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-rw-r--r--lib/Transforms/Instrumentation/AddressSanitizer.cpp39
-rw-r--r--test/Instrumentation/AddressSanitizer/asan-vs-gvn.ll2
-rw-r--r--test/Instrumentation/AddressSanitizer/instrument_global.ll65
3 files changed, 97 insertions, 9 deletions
diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 7ced56b..de0a43b 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -23,6 +23,7 @@
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Triple.h"
#include "llvm/DIBuilder.h"
@@ -193,6 +194,13 @@ static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug man inst"),
cl::Hidden, cl::init(-1));
+STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
+STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
+STATISTIC(NumOptimizedAccessesToGlobalArray,
+ "Number of optimized accesses to global arrays");
+STATISTIC(NumOptimizedAccessesToGlobalVar,
+ "Number of optimized accesses to global vars");
+
namespace {
/// A set of dynamically initialized globals extracted from metadata.
class SetOfDynamicallyInitializedGlobals {
@@ -315,6 +323,7 @@ struct AddressSanitizer : public FunctionPass {
bool ShouldInstrumentGlobal(GlobalVariable *G);
bool LooksLikeCodeInBug11395(Instruction *I);
void FindDynamicInitializers(Module &M);
+ bool GlobalIsLinkerInitialized(GlobalVariable *G);
bool CheckInitOrder;
bool CheckUseAfterReturn;
@@ -655,6 +664,13 @@ static Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite) {
return NULL;
}
+bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
+ // If a global variable does not have dynamic initialization we don't
+ // have to instrument it. However, if a global does not have initializer
+ // at all, we assume it has dynamic initializer (in other TU).
+ return G->hasInitializer() && !DynamicallyInitializedGlobals.Contains(G);
+}
+
void AddressSanitizer::instrumentMop(Instruction *I) {
bool IsWrite = false;
Value *Addr = isInterestingMemoryAccess(I, &IsWrite);
@@ -663,13 +679,19 @@ void AddressSanitizer::instrumentMop(Instruction *I) {
if (GlobalVariable *G = dyn_cast<GlobalVariable>(Addr)) {
// If initialization order checking is disabled, a simple access to a
// dynamically initialized global is always valid.
- if (!CheckInitOrder)
- return;
- // If a global variable does not have dynamic initialization we don't
- // have to instrument it. However, if a global does not have initailizer
- // at all, we assume it has dynamic initializer (in other TU).
- if (G->hasInitializer() && !DynamicallyInitializedGlobals.Contains(G))
+ if (!CheckInitOrder || GlobalIsLinkerInitialized(G)) {
+ NumOptimizedAccessesToGlobalVar++;
return;
+ }
+ }
+ ConstantExpr *CE = dyn_cast<ConstantExpr>(Addr);
+ if (CE && CE->isGEPWithNoNotionalOverIndexing()) {
+ if (GlobalVariable *G = dyn_cast<GlobalVariable>(CE->getOperand(0))) {
+ if (CE->getOperand(1)->isNullValue() && GlobalIsLinkerInitialized(G)) {
+ NumOptimizedAccessesToGlobalArray++;
+ return;
+ }
+ }
}
}
@@ -681,6 +703,11 @@ void AddressSanitizer::instrumentMop(Instruction *I) {
assert((TypeSize % 8) == 0);
+ if (IsWrite)
+ NumInstrumentedWrites++;
+ else
+ NumInstrumentedReads++;
+
// Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check.
if (TypeSize == 8 || TypeSize == 16 ||
TypeSize == 32 || TypeSize == 64 || TypeSize == 128)
diff --git a/test/Instrumentation/AddressSanitizer/asan-vs-gvn.ll b/test/Instrumentation/AddressSanitizer/asan-vs-gvn.ll
index da8f541..1087c9a 100644
--- a/test/Instrumentation/AddressSanitizer/asan-vs-gvn.ll
+++ b/test/Instrumentation/AddressSanitizer/asan-vs-gvn.ll
@@ -9,7 +9,7 @@ target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f3
%struct_of_7_bytes_4_aligned = type { i32, i8, i8, i8}
-@f = global %struct_of_7_bytes_4_aligned zeroinitializer, align 4
+@f = external global %struct_of_7_bytes_4_aligned , align 4
; Accessing bytes 4 and 6, not ok to widen to i32 if sanitize_address is set.
diff --git a/test/Instrumentation/AddressSanitizer/instrument_global.ll b/test/Instrumentation/AddressSanitizer/instrument_global.ll
index 2c183f5..4717277 100644
--- a/test/Instrumentation/AddressSanitizer/instrument_global.ll
+++ b/test/Instrumentation/AddressSanitizer/instrument_global.ll
@@ -9,12 +9,73 @@ target triple = "x86_64-unknown-linux-gnu"
; CHECK: llvm.global_ctors
; CHECK: llvm.global_dtors
-; CHECK: define internal void @asan.module_ctor
+; Test that we don't instrument global arrays with static initializer
+; indexed with constants in-bounds. But instrument all other cases.
+
+@GlobSt = global [10 x i32] zeroinitializer, align 16 ; static initializer
+@GlobDy = global [10 x i32] zeroinitializer, align 16 ; dynamic initializer
+@GlobEx = external global [10 x i32] , align 16 ; extern initializer
+
+; GlobSt is declared here, and has static initializer -- ok to optimize.
+define i32 @AccessGlobSt_0_2() sanitize_address {
+entry:
+ %0 = load i32* getelementptr inbounds ([10 x i32]* @GlobSt, i64 0, i64 2), align 8
+ ret i32 %0
+; CHECK-LABEL: define i32 @AccessGlobSt_0_2
+; CHECK-NOT: __asan_report
+; CHECK: ret i32 %0
+}
+
+; GlobSt is accessed out of bounds -- can't optimize
+define i32 @AccessGlobSt_0_12() sanitize_address {
+entry:
+ %0 = load i32* getelementptr inbounds ([10 x i32]* @GlobSt, i64 0, i64 12), align 8
+ ret i32 %0
+; CHECK-LABEL: define i32 @AccessGlobSt_0_12
+; CHECK: __asan_report
+; CHECK: ret i32
+}
+
+; GlobSt is accessed with Gep that has non-0 first index -- can't optimize.
+define i32 @AccessGlobSt_1_2() sanitize_address {
+entry:
+ %0 = load i32* getelementptr inbounds ([10 x i32]* @GlobSt, i64 1, i64 2), align 8
+ ret i32 %0
+; CHECK-LABEL: define i32 @AccessGlobSt_1_2
+; CHECK: __asan_report
+; CHECK: ret i32
+}
+
+; GlobDy is declared with dynamic initializer -- can't optimize.
+define i32 @AccessGlobDy_0_2() sanitize_address {
+entry:
+ %0 = load i32* getelementptr inbounds ([10 x i32]* @GlobDy, i64 0, i64 2), align 8
+ ret i32 %0
+; CHECK-LABEL: define i32 @AccessGlobDy_0_2
+; CHECK: __asan_report
+; CHECK: ret i32
+}
+
+; GlobEx is an external global -- can't optimize.
+define i32 @AccessGlobEx_0_2() sanitize_address {
+entry:
+ %0 = load i32* getelementptr inbounds ([10 x i32]* @GlobEx, i64 0, i64 2), align 8
+ ret i32 %0
+; CHECK-LABEL: define i32 @AccessGlobEx_0_2
+; CHECK: __asan_report
+; CHECK: ret i32
+}
+
+
+!llvm.asan.dynamically_initialized_globals = !{!0}
+!0 = metadata !{[10 x i32]* @GlobDy}
+
+; CHECK-LABEL: define internal void @asan.module_ctor
; CHECK-NOT: ret
; CHECK: call void @__asan_register_globals
; CHECK: ret
-; CHECK: define internal void @asan.module_dtor
+; CHECK-LABEL: define internal void @asan.module_dtor
; CHECK-NOT: ret
; CHECK: call void @__asan_unregister_globals
; CHECK: ret
generated by cgit v1.1 at 2024-05-28 14:00:40 +0000