diff --git a/js/public/HeapAPI.h b/js/public/HeapAPI.h index fef6c0c78..d033d3706 100644 --- a/js/public/HeapAPI.h +++ b/js/public/HeapAPI.h @@ -51,6 +51,7 @@ const size_t ChunkMarkBitmapBits = 129024; const size_t ChunkRuntimeOffset = ChunkSize - sizeof(void*); const size_t ChunkTrailerSize = 2 * sizeof(uintptr_t) + sizeof(uint64_t); const size_t ChunkLocationOffset = ChunkSize - ChunkTrailerSize; +const size_t ChunkStoreBufferOffset = ChunkSize - ChunkTrailerSize + sizeof(uint64_t); const size_t ArenaZoneOffset = sizeof(size_t); const size_t ArenaHeaderSize = sizeof(size_t) + 2 * sizeof(uintptr_t) + sizeof(size_t) + sizeof(uintptr_t); @@ -326,6 +327,20 @@ CellIsMarkedGray(const Cell* cell) extern JS_PUBLIC_API(bool) CellIsMarkedGrayIfKnown(const Cell* cell); +MOZ_ALWAYS_INLINE ChunkLocation GetCellLocation(const void* cell) { + uintptr_t addr = uintptr_t(cell); + addr &= ~js::gc::ChunkMask; + addr |= js::gc::ChunkLocationOffset; + return *reinterpret_cast(addr); +} + +MOZ_ALWAYS_INLINE bool NurseryCellHasStoreBuffer(const void* cell) { + uintptr_t addr = uintptr_t(cell); + addr &= ~js::gc::ChunkMask; + addr |= js::gc::ChunkStoreBufferOffset; + return *reinterpret_cast(addr) != nullptr; +} + } /* namespace detail */ MOZ_ALWAYS_INLINE bool @@ -341,6 +356,28 @@ IsInsideNursery(const js::gc::Cell* cell) return location == ChunkLocation::Nursery; } +MOZ_ALWAYS_INLINE bool IsCellPointerValid(const void* cell) { + auto addr = uintptr_t(cell); + if (addr < ChunkSize || addr % CellSize != 0) { + return false; + } + auto location = detail::GetCellLocation(cell); + if (location == ChunkLocation::TenuredHeap) { + return !!detail::GetGCThingZone(addr); + } + if (location == ChunkLocation::Nursery) { + return detail::NurseryCellHasStoreBuffer(cell); + } + return false; +} + +MOZ_ALWAYS_INLINE bool IsCellPointerValidOrNull(const void* cell) { + if (!cell) { + return true; + } + return IsCellPointerValid(cell); +} + } /* namespace gc */ } /* namespace js */ diff --git a/js/src/gc/Marking.cpp b/js/src/gc/Marking.cpp index 43e325394..b4db0297a 100644 --- a/js/src/gc/Marking.cpp +++ b/js/src/gc/Marking.cpp @@ -2267,6 +2267,8 @@ void js::gc::StoreBuffer::SlotsEdge::trace(TenuringTracer& mover) const { NativeObject* obj = object(); + if(!IsCellPointerValid(obj)) + return; // Beware JSObject::swap exchanging a native object for a non-native one. if (!obj->isNative()) @@ -2336,6 +2338,8 @@ js::gc::StoreBuffer::traceWholeCells(TenuringTracer& mover) { for (ArenaCellSet* cells = bufferWholeCell; cells; cells = cells->next) { Arena* arena = cells->arena; + if(!IsCellPointerValid(arena)) + continue; MOZ_ASSERT(arena->bufferedCells == cells); arena->bufferedCells = &ArenaCellSet::Empty; @@ -2364,6 +2368,7 @@ js::gc::StoreBuffer::CellPtrEdge::trace(TenuringTracer& mover) const { if (!*edge) return; + // XXX: We should check if the cell pointer is valid here too MOZ_ASSERT((*edge)->getTraceKind() == JS::TraceKind::Object); mover.traverse(reinterpret_cast(edge));