Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -681,7 +681,12 @@
 
 template <class ELFT> static void readCallGraphsFromObjectFiles() {
   auto FindSection = [&](const Symbol *Sym) -> const InputSectionBase * {
-    warnUnorderableSymbol(Sym);
+    // When linking a shared object, we may not link all object files and some
+    // symbols are left undefined. Don't warn on undefined symbols by relying on
+    // --shared implying UnresolvedPolicy::Ignore.
+    if (!Sym->isUndefined() ||
+        Config->UnresolvedSymbols != UnresolvedPolicy::Ignore)
+      warnUnorderableSymbol(Sym);
     if (const auto *SymD = dyn_cast<Defined>(Sym))
       return dyn_cast_or_null<InputSectionBase>(SymD->Section);
     return nullptr;
Index: test/ELF/cgprofile-shared-warn.s
===================================================================
--- /dev/null
+++ test/ELF/cgprofile-shared-warn.s
@@ -0,0 +1,11 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+# RUN: ld.lld --shared %t.o -o /dev/null 2>&1 | count 0
+# RUN: ld.lld -e A --unresolved-symbols=ignore-all %t.o -o /dev/null 2>&1 | count 0
+    .section    .text.A,"ax",@progbits
+    .globl  A
+A:
+    callq B
+
+    .cg_profile A, B, 10