nicolas/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[ASan] Improve blacklisting of global variables.

Browse Source 
This commit changes the way we blacklist global variables in ASan.
Now the global is excluded from instrumentation (either regular
bounds checking, or initialization-order checking) if:

1) Global is explicitly blacklisted by its mangled name.
This part is left unchanged.

2) SourceLocation of a global is in blacklisted source file.
This changes the old behavior, where instead of looking at the
SourceLocation of a variable we simply considered llvm::Module
identifier. This was wrong, as identifier may not correspond to
the file name, and we incorrectly disabled instrumentation
for globals coming from #include'd files.

3) Global is blacklisted by type.
Now we build the type of a global variable using Clang machinery
(QualType::getAsString()), instead of llvm::StructType::getName().

After this commit, the active users of ASan blacklist files
may have to revisit them (this is a backwards-incompatible change).

llvm-svn: 220097
This commit is contained in:
Alexey Samsonov
2014-10-17 22:37:33 +00:00
parent 2845fb29d8
commit a0ac3c2bf0
9 changed files with 78 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
clang/lib/CodeGen/CodeGenModule.cpp
View File

@@ -1186,6 +1186,34 @@ bool CodeGenModule::isInSanitizerBlacklist(llvm::Function *Fn,
return false;
}
bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
SourceLocation Loc, QualType Ty,
StringRef Category) const {
// For now globals can be blacklisted only in ASan.
if (!LangOpts.Sanitize.Address)
return false;
const auto &SanitizerBL = getContext().getSanitizerBlacklist();
if (SanitizerBL.isBlacklistedGlobal(GV->getName(), Category))
return true;
if (SanitizerBL.isBlacklistedLocation(Loc, Category))
return true;
// Check global type.
if (!Ty.isNull()) {
// Drill down the array types: if global variable of a fixed type is
// blacklisted, we also don't instrument arrays of them.
while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
Ty = AT->getElementType();
Ty = Ty.getCanonicalType().getUnqualifiedType();
// We allow to blacklist only record types (classes, structs etc.)
if (Ty->isRecordType()) {
std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
if (SanitizerBL.isBlacklistedType(TypeStr, Category))
return true;
}
}
return false;
}
bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
// Never defer when EmitAllDecls is specified.
if (LangOpts.EmitAllDecls)
@@ -2800,7 +2828,8 @@ CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
if (Entry)
*Entry = GV;
SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>");
SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
QualType());
return GV;
}