from->proc();
+  ProcUnwire(proc, from);
+  ProcWire(proc, to);
+  set_cur_thread(to);
+}
+
+ThreadState *FiberCreate(ThreadState *thr, uptr pc, unsigned flags) {
+  void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadState));
+  ThreadState *fiber = static_cast<ThreadState *>(mem);
+  internal_memset(fiber, 0, sizeof(*fiber));
+  int tid = ThreadCreate(thr, pc, 0, true);
+  FiberSwitchImpl(thr, fiber);
+  ThreadStart(fiber, tid, 0, ThreadType::Fiber);
+  FiberSwitchImpl(fiber, thr);
+  return fiber;
+}
+
+void FiberDestroy(ThreadState *thr, uptr pc, ThreadState *fiber) {
+  FiberSwitchImpl(thr, fiber);
+  ThreadFinish(fiber);
+  FiberSwitchImpl(fiber, thr);
+  internal_free(fiber);
+}
+
+void FiberSwitch(ThreadState *thr, uptr pc,
+                 ThreadState *fiber, unsigned flags) {
+  if (!(flags & FiberSwitchFlagNoSync))
+    Release(thr, pc, (uptr)fiber);
+  FiberSwitchImpl(thr, fiber);
+  if (!(flags & FiberSwitchFlagNoSync))
+    Acquire(fiber, pc, (uptr)fiber);
+}
+#endif
+
 }  // namespace __tsan