From f7077a445b4955b872a8033569a44addb592eb02 Mon Sep 17 00:00:00 2001
From: Evgeniy Stepanov <eugeni.stepanov@gmail.com>
Date: Tue, 15 Mar 2016 20:19:29 +0000
Subject: [PATCH] [cfi] Don't emit checks for disabled CFI kinds.
In the cross-DSO CFI mode clang emits __cfi_check_fail that handles
errors triggered from other modules with targets in the current
module. With this change, __cfi_check_fail will handle errors for
CFI kinds that are not enabled in the current module as if they
have the trapping behaviour (-fsanitize-trap=...).
This fixes a bug where some combinations of -fsanitize* flags may
result in a link failure due to a missing sanitizer runtime library
for the diagnostic calls in __cfi_check_fail.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@263578 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/CodeGen/CGExpr.cpp | 15 ++++----
test/CodeGen/cfi-check-fail.c | 3 +-
test/CodeGen/cfi-check-fail2.c | 70 ++++++++++++++++++++++++++++++++++
3 files changed, 79 insertions(+), 9 deletions(-)
create mode 100644 test/CodeGen/cfi-check-fail2.c
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index ccda7f4d1aa..1b99f100de1 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -2479,16 +2479,12 @@ void CodeGenFunction::EmitCheck(
assert(JointCond);
CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
- // In cross-DSO CFI mode this code is used to generate __cfi_check_fail, which
- // includes all checks, even those that are not in SanOpts.
- assert(CGM.getCodeGenOpts().SanitizeCfiCrossDso ||
- SanOpts.has(Checked[0].second));
+ assert(SanOpts.has(Checked[0].second));
#ifndef NDEBUG
for (int i = 1, n = Checked.size(); i < n; ++i) {
assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
"All recoverable kinds in a single check must be same!");
- assert(CGM.getCodeGenOpts().SanitizeCfiCrossDso ||
- SanOpts.has(Checked[i].second));
+ assert(SanOpts.has(Checked[i].second));
}
#endif
@@ -2670,8 +2666,11 @@ void CodeGenFunction::EmitCfiCheckFail() {
SanitizerMask Mask = CheckKindMaskPair.second;
llvm::Value *Cond =
Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
- EmitCheck(std::make_pair(Cond, Mask), "cfi_check_fail", {},
- {Data, Addr, ValidVtable});
+ if (CGM.getLangOpts().Sanitize.has(Mask))
+ EmitCheck(std::make_pair(Cond, Mask), "cfi_check_fail", {},
+ {Data, Addr, ValidVtable});
+ else
+ EmitTrapCheck(Cond);
}
FinishFunction();
diff --git a/test/CodeGen/cfi-check-fail.c b/test/CodeGen/cfi-check-fail.c
index e533830a40b..bb89a91b511 100644
--- a/test/CodeGen/cfi-check-fail.c
+++ b/test/CodeGen/cfi-check-fail.c
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 -triple x86_64-unknown-linux -O0 -fsanitize=cfi-icall -fsanitize-cfi-cross-dso \
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -O0 -fsanitize-cfi-cross-dso \
+// RUN: -fsanitize=cfi-icall,cfi-nvcall,cfi-vcall,cfi-unrelated-cast,cfi-derived-cast \
// RUN: -fsanitize-trap=cfi-icall,cfi-nvcall -fsanitize-recover=cfi-vcall,cfi-unrelated-cast \
// RUN: -emit-llvm -o - %s | FileCheck %s
diff --git a/test/CodeGen/cfi-check-fail2.c b/test/CodeGen/cfi-check-fail2.c
new file mode 100644
index 00000000000..b87e1a2433d
--- /dev/null
+++ b/test/CodeGen/cfi-check-fail2.c
@@ -0,0 +1,70 @@
+// __cfi_check_fail codegen when not all CFI checkers are enabled.
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -O0 -fsanitize-cfi-cross-dso \
+// RUN: -fsanitize=cfi-vcall \
+// RUN: -emit-llvm -o - %s | FileCheck %s
+
+void caller(void (*f)()) {
+ f();
+}
+
+// CHECK: define weak_odr hidden void @__cfi_check_fail(i8*, i8*) {
+// CHECK: store i8* %0, i8** %[[ALLOCA0:.*]], align 8
+// CHECK: store i8* %1, i8** %[[ALLOCA1:.*]], align 8
+// CHECK: %[[DATA:.*]] = load i8*, i8** %[[ALLOCA0]], align 8
+// CHECK: %[[ADDR:.*]] = load i8*, i8** %[[ALLOCA1]], align 8
+// CHECK: %[[ICMP_NOT_NULL:.*]] = icmp ne i8* %[[DATA]], null
+// CHECK: br i1 %[[ICMP_NOT_NULL]], label %[[CONT0:.*]], label %[[TRAP:.*]],
+
+// CHECK: [[TRAP]]:
+// CHECK-NEXT: call void @llvm.trap()
+// CHECK-NEXT: unreachable
+
+// CHECK: [[CONT0]]:
+// CHECK: %[[A:.*]] = bitcast i8* %[[DATA]] to { i8, { i8*, i32, i32 }, i8* }*
+// CHECK: %[[KINDPTR:.*]] = getelementptr {{.*}} %[[A]], i32 0, i32 0
+// CHECK: %[[KIND:.*]] = load i8, i8* %[[KINDPTR]], align 4
+// CHECK: %[[VTVALID0:.*]] = call i1 @llvm.bitset.test(i8* %[[ADDR]], metadata !"all-vtables")
+// CHECK: %[[VTVALID:.*]] = zext i1 %[[VTVALID0]] to i64
+// CHECK: %[[NOT_0:.*]] = icmp ne i8 %[[KIND]], 0
+// CHECK: br i1 %[[NOT_0]], label %[[CONT1:.*]], label %[[HANDLE0:.*]], !prof
+
+// CHECK: [[HANDLE0]]:
+// CHECK: %[[DATA0:.*]] = ptrtoint i8* %[[DATA]] to i64,
+// CHECK: %[[ADDR0:.*]] = ptrtoint i8* %[[ADDR]] to i64,
+// CHECK: call void @__ubsan_handle_cfi_check_fail_abort(i64 %[[DATA0]], i64 %[[ADDR0]], i64 %[[VTVALID]])
+// CHECK: unreachable
+
+// CHECK: [[CONT1]]:
+// CHECK: %[[NOT_1:.*]] = icmp ne i8 %[[KIND]], 1
+// CHECK: br i1 %[[NOT_1]], label %[[CONT2:.*]], label %[[HANDLE1:.*]], !nosanitize
+
+// CHECK: [[HANDLE1]]:
+// CHECK-NEXT: call void @llvm.trap()
+// CHECK-NEXT: unreachable
+
+// CHECK: [[CONT2]]:
+// CHECK: %[[NOT_2:.*]] = icmp ne i8 %[[KIND]], 2
+// CHECK: br i1 %[[NOT_2]], label %[[CONT3:.*]], label %[[HANDLE2:.*]], !nosanitize
+
+// CHECK: [[HANDLE2]]:
+// CHECK-NEXT: call void @llvm.trap()
+// CHECK-NEXT: unreachable
+
+// CHECK: [[CONT3]]:
+// CHECK: %[[NOT_3:.*]] = icmp ne i8 %[[KIND]], 3
+// CHECK: br i1 %[[NOT_3]], label %[[CONT4:.*]], label %[[HANDLE3:.*]], !nosanitize
+
+// CHECK: [[HANDLE3]]:
+// CHECK-NEXT: call void @llvm.trap()
+// CHECK-NEXT: unreachable
+
+// CHECK: [[CONT4]]:
+// CHECK: %[[NOT_4:.*]] = icmp ne i8 %[[KIND]], 4
+// CHECK: br i1 %[[NOT_4]], label %[[CONT5:.*]], label %[[HANDLE4:.*]], !nosanitize
+
+// CHECK: [[HANDLE4]]:
+// CHECK-NEXT: call void @llvm.trap()
+// CHECK-NEXT: unreachable
+
+// CHECK: [[CONT5]]:
+// CHECK: ret void
--
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