r212872 - [ASan] Collect unmangled names of global variables in Clang to print them in error reports.
Alexey Samsonov
vonosmas at gmail.com
Fri Jul 11 17:42:52 PDT 2014
Author: samsonov
Date: Fri Jul 11 19:42:52 2014
New Revision: 212872
URL: http://llvm.org/viewvc/llvm-project?rev=212872&view=rev
Log:
[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.
Modified:
cfe/trunk/lib/CodeGen/CGDecl.cpp
cfe/trunk/lib/CodeGen/CodeGenModule.cpp
cfe/trunk/lib/CodeGen/CodeGenModule.h
cfe/trunk/test/CodeGen/asan-globals.cpp
Modified: cfe/trunk/lib/CodeGen/CGDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDecl.cpp?rev=212872&r1=212871&r2=212872&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDecl.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDecl.cpp Fri Jul 11 19:42:52 2014
@@ -345,7 +345,7 @@ void CodeGenFunction::EmitStaticVarDecl(
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();
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.cpp?rev=212872&r1=212871&r2=212872&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp Fri Jul 11 19:42:52 2014
@@ -1952,7 +1952,7 @@ void CodeGenModule::EmitGlobalVarDefinit
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::EmitGlobalVarDefinit
}
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(l
// 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(l
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::GetAddrOfConstantStringFr
if (Entry)
Entry->setValue(GV);
- reportGlobalToASan(GV, S->getStrTokenLoc(0));
+ reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>");
return GV;
}
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.h?rev=212872&r1=212871&r2=212872&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.h Fri Jul 11 19:42:52 2014
@@ -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);
Modified: cfe/trunk/test/CodeGen/asan-globals.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/asan-globals.cpp?rev=212872&r1=212871&r2=212872&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/asan-globals.cpp (original)
+++ cfe/trunk/test/CodeGen/asan-globals.cpp Fri Jul 11 19:42:52 2014
@@ -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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