DataFlowSanitizer: wrappers of functions with local linkage should have the same...

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

llvm-svn: 328890

diff --git a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
index 1619985..0bfe38a 100644 (file)
--- a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -859,9 +859,17 @@ bool DataFlowSanitizer::runOnModule(Module &M) {
       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);
 

diff --git a/llvm/test/Instrumentation/DataFlowSanitizer/Inputs/abilist.txt b/llvm/test/Instrumentation/DataFlowSanitizer/Inputs/abilist.txt
index 97ce5e6..712440e 100644 (file)
--- a/llvm/test/Instrumentation/DataFlowSanitizer/Inputs/abilist.txt
+++ b/llvm/test/Instrumentation/DataFlowSanitizer/Inputs/abilist.txt
@@ -6,3 +6,5 @@ fun:functional=functional
 
 fun:custom*=uninstrumented
 fun:custom*=custom
+
+fun:uninstrumented*=uninstrumented

diff --git a/llvm/test/Instrumentation/DataFlowSanitizer/uninstrumented_local_functions.ll b/llvm/test/Instrumentation/DataFlowSanitizer/uninstrumented_local_functions.ll
new file mode 100644 (file)
index 0000000..12579ce
--- /dev/null
+++ b/llvm/test/Instrumentation/DataFlowSanitizer/uninstrumented_local_functions.ll
@@ -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"