[SanitizerBinaryMetadata] Respect no_sanitize("thread") function attribute

[melver]

Summary

To avoid false positives, respect no_sanitize("thread") when atomics
metadata is enabled.

[melver]

Fix test

clang/lib/CodeGen/CodeGenFunction.cpp

if (CGM.isInNoSanitizeList(SanitizerKind::ID, Fn, Loc))                    \
       SanOpts.set(SanitizerKind::ID, false);
 
 #include "clang/Basic/Sanitizers.def"
 #undef SANITIZER
   } while (false);
 
   if (D) {
     const bool SanitizeBounds = SanOpts.hasOneOf(SanitizerKind::Bounds);
+    SanitizerMask no_sanitize_mask;
     bool NoSanitizeCoverage = false;
 
     for (auto *Attr : D->specific_attrs<NoSanitizeAttr>()) {
-      // Apply the no_sanitize* attributes to SanOpts.
-      SanitizerMask mask = Attr->getMask();
-      SanOpts.Mask &= ~mask;
-      if (mask & SanitizerKind::Address)
-        SanOpts.set(SanitizerKind::KernelAddress, false);
-      if (mask & SanitizerKind::KernelAddress)
-        SanOpts.set(SanitizerKind::Address, false);
-      if (mask & SanitizerKind::HWAddress)
-        SanOpts.set(SanitizerKind::KernelHWAddress, false);
-      if (mask & SanitizerKind::KernelHWAddress)
-        SanOpts.set(SanitizerKind::HWAddress, false);
+      no_sanitize_mask |= Attr->getMask();
+      // SanitizeCoverage is not handled by SanOpts.
+      if (Attr->hasCoverage())
+        NoSanitizeCoverage = true;
+    }
+
+    SanOpts.Mask &= ~no_sanitize_mask;
+    if (no_sanitize_mask & SanitizerKind::Address)
+    if (no_sanitize_mask & SanitizerKind::KernelAddress)
+    if (no_sanitize_mask & SanitizerKind::HWAddress)
+    if (no_sanitize_mask & SanitizerKind::KernelHWAddress)
 
-      // SanitizeCoverage is not handled by SanOpts.
-      if (Attr->hasCoverage())
-        NoSanitizeCoverage = true;
-    }
-
     if (SanitizeBounds && !SanOpts.hasOneOf(SanitizerKind::Bounds))
       Fn->addFnAttr(llvm::Attribute::NoSanitizeBounds);
 
     if (NoSanitizeCoverage && CGM.getCodeGenOpts().hasSanitizeCoverage())
       Fn->addFnAttr(llvm::Attribute::NoSanitizeCoverage);
+
+    // Some passes need the non-negated no_sanitize attribute. Pass them on.
+    if (CGM.getCodeGenOpts().hasSanitizeBinaryMetadata()) {
+      if (no_sanitize_mask & SanitizerKind::Thread)
+        Fn->addFnAttr("no_sanitize_thread");
+    }
   }
 
   if (ShouldSkipSanitizerInstrumentation()) {
     CurFn->addFnAttr(llvm::Attribute::DisableSanitizerInstrumentation);
   } else {
     // Apply sanitizer attributes to the function.
     if (SanOpts.hasOneOf(SanitizerKind::Address | SanitizerKind::KernelAddress))
       Fn->addFnAttr(llvm::Attribute::SanitizeAddress);

clang/test/CodeGen/sanitize-metadata-nosanitize.c

+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --check-attributes --check-globals --version 2
+// RUN: %clang_cc1 -O -fexperimental-sanitize-metadata=covered -fexperimental-sanitize-metadata=atomics -fexperimental-sanitize-metadata=uar -triple x86_64-gnu-linux -x c -S -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK
+
+//.
+// CHECK: @__start_sanmd_covered = extern_weak hidden global ptr
+// CHECK: @__stop_sanmd_covered = extern_weak hidden global ptr
+// CHECK: @__start_sanmd_atomics = extern_weak hidden global ptr
+// CHECK: @__stop_sanmd_atomics = extern_weak hidden global ptr
+// CHECK: @llvm.used = appending global [4 x ptr] [ptr @__sanitizer_metadata_covered.module_ctor, ptr @__sanitizer_metadata_covered.module_dtor, ptr @__sanitizer_metadata_atomics.module_ctor, ptr @__sanitizer_metadata_atomics.module_dtor], section "llvm.metadata"
+// CHECK: @llvm.global_ctors = appending global [2 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 2, ptr @__sanitizer_metadata_covered.module_ctor, ptr @__sanitizer_metadata_covered.module_ctor }, { i32, ptr, ptr } { i32 2, ptr @__sanitizer_metadata_atomics.module_ctor, ptr @__sanitizer_metadata_atomics.module_ctor }]
+// CHECK: @llvm.global_dtors = appending global [2 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 2, ptr @__sanitizer_metadata_covered.module_dtor, ptr @__sanitizer_metadata_covered.module_dtor }, { i32, ptr, ptr } { i32 2, ptr @__sanitizer_metadata_atomics.module_dtor, ptr @__sanitizer_metadata_atomics.module_dtor }]
+//.
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(write, argmem: none, inaccessiblemem: none)
+// CHECK-LABEL: define dso_local void @escape
+// CHECK-SAME: (ptr noundef [[P:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] !pcsections !2 {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret void
+//
+__attribute__((noinline, not_tail_called)) void escape(const volatile void *p) {
+  static const volatile void *sink;
+  sink = p;
+}
+
+// CHECK: Function Attrs: mustprogress nofree norecurse nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: none)
+// CHECK-LABEL: define dso_local i32 @normal_function
+// CHECK-SAME: (ptr noundef [[X:%.*]], ptr nocapture noundef readonly [[Y:%.*]]) local_unnamed_addr #[[ATTR1:[0-9]+]] !pcsections !4 {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[X_ADDR:%.*]] = alloca ptr, align 8
+// CHECK-NEXT:    store ptr [[X]], ptr [[X_ADDR]], align 8, !tbaa [[TBAA6:![0-9]+]]
+// CHECK-NEXT:    store atomic i32 1, ptr [[X]] monotonic, align 4, !pcsections !10
+// CHECK-NEXT:    notail call void @escape(ptr noundef nonnull [[X_ADDR]])
+// CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[Y]], align 4, !tbaa [[TBAA11:![0-9]+]]
+// CHECK-NEXT:    ret i32 [[TMP0]]
+//
+int normal_function(int *x, int *y) {
+  __atomic_store_n(x, 1, __ATOMIC_RELAXED);
+  escape(&x);
+  return *y;
+}
+
+// CHECK: Function Attrs: disable_sanitizer_instrumentation mustprogress nofree norecurse nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: none)
+// CHECK-LABEL: define dso_local i32 @test_disable_sanitize_instrumentation
+// CHECK-SAME: (ptr noundef [[X:%.*]], ptr nocapture noundef readonly [[Y:%.*]]) local_unnamed_addr #[[ATTR2:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[X_ADDR:%.*]] = alloca ptr, align 8
+// CHECK-NEXT:    store ptr [[X]], ptr [[X_ADDR]], align 8, !tbaa [[TBAA6]]
+// CHECK-NEXT:    store atomic i32 1, ptr [[X]] monotonic, align 4
+// CHECK-NEXT:    notail call void @escape(ptr noundef nonnull [[X_ADDR]])
+// CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[Y]], align 4, !tbaa [[TBAA11]]
+// CHECK-NEXT:    ret i32 [[TMP0]]
+//
+__attribute__((disable_sanitizer_instrumentation)) int test_disable_sanitize_instrumentation(int *x, int *y) {
+  __atomic_store_n(x, 1, __ATOMIC_RELAXED);
+  escape(&x);
+  return *y;
+}
+
+// CHECK: Function Attrs: mustprogress nofree norecurse nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: none)
+// CHECK-LABEL: define dso_local i32 @test_no_sanitize_thread
+// CHECK-SAME: (ptr noundef [[X:%.*]], ptr nocapture noundef readonly [[Y:%.*]]) local_unnamed_addr #[[ATTR3:[0-9]+]] !pcsections !13 {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[X_ADDR:%.*]] = alloca ptr, align 8
+// CHECK-NEXT:    store ptr [[X]], ptr [[X_ADDR]], align 8, !tbaa [[TBAA6]]
+// CHECK-NEXT:    store atomic i32 1, ptr [[X]] monotonic, align 4, !pcsections !10
+// CHECK-NEXT:    notail call void @escape(ptr noundef nonnull [[X_ADDR]])
+// CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[Y]], align 4, !tbaa [[TBAA11]]
+// CHECK-NEXT:    ret i32 [[TMP0]]
+//
+__attribute__((no_sanitize("thread"))) int test_no_sanitize_thread(int *x, int *y) {
+  __atomic_store_n(x, 1, __ATOMIC_RELAXED);
+  escape(&x);
+  return *y;
+}
+
+// CHECK: Function Attrs: mustprogress nofree norecurse nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: none)
+// CHECK-LABEL: define dso_local i32 @test_no_sanitize_all
+// CHECK-SAME: (ptr noundef [[X:%.*]], ptr nocapture noundef readonly [[Y:%.*]]) local_unnamed_addr #[[ATTR3]] !pcsections !13 {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[X_ADDR:%.*]] = alloca ptr, align 8
+// CHECK-NEXT:    store ptr [[X]], ptr [[X_ADDR]], align 8, !tbaa [[TBAA6]]
+// CHECK-NEXT:    store atomic i32 1, ptr [[X]] monotonic, align 4, !pcsections !10
+// CHECK-NEXT:    notail call void @escape(ptr noundef nonnull [[X_ADDR]])
+// CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[Y]], align 4, !tbaa [[TBAA11]]
+// CHECK-NEXT:    ret i32 [[TMP0]]
+//
+__attribute__((no_sanitize("all"))) int test_no_sanitize_all(int *x, int *y) {
+  __atomic_store_n(x, 1, __ATOMIC_RELAXED);
+  escape(&x);
+  return *y;
+}
+//.
+// CHECK: attributes #0 = { mustprogress nofree noinline norecurse nosync nounwind willreturn memory(write, argmem: none, inaccessiblemem: none) "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+// CHECK: attributes #1 = { mustprogress nofree norecurse nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: none) "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+// CHECK: attributes #2 = { disable_sanitizer_instrumentation mustprogress nofree norecurse nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: none) "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+// CHECK: attributes #3 = { mustprogress nofree norecurse nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: none) "min-legal-vector-width"="0" "no-trapping-math"="true" "no_sanitize_thread" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+// CHECK: attributes #4 = { nounwind }
+//.
+// CHECK: !2 = !{!"sanmd_covered!C", !3}
+// CHECK: !3 = !{i64 0}
+// CHECK: !4 = !{!"sanmd_covered!C", !5}
+// CHECK: !5 = !{i64 3}
+// CHECK: !6 = !{!7, !7, i64 0}
+// CHECK: !7 = !{!"any pointer", !8, i64 0}
+// CHECK: !8 = !{!"omnipotent char", !9, i64 0}
+// CHECK: !9 = !{!"Simple C/C++ TBAA"}
+// CHECK: !10 = !{!"sanmd_atomics!C"}
+// CHECK: !11 = !{!12, !12, i64 0}
+// CHECK: !12 = !{!"int", !8, i64 0}
+// CHECK: !13 = !{!"sanmd_covered!C", !14}
+// CHECK: !14 = !{i64 2}
+//.

llvm/lib/Transforms/Instrumentation/SanitizerBinaryMetadata.cpp

 using MetadataInfoSet = SetVector<const MetadataInfo *>;
 
 //===--- Command-line options ---------------------------------------------===//
 
 cl::opt<bool> ClWeakCallbacks(
     "sanitizer-metadata-weak-callbacks",
     cl::desc("Declare callbacks extern weak, and only call if non-null."),
     cl::Hidden, cl::init(true));
+cl::opt<bool>
+    ClNoSanitize("sanitizer-metadata-nosanitize-attr",
+                 cl::desc("Mark some metadata features uncovered in functions "
+                          "with associated no_sanitize attributes."),
+                 cl::Hidden, cl::init(true));
 
 cl::opt<bool> ClEmitCovered("sanitizer-metadata-covered",
                             cl::desc("Emit PCs for covered functions."),
                             cl::Hidden, cl::init(false));
 cl::opt<bool> ClEmitAtomics("sanitizer-metadata-atomics",
                             cl::desc("Emit PCs for atomic operations."),
                             cl::Hidden, cl::init(false));
 cl::opt<bool> ClEmitUAR("sanitizer-metadata-uar",
void SanitizerBinaryMetadata::runOn(Function &F, MetadataInfoSet &MIS) {
   bool RequiresCovered = false;
 
   if (Options.Atomics || Options.UAR) {
     for (BasicBlock &BB : F)
       for (Instruction &I : BB)
         RequiresCovered |= runOn(I, MIS, MDB, FeatureMask);
   }
 
+  if (ClNoSanitize && F.hasFnAttribute("no_sanitize_thread"))
+    FeatureMask &= ~kSanitizerBinaryMetadataAtomics;
   if (F.isVarArg())
     FeatureMask &= ~kSanitizerBinaryMetadataUAR;
   if (FeatureMask & kSanitizerBinaryMetadataUAR) {
     RequiresCovered = true;
     NumMetadataUAR++;
   }
 
   // Covered metadata is always emitted if explicitly requested, otherwise only