[llvm-branch-commits] [llvm-branch] r276810 - Merging r276015:

[Hans Wennborg via llvm-branch-commits]

Author: hans
Date: Tue Jul 26 16:22:57 2016
New Revision: 276810

URL: http://llvm.org/viewvc/llvm-project?rev=276810&view=rev
Log:
Merging r276015:
------------------------------------------------------------------------
r276015 | vedantk | 2016-07-19 13:16:08 -0700 (Tue, 19 Jul 2016) | 7 lines

[tsan] Don't instrument __llvm_gcov_global_state_pred or __llvm_gcda*

r274801 did not go far enough to allow gcov+tsan to cooperate. With this
commit it's possible to run the following code without false positives:

  std::thread T1(fib), T2(fib);
  T1.join(); T2.join();
------------------------------------------------------------------------

Modified:
    llvm/branches/release_39/   (props changed)
    llvm/branches/release_39/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
    llvm/branches/release_39/test/Instrumentation/ThreadSanitizer/do-not-instrument-memory-access.ll

Propchange: llvm/branches/release_39/
------------------------------------------------------------------------------
--- svn:mergeinfo (original)
+++ svn:mergeinfo Tue Jul 26 16:22:57 2016
@@ -1,3 +1,3 @@
 /llvm/branches/Apple/Pertwee:110850,110961
 /llvm/branches/type-system-rewrite:133420-134817
-/llvm/trunk:155241,275870,275879,275898,275928,275935,275946,276077,276109,276181,276236-276237,276358,276364,276368,276389,276438,276479,276510
+/llvm/trunk:155241,275870,275879,275898,275928,275935,275946,276015,276077,276109,276181,276236-276237,276358,276364,276368,276389,276438,276479,276510

Modified: llvm/branches/release_39/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_39/lib/Transforms/Instrumentation/ThreadSanitizer.cpp?rev=276810&r1=276809&r2=276810&view=diff
==============================================================================
--- llvm/branches/release_39/lib/Transforms/Instrumentation/ThreadSanitizer.cpp (original)
+++ llvm/branches/release_39/lib/Transforms/Instrumentation/ThreadSanitizer.cpp Tue Jul 26 16:22:57 2016
@@ -272,8 +272,9 @@ static bool shouldInstrumentReadWriteFro
         return false;
     }
 
-    // Check if the global is in a GCOV counter array.
-    if (GV->getName().startswith("__llvm_gcov_ctr"))
+    // Check if the global is private gcov data.
+    if (GV->getName().startswith("__llvm_gcov") ||
+        GV->getName().startswith("__llvm_gcda"))
       return false;
   }
 

Modified: llvm/branches/release_39/test/Instrumentation/ThreadSanitizer/do-not-instrument-memory-access.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_39/test/Instrumentation/ThreadSanitizer/do-not-instrument-memory-access.ll?rev=276810&r1=276809&r2=276810&view=diff
==============================================================================
--- llvm/branches/release_39/test/Instrumentation/ThreadSanitizer/do-not-instrument-memory-access.ll (original)
+++ llvm/branches/release_39/test/Instrumentation/ThreadSanitizer/do-not-instrument-memory-access.ll Tue Jul 26 16:22:57 2016
@@ -13,6 +13,8 @@ target triple = "x86_64-apple-macosx10.9
 
 @__llvm_gcov_ctr = internal global [1 x i64] zeroinitializer
 @__llvm_gcov_ctr.1 = internal global [1 x i64] zeroinitializer
+ at __llvm_gcov_global_state_pred = internal global i32 0
+ at __llvm_gcda_foo = internal global i32 0
 
 define i32 @test_gep() sanitize_thread {
 entry:
@@ -42,5 +44,16 @@ entry:
   ret i32 undef
 }
 
+define void @test_load() sanitize_thread {
+entry:
+  %0 = load i32, i32* @__llvm_gcov_global_state_pred
+  store i32 1, i32* @__llvm_gcov_global_state_pred
+
+  %1 = load i32, i32* @__llvm_gcda_foo
+  store i32 1, i32* @__llvm_gcda_foo
+
+  ret void
+}
+
 ; CHECK-NOT: {{call void @__tsan_write}}
 ; CHECK: __tsan_init