Ensure embedded constants aren't disassembled as instructions.

BUG=chromium:1228666

Change-Id: Id5ef86170d5be8db507da80202836558a2fa6eb1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3030703
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75742}

src/codegen/arm/assembler-arm.cc

@@ -5237,7 +5237,8 @@ void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
   DCHECK(is_const_pool_blocked() || pending_32_bit_constants_.empty());
   CheckBuffer();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   base::WriteUnalignedValue(reinterpret_cast<Address>(pc_), data);
@@ -5250,7 +5251,8 @@ void Assembler::dq(uint64_t value, RelocInfo::Mode rmode) {
   DCHECK(is_const_pool_blocked() || pending_32_bit_constants_.empty());
   CheckBuffer();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   base::WriteUnalignedValue(reinterpret_cast<Address>(pc_), value);

src/codegen/arm64/assembler-arm64.cc

@@ -4345,12 +4345,14 @@ void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data,
       (rmode == RelocInfo::CONST_POOL) || (rmode == RelocInfo::VENEER_POOL) ||
       (rmode == RelocInfo::DEOPT_SCRIPT_OFFSET) ||
       (rmode == RelocInfo::DEOPT_INLINING_ID) ||
-      (rmode == RelocInfo::DEOPT_REASON) || (rmode == RelocInfo::DEOPT_ID)) {
+      (rmode == RelocInfo::DEOPT_REASON) || (rmode == RelocInfo::DEOPT_ID) ||
+      (rmode == RelocInfo::LITERAL_CONSTANT)) {
     // Adjust code for new modes.
     DCHECK(RelocInfo::IsDeoptReason(rmode) || RelocInfo::IsDeoptId(rmode) ||
            RelocInfo::IsDeoptPosition(rmode) ||
            RelocInfo::IsInternalReference(rmode) ||
            RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode) ||
            RelocInfo::IsConstPool(rmode) || RelocInfo::IsVeneerPool(rmode));
     // These modes do not need an entry in the constant pool.
   } else if (constant_pool_mode == NEEDS_POOL_ENTRY) {

src/codegen/arm64/assembler-arm64.h

@@ -2067,7 +2067,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void dd(uint32_t data, RelocInfo::Mode rmode = RelocInfo::NONE) {
     BlockPoolsScope no_pool_scope(this);
     if (!RelocInfo::IsNone(rmode)) {
-      DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+      DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+             RelocInfo::IsLiteralConstant(rmode));
       RecordRelocInfo(rmode);
     }
     dc32(data);
@@ -2075,7 +2076,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void dq(uint64_t data, RelocInfo::Mode rmode = RelocInfo::NONE) {
     BlockPoolsScope no_pool_scope(this);
     if (!RelocInfo::IsNone(rmode)) {
-      DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+      DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+             RelocInfo::IsLiteralConstant(rmode));
       RecordRelocInfo(rmode);
     }
     dc64(data);
@@ -2083,7 +2085,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void dp(uintptr_t data, RelocInfo::Mode rmode = RelocInfo::NONE) {
     BlockPoolsScope no_pool_scope(this);
     if (!RelocInfo::IsNone(rmode)) {
-      DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+      DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+             RelocInfo::IsLiteralConstant(rmode));
       RecordRelocInfo(rmode);
     }
     dc64(data);

src/codegen/assembler.h

@@ -404,6 +404,9 @@ class V8_EXPORT_PRIVATE AssemblerBase : public Malloced {
         !options().record_reloc_info_for_serialization && !FLAG_debug_code) {
       return false;
     }
+#ifndef ENABLE_DISASSEMBLER
+    if (RelocInfo::IsLiteralConstant(rmode)) return false;
+#endif
     return true;
   }
 

src/codegen/ia32/assembler-ia32.cc

@@ -3494,7 +3494,8 @@ void Assembler::db(uint8_t data) {
 void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   emit(data);

src/codegen/mips/assembler-mips.cc

@@ -3592,7 +3592,8 @@ void Assembler::db(uint8_t data) {
 void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
   CheckForEmitInForbiddenSlot();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uint32_t*>(pc_) = data;
@@ -3602,7 +3603,8 @@ void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
 void Assembler::dq(uint64_t data, RelocInfo::Mode rmode) {
   CheckForEmitInForbiddenSlot();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uint64_t*>(pc_) = data;

src/codegen/mips64/assembler-mips64.cc

@@ -3790,7 +3790,8 @@ void Assembler::db(uint8_t data) {
 void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
   CheckForEmitInForbiddenSlot();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uint32_t*>(pc_) = data;
@@ -3800,7 +3801,8 @@ void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
 void Assembler::dq(uint64_t data, RelocInfo::Mode rmode) {
   CheckForEmitInForbiddenSlot();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uint64_t*>(pc_) = data;

src/codegen/ppc/assembler-ppc.cc

@@ -2003,7 +2003,8 @@ void Assembler::db(uint8_t data) {
 void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
   CheckBuffer();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uint32_t*>(pc_) = data;
@@ -2013,7 +2014,8 @@ void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
 void Assembler::dq(uint64_t value, RelocInfo::Mode rmode) {
   CheckBuffer();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uint64_t*>(pc_) = value;
@@ -2023,7 +2025,8 @@ void Assembler::dq(uint64_t value, RelocInfo::Mode rmode) {
 void Assembler::dp(uintptr_t data, RelocInfo::Mode rmode) {
   CheckBuffer();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uintptr_t*>(pc_) = data;

src/codegen/reloc-info.cc

@@ -422,6 +422,8 @@ const char* RelocInfo::RelocModeName(RelocInfo::Mode rmode) {
       return "deopt reason";
     case DEOPT_ID:
       return "deopt index";
+    case LITERAL_CONSTANT:
+      return "literal constant";
     case CONST_POOL:
       return "constant pool";
     case VENEER_POOL:
@@ -525,6 +527,7 @@ void RelocInfo::Verify(Isolate* isolate) {
     case DEOPT_INLINING_ID:
     case DEOPT_REASON:
     case DEOPT_ID:
+    case LITERAL_CONSTANT:
     case CONST_POOL:
     case VENEER_POOL:
     case WASM_CALL:

src/codegen/reloc-info.h

@@ -89,6 +89,8 @@ class RelocInfo {
     DEOPT_REASON,       // Deoptimization reason index.
     DEOPT_ID,           // Deoptimization inlining id.
 
+    LITERAL_CONSTANT,  // An constant embedded in the instruction stream.
+
     // This is not an actual reloc mode, but used to encode a long pc jump that
     // cannot be encoded as part of another record.
     PC_JUMP,
@@ -169,6 +171,9 @@ class RelocInfo {
     return mode == DEOPT_REASON;
   }
   static constexpr bool IsDeoptId(Mode mode) { return mode == DEOPT_ID; }
+  static constexpr bool IsLiteralConstant(Mode mode) {
+    return mode == LITERAL_CONSTANT;
+  }
   static constexpr bool IsExternalReference(Mode mode) {
     return mode == EXTERNAL_REFERENCE;
   }

src/codegen/riscv64/assembler-riscv64.cc

@@ -2809,7 +2809,8 @@ void Assembler::db(uint8_t data) {
 
 void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   if (!is_buffer_growth_blocked()) CheckBuffer();
@@ -2819,7 +2820,8 @@ void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
 
 void Assembler::dq(uint64_t data, RelocInfo::Mode rmode) {
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   if (!is_buffer_growth_blocked()) CheckBuffer();

src/codegen/s390/assembler-s390.cc

@@ -799,7 +799,8 @@ void Assembler::db(uint8_t data) {
 void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
   CheckBuffer();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uint32_t*>(pc_) = data;
@@ -809,7 +810,8 @@ void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
 void Assembler::dq(uint64_t value, RelocInfo::Mode rmode) {
   CheckBuffer();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uint64_t*>(pc_) = value;
@@ -819,7 +821,8 @@ void Assembler::dq(uint64_t value, RelocInfo::Mode rmode) {
 void Assembler::dp(uintptr_t data, RelocInfo::Mode rmode) {
   CheckBuffer();
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   *reinterpret_cast<uintptr_t*>(pc_) = data;

src/codegen/x64/assembler-x64.cc

@@ -4302,7 +4302,8 @@ void Assembler::db(uint8_t data) {
 void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   emitl(data);
@@ -4311,7 +4312,8 @@ void Assembler::dd(uint32_t data, RelocInfo::Mode rmode) {
 void Assembler::dq(uint64_t data, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
   if (!RelocInfo::IsNone(rmode)) {
-    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode));
+    DCHECK(RelocInfo::IsDataEmbeddedObject(rmode) ||
+           RelocInfo::IsLiteralConstant(rmode));
     RecordRelocInfo(rmode);
   }
   emitq(data);

src/compiler/backend/code-generator.cc

@@ -171,7 +171,7 @@ void CodeGenerator::AssembleDeoptImmediateArgs(
 
     switch (constant.type()) {
       case Constant::kInt32:
-        tasm()->dp(constant.ToInt32());
+        tasm()->dp(constant.ToInt32(), RelocInfo::LITERAL_CONSTANT);
         break;
 #ifdef V8_TARGET_ARCH_64_BIT
       case Constant::kInt64:
@@ -181,7 +181,7 @@ void CodeGenerator::AssembleDeoptImmediateArgs(
       case Constant::kFloat64: {
         int smi;
         CHECK(DoubleToSmiInteger(constant.ToFloat64().value(), &smi));
-        tasm()->dp(Smi::FromInt(smi).ptr());
+        tasm()->dp(Smi::FromInt(smi).ptr(), RelocInfo::LITERAL_CONSTANT);
         break;
       }
       case Constant::kCompressedHeapObject:

src/diagnostics/disassembler.cc

@@ -319,13 +319,24 @@ static int DecodeIt(Isolate* isolate, ExternalReferenceEncoder* ref_encoder,
         pc += 4;
       } else if (it != nullptr && !it->done() &&
                  it->rinfo()->pc() == reinterpret_cast<Address>(pc) &&
-                 it->rinfo()->rmode() == RelocInfo::INTERNAL_REFERENCE) {
+                 (it->rinfo()->rmode() == RelocInfo::INTERNAL_REFERENCE ||
+                  it->rinfo()->rmode() == RelocInfo::LITERAL_CONSTANT ||
+                  it->rinfo()->rmode() == RelocInfo::DATA_EMBEDDED_OBJECT)) {
         // raw pointer embedded in code stream, e.g., jump table
         byte* ptr =
             base::ReadUnalignedValue<byte*>(reinterpret_cast<Address>(pc));
-        SNPrintF(decode_buffer, "%08" V8PRIxPTR "      jump table entry %4zu",
-                 reinterpret_cast<intptr_t>(ptr),
-                 static_cast<size_t>(ptr - begin));
+        if (RelocInfo::IsInternalReference(it->rinfo()->rmode())) {
+          SNPrintF(decode_buffer, "%08" V8PRIxPTR "      jump table entry %4zu",
+                   reinterpret_cast<intptr_t>(ptr),
+                   static_cast<size_t>(ptr - begin));
+        } else {
+          const char* kType = RelocInfo::IsLiteralConstant(it->rinfo()->rmode())
+                                  ? "    literal constant"
+                                  : "embedded data object";
+          SNPrintF(decode_buffer, "%08" V8PRIxPTR "      %s 0x%08" V8PRIxPTR,
+                   reinterpret_cast<intptr_t>(ptr), kType,
+                   reinterpret_cast<intptr_t>(ptr));
+        }
         pc += sizeof(ptr);
       } else {
         decode_buffer[0] = '\0';