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[CodeGen] -fsanitize=alignment: add cl::opt sanitize-alignment-builti…
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…n to disable memcpy instrumentation (#69240)

Deploying #67766 to a large internal codebase uncovers many bugs (many
are
probably benign but need cleaning up). There are also issues in
high-profile
open-source projects like v8. Add a cl::opt to disable builtin
instrumentation
for -fsanitize=alignment to help large codebase users.

In the long term, this cl::opt option may still be useful to debug
-fsanitize=alignment instrumentation on builtins, so we probably want to
keep it around.
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@MaskRay
MaskRay authored Oct 18, 2023
1 parent 8a70102 commit e8fe4de
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Showing 2 changed files with 37 additions and 15 deletions.
7 changes: 6 additions & 1 deletion clang/lib/CodeGen/CGBuiltin.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -66,6 +66,11 @@ using namespace clang;
using namespace CodeGen;
using namespace llvm;

static llvm::cl::opt<bool> ClSanitizeAlignmentBuiltin(
"sanitize-alignment-builtin", llvm::cl::Hidden,
llvm::cl::desc("Instrument builtin functions for -fsanitize=alignment"),
llvm::cl::init(true));

static void initializeAlloca(CodeGenFunction &CGF, AllocaInst *AI, Value *Size,
Align AlignmentInBytes) {
ConstantInt *Byte;
Expand Down Expand Up @@ -2801,7 +2806,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
EmitNonNullArgCheck(RValue::get(Val), Arg->getType(), Arg->getExprLoc(), FD,
ParmNum);

if (SanOpts.has(SanitizerKind::Alignment)) {
if (SanOpts.has(SanitizerKind::Alignment) && ClSanitizeAlignmentBuiltin) {
SanitizerSet SkippedChecks;
SkippedChecks.set(SanitizerKind::All);
SkippedChecks.clear(SanitizerKind::Alignment);
Expand Down
45 changes: 31 additions & 14 deletions clang/test/CodeGen/catch-undef-behavior.c
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Original file line number Diff line number Diff line change
@@ -1,6 +1,8 @@
// RUN: %clang_cc1 -fsanitize=alignment,null,object-size,shift-base,shift-exponent,return,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -fsanitize-recover=alignment,null,object-size,shift-base,shift-exponent,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefix=CHECK-COMMON --check-prefix=CHECK-UBSAN
// RUN: %clang_cc1 -fsanitize-trap=alignment,null,object-size,shift-base,shift-exponent,return,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -fsanitize-recover=alignment,null,object-size,shift-base,shift-exponent,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -fsanitize=alignment,null,object-size,shift-base,shift-exponent,return,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -fsanitize-recover=alignment,null,object-size,shift-base,shift-exponent,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefix=CHECK-COMMON --check-prefix=CHECK-TRAP
// RUN: %clang_cc1 -fsanitize=alignment,null,object-size,shift-base,shift-exponent,return,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -fsanitize-recover=alignment,null,object-size,shift-base,shift-exponent,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefixes=CHECK-COMMON,CHECK-UBSAN,CHECK-ALIGNMENT-BUILTIN
// RUN: %clang_cc1 -fsanitize-trap=alignment,null,object-size,shift-base,shift-exponent,return,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -fsanitize-recover=alignment,null,object-size,shift-base,shift-exponent,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -fsanitize=alignment,null,object-size,shift-base,shift-exponent,return,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -fsanitize-recover=alignment,null,object-size,shift-base,shift-exponent,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefixes=CHECK-COMMON,CHECK-ALIGNMENT-BUILTIN,CHECK-TRAP
// RUN: %clang_cc1 -fsanitize=signed-integer-overflow -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefix=CHECK-OVERFLOW
/// A variant of CHECK-UBSAN with -sanitize-alignment-builtin disabled
// RUN: %clang_cc1 -fsanitize=alignment,null,object-size,shift-base,shift-exponent,return,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -fsanitize-recover=alignment,null,object-size,shift-base,shift-exponent,signed-integer-overflow,vla-bound,float-cast-overflow,integer-divide-by-zero,bool,returns-nonnull-attribute,nonnull-attribute -emit-llvm %s -o - -triple x86_64-linux-gnu -mllvm -sanitize-alignment-builtin=0 | FileCheck %s --check-prefixes=CHECK-COMMON,CHECK-UBSAN-NO-ALIGNMENT-BUILTIN

// CHECK-UBSAN: @[[INT:.*]] = private unnamed_addr constant { i16, i16, [6 x i8] } { i16 0, i16 11, [6 x i8] c"'int'\00" }

Expand Down Expand Up @@ -363,11 +365,13 @@ extern void *memcpy(void *, const void *, unsigned long) __attribute__((nonnull(
void call_memcpy_nonnull(void *p, void *q, int sz) {
// CHECK-COMMON: icmp ne ptr {{.*}}, null
// CHECK-UBSAN: call void @__ubsan_handle_nonnull_arg
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN: call void @__ubsan_handle_nonnull_arg
// CHECK-TRAP: call void @llvm.ubsantrap(i8 16)
// CHECK-COMMON-NOT: call

// CHECK-COMMON: icmp ne ptr {{.*}}, null
// CHECK-UBSAN: call void @__ubsan_handle_nonnull_arg
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN: call void @__ubsan_handle_nonnull_arg
// CHECK-TRAP: call void @llvm.ubsantrap(i8 16)
// CHECK-COMMON-NOT: call

Expand All @@ -379,18 +383,23 @@ void call_memcpy_nonnull(void *p, void *q, int sz) {
void call_memcpy(long *p, short *q, int sz) {
// CHECK-COMMON: icmp ne ptr {{.*}}, null
// CHECK-UBSAN: call void @__ubsan_handle_nonnull_arg(
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN: call void @__ubsan_handle_nonnull_arg(
// CHECK-TRAP: call void @llvm.ubsantrap(i8 16)
// CHECK-COMMON: and i64 %[[#]], 7, !nosanitize
// CHECK-COMMON: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: and i64 %[[#]], 7, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-UBSAN: call void @__ubsan_handle_type_mismatch_v1(ptr @[[LINE_1600]]
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN-NOT: call void @__ubsan_handle_type_mismatch_v1(
// CHECK-TRAP: call void @llvm.ubsantrap(i8 22)

// CHECK-COMMON: icmp ne ptr {{.*}}, null
// CHECK-UBSAN: call void @__ubsan_handle_nonnull_arg(
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN: call void @__ubsan_handle_nonnull_arg(
// CHECK-UBSAN-DISABLE-BUILTIN: call
// CHECK-TRAP: call void @llvm.ubsantrap(i8 16)
// CHECK-COMMON: and i64 %[[#]], 1, !nosanitize
// CHECK-COMMON: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: and i64 %[[#]], 1, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-UBSAN: call void @__ubsan_handle_type_mismatch_v1(
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN-NOT: call
// CHECK-TRAP: call void @llvm.ubsantrap(i8 22)

// CHECK-COMMON: call void @llvm.memcpy.p0.p0.i64(ptr align 8 %0, ptr align 2 %1, i64 %conv, i1 false)
Expand All @@ -405,14 +414,16 @@ void call_memcpy(long *p, short *q, int sz) {

// CHECK-COMMON-LABEL: define{{.*}} void @call_memcpy_inline(
void call_memcpy_inline(long *p, short *q) {
// CHECK-COMMON: and i64 %[[#]], 7, !nosanitize
// CHECK-COMMON: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: and i64 %[[#]], 7, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-UBSAN: call void @__ubsan_handle_type_mismatch_v1(
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN-NOT: call
// CHECK-TRAP: call void @llvm.ubsantrap(i8 22)

// CHECK-COMMON: and i64 %[[#]], 1, !nosanitize
// CHECK-COMMON: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: and i64 %[[#]], 1, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-UBSAN: call void @__ubsan_handle_type_mismatch_v1(
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN-NOT: call
// CHECK-TRAP: call void @llvm.ubsantrap(i8 22)

// CHECK-COMMON: call void @llvm.memcpy.inline.p0.p0.i64(ptr align 8 %0, ptr align 2 %1, i64 2, i1 false)
Expand All @@ -425,10 +436,12 @@ extern void *memmove(void *, const void *, unsigned long) __attribute__((nonnull
void call_memmove_nonnull(void *p, void *q, int sz) {
// CHECK-COMMON: icmp ne ptr {{.*}}, null
// CHECK-UBSAN: call void @__ubsan_handle_nonnull_arg
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN: call void @__ubsan_handle_nonnull_arg(
// CHECK-TRAP: call void @llvm.ubsantrap(i8 16)

// CHECK-COMMON: icmp ne ptr {{.*}}, null
// CHECK-UBSAN: call void @__ubsan_handle_nonnull_arg
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN: call void @__ubsan_handle_nonnull_arg(
// CHECK-TRAP: call void @llvm.ubsantrap(i8 16)
memmove(p, q, sz);
}
Expand All @@ -437,18 +450,22 @@ void call_memmove_nonnull(void *p, void *q, int sz) {
void call_memmove(long *p, short *q, int sz) {
// CHECK-COMMON: icmp ne ptr {{.*}}, null
// CHECK-UBSAN: call void @__ubsan_handle_nonnull_arg(
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN: call void @__ubsan_handle_nonnull_arg(
// CHECK-TRAP: call void @llvm.ubsantrap(i8 16)
// CHECK-COMMON: and i64 %[[#]], 7, !nosanitize
// CHECK-COMMON: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: and i64 %[[#]], 7, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-UBSAN: call void @__ubsan_handle_type_mismatch_v1(
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN-NOT: call
// CHECK-TRAP: call void @llvm.ubsantrap(i8 22)

// CHECK-COMMON: icmp ne ptr {{.*}}, null
// CHECK-UBSAN: call void @__ubsan_handle_nonnull_arg(
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN: call void @__ubsan_handle_nonnull_arg(
// CHECK-TRAP: call void @llvm.ubsantrap(i8 16)
// CHECK-COMMON: and i64 %[[#]], 1, !nosanitize
// CHECK-COMMON: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: and i64 %[[#]], 1, !nosanitize
// CHECK-ALIGNMENT-BUILTIN: icmp eq i64 %[[#]], 0, !nosanitize
// CHECK-UBSAN: call void @__ubsan_handle_type_mismatch_v1(
// CHECK-UBSAN-NO-ALIGNMENT-BUILTIN-NOT: call
// CHECK-TRAP: call void @llvm.ubsantrap(i8 22)

// CHECK-COMMON: call void @llvm.memmove.p0.p0.i64(ptr align 8 %0, ptr align 2 %1, i64 %conv, i1 false)
Expand Down

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