tor-browser

commit f49212e6d50613b3ce7f7aedac5c364a33d542ae
parent 5fca0dd3b2149782d64aaacd4e8d4f83fa556341
Author: Andy Wingo <wingo@igalia.com>
Date:   Mon,  8 Dec 2025 16:02:52 +0000

Bug 1977854 - Add PageSize to wasm::Limits.  r=rhunt,bvisness

Differential Revision: https://phabricator.services.mozilla.com/D257725

Diffstat:
M
js/src/wasm/AsmJS.cpp
 | 
4
+++-
M
js/src/wasm/WasmBuiltinModule.cpp
 | 
4
++--
M
js/src/wasm/WasmJS.cpp
 | 
10
+++++++---
M
js/src/wasm/WasmModuleTypes.h
 | 
16
++++++++++------
M
js/src/wasm/WasmValidate.cpp
 | 
4
++++

5 files changed, 26 insertions(+), 12 deletions(-)
diff --git a/js/src/wasm/AsmJS.cpp b/js/src/wasm/AsmJS.cpp
@@ -2094,7 +2094,8 @@ class MOZ_STACK_CLASS ModuleValidator : public ModuleValidatorShared {
       return false;
     }
 
-    Limits limits = Limits(mask + 1, Nothing(), Shareable::False);
+    Limits limits =
+        Limits(mask + 1, Nothing(), Shareable::False, PageSize::Standard);
     codeMeta_->asmJSSigToTableIndex[sigIndex] = codeMeta_->tables.length();
     if (!codeMeta_->tables.emplaceBack(limits, RefType::func(),
                                        /* initExpr */ Nothing(),
@@ -2159,6 +2160,7 @@ class MOZ_STACK_CLASS ModuleValidator : public ModuleValidatorShared {
       limits.initial = memory_.minPages();
       limits.maximum = Nothing();
       limits.addressType = AddressType::I32;
+      limits.pageSize = PageSize::Standard;
       if (!codeMeta_->memories.append(MemoryDesc(limits))) {
         return nullptr;
       }
diff --git a/js/src/wasm/WasmBuiltinModule.cpp b/js/src/wasm/WasmBuiltinModule.cpp
@@ -192,8 +192,8 @@ bool CompileBuiltinModule(JSContext* cx,
       ReportOutOfMemory(cx);
       return false;
     }
-    if (!codeMeta->memories.append(
-            MemoryDesc(Limits(0, Nothing(), memory->shared)))) {
+    if (!codeMeta->memories.append(MemoryDesc(
+            Limits(0, Nothing(), memory->shared, PageSize::Standard)))) {
       ReportOutOfMemory(cx);
       return false;
     }
diff --git a/js/src/wasm/WasmJS.cpp b/js/src/wasm/WasmJS.cpp
@@ -789,6 +789,10 @@ static bool GetLimits(JSContext* cx, HandleObject obj, LimitsKind kind,
         }
       }
     }
+
+    // TODO: Should be updated when the JS API for custom page sizes
+    // is finalized, see https://bugzilla.mozilla.org/show_bug.cgi?id=1985679
+    limits->pageSize = PageSize::Standard;
   }
 
   return true;
@@ -2178,8 +2182,8 @@ bool WasmMemoryObject::construct(JSContext* cx, unsigned argc, Value* vp) {
     return false;
   }
 
-  if (Pages::fromPageCount(limits.initial, PageSize::Standard) >
-      MaxMemoryPages(limits.addressType, PageSize::Standard)) {
+  if (Pages::fromPageCount(limits.initial, limits.pageSize) >
+      MaxMemoryPages(limits.addressType, limits.pageSize)) {
     JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr,
                              JSMSG_WASM_MEM_IMP_LIMIT);
     return false;
@@ -2662,7 +2666,7 @@ uint64_t WasmMemoryObject::grow(Handle<WasmMemoryObject*> memory,
   // TODO (large ArrayBuffer): See more information at the definition of
   // MaxMemoryBytes().
   MOZ_ASSERT(
-      MaxMemoryBytes(memory->addressType(), PageSize::Standard) <= UINT32_MAX,
+      MaxMemoryBytes(memory->addressType(), memory->pageSize()) <= UINT32_MAX,
       "Avoid 32-bit overflows");
 #endif
 
diff --git a/js/src/wasm/WasmModuleTypes.h b/js/src/wasm/WasmModuleTypes.h
@@ -796,16 +796,20 @@ struct Limits {
   // memories.
   Shareable shared;
 
-  WASM_CHECK_CACHEABLE_POD(addressType, initial, maximum, shared);
+  // `pageSize` is used only for memories. Defaults to the standard page size
+  // but may be set to other values with the custom page size proposal.
+  PageSize pageSize = PageSize::Standard;
+
+  WASM_CHECK_CACHEABLE_POD(addressType, initial, maximum, shared, pageSize);
 
   Limits() = default;
-  explicit Limits(uint64_t initial,
-                  const mozilla::Maybe<uint64_t>& maximum = mozilla::Nothing(),
-                  Shareable shared = Shareable::False)
+  Limits(uint64_t initial, const mozilla::Maybe<uint64_t>& maximum,
+         Shareable shared, PageSize pageSize)
       : addressType(AddressType::I32),
         initial(initial),
         maximum(maximum),
-        shared(shared) {}
+        shared(shared),
+        pageSize(pageSize) {}
 };
 
 WASM_DECLARE_CACHEABLE_POD(Limits);
@@ -834,7 +838,7 @@ struct MemoryDesc {
 
   AddressType addressType() const { return limits.addressType; }
 
-  PageSize pageSize() const { return PageSize::Standard; }
+  PageSize pageSize() const { return limits.pageSize; }
 
   // The initial length of this memory in pages.
   Pages initialPages() const {
diff --git a/js/src/wasm/WasmValidate.cpp b/js/src/wasm/WasmValidate.cpp
@@ -2855,6 +2855,10 @@ static bool DecodeLimits(Decoder& d, LimitsKind kind, Limits* limits) {
     limits->maximum.emplace(maximum);
   }
 
+  if (kind == LimitsKind::Memory) {
+    limits->pageSize = PageSize::Standard;
+  }
+
   return true;
 }