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-rw-r--r--lib/Transforms/Instrumentation/AddressSanitizer.cpp79
-rw-r--r--test/Instrumentation/AddressSanitizer/coverage.ll35
2 files changed, 74 insertions, 40 deletions
diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index c03075c9ea..fe875192f5 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -33,6 +33,7 @@
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/InstVisitor.h"
@@ -130,8 +131,9 @@ static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
// This flag may need to be replaced with -f[no]asan-globals.
static cl::opt<bool> ClGlobals("asan-globals",
cl::desc("Handle global objects"), cl::Hidden, cl::init(true));
-static cl::opt<bool> ClCoverage("asan-coverage",
- cl::desc("ASan coverage"), cl::Hidden, cl::init(false));
+static cl::opt<int> ClCoverage("asan-coverage",
+ cl::desc("ASan coverage. 0: none, 1: entry block, 2: all blocks"),
+ cl::Hidden, cl::init(false));
static cl::opt<bool> ClInitializers("asan-initialization-order",
cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(false));
static cl::opt<bool> ClMemIntrin("asan-memintrin",
@@ -320,7 +322,8 @@ struct AddressSanitizer : public FunctionPass {
bool LooksLikeCodeInBug11395(Instruction *I);
void FindDynamicInitializers(Module &M);
bool GlobalIsLinkerInitialized(GlobalVariable *G);
- bool InjectCoverage(Function &F);
+ bool InjectCoverage(Function &F, const ArrayRef<BasicBlock*> AllBlocks);
+ void InjectCoverageAtBlock(Function &F, BasicBlock &BB);
bool CheckInitOrder;
bool CheckUseAfterReturn;
@@ -1076,7 +1079,7 @@ void AddressSanitizer::initializeCallbacks(Module &M) {
AsanHandleNoReturnFunc = checkInterfaceFunction(M.getOrInsertFunction(
kAsanHandleNoReturnName, IRB.getVoidTy(), NULL));
AsanCovFunction = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanCovName, IRB.getVoidTy(), IntptrTy, NULL));
+ kAsanCovName, IRB.getVoidTy(), NULL));
// We insert an empty inline asm after __asan_report* to avoid callback merge.
EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
StringRef(""), StringRef(""),
@@ -1148,33 +1151,11 @@ bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
return false;
}
-// Poor man's coverage that works with ASan.
-// We create a Guard boolean variable with the same linkage
-// as the function and inject this code into the entry block:
-// if (*Guard) {
-// __sanitizer_cov(&F);
-// *Guard = 1;
-// }
-// The accesses to Guard are atomic. The rest of the logic is
-// in __sanitizer_cov (it's fine to call it more than once).
-//
-// This coverage implementation provides very limited data:
-// it only tells if a given function was ever executed.
-// No counters, no per-basic-block or per-edge data.
-// But for many use cases this is what we need and the added slowdown
-// is negligible. This simple implementation will probably be obsoleted
-// by the upcoming Clang-based coverage implementation.
-// By having it here and now we hope to
-// a) get the functionality to users earlier and
-// b) collect usage statistics to help improve Clang coverage design.
-bool AddressSanitizer::InjectCoverage(Function &F) {
- if (!ClCoverage) return false;
-
+void AddressSanitizer::InjectCoverageAtBlock(Function &F, BasicBlock &BB) {
+ BasicBlock::iterator IP = BB.getFirstInsertionPt(), BE = BB.end();
// Skip static allocas at the top of the entry block so they don't become
// dynamic when we split the block. If we used our optimized stack layout,
// then there will only be one alloca and it will come first.
- BasicBlock &Entry = F.getEntryBlock();
- BasicBlock::iterator IP = Entry.getFirstInsertionPt(), BE = Entry.end();
for (; IP != BE; ++IP) {
AllocaInst *AI = dyn_cast<AllocaInst>(IP);
if (!AI || !AI->isStaticAlloca())
@@ -1190,14 +1171,48 @@ bool AddressSanitizer::InjectCoverage(Function &F) {
Load->setAtomic(Monotonic);
Load->setAlignment(1);
Value *Cmp = IRB.CreateICmpEQ(Constant::getNullValue(Int8Ty), Load);
- Instruction *Ins = SplitBlockAndInsertIfThen(Cmp, IP, false);
+ Instruction *Ins = SplitBlockAndInsertIfThen(
+ Cmp, IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
IRB.SetInsertPoint(Ins);
// We pass &F to __sanitizer_cov. We could avoid this and rely on
// GET_CALLER_PC, but having the PC of the first instruction is just nice.
- IRB.CreateCall(AsanCovFunction, IRB.CreatePointerCast(&F, IntptrTy));
+ Instruction *Call = IRB.CreateCall(AsanCovFunction);
+ Call->setDebugLoc(IP->getDebugLoc());
StoreInst *Store = IRB.CreateStore(ConstantInt::get(Int8Ty, 1), Guard);
Store->setAtomic(Monotonic);
Store->setAlignment(1);
+}
+
+// Poor man's coverage that works with ASan.
+// We create a Guard boolean variable with the same linkage
+// as the function and inject this code into the entry block (-asan-coverage=1)
+// or all blocks (-asan-coverage=2):
+// if (*Guard) {
+// __sanitizer_cov(&F);
+// *Guard = 1;
+// }
+// The accesses to Guard are atomic. The rest of the logic is
+// in __sanitizer_cov (it's fine to call it more than once).
+//
+// This coverage implementation provides very limited data:
+// it only tells if a given function (block) was ever executed.
+// No counters, no per-edge data.
+// But for many use cases this is what we need and the added slowdown
+// is negligible. This simple implementation will probably be obsoleted
+// by the upcoming Clang-based coverage implementation.
+// By having it here and now we hope to
+// a) get the functionality to users earlier and
+// b) collect usage statistics to help improve Clang coverage design.
+bool AddressSanitizer::InjectCoverage(Function &F,
+ const ArrayRef<BasicBlock *> AllBlocks) {
+ if (!ClCoverage) return false;
+
+ if (ClCoverage == 1) {
+ InjectCoverageAtBlock(F, F.getEntryBlock());
+ } else {
+ for (size_t i = 0, n = AllBlocks.size(); i < n; i++)
+ InjectCoverageAtBlock(F, *AllBlocks[i]);
+ }
return true;
}
@@ -1222,12 +1237,14 @@ bool AddressSanitizer::runOnFunction(Function &F) {
SmallSet<Value*, 16> TempsToInstrument;
SmallVector<Instruction*, 16> ToInstrument;
SmallVector<Instruction*, 8> NoReturnCalls;
+ SmallVector<BasicBlock*, 16> AllBlocks;
int NumAllocas = 0;
bool IsWrite;
// Fill the set of memory operations to instrument.
for (Function::iterator FI = F.begin(), FE = F.end();
FI != FE; ++FI) {
+ AllBlocks.push_back(FI);
TempsToInstrument.clear();
int NumInsnsPerBB = 0;
for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
@@ -1297,7 +1314,7 @@ bool AddressSanitizer::runOnFunction(Function &F) {
bool res = NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty();
- if (InjectCoverage(F))
+ if (InjectCoverage(F, AllBlocks))
res = true;
DEBUG(dbgs() << "ASAN done instrumenting: " << res << " " << F << "\n");
diff --git a/test/Instrumentation/AddressSanitizer/coverage.ll b/test/Instrumentation/AddressSanitizer/coverage.ll
index 47a54c0ef8..6697f4b0f2 100644
--- a/test/Instrumentation/AddressSanitizer/coverage.ll
+++ b/test/Instrumentation/AddressSanitizer/coverage.ll
@@ -1,13 +1,30 @@
-; RUN: opt < %s -asan -asan-coverage=1 -S | FileCheck %s
+; RUN: opt < %s -asan -asan-coverage=1 -S | FileCheck %s --check-prefix=CHECK1
+; RUN: opt < %s -asan -asan-coverage=2 -S | FileCheck %s --check-prefix=CHECK2
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-unknown-linux-gnu"
-define i32 @foo(i32* %a) sanitize_address {
+define void @foo(i32* %a) sanitize_address {
entry:
- ret i32 0
+ %tobool = icmp eq i32* %a, null
+ br i1 %tobool, label %if.end, label %if.then
+
+ if.then: ; preds = %entry
+ store i32 0, i32* %a, align 4
+ br label %if.end
+
+ if.end: ; preds = %entry, %if.then
+ ret void
}
-; CHECK: define i32 @foo(i32* %a) #0 {
-; CHECK: %0 = load atomic i8* @__asan_gen_cov_foo monotonic, align 1
-; CHECK: %1 = icmp eq i8 0, %0
-; CHECK: br i1 %1, label %2, label %3
-; CHECK: call void @__sanitizer_cov(i64 ptrtoint (i32 (i32*)* @foo to i64))
-; CHECK: store atomic i8 1, i8* @__asan_gen_cov_foo monotonic, align 1
+; CHECK1-LABEL: define void @foo
+; CHECK1: %0 = load atomic i8* @__asan_gen_cov_foo monotonic, align 1
+; CHECK1: %1 = icmp eq i8 0, %0
+; CHECK1: br i1 %1, label %2, label %3
+; CHECK1: call void @__sanitizer_cov
+; CHECK1-NOT: call void @__sanitizer_cov
+; CHECK1: store atomic i8 1, i8* @__asan_gen_cov_foo monotonic, align 1
+
+; CHECK2-LABEL: define void @foo
+; CHECK2: call void @__sanitizer_cov
+; CHECK2: call void @__sanitizer_cov
+; CHECK2: call void @__sanitizer_cov
+; CHECK2-NOT: call void @__sanitizer_cov
+; CHECK2: ret void
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-29 19:17:02 +0000