Index: lib/Transforms/Instrumentation/InstrProfiling.cpp
===================================================================
--- lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -288,6 +288,8 @@
 
 void InstrProfiling::emitRuntimeHook() {
 
+  if (Triple(M->getTargetTriple()).isOSLinux()) return;
+
   // If the module's provided its own runtime, we don't need to do anything.
   if (M->getGlobalVariable(getInstrProfRuntimeHookVarName())) return;
 
Index: test/Instrumentation/InstrProfiling/linkage.ll
===================================================================
--- test/Instrumentation/InstrProfiling/linkage.ll
+++ test/Instrumentation/InstrProfiling/linkage.ll
@@ -1,7 +1,7 @@
 ;; Check that runtime symbols get appropriate linkage.
 
 ; RUN: opt < %s -mtriple=x86_64-apple-macosx10.10.0 -instrprof -S | FileCheck %s
-; RUN: opt < %s -mtriple=x86_64-unknown-linux -instrprof -S | FileCheck %s
+; RUN: opt < %s -mtriple=x86_64-unknown-linux -instrprof -S | FileCheck %s --check-prefix=LINUX
 
 @__llvm_profile_name_foo = hidden constant [3 x i8] c"foo"
 @__llvm_profile_name_foo_weak = weak hidden constant [8 x i8] c"foo_weak"
@@ -10,6 +10,8 @@
 
 ; CHECK: @__llvm_profile_counters_foo = hidden global
 ; CHECK: @__llvm_profile_data_foo = hidden constant
+; LINUX: @__llvm_profile_counters_foo = hidden global
+; LINUX: @__llvm_profile_data_foo = hidden constant
 define void @foo() {
   call void @llvm.instrprof.increment(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @__llvm_profile_name_foo, i32 0, i32 0), i64 0, i32 1, i32 0)
   ret void
@@ -17,6 +19,8 @@
 
 ; CHECK: @__llvm_profile_counters_foo_weak = weak hidden global
 ; CHECK: @__llvm_profile_data_foo_weak = weak hidden constant
+; LINUX: @__llvm_profile_counters_foo_weak = weak hidden global
+; LINUX: @__llvm_profile_data_foo_weak = weak hidden constant
 define weak void @foo_weak() {
   call void @llvm.instrprof.increment(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @__llvm_profile_name_foo_weak, i32 0, i32 0), i64 0, i32 1, i32 0)
   ret void
@@ -24,6 +28,8 @@
 
 ; CHECK: @"__llvm_profile_counters_linkage.ll:foo_internal" = internal global
 ; CHECK: @"__llvm_profile_data_linkage.ll:foo_internal" = internal constant
+; LINUX: @"__llvm_profile_counters_linkage.ll:foo_internal" = internal global
+; LINUX: @"__llvm_profile_data_linkage.ll:foo_internal" = internal constant
 define internal void @foo_internal() {
   call void @llvm.instrprof.increment(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @"__llvm_profile_name_linkage.ll:foo_internal", i32 0, i32 0), i64 0, i32 1, i32 0)
   ret void
@@ -31,6 +37,8 @@
 
 ; CHECK: @__llvm_profile_counters_foo_inline = linkonce_odr hidden global
 ; CHECK: @__llvm_profile_data_foo_inline = linkonce_odr hidden constant
+; LINUX: @__llvm_profile_counters_foo_inline = linkonce_odr hidden global
+; LINUX: @__llvm_profile_data_foo_inline = linkonce_odr hidden constant
 define linkonce_odr void @foo_inline() {
   call void @llvm.instrprof.increment(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @__llvm_profile_name_foo_inline, i32 0, i32 0), i64 0, i32 1, i32 0)
   ret void
@@ -39,8 +47,11 @@
 declare void @llvm.instrprof.increment(i8*, i64, i32, i32)
 
 ; CHECK: @__llvm_profile_runtime = external global i32
+; LINUX-NOT: @__llvm_profile_runtime = external global i32
 
 ; CHECK: define linkonce_odr hidden i32 @__llvm_profile_runtime_user() {{.*}} {
 ; CHECK:   %[[REG:.*]] = load i32, i32* @__llvm_profile_runtime
 ; CHECK:   ret i32 %[[REG]]
 ; CHECK: }
+; LINUX-NOT: define linkonce_odr hidden i32 @__llvm_profile_runtime_user() {{.*}} {
+; LINUX-NOT:   %[[REG:.*]] = load i32, i32* @__llvm_profile_runtime