[clang] [compiler-rt] [UBSan] Diagnose assumption violation (PR #104741)
Yingwei Zheng via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 24 22:11:06 PDT 2024
https://github.com/dtcxzyw updated https://github.com/llvm/llvm-project/pull/104741
>From fdadb0fdc2288b18d4dfe4f4510d057a7552ee39 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Mon, 19 Aug 2024 15:22:39 +0800
Subject: [PATCH 1/4] [UBSan] Diagnose assumption violation
---
clang/lib/CodeGen/CGBuiltin.cpp | 18 ++++++++++++------
clang/lib/CodeGen/CGStmt.cpp | 3 ++-
clang/lib/CodeGen/CodeGenFunction.h | 1 +
clang/test/CodeGen/ubsan-builtin-checks.c | 17 +++++++++++++++++
compiler-rt/lib/ubsan/ubsan_handlers.cpp | 9 ++++++---
compiler-rt/lib/ubsan/ubsan_handlers.h | 1 +
.../test/ubsan/TestCases/Misc/builtins.cpp | 16 ++++++++++++++--
7 files changed, 53 insertions(+), 12 deletions(-)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 942468204f054c..7e93e46d3f92b9 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1997,16 +1997,21 @@ 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 ||
+ Kind == BCK_AssumePassedFalse) &&
+ "Unsupported builtin check kind");
- Value *ArgValue = EmitScalarExpr(E);
+ Value *ArgValue =
+ Kind == BCK_AssumePassedFalse ? EvaluateExprAsBool(E) : EmitScalarExpr(E);
if (!SanOpts.has(SanitizerKind::Builtin))
return ArgValue;
SanitizerScope SanScope(this);
- Value *Cond = Builder.CreateICmpNE(
- ArgValue, llvm::Constant::getNullValue(ArgValue->getType()));
+ Value *Cond =
+ Kind == BCK_AssumePassedFalse
+ ? ArgValue
+ : Builder.CreateICmpNE(
+ ArgValue, llvm::Constant::getNullValue(ArgValue->getType()));
EmitCheck(std::make_pair(Cond, SanitizerKind::Builtin),
SanitizerHandler::InvalidBuiltin,
{EmitCheckSourceLocation(E->getExprLoc()),
@@ -3428,7 +3433,8 @@ 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 =
+ EmitCheckedArgForBuiltin(E->getArg(0), BCK_AssumePassedFalse);
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..470ba3af0edc9b 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -754,7 +754,8 @@ 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 =
+ EmitCheckedArgForBuiltin(Assumption, BCK_AssumePassedFalse);
Builder.CreateAssumption(AssumptionVal);
}
} break;
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 2df17e83bae2ee..aa312e055ce71f 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -5084,6 +5084,7 @@ 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
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..bc8fc02d4d203e 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;
}
>From 6cce5061d91345182b295696cc2f2abb84ff39a5 Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka at google.com>
Date: Tue, 24 Sep 2024 15:54:18 -0700
Subject: [PATCH 2/4] Extract EmitCheckedArgForAssume
---
clang/lib/CodeGen/CGBuiltin.cpp | 33 ++++++++++++++++++-----------
clang/lib/CodeGen/CGStmt.cpp | 3 +--
clang/lib/CodeGen/CodeGenFunction.h | 4 ++++
3 files changed, 26 insertions(+), 14 deletions(-)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 7e93e46d3f92b9..ac7b54a32c8009 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1997,21 +1997,16 @@ struct CallObjCArcUse final : EHScopeStack::Cleanup {
Value *CodeGenFunction::EmitCheckedArgForBuiltin(const Expr *E,
BuiltinCheckKind Kind) {
- assert((Kind == BCK_CLZPassedZero || Kind == BCK_CTZPassedZero ||
- Kind == BCK_AssumePassedFalse) &&
- "Unsupported builtin check kind");
+ assert((Kind == BCK_CLZPassedZero || Kind == BCK_CTZPassedZero)
+ && "Unsupported builtin check kind");
- Value *ArgValue =
- Kind == BCK_AssumePassedFalse ? EvaluateExprAsBool(E) : EmitScalarExpr(E);
+ Value *ArgValue = EmitScalarExpr(E);
if (!SanOpts.has(SanitizerKind::Builtin))
return ArgValue;
SanitizerScope SanScope(this);
- Value *Cond =
- Kind == BCK_AssumePassedFalse
- ? ArgValue
- : Builder.CreateICmpNE(
- ArgValue, llvm::Constant::getNullValue(ArgValue->getType()));
+ Value *Cond = Builder.CreateICmpNE(
+ ArgValue, llvm::Constant::getNullValue(ArgValue->getType()));
EmitCheck(std::make_pair(Cond, SanitizerKind::Builtin),
SanitizerHandler::InvalidBuiltin,
{EmitCheckSourceLocation(E->getExprLoc()),
@@ -2020,6 +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,
@@ -3433,8 +3443,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
if (E->getArg(0)->HasSideEffects(getContext()))
return RValue::get(nullptr);
- Value *ArgValue =
- EmitCheckedArgForBuiltin(E->getArg(0), BCK_AssumePassedFalse);
+ 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 470ba3af0edc9b..9bf15fca0de489 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -754,8 +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 =
- EmitCheckedArgForBuiltin(Assumption, BCK_AssumePassedFalse);
+ llvm::Value *AssumptionVal = EmitCheckedArgForAssume(Assumption);
Builder.CreateAssumption(AssumptionVal);
}
} break;
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index aa312e055ce71f..d4e46f77868eca 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -5091,6 +5091,10 @@ class CodeGenFunction : public CodeGenTypeCache {
/// 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);
>From 7bcaa3bb81e54edc440abc2b4d5ac85289c6b522 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Wed, 25 Sep 2024 12:58:16 +0800
Subject: [PATCH 3/4] format
---
clang/lib/CodeGen/CGBuiltin.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index ac7b54a32c8009..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))
>From 78c2bcc6a5e2cc0181cd210414401d4f738b9954 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Wed, 25 Sep 2024 13:10:31 +0800
Subject: [PATCH 4/4] Format
---
compiler-rt/lib/ubsan/ubsan_handlers.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/compiler-rt/lib/ubsan/ubsan_handlers.cpp b/compiler-rt/lib/ubsan/ubsan_handlers.cpp
index bc8fc02d4d203e..a419cf0b2b5557 100644
--- a/compiler-rt/lib/ubsan/ubsan_handlers.cpp
+++ b/compiler-rt/lib/ubsan/ubsan_handlers.cpp
@@ -637,7 +637,7 @@ static void handleInvalidBuiltin(InvalidBuiltinData *Data, ReportOptions Opts) {
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")
+ "passing zero to __builtin_%0(), which is not a valid argument")
<< ((Data->Kind == BCK_CTZPassedZero) ? "ctz" : "clz");
}
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