From a9b243cdf1b4b0adfb6a74e8c96638138634e979 Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <vonosmas@gmail.com>
Date: Sat, 12 Jul 2014 00:42:52 +0000
Subject: [PATCH] [ASan] Collect unmangled names of global variables in Clang
to print them in error reports.
Currently ASan instrumentation pass creates a string with global name
for each instrumented global (to include global names in the error report). Global
name is already mangled at this point, and we may not be able to demangle it
at runtime (e.g. there is no __cxa_demangle on Android).
Instead, create a string with fully qualified global name in Clang, and pass it
to ASan instrumentation pass in llvm.asan.globals metadata. If there is no metadata
for some global, ASan will use the original algorithm.
This fixes https://code.google.com/p/address-sanitizer/issues/detail?id=264.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212872 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/CodeGen/CGDecl.cpp | 2 +-
lib/CodeGen/CodeGenModule.cpp | 42 +++++++++++++++++++++++------------
lib/CodeGen/CodeGenModule.h | 4 +++-
test/CodeGen/asan-globals.cpp | 24 +++++++++++---------
4 files changed, 46 insertions(+), 26 deletions(-)
diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 9bd61d7164f..91f80419304 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -345,7 +345,7 @@ void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
DMEntry = castedAddr;
CGM.setStaticLocalDeclAddress(&D, castedAddr);
- CGM.reportGlobalToASan(var, D.getLocation());
+ CGM.reportGlobalToASan(var, D);
// Emit global variable debug descriptor for static vars.
CGDebugInfo *DI = getDebugInfo();
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 2f87392c360..66ac524f2b9 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -1952,7 +1952,7 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
if (NeedsGlobalCtor || NeedsGlobalDtor)
EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
- reportGlobalToASan(GV, D->getLocation(), NeedsGlobalCtor);
+ reportGlobalToASan(GV, *D, NeedsGlobalCtor);
// Emit global variable debug information.
if (CGDebugInfo *DI = getModuleDebugInfo())
@@ -1961,24 +1961,25 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
}
void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV,
- SourceLocation Loc, bool IsDynInit) {
+ SourceLocation Loc, StringRef Name,
+ bool IsDynInit) {
if (!LangOpts.Sanitize.Address)
return;
IsDynInit &= !SanitizerBL.isIn(*GV, "init");
bool IsBlacklisted = SanitizerBL.isIn(*GV);
- llvm::LLVMContext &LLVMCtx = TheModule.getContext();
-
llvm::GlobalVariable *LocDescr = nullptr;
+ llvm::GlobalVariable *GlobalName = nullptr;
if (!IsBlacklisted) {
- // Don't generate source location if a global is blacklisted - it won't
- // be instrumented anyway.
+ // Don't generate source location and global name if it is blacklisted -
+ // it won't be instrumented anyway.
PresumedLoc PLoc = Context.getSourceManager().getPresumedLoc(Loc);
if (PLoc.isValid()) {
llvm::Constant *LocData[] = {
GetAddrOfConstantCString(PLoc.getFilename()),
- llvm::ConstantInt::get(llvm::Type::getInt32Ty(LLVMCtx), PLoc.getLine()),
- llvm::ConstantInt::get(llvm::Type::getInt32Ty(LLVMCtx),
+ llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
+ PLoc.getLine()),
+ llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
PLoc.getColumn()),
};
auto LocStruct = llvm::ConstantStruct::getAnon(LocData);
@@ -1990,14 +1991,17 @@ void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV,
// the optimizer before the ASan instrumentation pass.
addCompilerUsedGlobal(LocDescr);
}
+ if (!Name.empty()) {
+ GlobalName = GetAddrOfConstantCString(Name);
+ // GlobalName shouldn't be removed by the optimizer.
+ addCompilerUsedGlobal(GlobalName);
+ }
}
llvm::Value *GlobalMetadata[] = {
- GV,
- LocDescr,
- llvm::ConstantInt::get(llvm::Type::getInt1Ty(LLVMCtx), IsDynInit),
- llvm::ConstantInt::get(llvm::Type::getInt1Ty(LLVMCtx), IsBlacklisted)
- };
+ GV, LocDescr, GlobalName,
+ llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsDynInit),
+ llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsBlacklisted)};
llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalMetadata);
llvm::NamedMDNode *AsanGlobals =
@@ -2005,6 +2009,16 @@ void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV,
AsanGlobals->addOperand(ThisGlobal);
}
+void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV,
+ const VarDecl &D, bool IsDynInit) {
+ if (!LangOpts.Sanitize.Address)
+ return;
+ std::string QualName;
+ llvm::raw_string_ostream OS(QualName);
+ D.printQualifiedName(OS);
+ reportGlobalToASan(GV, D.getLocation(), OS.str(), IsDynInit);
+}
+
static bool isVarDeclStrongDefinition(const VarDecl *D, bool NoCommon) {
// Don't give variables common linkage if -fno-common was specified unless it
// was overridden by a NoCommon attribute.
@@ -2810,7 +2824,7 @@ CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) {
if (Entry)
Entry->setValue(GV);
- reportGlobalToASan(GV, S->getStrTokenLoc(0));
+ reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>");
return GV;
}
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index 34254697467..d6b694a8824 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -1015,8 +1015,10 @@ public:
return SanitizerBL;
}
- void reportGlobalToASan(llvm::GlobalVariable *GV, SourceLocation Loc,
+ void reportGlobalToASan(llvm::GlobalVariable *GV, const VarDecl &D,
bool IsDynInit = false);
+ void reportGlobalToASan(llvm::GlobalVariable *GV, SourceLocation Loc,
+ StringRef Name, bool IsDynInit = false);
void addDeferredVTable(const CXXRecordDecl *RD) {
DeferredVTables.push_back(RD);
diff --git a/test/CodeGen/asan-globals.cpp b/test/CodeGen/asan-globals.cpp
index 2702f1d4500..d9ecc646154 100644
--- a/test/CodeGen/asan-globals.cpp
+++ b/test/CodeGen/asan-globals.cpp
@@ -6,27 +6,31 @@
int global;
// CHECK: [[GLOBAL_LOC:@.asan_loc_descr[0-9]*]] = private unnamed_addr constant {{.*}} i32 [[@LINE-1]], i32 5
+// CHECK: [[GLOBAL_NAME:@.str[0-9]+]] = private unnamed_addr constant {{.*}} c"global\00"
int dyn_init_global = global;
// CHECK: [[DYN_INIT_LOC:@.asan_loc_descr[0-9]*]] = {{.*}} i32 [[@LINE-1]], i32 5
+// CHECK: [[DYN_INIT_NAME:@.str[0-9]+]] = private unnamed_addr constant {{.*}} c"dyn_init_global\00"
int blacklisted_global;
void func() {
static int static_var = 0;
// CHECK: [[STATIC_LOC:@.asan_loc_descr[0-9]*]] = {{.*}} i32 [[@LINE-1]], i32 14
+ // CHECK: [[STATIC_NAME:@.str[0-9]+]] = private unnamed_addr constant {{.*}} c"static_var\00"
const char *literal = "Hello, world!";
// CHECK: [[LITERAL_LOC:@.asan_loc_descr[0-9]*]] = {{.*}} i32 [[@LINE-1]], i32 25
+ // CHECK: [[LITERAL_NAME:@.str[0-9]+]] = private unnamed_addr constant {{.*}} c"<string literal>\00"
}
// CHECK: !llvm.asan.globals = !{![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[BLACKLISTED_GLOBAL:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]}
-// CHECK: ![[GLOBAL]] = metadata !{{{.*}} [[GLOBAL_LOC]], i1 false, i1 false}
-// CHECK: ![[DYN_INIT_GLOBAL]] = metadata !{{{.*}} [[DYN_INIT_LOC]], i1 true, i1 false}
-// CHECK: ![[BLACKLISTED_GLOBAL]] = metadata !{{{.*}}, null, i1 false, i1 true}
-// CHECK: ![[STATIC_VAR]] = metadata !{{{.*}} [[STATIC_LOC]], i1 false, i1 false}
-// CHECK: ![[LITERAL]] = metadata !{{{.*}} [[LITERAL_LOC]], i1 false, i1 false}
+// CHECK: ![[GLOBAL]] = metadata !{{{.*}} [[GLOBAL_LOC]], {{.*}} [[GLOBAL_NAME]], i1 false, i1 false}
+// CHECK: ![[DYN_INIT_GLOBAL]] = metadata !{{{.*}} [[DYN_INIT_LOC]], {{.*}} [[DYN_INIT_NAME]], i1 true, i1 false}
+// CHECK: ![[BLACKLISTED_GLOBAL]] = metadata !{{{.*}}, null, null, i1 false, i1 true}
+// CHECK: ![[STATIC_VAR]] = metadata !{{{.*}} [[STATIC_LOC]], {{.*}} [[STATIC_NAME]], i1 false, i1 false}
+// CHECK: ![[LITERAL]] = metadata !{{{.*}} [[LITERAL_LOC]], {{.*}} [[LITERAL_NAME]], i1 false, i1 false}
// BLACKLIST-SRC: !llvm.asan.globals = !{![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[BLACKLISTED_GLOBAL:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]}
-// BLACKLIST-SRC: ![[GLOBAL]] = metadata !{{{.*}} null, i1 false, i1 true}
-// BLACKLIST-SRC: ![[DYN_INIT_GLOBAL]] = metadata !{{{.*}} null, i1 true, i1 true}
-// BLACKLIST-SRC: ![[BLACKLISTED_GLOBAL]] = metadata !{{{.*}}, null, i1 false, i1 true}
-// BLACKLIST-SRC: ![[STATIC_VAR]] = metadata !{{{.*}} null, i1 false, i1 true}
-// BLACKLIST-SRC: ![[LITERAL]] = metadata !{{{.*}} null, i1 false, i1 true}
+// BLACKLIST-SRC: ![[GLOBAL]] = metadata !{{{.*}} null, null, i1 false, i1 true}
+// BLACKLIST-SRC: ![[DYN_INIT_GLOBAL]] = metadata !{{{.*}} null, null, i1 true, i1 true}
+// BLACKLIST-SRC: ![[BLACKLISTED_GLOBAL]] = metadata !{{{.*}}, null, null, i1 false, i1 true}
+// BLACKLIST-SRC: ![[STATIC_VAR]] = metadata !{{{.*}} null, null, i1 false, i1 true}
+// BLACKLIST-SRC: ![[LITERAL]] = metadata !{{{.*}} null, null, i1 false, i1 true}
--
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