[ASan] Do not instrument globals from the llvm.metadata section.

Fixes https://code.google.com/p/address-sanitizer/issues/detail?id=279.

llvm-svn: 204331

2 files changed, 14 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 5c35cc8faf8..a19e1f70631 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -927,6 +927,8 @@ bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
       DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
       return false;
     }
+    // Globals from llvm.metadata aren't emitted, do not instrument them.
+    if (Section == "llvm.metadata") return false;
   }
 
   return true;
diff --git a/llvm/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll b/llvm/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll
new file mode 100644
index 00000000000..fbfc0965771
--- /dev/null
+++ b/llvm/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll
@@ -0,0 +1,12 @@
+; This test checks that we are not instrumenting globals in llvm.metadata.
+; RUN: opt < %s -asan -asan-module -S | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@.str_noinst = private unnamed_addr constant [4 x i8] c"aaa\00", section "llvm.metadata"
+@.str_inst = private unnamed_addr constant [4 x i8] c"aaa\00",
+
+; CHECK-NOT: {{asan_gen.*str_noinst}}
+; CHECK: {{asan_gen.*str_inst}}
+; CHECK: @asan.module_ctor