diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/wasm-interpreter.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/src/wasm-interpreter.h b/src/wasm-interpreter.h index e69e9c9aa..a935d2069 100644 --- a/src/wasm-interpreter.h +++ b/src/wasm-interpreter.h @@ -25,6 +25,10 @@ int32_t safe_ctz(int32_t v) { return __builtin_ctz(v); } +enum { + pageSize = 64*1024 +}; + // // An instance of a WebAssembly module, which can execute it via AST interpretation // @@ -643,12 +647,16 @@ private: Flow visitHost(Host *curr) override { NOTE_ENTER("Host"); switch (curr->op) { - case PageSize: return Literal(64*1024); + case PageSize: return Literal(pageSize); case MemorySize: return Literal(instance.memorySize); case GrowMemory: { Flow flow = visit(curr->operands[0]); if (flow.breaking()) return flow; - size_t newSize = instance.memorySize + flow.value.getInteger(); + uint32_t delta = flow.value.geti32(); + if (delta % pageSize != 0) trap(); + if (delta > uint32_t(-1) - pageSize) trap(); + if (instance.memorySize >= uint32_t(-1) - delta) trap(); + uint32_t newSize = instance.memorySize + delta; if (newSize > instance.wasm.memory.max) trap(); instance.externalInterface->growMemory(instance.memorySize, newSize); instance.memorySize = newSize; |