From: Kostya Serebryany <kcc@google.com>
Date: Wed, 24 Sep 2014 22:41:55 +0000 (+0000)
Subject: [asan] don't instrument module CTORs that may be run before asan.module_ctor. This... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0e9d1148656105a17365494044a0a82d547ee76f;p=oota-llvm.git

[asan] don't instrument module CTORs that may be run before asan.module_ctor. This fixes asan running together -coverage

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218421 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 83b64606985..03b80cc50d5 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -71,7 +71,7 @@ static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
 
 static const char *const kAsanModuleCtorName = "asan.module_ctor";
 static const char *const kAsanModuleDtorName = "asan.module_dtor";
-static const int         kAsanCtorAndDtorPriority = 1;
+static const uint64_t    kAsanCtorAndDtorPriority = 1;
 static const char *const kAsanReportErrorTemplate = "__asan_report_";
 static const char *const kAsanReportLoadN = "__asan_report_load_n";
 static const char *const kAsanReportStoreN = "__asan_report_store_n";
@@ -928,10 +928,12 @@ void AddressSanitizerModule::createInitializerPoisonCalls(
     ConstantStruct *CS = cast<ConstantStruct>(OP);
 
     // Must have a function or null ptr.
-    // (CS->getOperand(0) is the init priority.)
     if (Function* F = dyn_cast<Function>(CS->getOperand(1))) {
-      if (F->getName() != kAsanModuleCtorName)
-        poisonOneInitializer(*F, ModuleName);
+      if (F->getName() == kAsanModuleCtorName) continue;
+      ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
+      // Don't instrument CTORs that will run before asan.module_ctor.
+      if (Priority->getLimitedValue() <= kAsanCtorAndDtorPriority) continue;
+      poisonOneInitializer(*F, ModuleName);
     }
   }
 }
diff --git a/test/Instrumentation/AddressSanitizer/instrument_initializer_metadata.ll b/test/Instrumentation/AddressSanitizer/instrument_initializer_metadata.ll
index c119879351a..c2bb0aa845c 100644
--- a/test/Instrumentation/AddressSanitizer/instrument_initializer_metadata.ll
+++ b/test/Instrumentation/AddressSanitizer/instrument_initializer_metadata.ll
@@ -25,29 +25,39 @@ entry:
   ret void
 }
 
-@llvm.global_ctors = appending global [1 x { i32, void ()* }] [{ i32, void ()* } { i32 65535, void ()* @_GLOBAL__I_a }]
+@llvm.global_ctors = appending global [2 x { i32, void ()* }] [{ i32, void ()* } { i32 65535, void ()* @__late_ctor }, { i32, void ()* } { i32 0, void ()* @__early_ctor }]
 
-define internal void @_GLOBAL__I_a() sanitize_address section ".text.startup" {
+define internal void @__late_ctor() sanitize_address section ".text.startup" {
 entry:
   call void @__cxx_global_var_init()
   ret void
 }
 
 ; Clang indicated that @xxx was dynamically initailized.
-; __asan_{before,after}_dynamic_init should be called from _GLOBAL__I_a
+; __asan_{before,after}_dynamic_init should be called from __late_ctor
 
-; CHECK: define internal void @_GLOBAL__I_a
+; CHECK-LABEL: define internal void @__late_ctor
 ; CHECK-NOT: ret
 ; CHECK: call void @__asan_before_dynamic_init
 ; CHECK: call void @__cxx_global_var_init
 ; CHECK: call void @__asan_after_dynamic_init
 ; CHECK: ret
 
+; CTOR with priority 0 should not be instrumented.
+define internal void @__early_ctor() sanitize_address section ".text.startup" {
+entry:
+  call void @__cxx_global_var_init()
+  ret void
+}
+; CHECK-LABEL: define internal void @__early_ctor
+; CHECK-NOT: __asan
+; CHECK: ret
+
 ; Check that xxx is instrumented.
 define void @touch_xxx() sanitize_address {
   store i32 0, i32 *@xxx, align 4
   ret void
-; CHECK: define void @touch_xxx
+; CHECK-LABEL: touch_xxx
 ; CHECK: call void @__asan_report_store4
 ; CHECK: ret void
 }