Add the ShadowCallStack attribute

Summary:
Introduce the ShadowCallStack function attribute. It's added to
functions compiled with -fsanitize=shadow-call-stack in order to mark
functions to be instrumented by a ShadowCallStack pass to be submitted
in a separate change.

Reviewers: pcc, kcc, kubamracek

Reviewed By: pcc, kcc

Subscribers: cryptoad, mehdi_amini, javed.absar, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D44800

llvm-svn: 329108

9 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 645d9aae6ea..54c4c595c34 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -665,6 +665,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(sspstrong);
   KEYWORD(strictfp);
   KEYWORD(safestack);
+  KEYWORD(shadowcallstack);
   KEYWORD(sanitize_address);
   KEYWORD(sanitize_hwaddress);
   KEYWORD(sanitize_thread);
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index d59b21dd4c7..0f28864534e 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -1148,6 +1148,8 @@ bool LLParser::ParseFnAttributeValuePairs(AttrBuilder &B,
     case lltok::kw_sspstrong:
       B.addAttribute(Attribute::StackProtectStrong); break;
     case lltok::kw_safestack: B.addAttribute(Attribute::SafeStack); break;
+    case lltok::kw_shadowcallstack:
+      B.addAttribute(Attribute::ShadowCallStack); break;
     case lltok::kw_sanitize_address:
       B.addAttribute(Attribute::SanitizeAddress); break;
     case lltok::kw_sanitize_hwaddress:
@@ -1485,6 +1487,7 @@ bool LLParser::ParseOptionalParamAttrs(AttrBuilder &B) {
     case lltok::kw_sspreq:
     case lltok::kw_sspstrong:
     case lltok::kw_safestack:
+    case lltok::kw_shadowcallstack:
     case lltok::kw_strictfp:
     case lltok::kw_uwtable:
       HaveError |= Error(Lex.getLoc(), "invalid use of function-only attribute");
@@ -1580,6 +1583,7 @@ bool LLParser::ParseOptionalReturnAttrs(AttrBuilder &B) {
     case lltok::kw_sspreq:
     case lltok::kw_sspstrong:
     case lltok::kw_safestack:
+    case lltok::kw_shadowcallstack:
     case lltok::kw_strictfp:
     case lltok::kw_uwtable:
       HaveError |= Error(Lex.getLoc(), "invalid use of function-only attribute");
diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
index d24f74a145c..5e05f54509f 100644
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -214,6 +214,7 @@ enum Kind {
   kw_sspreq,
   kw_sspstrong,
   kw_safestack,
+  kw_shadowcallstack,
   kw_sret,
   kw_sanitize_thread,
   kw_sanitize_memory,
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 5867db46272..75374e7bef3 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1162,6 +1162,7 @@ static uint64_t getRawAttributeMask(Attribute::AttrKind Val) {
   case Attribute::SanitizeHWAddress: return 1ULL << 56;
   case Attribute::NoCfCheck:       return 1ULL << 57;
   case Attribute::OptForFuzzing:   return 1ULL << 58;
+  case Attribute::ShadowCallStack: return 1ULL << 59;
   case Attribute::Dereferenceable:
     llvm_unreachable("dereferenceable attribute not supported in raw format");
     break;
@@ -1372,6 +1373,8 @@ static Attribute::AttrKind getAttrFromCode(uint64_t Code) {
     return Attribute::StackProtectStrong;
   case bitc::ATTR_KIND_SAFESTACK:
     return Attribute::SafeStack;
+  case bitc::ATTR_KIND_SHADOWCALLSTACK:
+    return Attribute::ShadowCallStack;
   case bitc::ATTR_KIND_STRICT_FP:
     return Attribute::StrictFP;
   case bitc::ATTR_KIND_STRUCT_RET:
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 99eef651e26..3b37c31e843 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -673,6 +673,8 @@ static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
   case Attribute::SafeStack:
     return bitc::ATTR_KIND_SAFESTACK;
+  case Attribute::ShadowCallStack:
+    return bitc::ATTR_KIND_SHADOWCALLSTACK;
   case Attribute::StrictFP:
     return bitc::ATTR_KIND_STRICT_FP;
   case Attribute::StructRet:
diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
index bc0f5a27076..b6c16a8a10c 100644
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -332,6 +332,8 @@ std::string Attribute::getAsString(bool InAttrGrp) const {
     return "sspstrong";
   if (hasAttribute(Attribute::SafeStack))
     return "safestack";
+  if (hasAttribute(Attribute::ShadowCallStack))
+    return "shadowcallstack";
   if (hasAttribute(Attribute::StrictFP))
     return "strictfp";
   if (hasAttribute(Attribute::StructRet))
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 4cb16613046..92bb53b29d2 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -1413,6 +1413,7 @@ static bool isFuncOnlyAttr(Attribute::AttrKind Kind) {
   case Attribute::StackProtectReq:
   case Attribute::StackProtectStrong:
   case Attribute::SafeStack:
+  case Attribute::ShadowCallStack:
   case Attribute::NoRedZone:
   case Attribute::NoImplicitFloat:
   case Attribute::Naked:
diff --git a/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp b/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp
index f7cdd416fd8..54ab9843fce 100644
--- a/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp
@@ -53,6 +53,7 @@ static Attribute::AttrKind parseAttrKind(StringRef Kind) {
       .Case("argmemonly", Attribute::ArgMemOnly)
       .Case("returns_twice", Attribute::ReturnsTwice)
       .Case("safestack", Attribute::SafeStack)
+      .Case("shadowcallstack", Attribute::SafeStack)
       .Case("sanitize_address", Attribute::SanitizeAddress)
       .Case("sanitize_hwaddress", Attribute::SanitizeHWAddress)
       .Case("sanitize_memory", Attribute::SanitizeMemory)
diff --git a/llvm/lib/Transforms/Utils/CodeExtractor.cpp b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
index d87eccf4c27..573ccc3cf6a 100644
--- a/llvm/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
@@ -688,6 +688,7 @@ Function *CodeExtractor::constructFunction(const ValueSet &inputs,
       case Attribute::OptimizeNone:
       case Attribute::OptimizeForSize:
       case Attribute::SafeStack:
+      case Attribute::ShadowCallStack:
       case Attribute::SanitizeAddress:
       case Attribute::SanitizeMemory:
       case Attribute::SanitizeThread: