diff --git a/compiler-rt/lib/asan/asan_thread.cpp b/compiler-rt/lib/asan/asan_thread.cpp
--- a/compiler-rt/lib/asan/asan_thread.cpp
+++ b/compiler-rt/lib/asan/asan_thread.cpp
@@ -507,15 +507,30 @@
 
 void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches) {}
 
-void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
-                            void *arg) {
+void GetThreadExtraStackRangesLocked(tid_t os_id,
+                                     InternalMmapVector<Range> *ranges) {
   __asan::AsanThread *t = __asan::GetAsanThreadByOsIDLocked(os_id);
   if (!t)
     return;
   __asan::FakeStack *fake_stack = t->get_fake_stack();
   if (!fake_stack)
     return;
-  fake_stack->ForEachFakeFrame(callback, arg);
+
+  fake_stack->ForEachFakeFrame(
+      [](uptr begin, uptr end, void *arg) {
+        reinterpret_cast<InternalMmapVector<Range> *>(arg)->push_back(
+            {begin : begin, end : end});
+      },
+      ranges);
+}
+
+void GetThreadExtraStackRangesLocked(InternalMmapVector<Range> *ranges) {
+  GetAsanThreadRegistryLocked()->RunCallbackForEachThreadLocked(
+      [](ThreadContextBase *tctx, void *arg) {
+        GetThreadExtraStackRangesLocked(
+            tctx->os_id, reinterpret_cast<InternalMmapVector<Range> *>(arg));
+      },
+      ranges);
 }
 
 void GetAdditionalThreadContextPtrsLocked(InternalMmapVector<uptr> *ptrs) {
diff --git a/compiler-rt/lib/hwasan/hwasan_thread.cpp b/compiler-rt/lib/hwasan/hwasan_thread.cpp
--- a/compiler-rt/lib/hwasan/hwasan_thread.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_thread.cpp
@@ -194,8 +194,9 @@
 
 void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches) {}
 
-void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
-                            void *arg) {}
+void GetThreadExtraStackRangesLocked(tid_t os_id,
+                                     InternalMmapVector<Range> *ranges) {}
+void GetThreadExtraStackRangesLocked(InternalMmapVector<Range> *ranges) {}
 
 void GetAdditionalThreadContextPtrsLocked(InternalMmapVector<uptr> *ptrs) {}
 void GetRunningThreadsLocked(InternalMmapVector<tid_t> *threads) {}
diff --git a/compiler-rt/lib/lsan/lsan_common.h b/compiler-rt/lib/lsan/lsan_common.h
--- a/compiler-rt/lib/lsan/lsan_common.h
+++ b/compiler-rt/lib/lsan/lsan_common.h
@@ -79,6 +79,11 @@
   kIgnoreObjectInvalid
 };
 
+struct Range {
+  uptr begin;
+  uptr end;
+};
+
 //// --------------------------------------------------------------------------
 //// Poisoning prototypes.
 //// --------------------------------------------------------------------------
@@ -105,8 +110,9 @@
                            uptr *tls_begin, uptr *tls_end, uptr *cache_begin,
                            uptr *cache_end, DTLS **dtls);
 void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches);
-void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
-                            void *arg);
+void GetThreadExtraStackRangesLocked(InternalMmapVector<Range> *ranges);
+void GetThreadExtraStackRangesLocked(tid_t os_id,
+                                     InternalMmapVector<Range> *ranges);
 void GetAdditionalThreadContextPtrsLocked(InternalMmapVector<uptr> *ptrs);
 void GetRunningThreadsLocked(InternalMmapVector<tid_t> *threads);
 
@@ -250,7 +256,6 @@
 InternalMmapVectorNoCtor<RootRegion> const *GetRootRegions();
 void ScanRootRegion(Frontier *frontier, RootRegion const &region,
                     uptr region_begin, uptr region_end, bool is_readable);
-void ForEachExtraStackRangeCb(uptr begin, uptr end, void *arg);
 // Run stoptheworld while holding any platform-specific locks, as well as the
 // allocator and thread registry locks.
 void LockStuffAndStopTheWorld(StopTheWorldCallback callback,
@@ -260,6 +265,7 @@
                           Frontier *frontier,
                           const char *region_type, ChunkTag tag);
 void ScanGlobalRange(uptr begin, uptr end, Frontier *frontier);
+void ScanExtraStackRanges(tid_t os_id, Frontier *frontier);
 
 // Functions called from the parent tool.
 const char *MaybeCallLsanDefaultOptions();
diff --git a/compiler-rt/lib/lsan/lsan_common.cpp b/compiler-rt/lib/lsan/lsan_common.cpp
--- a/compiler-rt/lib/lsan/lsan_common.cpp
+++ b/compiler-rt/lib/lsan/lsan_common.cpp
@@ -353,9 +353,12 @@
   }
 }
 
-void ForEachExtraStackRangeCb(uptr begin, uptr end, void *arg) {
-  Frontier *frontier = reinterpret_cast<Frontier *>(arg);
-  ScanRangeForPointers(begin, end, frontier, "FAKE STACK", kReachable);
+void ScanExtraStackRanges(const InternalMmapVector<Range> &ranges,
+                          Frontier *frontier) {
+  for (uptr i = 0; i < ranges.size(); i++) {
+    ScanRangeForPointers(ranges[i].begin, ranges[i].end, frontier, "FAKE STACK",
+                         kReachable);
+  }
 }
 
 #  if SANITIZER_FUCHSIA
@@ -397,6 +400,7 @@
                            Frontier *frontier, tid_t caller_tid,
                            uptr caller_sp) {
   InternalMmapVector<uptr> registers;
+  InternalMmapVector<Range> extra_ranges;
   for (uptr i = 0; i < suspended_threads.ThreadCount(); i++) {
     tid_t os_id = static_cast<tid_t>(suspended_threads.GetThreadID(i));
     LOG_THREADS("Processing thread %llu.\n", os_id);
@@ -457,7 +461,9 @@
       }
       ScanRangeForPointers(stack_begin, stack_end, frontier, "STACK",
                            kReachable);
-      ForEachExtraStackRange(os_id, ForEachExtraStackRangeCb, frontier);
+      extra_ranges.clear();
+      GetThreadExtraStackRangesLocked(os_id, &extra_ranges);
+      ScanExtraStackRanges(extra_ranges, frontier);
     }
 
     if (flags()->use_tls) {
diff --git a/compiler-rt/lib/lsan/lsan_common_fuchsia.cpp b/compiler-rt/lib/lsan/lsan_common_fuchsia.cpp
--- a/compiler-rt/lib/lsan/lsan_common_fuchsia.cpp
+++ b/compiler-rt/lib/lsan/lsan_common_fuchsia.cpp
@@ -144,17 +144,13 @@
 
         // We don't use the thread registry at all for enumerating the threads
         // and their stacks, registers, and TLS regions.  So use it separately
-        // just for the allocator cache, and to call ForEachExtraStackRange,
+        // just for the allocator cache, and to call ScanExtraStackRanges,
         // which ASan needs.
         if (flags()->use_stacks) {
-          GetLsanThreadRegistryLocked()->RunCallbackForEachThreadLocked(
-              [](ThreadContextBase *tctx, void *arg) {
-                ForEachExtraStackRange(tctx->os_id, ForEachExtraStackRangeCb,
-                                       arg);
-              },
-              &params->argument->frontier);
+          InternalMmapVector<Range> ranges;
+          GetThreadExtraStackRangesLocked(&ranges);
+          ScanExtraStackRanges(ranges, &params->argument->frontier);
         }
-
         params->callback(SuspendedThreadsListFuchsia(), params->argument);
       },
       &params);
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
@@ -75,8 +75,9 @@
 
 ///// Interface to the common LSan module. /////
 
-void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
-                            void *arg) {}
+void GetThreadExtraStackRangesLocked(tid_t os_id,
+                                     InternalMmapVector<Range> *ranges) {}
+void GetThreadExtraStackRangesLocked(InternalMmapVector<Range> *ranges) {}
 
 void LockThreadRegistry() { thread_registry->Lock(); }