[llvm][AddressSanitizer] option for applying AddressSanitizer to specific address spaces #167770
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@llvm/pr-subscribers-compiler-rt-sanitizer Author: Emil Tsalapatis (etsal) ChangesFor some backends, e.g., BPF, it is desirable to only sanitize memory belonging to specific address spaces. More specifically, it is sometimes desirable to only apply address sanitization for arena memory belonging to address space 1. However, AddressSanitizer currently does not support selectively sanitizing address spaces. Add a new option to select which address spaces to apply AddressSanitizer to. No functional change for existing targets (namely AMD GPU) that hardcode which address spaces to sanitize Full diff: https://github.com/llvm/llvm-project/pull/167770.diff 1 Files Affected:
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 7c364f86fb0e8..e43da407aadfe 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -436,6 +436,11 @@ static cl::opt<AsanDtorKind> ClOverrideDestructorKind(
"Use global destructors")),
cl::init(AsanDtorKind::Invalid), cl::Hidden);
+static cl::list<int> ClAddrSpaces(
+ "asan-instrument-address-spaces",
+ cl::desc("Only instrument variables in the specified address spaces."),
+ cl::Hidden, cl::CommaSeparated, cl::ZeroOrMore);
+
// Debug flags.
static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
@@ -1355,11 +1360,26 @@ static bool GlobalWasGeneratedByCompiler(GlobalVariable *G) {
static bool isUnsupportedAMDGPUAddrspace(Value *Addr) {
Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
unsigned int AddrSpace = PtrTy->getPointerAddressSpace();
+ // Globals in address space 1 and 4 are supported for AMDGPU.
if (AddrSpace == 3 || AddrSpace == 5)
return true;
return false;
}
+static bool isSupportedAddrspace(const Triple &TargetTriple, Value *Addr) {
+ Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
+ unsigned int AddrSpace = PtrTy->getPointerAddressSpace();
+
+ if (!ClAddrSpaces.empty())
+ return std::find(ClAddrSpaces.begin(), ClAddrSpaces.end(), AddrSpace) !=
+ ClAddrSpaces.end();
+
+ if (TargetTriple.isAMDGPU())
+ return !isUnsupportedAMDGPUAddrspace(Addr);
+
+ return AddrSpace == 0;
+}
+
Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
// Shadow >> scale
Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
@@ -1423,10 +1443,9 @@ bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
}
bool AddressSanitizer::ignoreAccess(Instruction *Inst, Value *Ptr) {
- // Instrument accesses from different address spaces only for AMDGPU.
- Type *PtrTy = cast<PointerType>(Ptr->getType()->getScalarType());
- if (PtrTy->getPointerAddressSpace() != 0 &&
- !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(Ptr)))
+ // Check whether the target supports sanitizing the address space
+ // of the pointer.
+ if (!isSupportedAddrspace(TargetTriple, Ptr))
return true;
// Ignore swifterror addresses.
@@ -2089,9 +2108,7 @@ bool ModuleAddressSanitizer::shouldInstrumentGlobal(GlobalVariable *G) const {
return false;
if (!Ty->isSized()) return false;
if (!G->hasInitializer()) return false;
- // Globals in address space 1 and 4 are supported for AMDGPU.
- if (G->getAddressSpace() &&
- !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(G)))
+ if (!isSupportedAddrspace(TargetTriple, G))
return false;
if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
// Two problems with thread-locals:
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@llvm/pr-subscribers-llvm-transforms Author: Emil Tsalapatis (etsal) ChangesFor some backends, e.g., BPF, it is desirable to only sanitize memory belonging to specific address spaces. More specifically, it is sometimes desirable to only apply address sanitization for arena memory belonging to address space 1. However, AddressSanitizer currently does not support selectively sanitizing address spaces. Add a new option to select which address spaces to apply AddressSanitizer to. No functional change for existing targets (namely AMD GPU) that hardcode which address spaces to sanitize Full diff: https://github.com/llvm/llvm-project/pull/167770.diff 1 Files Affected:
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 7c364f86fb0e8..e43da407aadfe 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -436,6 +436,11 @@ static cl::opt<AsanDtorKind> ClOverrideDestructorKind(
"Use global destructors")),
cl::init(AsanDtorKind::Invalid), cl::Hidden);
+static cl::list<int> ClAddrSpaces(
+ "asan-instrument-address-spaces",
+ cl::desc("Only instrument variables in the specified address spaces."),
+ cl::Hidden, cl::CommaSeparated, cl::ZeroOrMore);
+
// Debug flags.
static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
@@ -1355,11 +1360,26 @@ static bool GlobalWasGeneratedByCompiler(GlobalVariable *G) {
static bool isUnsupportedAMDGPUAddrspace(Value *Addr) {
Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
unsigned int AddrSpace = PtrTy->getPointerAddressSpace();
+ // Globals in address space 1 and 4 are supported for AMDGPU.
if (AddrSpace == 3 || AddrSpace == 5)
return true;
return false;
}
+static bool isSupportedAddrspace(const Triple &TargetTriple, Value *Addr) {
+ Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
+ unsigned int AddrSpace = PtrTy->getPointerAddressSpace();
+
+ if (!ClAddrSpaces.empty())
+ return std::find(ClAddrSpaces.begin(), ClAddrSpaces.end(), AddrSpace) !=
+ ClAddrSpaces.end();
+
+ if (TargetTriple.isAMDGPU())
+ return !isUnsupportedAMDGPUAddrspace(Addr);
+
+ return AddrSpace == 0;
+}
+
Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
// Shadow >> scale
Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
@@ -1423,10 +1443,9 @@ bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
}
bool AddressSanitizer::ignoreAccess(Instruction *Inst, Value *Ptr) {
- // Instrument accesses from different address spaces only for AMDGPU.
- Type *PtrTy = cast<PointerType>(Ptr->getType()->getScalarType());
- if (PtrTy->getPointerAddressSpace() != 0 &&
- !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(Ptr)))
+ // Check whether the target supports sanitizing the address space
+ // of the pointer.
+ if (!isSupportedAddrspace(TargetTriple, Ptr))
return true;
// Ignore swifterror addresses.
@@ -2089,9 +2108,7 @@ bool ModuleAddressSanitizer::shouldInstrumentGlobal(GlobalVariable *G) const {
return false;
if (!Ty->isSized()) return false;
if (!G->hasInitializer()) return false;
- // Globals in address space 1 and 4 are supported for AMDGPU.
- if (G->getAddressSpace() &&
- !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(G)))
+ if (!isSupportedAddrspace(TargetTriple, G))
return false;
if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
// Two problems with thread-locals:
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| unsigned int AddrSpace = PtrTy->getPointerAddressSpace(); | ||
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| if (!ClAddrSpaces.empty()) | ||
| return std::find(ClAddrSpaces.begin(), ClAddrSpaces.end(), AddrSpace) != |
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Linearly searching through the list every time seems inefficient. Maybe preprocess the list into an array, and directly index into it?
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Sounds good, I will update the diff.
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| if (!SrcAddrSpaces.empty()) | ||
| return SrcAddrSpaces.count(AddrSpace); | ||
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| if (TargetTriple.isAMDGPU()) |
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Optional: this function could be simplified to always check SrcAddrSpaces, by populating SrcAddrSpaces at the start of the pass with the AMDGPU or default address space values as appropriate.
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@etsal Congratulations on having your first Pull Request (PR) merged into the LLVM Project! Your changes will be combined with recent changes from other authors, then tested by our build bots. If there is a problem with a build, you may receive a report in an email or a comment on this PR. Please check whether problems have been caused by your change specifically, as the builds can include changes from many authors. It is not uncommon for your change to be included in a build that fails due to someone else's changes, or infrastructure issues. How to do this, and the rest of the post-merge process, is covered in detail here. If your change does cause a problem, it may be reverted, or you can revert it yourself. This is a normal part of LLVM development. You can fix your changes and open a new PR to merge them again. If you don't get any reports, no action is required from you. Your changes are working as expected, well done! |
3 participants
For some backends, e.g., BPF, it is desirable to only sanitize memory belonging to specific address spaces. More specifically, it is sometimes desirable to only apply address sanitization for arena memory belonging to address space 1. However, AddressSanitizer currently does not support selectively sanitizing address spaces. Add a new option to select which address spaces to apply AddressSanitizer to.
No functional change for existing targets (namely AMD GPU) that hardcode which address spaces to sanitize