1 files changed, 37 insertions, 0 deletions

diff --git a/compiler-rt/lib/tsan/rtl/tsan_mman.cc b/compiler-rt/lib/tsan/rtl/tsan_mman.cc
index 038407f0749..d3af9a08c19 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_mman.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_mman.cc
@@ -63,10 +63,29 @@ Allocator *allocator() {
   return reinterpret_cast<Allocator*>(&allocator_placeholder);
 }
 
+struct GlobalProc {
+  Mutex mtx;
+  Processor *proc;
+
+  GlobalProc()
+      : mtx(MutexTypeGlobalProc, StatMtxGlobalProc)
+      , proc(ProcCreate()) {
+  }
+};
+
+static char global_proc_placeholder[sizeof(GlobalProc)] ALIGNED(64);
+GlobalProc *global_proc() {
+  return reinterpret_cast<GlobalProc*>(&global_proc_placeholder);
+}
+
 void InitializeAllocator() {
   allocator()->Init(common_flags()->allocator_may_return_null);
 }
 
+void InitializeAllocatorLate() {
+  new(global_proc()) GlobalProc();
+}
+
 void AllocatorProcStart(Processor *proc) {
   allocator()->InitCache(&proc->alloc_cache);
   internal_allocator()->InitCache(&proc->internal_alloc_cache);
@@ -118,11 +137,29 @@ void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
 }
 
 void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
+  GlobalProc *gp = nullptr;
+  if (thr->proc() == nullptr) {
+    // If we don't have a proc, use the global one.
+    // There is currently only one known case where this path is triggered:
+    //   __interceptor_free
+    //   __nptl_deallocate_tsd
+    //   start_thread
+    //   clone
+    // Ideally, we destroy thread state (and unwire proc) when a thread actually
+    // exits (i.e. when we join/wait it). Then we would not need the global proc
+    gp = global_proc();
+    gp->mtx.Lock();
+    ProcWire(gp->proc, thr);
+  }
   if (ctx && ctx->initialized)
     OnUserFree(thr, pc, (uptr)p, true);
   allocator()->Deallocate(&thr->proc()->alloc_cache, p);
   if (signal)
     SignalUnsafeCall(thr, pc);
+  if (gp) {
+    ProcUnwire(gp->proc, thr);
+    gp->mtx.Unlock();
+  }
 }
 
 void OnUserAlloc(ThreadState *thr, uptr pc, uptr p, uptr sz, bool write) {