1//===--- SanitizerMetadata.cpp - Ignored entities for sanitizers ----------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Class which emits metadata consumed by sanitizer instrumentation passes.
10//
11//===----------------------------------------------------------------------===//
12#include "SanitizerMetadata.h"
13#include "CodeGenModule.h"
14#include "clang/AST/Attr.h"
15#include "clang/AST/Type.h"
16#include "clang/Basic/SourceManager.h"
17#include "llvm/ADT/StringRef.h"
18#include "llvm/IR/Constants.h"
19
20using namespace clang;
21using namespace CodeGen;
22
23SanitizerMetadata::SanitizerMetadata(CodeGenModule &CGM) : CGM(CGM) {}
24
25static bool isAsanHwasanOrMemTag(const SanitizerSet &SS) {
26 return SS.hasOneOf(K: SanitizerKind::Address | SanitizerKind::KernelAddress |
27 SanitizerKind::HWAddress | SanitizerKind::MemTag);
28}
29
30SanitizerMask expandKernelSanitizerMasks(SanitizerMask Mask) {
31 if (Mask & (SanitizerKind::Address | SanitizerKind::KernelAddress))
32 Mask |= SanitizerKind::Address | SanitizerKind::KernelAddress;
33 // Note: KHWASan doesn't support globals.
34 return Mask;
35}
36
37void SanitizerMetadata::reportGlobal(llvm::GlobalVariable *GV,
38 SourceLocation Loc, StringRef Name,
39 QualType Ty,
40 SanitizerMask NoSanitizeAttrMask,
41 bool IsDynInit) {
42 SanitizerSet FsanitizeArgument = CGM.getLangOpts().Sanitize;
43 if (!isAsanHwasanOrMemTag(SS: FsanitizeArgument))
44 return;
45
46 FsanitizeArgument.Mask = expandKernelSanitizerMasks(Mask: FsanitizeArgument.Mask);
47 NoSanitizeAttrMask = expandKernelSanitizerMasks(Mask: NoSanitizeAttrMask);
48 SanitizerSet NoSanitizeAttrSet = {.Mask: NoSanitizeAttrMask &
49 FsanitizeArgument.Mask};
50
51 llvm::GlobalVariable::SanitizerMetadata Meta;
52 if (GV->hasSanitizerMetadata())
53 Meta = GV->getSanitizerMetadata();
54
55 Meta.NoAddress |= NoSanitizeAttrSet.hasOneOf(K: SanitizerKind::Address);
56 Meta.NoAddress |= CGM.isInNoSanitizeList(
57 Kind: FsanitizeArgument.Mask & SanitizerKind::Address, GV, Loc, Ty);
58
59 Meta.NoHWAddress |= NoSanitizeAttrSet.hasOneOf(K: SanitizerKind::HWAddress);
60 Meta.NoHWAddress |= CGM.isInNoSanitizeList(
61 Kind: FsanitizeArgument.Mask & SanitizerKind::HWAddress, GV, Loc, Ty);
62
63 Meta.Memtag |=
64 static_cast<bool>(FsanitizeArgument.Mask & SanitizerKind::MemtagGlobals);
65 Meta.Memtag &= !NoSanitizeAttrSet.hasOneOf(K: SanitizerKind::MemTag);
66 Meta.Memtag &= !CGM.isInNoSanitizeList(
67 Kind: FsanitizeArgument.Mask & SanitizerKind::MemTag, GV, Loc, Ty);
68
69 Meta.IsDynInit = IsDynInit && !Meta.NoAddress &&
70 FsanitizeArgument.has(K: SanitizerKind::Address) &&
71 !CGM.isInNoSanitizeList(Kind: SanitizerKind::Address |
72 SanitizerKind::KernelAddress,
73 GV, Loc, Ty, Category: "init");
74
75 GV->setSanitizerMetadata(Meta);
76}
77
78void SanitizerMetadata::reportGlobal(llvm::GlobalVariable *GV, const VarDecl &D,
79 bool IsDynInit) {
80 if (!isAsanHwasanOrMemTag(SS: CGM.getLangOpts().Sanitize))
81 return;
82 std::string QualName;
83 llvm::raw_string_ostream OS(QualName);
84 D.printQualifiedName(OS);
85
86 auto getNoSanitizeMask = [](const VarDecl &D) {
87 if (D.hasAttr<DisableSanitizerInstrumentationAttr>())
88 return SanitizerKind::All;
89
90 SanitizerMask NoSanitizeMask;
91 for (auto *Attr : D.specific_attrs<NoSanitizeAttr>())
92 NoSanitizeMask |= Attr->getMask();
93
94 return NoSanitizeMask;
95 };
96
97 reportGlobal(GV, Loc: D.getLocation(), Name: OS.str(), Ty: D.getType(), NoSanitizeAttrMask: getNoSanitizeMask(D),
98 IsDynInit);
99}
100
101void SanitizerMetadata::disableSanitizerForGlobal(llvm::GlobalVariable *GV) {
102 reportGlobal(GV, Loc: SourceLocation(), Name: "", Ty: QualType(), NoSanitizeAttrMask: SanitizerKind::All);
103}
104