diff --git a/compiler-rt/lib/msan/msan.cpp b/compiler-rt/lib/msan/msan.cpp
--- a/compiler-rt/lib/msan/msan.cpp
+++ b/compiler-rt/lib/msan/msan.cpp
@@ -584,24 +584,21 @@
 // 'descr' is created at compile time and contains '----' in the beginning.
 // When we see descr for the first time we replace '----' with a uniq id
 // and set the origin to (id | (31-th bit)).
-void __msan_set_alloca_origin(void *a, uptr size, char *descr) {
+void __msan_set_alloca_origin(void *a, uptr size, u32 *id_ptr, char *descr) {
   __msan_set_alloca_origin4(
-      a, size, descr,
+      a, size, id_ptr, descr,
       StackTrace::GetPreviousInstructionPc(
           reinterpret_cast<uptr>(__builtin_return_address(0))));
 }
 
-void __msan_set_alloca_origin4(void *a, uptr size, char *descr, uptr pc) {
-  static const u32 dash = '-';
-  static const u32 first_timer =
-      dash + (dash << 8) + (dash << 16) + (dash << 24);
-  u32 *id_ptr = (u32*)descr;
-  bool print = false;  // Previously: internal_strstr(descr + 4, "AllocaTOTest") != 0;
+void __msan_set_alloca_origin4(void *a, uptr size, u32 *id_ptr, char *descr,
+                               uptr pc) {
+  bool print = false;
   u32 id = *id_ptr;
-  if (id == first_timer || id == 0) {
+  if (id == 0) {
     u32 idx = atomic_fetch_add(&NumStackOriginDescrs, 1, memory_order_relaxed);
     CHECK_LT(idx, kNumStackOriginDescrs);
-    StackOriginDescr[idx] = descr + 4;
+    StackOriginDescr[idx] = descr;
 #if SANITIZER_PPC64V1
     // On PowerPC64 ELFv1, the address of a function actually points to a
     // three-doubleword data structure with the first field containing
@@ -613,10 +610,10 @@
     id = Origin::CreateStackOrigin(idx).raw_id();
     *id_ptr = id;
     if (print)
-      Printf("First time: idx=%d id=%d %s 0x%zx \n", idx, id, descr + 4, pc);
+      Printf("First time: idx=%d id=%d %s 0x%zx \n", idx, id, descr, pc);
   }
   if (print)
-    Printf("__msan_set_alloca_origin: descr=%s id=%x\n", descr + 4, id);
+    Printf("__msan_set_alloca_origin: descr=%s id=%x\n", descr, id);
   __msan_set_origin(a, size, id);
 }
 
diff --git a/compiler-rt/lib/msan/msan_interface_internal.h b/compiler-rt/lib/msan/msan_interface_internal.h
--- a/compiler-rt/lib/msan/msan_interface_internal.h
+++ b/compiler-rt/lib/msan/msan_interface_internal.h
@@ -105,9 +105,10 @@
 SANITIZER_INTERFACE_ATTRIBUTE
 void __msan_set_origin(const void *a, uptr size, u32 origin);
 SANITIZER_INTERFACE_ATTRIBUTE
-void __msan_set_alloca_origin(void *a, uptr size, char *descr);
+void __msan_set_alloca_origin(void *a, uptr size, u32 *id_ptr, char *descr);
 SANITIZER_INTERFACE_ATTRIBUTE
-void __msan_set_alloca_origin4(void *a, uptr size, char *descr, uptr pc);
+void __msan_set_alloca_origin4(void *a, uptr size, u32 *id_ptr, char *descr,
+                               uptr pc);
 SANITIZER_INTERFACE_ATTRIBUTE
 u32 __msan_chain_origin(u32 id);
 SANITIZER_INTERFACE_ATTRIBUTE
diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -686,7 +686,6 @@
   OS << ">";
 }
 
-#ifdef kda_COMMENTED_OUT
 /// Create a non-const global initialized with the given string.
 ///
 /// Creates a writable global for Str so that we can pass it to the
@@ -695,10 +694,9 @@
 static GlobalVariable *createPrivateNonConstGlobalForString(Module &M,
                                                             StringRef Str) {
   Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
-  return new GlobalVariable(M, StrConst->getType(), /*isConstant=*/false,
+  return new GlobalVariable(M, StrConst->getType(), /*isConstant=*/true,
                             GlobalValue::PrivateLinkage, StrConst, "");
 }
-#endif  /* kda_COMMENTED_OUT */
 
 /// Create KMSAN API callbacks.
 void MemorySanitizer::createKernelApi(Module &M) {
@@ -829,7 +827,7 @@
 
   MsanSetAllocaOriginFn = M.getOrInsertFunction(
     "__msan_set_alloca_origin", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy,
-    IRB.getInt8PtrTy());
+    IRB.getInt8PtrTy(), IRB.getInt8PtrTy());
   MsanPoisonStackFn =
       M.getOrInsertFunction("__msan_poison_stack", IRB.getVoidTy(),
                             IRB.getInt8PtrTy(), IntptrTy);
@@ -3869,19 +3867,7 @@
                                   "_msphi_o"));
   }
 
-  Value *getLocalVarOrigin(AllocaInst &I) {
-#ifdef kda_COMMENTED_OUT
-    SmallString<2048> StackDescriptionStorage;
-    raw_svector_ostream StackDescription(StackDescriptionStorage);
-    // We create a string with a description of the stack allocation and
-    // pass it into __msan_set_alloca_origin.
-    // It will be printed by the run-time if stack-originated UMR is found.
-    // The first 4 bytes of the string are set to '----' and will be replaced
-    // by __msan_va_arg_overflow_size_tls at the first call.
-    StackDescription << "----" << I.getName();
-    return createPrivateNonConstGlobalForString(*F.getParent(),
-                                                StackDescription.str());
-#endif  /* kda_COMMENTED_OUT */
+  Value *getLocalVarIdptr(AllocaInst &I) {
     ConstantInt *IntConst =
         ConstantInt::get(Type::getInt32Ty((*F.getParent()).getContext()), 0);
     return new GlobalVariable(*F.getParent(), IntConst->getType(),
@@ -3889,6 +3875,16 @@
                               IntConst);
   }
 
+  Value *getLocalVarDescription(AllocaInst &I) {
+    SmallString<2048> StackDescriptionStorage;
+    raw_svector_ostream StackDescription(StackDescriptionStorage);
+    // Create a string with a description of the stack allocation and
+    // pass it into __msan_set_alloca_origin.
+    StackDescription << I.getName();
+    return createPrivateNonConstGlobalForString(*F.getParent(),
+                                                StackDescription.str());
+  }
+
   void poisonAllocaUserspace(AllocaInst &I, IRBuilder<> &IRB, Value *Len) {
     if (PoisonStack && ClPoisonStackWithCall) {
       IRB.CreateCall(MS.MsanPoisonStackFn,
@@ -3903,19 +3899,23 @@
     }
 
     if (PoisonStack && MS.TrackOrigins) {
-      Value *Origin = getLocalVarOrigin(I);
+      Value *Idptr = getLocalVarIdptr(I);
+      Value *Descr = getLocalVarDescription(I);
       IRB.CreateCall(MS.MsanSetAllocaOriginFn,
                      {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len,
-                      IRB.CreatePointerCast(Origin, IRB.getInt8PtrTy())});
+                      IRB.CreatePointerCast(Idptr, IRB.getInt8PtrTy()),
+                      IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy())});
     }
   }
 
   void poisonAllocaKmsan(AllocaInst &I, IRBuilder<> &IRB, Value *Len) {
-    Value *Origin = getLocalVarOrigin(I);
+    Value *Idptr = getLocalVarIdptr(I);
+    Value *Descr = getLocalVarDescription(I);
     if (PoisonStack) {
       IRB.CreateCall(MS.MsanPoisonAllocaFn,
                      {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len,
-                      IRB.CreatePointerCast(Origin, IRB.getInt8PtrTy())});
+                      IRB.CreatePointerCast(Idptr, IRB.getInt8PtrTy()),
+                      IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy())});
     } else {
       IRB.CreateCall(MS.MsanUnpoisonAllocaFn,
                      {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len});