wasm: change the module memory size to be multiples of the page size, 64k.

BUG=

Review URL: https://codereview.chromium.org/1597163002

Cr-Commit-Position: refs/heads/master@{#34450}

src/wasm/module-decoder.cc

@@ -45,8 +45,8 @@ class ModuleDecoder : public Decoder {
     pc_ = start_;
     module->module_start = start_;
     module->module_end = limit_;
-    module->min_mem_size_log2 = 0;
-    module->max_mem_size_log2 = 0;
+    module->min_mem_pages = 0;
+    module->max_mem_pages = 0;
     module->mem_export = false;
     module->mem_external = false;
     module->origin = origin_;
@@ -92,8 +92,9 @@ class ModuleDecoder : public Decoder {
           limit_ = pc_;
           break;
         case kDeclMemory:
-          module->min_mem_size_log2 = consume_u8("min memory");
-          module->max_mem_size_log2 = consume_u8("max memory");
+          int length;
+          module->min_mem_pages = consume_u32v(&length, "min memory");
+          module->max_mem_pages = consume_u32v(&length, "max memory");
           module->mem_export = consume_u8("export memory") != 0;
           break;
         case kDeclSignatures: {
@@ -464,7 +465,8 @@ class ModuleDecoder : public Decoder {
 
     // Validate that the segment will fit into the (minimum) memory.
     uint32_t memory_limit =
-        1 << (module ? module->min_mem_size_log2 : WasmModule::kMaxMemSize);
+        WasmModule::kPageSize * (module ? module->min_mem_pages
+                                        : WasmModule::kMaxMemPages);
     if (!IsWithinLimit(memory_limit, segment->dest_addr,
                        segment->source_size)) {
       error(pc_ - sizeof(uint32_t), "segment out of bounds of memory");

src/wasm/wasm-module.cc

@@ -21,8 +21,8 @@ namespace wasm {
 
 std::ostream& operator<<(std::ostream& os, const WasmModule& module) {
   os << "WASM module with ";
-  os << (1 << module.min_mem_size_log2) << " min mem";
-  os << (1 << module.max_mem_size_log2) << " max mem";
+  os << (module.min_mem_pages * module.kPageSize) << " min mem";
+  os << (module.max_mem_pages * module.kPageSize) << " max mem";
   os << module.functions.size() << " functions";
   os << module.functions.size() << " globals";
   os << module.functions.size() << " data segments";
@@ -167,6 +167,7 @@ size_t AllocateGlobalsOffsets(std::vector<WasmGlobal>& globals) {
 void LoadDataSegments(WasmModule* module, byte* mem_addr, size_t mem_size) {
   for (const WasmDataSegment& segment : module->data_segments) {
     if (!segment.init) continue;
+    if (!segment.source_size) continue;
     CHECK_LT(segment.dest_addr, mem_size);
     CHECK_LE(segment.source_size, mem_size);
     CHECK_LE(segment.dest_addr + segment.source_size, mem_size);
@@ -192,7 +193,7 @@ Handle<FixedArray> BuildFunctionTable(Isolate* isolate, WasmModule* module) {
 
 Handle<JSArrayBuffer> NewArrayBuffer(Isolate* isolate, size_t size,
                                      byte** backing_store) {
-  if (size > (1 << WasmModule::kMaxMemSize)) {
+  if (size > (WasmModule::kMaxMemPages * WasmModule::kPageSize)) {
     // TODO(titzer): lift restriction on maximum memory allocated here.
     *backing_store = nullptr;
     return Handle<JSArrayBuffer>::null();
@@ -234,12 +235,11 @@ bool AllocateMemory(ErrorThrower* thrower, Isolate* isolate,
   DCHECK(instance->module);
   DCHECK(instance->mem_buffer.is_null());
 
-  if (instance->module->min_mem_size_log2 > WasmModule::kMaxMemSize) {
+  if (instance->module->min_mem_pages > WasmModule::kMaxMemPages) {
     thrower->Error("Out of memory: wasm memory too large");
     return false;
   }
-  instance->mem_size = static_cast<size_t>(1)
-                       << instance->module->min_mem_size_log2;
+  instance->mem_size = WasmModule::kPageSize * instance->module->min_mem_pages;
   instance->mem_buffer =
       NewArrayBuffer(isolate, instance->mem_size, &instance->mem_start);
   if (!instance->mem_start) {
@@ -271,8 +271,8 @@ WasmModule::WasmModule()
     : shared_isolate(nullptr),
       module_start(nullptr),
       module_end(nullptr),
-      min_mem_size_log2(0),
-      max_mem_size_log2(0),
+      min_mem_pages(0),
+      max_mem_pages(0),
       mem_export(false),
       mem_external(false),
       start_function_index(-1),

src/wasm/wasm-module.h

@@ -103,14 +103,15 @@ enum ModuleOrigin { kWasmOrigin, kAsmJsOrigin };
 
 // Static representation of a module.
 struct WasmModule {
-  static const uint8_t kMinMemSize = 12;  // Minimum memory size = 4kb
-  static const uint8_t kMaxMemSize = 30;  // Maximum memory size = 1gb
+  static const uint32_t kPageSize = 0x10000;    // Page size, 64kb.
+  static const uint32_t kMinMemPages = 1;       // Minimum memory size = 64kb
+  static const uint32_t kMaxMemPages = 16384;   // Maximum memory size =  1gb
 
   Isolate* shared_isolate;    // isolate for storing shared code.
   const byte* module_start;   // starting address for the module bytes.
   const byte* module_end;     // end address for the module bytes.
-  uint8_t min_mem_size_log2;  // minimum size of the memory (log base 2).
-  uint8_t max_mem_size_log2;  // maximum size of the memory (log base 2).
+  uint32_t min_mem_pages;     // minimum size of the memory in 64k pages.
+  uint32_t max_mem_pages;     // maximum size of the memory in 64k pages.
   bool mem_export;            // true if the memory is exported.
   bool mem_external;          // true if the memory is external.
   int start_function_index;   // start function, if any.

test/mjsunit/wasm/calls.js

@@ -13,7 +13,7 @@ var module = (function () {
   return _WASMEXP_.instantiateModule(bytesWithHeader(
     // -- memory
     kDeclMemory,
-    12, 12, 1,
+    1, 1, 1,
     // -- signatures
     kDeclSignatures, 1,
     2, kAstI32, kAstI32, kAstI32, // int, int -> int
@@ -50,7 +50,7 @@ for (var i = 0; i < 4; i++) {
   assertEquals(mem, module.memory);
 }
 
-assertEquals(4096, module.memory.byteLength);
+assertEquals(65536, module.memory.byteLength);
 
 // Check the properties of the sub function.
 assertEquals("function", typeof module.sub);
@@ -67,7 +67,7 @@ var module = (function() {
   return _WASMEXP_.instantiateModule(bytesWithHeader(
     // -- memory
     kDeclMemory,
-    12, 12, 1,
+    1, 1, 1,
     // -- signatures
     kDeclSignatures, 1,
     0, kAstStmt,                // signature: void -> void
@@ -101,7 +101,7 @@ for (var i = 0; i < 4; i++) {
   assertEquals(mem, module.memory);
 }
 
-assertEquals(4096, module.memory.byteLength);
+assertEquals(65536, module.memory.byteLength);
 
 // Check the properties of the sub function.
 assertFalse(module.nop === undefined);
@@ -118,7 +118,7 @@ assertEquals(undefined, module.nop());
   var data = bytesWithHeader(
     // -- memory
     kDeclMemory,
-    12, 12, 1,
+    1, 1, 1,
     // -- signatures
     kDeclSignatures, 1,
     2, kAstI32, kAstF64, kAstF64, // (f64,f64)->int

test/mjsunit/wasm/ffi-error.js

@@ -13,7 +13,7 @@ function testCallFFI(ffi) {
 
   var data = bytesWithHeader(
     kDeclMemory,
-    12, 12, 1,                  // memory
+    1, 1, 1,                    // memory
     // -- signatures
     kDeclSignatures, 1,
     2, kAstI32, kAstF64, kAstF64, // (f64,f64)->int

test/mjsunit/wasm/instantiate-module-basic.js

@@ -14,7 +14,7 @@ var kNameOffset = kHeaderSize + 19 + kBodySize + 1;
 var data = bytesWithHeader(
   // -- memory
   kDeclMemory,
-  10, 10, 1,
+  1, 1, 1,
   // -- signatures
   kDeclSignatures, 1,
   0, kAstI32,                 // signature: void -> int
@@ -51,7 +51,7 @@ for (var i = 0; i < 4; i++) {
   assertEquals(mem, module.memory);
 }
 
-assertEquals(1024, module.memory.byteLength);
+assertEquals(65536, module.memory.byteLength);
 
 // Check the properties of the main function.
 assertFalse(module.main === undefined);

test/mjsunit/wasm/module-memory.js

@@ -6,7 +6,7 @@
 
 load("test/mjsunit/wasm/wasm-constants.js");
 
-var kMemSize = 4096;
+var kMemSize = 65536;
 
 function genModule(memory) {
   var kBodySize = 27;
@@ -14,7 +14,7 @@ function genModule(memory) {
 
   var data = bytesWithHeader(
     kDeclMemory,
-    12, 12, 1,                  // memory
+    1, 1, 1,                    // memory
     // -- signatures
     kDeclSignatures, 1,
     1, kAstI32, kAstI32,        // int->int
@@ -137,7 +137,7 @@ function testOOBThrows() {
 
   var data = bytesWithHeader(
     kDeclMemory,
-    12, 12, 1,                     // memory = 4KB
+    1, 1, 1,                       // memory = 64KB
     // -- signatures
     kDeclSignatures, 1,
     2, kAstI32, kAstI32, kAstI32,  // int->int
@@ -166,13 +166,13 @@ function testOOBThrows() {
   function read() { return module.geti(0, offset); }
   function write() { return module.geti(offset, 0); }
 
-  for (offset = 0; offset < 4092; offset++) {
+  for (offset = 0; offset < 65533; offset++) {
     assertEquals(0, read());
     assertEquals(0, write());
   }
 
 
-  for (offset = 4093; offset < 4124; offset++) {
+  for (offset = 65534; offset < 66536; offset++) {
     assertTraps(kTrapMemOutOfBounds, read);
     assertTraps(kTrapMemOutOfBounds, write);
   }

test/mjsunit/wasm/params.js

@@ -20,7 +20,7 @@ function testSelect2(type) {
     var data = bytesWithHeader(
       // -- memory
       kDeclMemory,
-      12, 12, 1,                  // memory
+      1, 1, 1,                    // memory
       // -- signatures
       kDeclSignatures, 1,
       2, type, type, type,        // signature: (t,t)->t
@@ -96,7 +96,7 @@ function testSelect10(type) {
     var t = type;
     var data = bytesWithHeader(
       kDeclMemory,
-      12, 12, 1,                  // memory
+      1, 1, 1,                    // memory
       // signatures
       kDeclSignatures, 1,
       10, t,t,t,t,t,t,t,t,t,t,t,  // (tx10)->t

test/unittests/wasm/module-decoder-unittest.cc

@@ -616,7 +616,7 @@ TEST_F(WasmModuleVerifyTest, TwoDataSegments) {
 
 TEST_F(WasmModuleVerifyTest, DataSegmentWithInvalidSource) {
   const int dest_addr = 0x100;
-  const byte mem_size_log2 = 15;
+  const byte mem_pages = 1;
   const int kHeaderSize = 8;
   const int kDataSize = 19;
   const int kTotalSize = kHeaderSize + kDataSize;
@@ -625,8 +625,8 @@ TEST_F(WasmModuleVerifyTest, DataSegmentWithInvalidSource) {
     for (int source_size = -1; source_size < 5 + kDataSize; source_size += 3) {
       byte data[] = {
           kDeclMemory,
-          mem_size_log2,
-          mem_size_log2,
+          mem_pages,
+          mem_pages,
           1,
           kDeclDataSegments,
           1,
@@ -653,15 +653,15 @@ TEST_F(WasmModuleVerifyTest, DataSegmentWithInvalidDest) {
   const int source_size = 3;
   const int source_offset = 11;
 
-  for (byte mem_size_log2 = 12; mem_size_log2 < 20; mem_size_log2++) {
-    int mem_size = 1 << mem_size_log2;
+  for (byte mem_pages = 1; mem_pages < 16; mem_pages++) {
+    int mem_size = mem_pages * 0x10000;  // 64k pages.
 
     for (int dest_addr = mem_size - source_size;
          dest_addr < mem_size + source_size; dest_addr++) {
       byte data[] = {
           kDeclMemory,
-          mem_size_log2,
-          mem_size_log2,
+          mem_pages,
+          mem_pages,
           1,
           kDeclDataSegments,
           1,