[llvm] r328890 - DataFlowSanitizer: wrappers of functions with local linkage should have the same linkage as the function being wrapped

[Peter Collingbourne via llvm-commits]

Author: pcc
Date: Fri Mar 30 11:37:55 2018
New Revision: 328890

URL: http://llvm.org/viewvc/llvm-project?rev=328890&view=rev
Log:
DataFlowSanitizer: wrappers of functions with local linkage should have the same linkage as the function being wrapped

This patch resolves link errors when the address of a static function is taken, and that function is uninstrumented by DFSan.

This change resolves bug 36314.

Patch by Sam Kerner!

Differential Revision: https://reviews.llvm.org/D44784

Added:
    llvm/trunk/test/Instrumentation/DataFlowSanitizer/uninstrumented_local_functions.ll
Modified:
    llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
    llvm/trunk/test/Instrumentation/DataFlowSanitizer/Inputs/abilist.txt

Modified: llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp?rev=328890&r1=328889&r2=328890&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp Fri Mar 30 11:37:55 2018
@@ -859,9 +859,17 @@ bool DataFlowSanitizer::runOnModule(Modu
       FunctionType *NewFT = getInstrumentedABI() == IA_Args
                                 ? getArgsFunctionType(FT)
                                 : FT;
+
+      // If the function being wrapped has local linkage, then preserve the
+      // function's linkage in the wrapper function.
+      GlobalValue::LinkageTypes wrapperLinkage =
+          F.hasLocalLinkage()
+              ? F.getLinkage()
+              : GlobalValue::LinkOnceODRLinkage;
+
       Function *NewF = buildWrapperFunction(
           &F, std::string("dfsw$") + std::string(F.getName()),
-          GlobalValue::LinkOnceODRLinkage, NewFT);
+          wrapperLinkage, NewFT);
       if (getInstrumentedABI() == IA_TLS)
         NewF->removeAttributes(AttributeList::FunctionIndex, ReadOnlyNoneAttrs);
 

Modified: llvm/trunk/test/Instrumentation/DataFlowSanitizer/Inputs/abilist.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/DataFlowSanitizer/Inputs/abilist.txt?rev=328890&r1=328889&r2=328890&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/DataFlowSanitizer/Inputs/abilist.txt (original)
+++ llvm/trunk/test/Instrumentation/DataFlowSanitizer/Inputs/abilist.txt Fri Mar 30 11:37:55 2018
@@ -6,3 +6,5 @@ fun:functional=functional
 
 fun:custom*=uninstrumented
 fun:custom*=custom
+
+fun:uninstrumented*=uninstrumented

Added: llvm/trunk/test/Instrumentation/DataFlowSanitizer/uninstrumented_local_functions.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/DataFlowSanitizer/uninstrumented_local_functions.ll?rev=328890&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/DataFlowSanitizer/uninstrumented_local_functions.ll (added)
+++ llvm/trunk/test/Instrumentation/DataFlowSanitizer/uninstrumented_local_functions.ll Fri Mar 30 11:37:55 2018
@@ -0,0 +1,24 @@
+; RUN: opt < %s -dfsan -dfsan-args-abi -dfsan-abilist=%S/Inputs/abilist.txt -S | FileCheck %s
+; RUN: opt < %s -dfsan                 -dfsan-abilist=%S/Inputs/abilist.txt -S | FileCheck %s
+
+target triple = "x86_64-unknown-linux-gnu"
+
+define internal i8 @uninstrumented_internal_fun(i8 %in) {
+  ret i8 %in
+}
+
+define i8 @call_uninstrumented_internal_fun(i8 %in) {
+  %call = call i8 @uninstrumented_internal_fun(i8 %in)
+  ret i8 %call
+}
+; CHECK: define internal {{(i8|{ i8, i16 })}} @"dfsw$uninstrumented_internal_fun"
+
+define private i8 @uninstrumented_private_fun(i8 %in) {
+  ret i8 %in
+}
+
+define i8 @call_uninstrumented_private_fun(i8 %in) {
+  %call = call i8 @uninstrumented_private_fun(i8 %in)
+  ret i8 %call
+}
+; CHECK: define private {{(i8|{ i8, i16 })}} @"dfsw$uninstrumented_private_fun"