[clang] d8f555d - [UBSan] Diagnose assumption violation (#104741)
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cfe-commits at lists.llvm.org
Tue Sep 24 22:59:13 PDT 2024
Author: Yingwei Zheng
Date: 2024-09-25T13:59:10+08:00
New Revision: d8f555d62546fc1fbee3d2a48b37779c629bf87b
URL: https://github.com/llvm/llvm-project/commit/d8f555d62546fc1fbee3d2a48b37779c629bf87b
DIFF: https://github.com/llvm/llvm-project/commit/d8f555d62546fc1fbee3d2a48b37779c629bf87b.diff
LOG: [UBSan] Diagnose assumption violation (#104741)
This patch extends [D34590](https://reviews.llvm.org/D34590) to check
assumption violations.
---------
Co-authored-by: Vitaly Buka <vitalybuka at google.com>
Added:
Modified:
clang/lib/CodeGen/CGBuiltin.cpp
clang/lib/CodeGen/CGStmt.cpp
clang/lib/CodeGen/CodeGenFunction.h
clang/test/CodeGen/ubsan-builtin-checks.c
compiler-rt/lib/ubsan/ubsan_handlers.cpp
compiler-rt/lib/ubsan/ubsan_handlers.h
compiler-rt/test/ubsan/TestCases/Misc/builtins.cpp
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 942468204f054c..7bbf22569e73ca 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1997,8 +1997,8 @@ struct CallObjCArcUse final : EHScopeStack::Cleanup {
Value *CodeGenFunction::EmitCheckedArgForBuiltin(const Expr *E,
BuiltinCheckKind Kind) {
- assert((Kind == BCK_CLZPassedZero || Kind == BCK_CTZPassedZero)
- && "Unsupported builtin check kind");
+ assert((Kind == BCK_CLZPassedZero || Kind == BCK_CTZPassedZero) &&
+ "Unsupported builtin check kind");
Value *ArgValue = EmitScalarExpr(E);
if (!SanOpts.has(SanitizerKind::Builtin))
@@ -2015,6 +2015,21 @@ Value *CodeGenFunction::EmitCheckedArgForBuiltin(const Expr *E,
return ArgValue;
}
+Value *CodeGenFunction::EmitCheckedArgForAssume(const Expr *E) {
+ Value *ArgValue = EvaluateExprAsBool(E);
+ if (!SanOpts.has(SanitizerKind::Builtin))
+ return ArgValue;
+
+ SanitizerScope SanScope(this);
+ EmitCheck(
+ std::make_pair(ArgValue, SanitizerKind::Builtin),
+ SanitizerHandler::InvalidBuiltin,
+ {EmitCheckSourceLocation(E->getExprLoc()),
+ llvm::ConstantInt::get(Builder.getInt8Ty(), BCK_AssumePassedFalse)},
+ std::nullopt);
+ return ArgValue;
+}
+
static Value *EmitAbs(CodeGenFunction &CGF, Value *ArgValue, bool HasNSW) {
return CGF.Builder.CreateBinaryIntrinsic(
Intrinsic::abs, ArgValue,
@@ -3428,7 +3443,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
if (E->getArg(0)->HasSideEffects(getContext()))
return RValue::get(nullptr);
- Value *ArgValue = EmitScalarExpr(E->getArg(0));
+ Value *ArgValue = EmitCheckedArgForAssume(E->getArg(0));
Function *FnAssume = CGM.getIntrinsic(Intrinsic::assume);
Builder.CreateCall(FnAssume, ArgValue);
return RValue::get(nullptr);
diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index 623857b43a5575..9bf15fca0de489 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -754,7 +754,7 @@ void CodeGenFunction::EmitAttributedStmt(const AttributedStmt &S) {
const Expr *Assumption = cast<CXXAssumeAttr>(A)->getAssumption();
if (getLangOpts().CXXAssumptions && Builder.GetInsertBlock() &&
!Assumption->HasSideEffects(getContext())) {
- llvm::Value *AssumptionVal = EvaluateExprAsBool(Assumption);
+ llvm::Value *AssumptionVal = EmitCheckedArgForAssume(Assumption);
Builder.CreateAssumption(AssumptionVal);
}
} break;
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 2df17e83bae2ee..d4e46f77868eca 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -5084,12 +5084,17 @@ class CodeGenFunction : public CodeGenTypeCache {
enum BuiltinCheckKind {
BCK_CTZPassedZero,
BCK_CLZPassedZero,
+ BCK_AssumePassedFalse,
};
/// Emits an argument for a call to a builtin. If the builtin sanitizer is
/// enabled, a runtime check specified by \p Kind is also emitted.
llvm::Value *EmitCheckedArgForBuiltin(const Expr *E, BuiltinCheckKind Kind);
+ /// Emits an argument for a call to a `__builtin_assume`. If the builtin
+ /// sanitizer is enabled, a runtime check is also emitted.
+ llvm::Value *EmitCheckedArgForAssume(const Expr *E);
+
/// Emit a description of a type in a format suitable for passing to
/// a runtime sanitizer handler.
llvm::Constant *EmitCheckTypeDescriptor(QualType T);
diff --git a/clang/test/CodeGen/ubsan-builtin-checks.c b/clang/test/CodeGen/ubsan-builtin-checks.c
index c7f6078f903bad..8535ec915ac346 100644
--- a/clang/test/CodeGen/ubsan-builtin-checks.c
+++ b/clang/test/CodeGen/ubsan-builtin-checks.c
@@ -51,3 +51,20 @@ void check_clz(int n) {
// CHECK: call void @__ubsan_handle_invalid_builtin
__builtin_clzg((unsigned int)n);
}
+
+// CHECK: define{{.*}} void @check_assume
+void check_assume(int n) {
+ // CHECK: [[TOBOOL:%.*]] = icmp ne i32 [[N:%.*]], 0
+ // CHECK-NEXT: br i1 [[TOBOOL]]
+ //
+ // Handler block:
+ // CHECK: call void @__ubsan_handle_invalid_builtin
+ // CHECK-NEXT: unreachable
+ //
+ // Continuation block:
+ // CHECK: call void @llvm.assume(i1 [[TOBOOL]])
+ __builtin_assume(n);
+
+ // CHECK: call void @__ubsan_handle_invalid_builtin
+ __attribute__((assume(n)));
+}
diff --git a/compiler-rt/lib/ubsan/ubsan_handlers.cpp b/compiler-rt/lib/ubsan/ubsan_handlers.cpp
index 9dbe8e6c0c1745..a419cf0b2b5557 100644
--- a/compiler-rt/lib/ubsan/ubsan_handlers.cpp
+++ b/compiler-rt/lib/ubsan/ubsan_handlers.cpp
@@ -633,9 +633,12 @@ static void handleInvalidBuiltin(InvalidBuiltinData *Data, ReportOptions Opts) {
ScopedReport R(Opts, Loc, ET);
- Diag(Loc, DL_Error, ET,
- "passing zero to __builtin_%0(), which is not a valid argument")
- << ((Data->Kind == BCK_CTZPassedZero) ? "ctz" : "clz");
+ if (Data->Kind == BCK_AssumePassedFalse)
+ Diag(Loc, DL_Error, ET, "assumption is violated during execution");
+ else
+ Diag(Loc, DL_Error, ET,
+ "passing zero to __builtin_%0(), which is not a valid argument")
+ << ((Data->Kind == BCK_CTZPassedZero) ? "ctz" : "clz");
}
void __ubsan::__ubsan_handle_invalid_builtin(InvalidBuiltinData *Data) {
diff --git a/compiler-rt/lib/ubsan/ubsan_handlers.h b/compiler-rt/lib/ubsan/ubsan_handlers.h
index bae661a56833dd..4ffa1439a1323f 100644
--- a/compiler-rt/lib/ubsan/ubsan_handlers.h
+++ b/compiler-rt/lib/ubsan/ubsan_handlers.h
@@ -159,6 +159,7 @@ RECOVERABLE(implicit_conversion, ImplicitConversionData *Data, ValueHandle Src,
enum BuiltinCheckKind : unsigned char {
BCK_CTZPassedZero,
BCK_CLZPassedZero,
+ BCK_AssumePassedFalse,
};
struct InvalidBuiltinData {
diff --git a/compiler-rt/test/ubsan/TestCases/Misc/builtins.cpp b/compiler-rt/test/ubsan/TestCases/Misc/builtins.cpp
index a635f7fcc686ed..2702065bce0678 100644
--- a/compiler-rt/test/ubsan/TestCases/Misc/builtins.cpp
+++ b/compiler-rt/test/ubsan/TestCases/Misc/builtins.cpp
@@ -1,8 +1,8 @@
// REQUIRES: target={{x86_64.*}}
//
-// RUN: %clangxx -fsanitize=builtin -w %s -O3 -o %t
+// RUN: %clangxx -fsanitize=builtin -fno-inline -w %s -O3 -o %t
// RUN: %run %t 2>&1 | FileCheck %s --check-prefix=RECOVER
-// RUN: %clangxx -fsanitize=builtin -fno-sanitize-recover=builtin -w %s -O3 -o %t.abort
+// RUN: %clangxx -fsanitize=builtin -fno-inline -fno-sanitize-recover=builtin -w %s -O3 -o %t.abort
// RUN: not %run %t.abort 2>&1 | FileCheck %s --check-prefix=ABORT
void check_ctz(int n) {
@@ -28,8 +28,20 @@ void check_clz(int n) {
__builtin_clzll(n);
}
+void check_assume(int n) {
+ // RECOVER: builtins.cpp:[[@LINE+1]]:20: runtime error: assumption is violated during execution
+ __builtin_assume(n);
+}
+
+void check_assume_attr(int n) {
+ // RECOVER: builtins.cpp:[[@LINE+1]]:25: runtime error: assumption is violated during execution
+ __attribute__((assume(n)));
+}
+
int main() {
check_ctz(0);
check_clz(0);
+ check_assume(0);
+ check_assume_attr(0);
return 0;
}
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