diff --git a/compiler-rt/lib/lsan/lsan_fuchsia.cpp b/compiler-rt/lib/lsan/lsan_fuchsia.cpp
--- a/compiler-rt/lib/lsan/lsan_fuchsia.cpp
+++ b/compiler-rt/lib/lsan/lsan_fuchsia.cpp
@@ -62,7 +62,7 @@
   OnCreatedArgs args;
   __sanitizer::GetThreadStackTopAndBottom(true, &args.stack_end,
                                           &args.stack_begin);
-  u32 tid = ThreadCreate(0, GetThreadSelf(), true, &args);
+  u32 tid = ThreadCreate(kMainTid, true, &args);
   CHECK_EQ(tid, 0);
   ThreadStart(tid);
 }
@@ -86,14 +86,13 @@
 void *__sanitizer_before_thread_create_hook(thrd_t thread, bool detached,
                                             const char *name, void *stack_base,
                                             size_t stack_size) {
-  uptr user_id = reinterpret_cast<uptr>(thread);
   ENSURE_LSAN_INITED;
   EnsureMainThreadIDIsCorrect();
   OnCreatedArgs args;
   args.stack_begin = reinterpret_cast<uptr>(stack_base);
   args.stack_end = args.stack_begin + stack_size;
   u32 parent_tid = GetCurrentThread();
-  u32 tid = ThreadCreate(parent_tid, user_id, detached, &args);
+  u32 tid = ThreadCreate(parent_tid, detached, &args);
   return reinterpret_cast<void *>(static_cast<uptr>(tid));
 }
 
diff --git a/compiler-rt/lib/lsan/lsan_interceptors.cpp b/compiler-rt/lib/lsan/lsan_interceptors.cpp
--- a/compiler-rt/lib/lsan/lsan_interceptors.cpp
+++ b/compiler-rt/lib/lsan/lsan_interceptors.cpp
@@ -468,8 +468,7 @@
     res = REAL(pthread_create)(th, attr, __lsan_thread_start_func, &p);
   }
   if (res == 0) {
-    int tid = ThreadCreate(GetCurrentThread(), *(uptr *)th,
-                           IsStateDetached(detached));
+    int tid = ThreadCreate(GetCurrentThread(), IsStateDetached(detached));
     CHECK_NE(tid, kMainTid);
     atomic_store(&p.tid, tid, memory_order_release);
     while (atomic_load(&p.tid, memory_order_acquire) != 0)
@@ -480,24 +479,6 @@
   return res;
 }
 
-INTERCEPTOR(int, pthread_join, void *th, void **ret) {
-  ENSURE_LSAN_INITED;
-  int tid = ThreadTid((uptr)th);
-  int res = REAL(pthread_join)(th, ret);
-  if (res == 0)
-    ThreadJoin(tid);
-  return res;
-}
-
-INTERCEPTOR(int, pthread_detach, void *th) {
-  ENSURE_LSAN_INITED;
-  int tid = ThreadTid((uptr)th);
-  int res = REAL(pthread_detach)(th);
-  if (res == 0)
-    ThreadDetach(tid);
-  return res;
-}
-
 INTERCEPTOR(void, _exit, int status) {
   if (status == 0 && HasReportedLeaks()) status = common_flags()->exitcode;
   REAL(_exit)(status);
@@ -530,8 +511,6 @@
   LSAN_MAYBE_INTERCEPT_MALLINFO;
   LSAN_MAYBE_INTERCEPT_MALLOPT;
   INTERCEPT_FUNCTION(pthread_create);
-  INTERCEPT_FUNCTION(pthread_detach);
-  INTERCEPT_FUNCTION(pthread_join);
   INTERCEPT_FUNCTION(_exit);
 
   LSAN_MAYBE_INTERCEPT__LWP_EXIT;
diff --git a/compiler-rt/lib/lsan/lsan_mac.cpp b/compiler-rt/lib/lsan/lsan_mac.cpp
--- a/compiler-rt/lib/lsan/lsan_mac.cpp
+++ b/compiler-rt/lib/lsan/lsan_mac.cpp
@@ -68,7 +68,7 @@
 ALWAYS_INLINE
 void lsan_register_worker_thread(int parent_tid) {
   if (GetCurrentThread() == kInvalidTid) {
-    u32 tid = ThreadCreate(parent_tid, 0, true);
+    u32 tid = ThreadCreate(parent_tid, true);
     ThreadStart(tid, GetTid());
     SetCurrentThread(tid);
   }
diff --git a/compiler-rt/lib/lsan/lsan_posix.cpp b/compiler-rt/lib/lsan/lsan_posix.cpp
--- a/compiler-rt/lib/lsan/lsan_posix.cpp
+++ b/compiler-rt/lib/lsan/lsan_posix.cpp
@@ -75,7 +75,7 @@
 }
 
 void InitializeMainThread() {
-  u32 tid = ThreadCreate(kMainTid, 0, true);
+  u32 tid = ThreadCreate(kMainTid, true);
   CHECK_EQ(tid, kMainTid);
   ThreadStart(tid, GetTid());
 }
diff --git a/compiler-rt/lib/lsan/lsan_thread.h b/compiler-rt/lib/lsan/lsan_thread.h
--- a/compiler-rt/lib/lsan/lsan_thread.h
+++ b/compiler-rt/lib/lsan/lsan_thread.h
@@ -45,11 +45,8 @@
 void InitializeThreadRegistry();
 void InitializeMainThread();
 
-u32 ThreadCreate(u32 tid, uptr uid, bool detached, void *arg = nullptr);
+u32 ThreadCreate(u32 tid, bool detached, void *arg = nullptr);
 void ThreadFinish();
-void ThreadDetach(u32 tid);
-void ThreadJoin(u32 tid);
-u32 ThreadTid(uptr uid);
 
 u32 GetCurrentThread();
 void SetCurrentThread(u32 tid);
diff --git a/compiler-rt/lib/lsan/lsan_thread.cpp b/compiler-rt/lib/lsan/lsan_thread.cpp
--- a/compiler-rt/lib/lsan/lsan_thread.cpp
+++ b/compiler-rt/lib/lsan/lsan_thread.cpp
@@ -44,8 +44,8 @@
   DTLS_Destroy();
 }
 
-u32 ThreadCreate(u32 parent_tid, uptr user_id, bool detached, void *arg) {
-  return thread_registry->CreateThread(user_id, detached, parent_tid, arg);
+u32 ThreadCreate(u32 parent_tid, bool detached, void *arg) {
+  return thread_registry->CreateThread(0, detached, parent_tid, arg);
 }
 
 void ThreadContextLsanBase::ThreadStart(u32 tid, tid_t os_id,
@@ -68,28 +68,6 @@
   return (ThreadContext *)thread_registry->GetThreadLocked(GetCurrentThread());
 }
 
-static bool FindThreadByUid(ThreadContextBase *tctx, void *arg) {
-  uptr uid = (uptr)arg;
-  if (tctx->user_id == uid && tctx->status != ThreadStatusInvalid) {
-    return true;
-  }
-  return false;
-}
-
-u32 ThreadTid(uptr uid) {
-  return thread_registry->FindThread(FindThreadByUid, (void *)uid);
-}
-
-void ThreadDetach(u32 tid) {
-  CHECK_NE(tid, kInvalidTid);
-  thread_registry->DetachThread(tid, /* arg */ nullptr);
-}
-
-void ThreadJoin(u32 tid) {
-  CHECK_NE(tid, kInvalidTid);
-  thread_registry->JoinThread(tid, /* arg */ nullptr);
-}
-
 void EnsureMainThreadIDIsCorrect() {
   if (GetCurrentThread() == kMainTid)
     CurrentThreadContext()->os_id = GetTid();