[llvm] r344985 - [hwasan] add stack frame descriptions.
Kostya Serebryany via llvm-commits
llvm-commits at lists.llvm.org
Mon Oct 22 17:50:40 PDT 2018
Author: kcc
Date: Mon Oct 22 17:50:40 2018
New Revision: 344985
URL: http://llvm.org/viewvc/llvm-project?rev=344985&view=rev
Log:
[hwasan] add stack frame descriptions.
Summary:
At compile-time, create an array of {PC,HumanReadableStackFrameDescription}
for every function that has an instrumented frame, and pass this array
to the run-time at the module-init time.
Similar to how we handle pc-table in SanitizerCoverage.
The run-time is dummy, will add the actual logic in later commits.
Reviewers: morehouse, eugenis
Reviewed By: eugenis
Subscribers: srhines, llvm-commits, kubamracek
Differential Revision: https://reviews.llvm.org/D53227
Added:
llvm/trunk/test/Instrumentation/HWAddressSanitizer/frame-descriptor.ll
Modified:
llvm/trunk/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
llvm/trunk/test/Instrumentation/HWAddressSanitizer/basic.ll
llvm/trunk/test/Instrumentation/HWAddressSanitizer/with-calls.ll
Modified: llvm/trunk/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp?rev=344985&r1=344984&r2=344985&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp Mon Oct 22 17:50:40 2018
@@ -44,6 +44,7 @@
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
#include "llvm/Transforms/Utils/PromoteMemToReg.h"
+#include <sstream>
using namespace llvm;
@@ -146,6 +147,11 @@ static cl::opt<bool>
cl::desc("Record stack frames with tagged allocations "
"in a thread-local ring buffer"),
cl::Hidden, cl::init(true));
+static cl::opt<bool>
+ ClCreateFrameDescriptions("hwasan-create-frame-descriptions",
+ cl::desc("create static frame descriptions"),
+ cl::Hidden, cl::init(true));
+
namespace {
/// An instrumentation pass implementing detection of addressability bugs
@@ -198,8 +204,27 @@ public:
private:
LLVMContext *C;
+ std::string CurModuleUniqueId;
Triple TargetTriple;
+ // Frame description is a way to pass names/sizes of local variables
+ // to the run-time w/o adding extra executable code in every function.
+ // We do this by creating a separate section with {PC,Descr} pairs and passing
+ // the section beg/end to __hwasan_init_frames() at module init time.
+ std::string createFrameString(ArrayRef<AllocaInst*> Allocas);
+ void createFrameGlobal(Function &F, const std::string &FrameString);
+ // Get the section name for frame descriptions. Currently ELF-only.
+ const char *getFrameSection() { return "__hwasan_frames"; }
+ const char *getFrameSectionBeg() { return "__start___hwasan_frames"; }
+ const char *getFrameSectionEnd() { return "__stop___hwasan_frames"; }
+ GlobalVariable *createFrameSectionBound(Module &M, Type *Ty,
+ const char *Name) {
+ auto GV = new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage,
+ nullptr, Name);
+ GV->setVisibility(GlobalValue::HiddenVisibility);
+ return GV;
+ }
+
/// This struct defines the shadow mapping using the rule:
/// shadow = (mem >> Scale) + Offset.
/// If InGlobal is true, then
@@ -207,7 +232,7 @@ private:
/// shadow = (mem >> Scale) + &__hwasan_shadow
/// If InTls is true, then
/// extern char *__hwasan_tls;
- /// shadow = (mem >> Scale) + align_up(__hwasan_shadow, kShadowBaseAlignment)
+ /// shadow = (mem>>Scale) + align_up(__hwasan_shadow, kShadowBaseAlignment)
struct ShadowMapping {
int Scale;
uint64_t Offset;
@@ -271,6 +296,7 @@ bool HWAddressSanitizer::doInitializatio
Mapping.init(TargetTriple);
C = &(M.getContext());
+ CurModuleUniqueId = getUniqueModuleId(&M);
IRBuilder<> IRB(*C);
IntptrTy = IRB.getIntPtrTy(DL);
Int8PtrTy = IRB.getInt8PtrTy();
@@ -285,6 +311,21 @@ bool HWAddressSanitizer::doInitializatio
/*InitArgs=*/{});
appendToGlobalCtors(M, HwasanCtorFunction, 0);
}
+
+ // Create a call to __hwasan_init_frames.
+ if (HwasanCtorFunction) {
+ // Create a dummy frame description for the CTOR function.
+ // W/o it we would have to create the call to __hwasan_init_frames after
+ // all functions are instrumented (i.e. need to have a ModulePass).
+ createFrameGlobal(*HwasanCtorFunction, "");
+ IRBuilder<> IRBCtor(HwasanCtorFunction->getEntryBlock().getTerminator());
+ IRBCtor.CreateCall(
+ declareSanitizerInitFunction(M, "__hwasan_init_frames",
+ {Int8PtrTy, Int8PtrTy}),
+ {createFrameSectionBound(M, Int8Ty, getFrameSectionBeg()),
+ createFrameSectionBound(M, Int8Ty, getFrameSectionEnd())});
+ }
+
if (!TargetTriple.isAndroid())
appendToCompilerUsed(
M, ThreadPtrGlobal = new GlobalVariable(
@@ -676,6 +717,36 @@ Value *HWAddressSanitizer::getHwasanThre
return nullptr;
}
+// Creates a string with a description of the stack frame (set of Allocas).
+// The string is intended to be human readable.
+// The current form is: Size1 Name1; Size2 Name2; ...
+std::string
+HWAddressSanitizer::createFrameString(ArrayRef<AllocaInst *> Allocas) {
+ std::ostringstream Descr;
+ for (auto AI : Allocas)
+ Descr << getAllocaSizeInBytes(*AI) << " " << AI->getName().str() << "; ";
+ return Descr.str();
+}
+
+// Creates a global in the frame section which consists of two pointers:
+// the function PC and the frame string constant.
+void HWAddressSanitizer::createFrameGlobal(Function &F,
+ const std::string &FrameString) {
+ Module &M = *F.getParent();
+ auto DescrGV = createPrivateGlobalForString(M, FrameString, true);
+ auto PtrPairTy = StructType::get(F.getType(), DescrGV->getType());
+ auto GV = new GlobalVariable(
+ M, PtrPairTy, /*isConstantGlobal*/ true, GlobalVariable::PrivateLinkage,
+ ConstantStruct::get(PtrPairTy, (Constant *)&F, (Constant *)DescrGV),
+ "__hwasan");
+ GV->setSection(getFrameSection());
+ appendToCompilerUsed(M, GV);
+ // Put GV into the F's Comadat so that if F is deleted GV can be deleted too.
+ if (&F != HwasanCtorFunction)
+ if (auto Comdat = GetOrCreateFunctionComdat(F, CurModuleUniqueId))
+ GV->setComdat(Comdat);
+}
+
Value *HWAddressSanitizer::emitPrologue(IRBuilder<> &IRB,
bool WithFrameRecord) {
if (!Mapping.InTls)
@@ -838,6 +909,9 @@ bool HWAddressSanitizer::runOnFunction(F
if (AllocasToInstrument.empty() && ToInstrument.empty())
return false;
+ if (ClCreateFrameDescriptions && !AllocasToInstrument.empty())
+ createFrameGlobal(F, createFrameString(AllocasToInstrument));
+
initializeCallbacks(*F.getParent());
assert(!LocalDynamicShadow);
Modified: llvm/trunk/test/Instrumentation/HWAddressSanitizer/basic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/HWAddressSanitizer/basic.ll?rev=344985&r1=344984&r2=344985&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/HWAddressSanitizer/basic.ll (original)
+++ llvm/trunk/test/Instrumentation/HWAddressSanitizer/basic.ll Mon Oct 22 17:50:40 2018
@@ -354,5 +354,6 @@ entry:
; CHECK: define internal void @hwasan.module_ctor() {
; CHECK-NEXT: call void @__hwasan_init()
+; CHECK-NEXT: call void @__hwasan_init_frames(
; CHECK-NEXT: ret void
; CHECK-NEXT: }
Added: llvm/trunk/test/Instrumentation/HWAddressSanitizer/frame-descriptor.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/HWAddressSanitizer/frame-descriptor.ll?rev=344985&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/HWAddressSanitizer/frame-descriptor.ll (added)
+++ llvm/trunk/test/Instrumentation/HWAddressSanitizer/frame-descriptor.ll Mon Oct 22 17:50:40 2018
@@ -0,0 +1,27 @@
+; Test frame descriptors
+;
+; RUN: opt < %s -hwasan -S | FileCheck %s
+
+target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+target triple = "aarch64--linux-android"
+
+declare void @use32(i32*, i64*)
+
+define void @test_alloca() sanitize_hwaddress {
+entry:
+ %XYZ = alloca i32, align 4
+ %ABC = alloca i64, align 4
+ call void @use32(i32* nonnull %XYZ, i64 *nonnull %ABC)
+ ret void
+}
+
+; CHECK: @[[STR:[0-9]*]] = private unnamed_addr constant [15 x i8] c"4 XYZ; 8 ABC; \00", align 1
+; CHECK: private constant { void ()*, [15 x i8]* } { void ()* @test_alloca, [15 x i8]* @[[STR]] }, section "__hwasan_frames", comdat($test_alloca)
+
+; CHECK-LABEL: @test_alloca(
+; CHECK: ret void
+
+; CHECK-LABEL: @hwasan.module_ctor
+; CHECK: call void @__hwasan_init_frames(i8* @__start___hwasan_frames, i8* @__stop___hwasan_frames)
+; CHECK: ret void
+
Modified: llvm/trunk/test/Instrumentation/HWAddressSanitizer/with-calls.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/HWAddressSanitizer/with-calls.ll?rev=344985&r1=344984&r2=344985&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/HWAddressSanitizer/with-calls.ll (original)
+++ llvm/trunk/test/Instrumentation/HWAddressSanitizer/with-calls.ll Mon Oct 22 17:50:40 2018
@@ -199,5 +199,6 @@ entry:
; CHECK: define internal void @hwasan.module_ctor() {
; CHECK-NEXT: call void @__hwasan_init()
+; CHECK-NEXT: call void @__hwasan_init_frames(
; CHECK-NEXT: ret void
; CHECK-NEXT: }
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