[PATCH] D21541: [asan] Do not instrument accesses to profiling globals

[Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL273444: [asan] Do not instrument accesses to profiling globals (authored by vedantk).

Changed prior to commit:
  http://reviews.llvm.org/D21541?vs=61327&id=61571#toc

Repository:
  rL LLVM

http://reviews.llvm.org/D21541

Files:
  llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
  llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-profiling-globals.ll

Index: llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-profiling-globals.ll
===================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-profiling-globals.ll
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-profiling-globals.ll
@@ -0,0 +1,9 @@
+; This test checks that we don't instrument globals created by profiling passes.
+; RUN: opt < %s -asan -asan-module -S | FileCheck %s
+
+ at __profc_test = private global [1 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
+ at __llvm_gcov_ctr = internal global [1 x i64] zeroinitializer
+
+; CHECK-DAG: @asan.module_ctor
+; CHECK-NOT: @__asan_gen{{.*}}__llvm_gcov_ctr
+; CHECK-NOT: @__asan_gen{{.*}}__profc_test
Index: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -857,10 +857,19 @@
   return GV;
 }
 
-static bool GlobalWasGeneratedByAsan(GlobalVariable *G) {
-  return G->getName().startswith(kAsanGenPrefix) ||
-         G->getName().startswith(kSanCovGenPrefix) ||
-         G->getName().startswith(kODRGenPrefix);
+/// \brief Check if \p G has been created by a trusted compiler pass.
+static bool GlobalWasGeneratedByCompiler(GlobalVariable *G) {
+  // Do not instrument asan globals.
+  if (G->getName().startswith(kAsanGenPrefix) ||
+      G->getName().startswith(kSanCovGenPrefix) ||
+      G->getName().startswith(kODRGenPrefix))
+    return true;
+
+  // Do not instrument gcov counter arrays.
+  if (G->getName() == "__llvm_gcov_ctr")
+    return true;
+
+  return false;
 }
 
 Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
@@ -1243,7 +1252,7 @@
   if (GlobalsMD.get(G).IsBlacklisted) return false;
   if (!Ty->isSized()) return false;
   if (!G->hasInitializer()) return false;
-  if (GlobalWasGeneratedByAsan(G)) return false;  // Our own global.
+  if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
   // Touch only those globals that will not be defined in other modules.
   // Don't handle ODR linkage types and COMDATs since other modules may be built
   // without ASan.


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