Index: compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
===================================================================
--- compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
+++ compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
@@ -885,19 +885,21 @@
 }
 
 namespace __tsan {
-void DestroyThreadState() {
-  ThreadState *thr = cur_thread();
-  Processor *proc = thr->proc();
-  ThreadFinish(thr);
-  ProcUnwire(proc, thr);
-  ProcDestroy(proc);
+void PlatformThreadFinished(ThreadState *thr) {
   ThreadSignalContext *sctx = thr->signal_ctx;
   if (sctx) {
-    thr->signal_ctx = 0;
+    thr->signal_ctx = nullptr;
     UnmapOrDie(sctx, sizeof(*sctx));
   }
-  DTLS_Destroy();
-  cur_thread_finalize();
+
+  if (thr->tctx->thread_type != ThreadType::Fiber) {
+    CHECK_EQ(thr, cur_thread());
+    Processor *proc = thr->proc();
+    ProcUnwire(proc, thr);
+    ProcDestroy(proc);
+    DTLS_Destroy();
+    cur_thread_finalize();
+  }
 }
 }  // namespace __tsan
 
@@ -912,7 +914,7 @@
     }
     return;
   }
-  DestroyThreadState();
+  ThreadFinish(cur_thread());
 }
 #endif
 
@@ -2551,7 +2553,7 @@
 #if SANITIZER_NETBSD
 TSAN_INTERCEPTOR(void, _lwp_exit) {
   SCOPED_TSAN_INTERCEPTOR(_lwp_exit);
-  DestroyThreadState();
+  ThreadFinish(cur_thread());
   REAL(_lwp_exit)();
 }
 #define TSAN_MAYBE_INTERCEPT__LWP_EXIT TSAN_INTERCEPT(_lwp_exit)
@@ -2562,7 +2564,7 @@
 #if SANITIZER_FREEBSD
 TSAN_INTERCEPTOR(void, thr_exit, tid_t *state) {
   SCOPED_TSAN_INTERCEPTOR(thr_exit, state);
-  DestroyThreadState();
+  ThreadFinish(cur_thread());
   REAL(thr_exit(state));
 }
 #define TSAN_MAYBE_INTERCEPT_THR_EXIT TSAN_INTERCEPT(thr_exit)
Index: compiler-rt/lib/tsan/rtl/tsan_platform.h
===================================================================
--- compiler-rt/lib/tsan/rtl/tsan_platform.h
+++ compiler-rt/lib/tsan/rtl/tsan_platform.h
@@ -1020,7 +1020,7 @@
     void *abstime), void *c, void *m, void *abstime,
     void(*cleanup)(void *arg), void *arg);
 
-void DestroyThreadState();
+void PlatformThreadFinished(ThreadState *thr);
 
 }  // namespace __tsan
 
Index: compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp
===================================================================
--- compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp
+++ compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp
@@ -460,7 +460,7 @@
 #if !SANITIZER_GO
 #if SANITIZER_ANDROID
 // On Android, one thread can call intercepted functions after
-// DestroyThreadState(), so add a fake thread state for "dead" threads.
+// ThreadFinish(), so add a fake thread state for "dead" threads.
 static ThreadState *dead_thread_state = nullptr;
 
 ThreadState *cur_thread() {
Index: compiler-rt/lib/tsan/rtl/tsan_platform_mac.cpp
===================================================================
--- compiler-rt/lib/tsan/rtl/tsan_platform_mac.cpp
+++ compiler-rt/lib/tsan/rtl/tsan_platform_mac.cpp
@@ -222,7 +222,7 @@
     if (thread == pthread_self()) {
       ThreadState *thr = cur_thread();
       if (thr->tctx) {
-        DestroyThreadState();
+        ThreadFinish(thr);
       }
     }
   }
Index: compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
===================================================================
--- compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
+++ compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
@@ -283,6 +283,9 @@
     DontNeedShadowFor(thr->tls_addr, thr->tls_size);
   thr->is_dead = true;
   ctx->thread_registry->FinishThread(thr->tid);
+#if !SANITIZER_GO
+  PlatformThreadFinished(thr);
+#endif
 }
 
 struct ConsumeThreadContext {
Index: compiler-rt/test/tsan/fiber_cleanup.cpp
===================================================================
--- /dev/null
+++ compiler-rt/test/tsan/fiber_cleanup.cpp
@@ -0,0 +1,67 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+// REQUIRES: linux
+#include "test.h"
+
+#include <fstream>
+#include <mutex>
+#include <sstream>
+#include <string>
+#include <sys/types.h>
+#include <unistd.h>
+
+long count_memory_mappings() {
+  pid_t my_pid = getpid();
+  std::ifstream proc_file{"/proc/" + std::to_string(my_pid) + "/maps"};
+
+  std::string line;
+  long line_count{0};
+  while (std::getline(proc_file, line)) {
+    line_count++;
+  }
+
+  return line_count;
+}
+
+void fiber_iteration() {
+  std::mutex mtx;
+
+  void *orig_fiber = __tsan_get_current_fiber();
+  void *fiber = __tsan_create_fiber(0);
+
+  // Running some code on the fiber that triggers handling of pending signals.
+  __tsan_switch_to_fiber(fiber, 0);
+  mtx.lock();
+  mtx.unlock();
+  __tsan_switch_to_fiber(orig_fiber, 0);
+
+  // We expect the fiber to clean up all resources (here the sigcontext) when destroyed.
+  __tsan_destroy_fiber(fiber);
+}
+
+// Magic-Number for some warmup iterations,
+// as tsan maps some memory for the first runs.
+const size_t num_warmup = 100;
+
+int main() {
+  for (size_t i = 0; i < num_warmup; i++) {
+    fiber_iteration();
+  }
+
+  long memory_mappings_before = count_memory_mappings();
+  fiber_iteration();
+  fiber_iteration();
+  long memory_mappings_after = count_memory_mappings();
+
+  // Is there a better way to detect a resource  leak in the
+  // ThreadState object? (i.e. a mmap not being freed)
+  if (memory_mappings_before == memory_mappings_after) {
+    fprintf(stderr, "PASS\n");
+  } else {
+    fprintf(stderr, "FAILED\n");
+  }
+
+  return 0;
+}
+
+// CHECK-NOT: WARNING: ThreadSanitizer:
+// CHECK: PASS