diff --git a/runtime/platform/globals.h b/runtime/platform/globals.h index ec996e98732..6171827ec2c 100644 --- a/runtime/platform/globals.h +++ b/runtime/platform/globals.h @@ -352,14 +352,6 @@ typedef simd128_value_t fpu_register_t; #error Unknown architecture. #endif -// Determine whether dual mapping of code pages is supported. -#if !defined(USING_SIMULATOR) && \ - (defined(HOST_OS_LINUX) || defined(HOST_OS_FUCHSIA)) && \ - !defined(HOST_OS_ANDROID) && !defined(TARGET_OS_ANDROID) && \ - !defined(TARGET_ARCH_IA32) -#define DUAL_MAPPING_SUPPORTED 1 -#endif - // Disable background threads by default on armv5te. The relevant // implementations are uniprocessors. #if !defined(TARGET_ARCH_ARM_5TE) diff --git a/runtime/tests/vm/vm.status b/runtime/tests/vm/vm.status index 6554bb2634b..a56a92ebb85 100644 --- a/runtime/tests/vm/vm.status +++ b/runtime/tests/vm/vm.status @@ -4,7 +4,6 @@ cc/AllocGeneric_Overflow: Crash, Fail # These tests are expected to crash on all platforms. cc/ArrayNew_Overflow_Crash: Crash, Fail # These tests are expected to crash on all platforms. -cc/CodeExecutability: Crash, Fail # These tests are expected to crash on all platforms. cc/CodeImmutability: Crash, Fail # These tests are expected to crash on all platforms. cc/Dart2JSCompileAll: Fail, Crash # Issue 27369 cc/Dart2JSCompilerStats: Fail, Crash # Issue 27369 @@ -29,7 +28,6 @@ dart/use_bare_instructions_flag_test: Pass, Slow # Spawns several subprocesses dart/appjit_cha_deopt_test: Pass, Slow # Quite slow in debug mode, uses --optimization-counter-threshold=100 [ $builder_tag == asan ] -cc/CodeExecutability: Fail, OK # Address Sanitizer turns a crash into a failure. cc/CodeImmutability: Fail, OK # Address Sanitizer turns a crash into a failure. [ $builder_tag == optimization_counter_threshold ] diff --git a/runtime/vm/code_patcher.cc b/runtime/vm/code_patcher.cc index 71682313562..49269267114 100644 --- a/runtime/vm/code_patcher.cc +++ b/runtime/vm/code_patcher.cc @@ -12,13 +12,6 @@ namespace dart { DEFINE_FLAG(bool, write_protect_code, true, "Write protect jitted code"); -#if defined(DUAL_MAPPING_SUPPORTED) -DEFINE_FLAG(bool, dual_map_code, true, "Dual map jitted code, RW and RX"); -#else -DEFINE_FLAG(bool, dual_map_code, false, "Dual map jitted code, RW and RX"); -#endif // defined(DUAL_MAPPING_SUPPORTED) - -#if defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_DBC) WritableInstructionsScope::WritableInstructionsScope(uword address, intptr_t size) : address_(address), size_(size) { @@ -34,7 +27,6 @@ WritableInstructionsScope::~WritableInstructionsScope() { VirtualMemory::kReadExecute); } } -#endif // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_DBC) bool MatchesPattern(uword end, const int16_t* pattern, intptr_t size) { // When breaking within generated code in GDB, it may overwrite individual diff --git a/runtime/vm/code_patcher.h b/runtime/vm/code_patcher.h index 239a69dac9c..6aa62af3b9e 100644 --- a/runtime/vm/code_patcher.h +++ b/runtime/vm/code_patcher.h @@ -19,12 +19,10 @@ class RawCode; class RawFunction; class RawObject; -#if defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_DBC) // Stack-allocated class to create a scope where the specified region // [address, address + size] has write access enabled. This is used // when patching generated code. Access is reset to read-execute in // the destructor of this scope. -// Dual mapping of instructions pages is not supported on these target arch. class WritableInstructionsScope : public ValueObject { public: WritableInstructionsScope(uword address, intptr_t size); @@ -34,7 +32,6 @@ class WritableInstructionsScope : public ValueObject { const uword address_; const intptr_t size_; }; -#endif // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_DBC) class CodePatcher : public AllStatic { public: diff --git a/runtime/vm/compiler/relocation.cc b/runtime/vm/compiler/relocation.cc index 5d4d35f2e49..467aa782efe 100644 --- a/runtime/vm/compiler/relocation.cc +++ b/runtime/vm/compiler/relocation.cc @@ -5,7 +5,6 @@ #include "vm/compiler/relocation.h" #include "vm/code_patcher.h" -#include "vm/heap/pages.h" #include "vm/instructions.h" #include "vm/object_store.h" #include "vm/stub_code.h" @@ -363,11 +362,8 @@ void CodeRelocator::ResolveCallToDestination(UnresolvedCall* unresolved_call, auto caller = Code::InstructionsOf(unresolved_call->caller); const int32_t distance = destination_text - call_text_offset; { - uword addr = Instructions::PayloadStart(caller) + call_offset; - if (FLAG_write_protect_code) { - addr -= HeapPage::Of(caller)->AliasOffset(); - } - PcRelativeCallPattern call(addr); + PcRelativeCallPattern call(Instructions::PayloadStart(caller) + + call_offset); ASSERT(call.IsValid()); call.set_distance(static_cast(distance)); ASSERT(call.distance() == distance); diff --git a/runtime/vm/heap/marker.cc b/runtime/vm/heap/marker.cc index da86a3622f7..03c9683956d 100644 --- a/runtime/vm/heap/marker.cc +++ b/runtime/vm/heap/marker.cc @@ -368,10 +368,6 @@ class MarkingVisitorBase : public ObjectPointerVisitor { } static bool TryAcquireMarkBit(RawObject* raw_obj) { - if (FLAG_write_protect_code && raw_obj->IsInstructions()) { - // A non-writable alias mapping may exist for instruction pages. - raw_obj = HeapPage::ToWritable(raw_obj); - } if (!sync) { raw_obj->SetMarkBitUnsynchronized(); return true; diff --git a/runtime/vm/heap/pages.cc b/runtime/vm/heap/pages.cc index 19d8f04bdc9..e1ac801e257 100644 --- a/runtime/vm/heap/pages.cc +++ b/runtime/vm/heap/pages.cc @@ -57,8 +57,11 @@ DEFINE_FLAG(bool, log_growth, false, "Log PageSpace growth policy decisions."); HeapPage* HeapPage::Allocate(intptr_t size_in_words, PageType type, const char* name) { + bool is_executable = (type == kExecutable); + // Create the new page executable (RWX) only if we're not in W^X mode + bool create_executable = !FLAG_write_protect_code && is_executable; VirtualMemory* memory = VirtualMemory::AllocateAligned( - size_in_words << kWordSizeLog2, kPageSize, type == kExecutable, name); + size_in_words << kWordSizeLog2, kPageSize, create_executable, name); if (memory == NULL) { return NULL; } @@ -211,7 +214,7 @@ void HeapPage::WriteProtect(bool read_only) { VirtualMemory::Protection prot; if (read_only) { - if ((type_ == kExecutable) && (memory_->AliasOffset() == 0)) { + if (type_ == kExecutable) { prot = VirtualMemory::kReadExecute; } else { prot = VirtualMemory::kReadOnly; diff --git a/runtime/vm/heap/pages.h b/runtime/vm/heap/pages.h index d7381d760b7..98d480f65cc 100644 --- a/runtime/vm/heap/pages.h +++ b/runtime/vm/heap/pages.h @@ -40,8 +40,7 @@ class HeapPage { HeapPage* next() const { return next_; } void set_next(HeapPage* next) { next_ = next; } - bool Contains(uword addr) const { return memory_->Contains(addr); } - intptr_t AliasOffset() const { return memory_->AliasOffset(); } + bool Contains(uword addr) { return memory_->Contains(addr); } uword object_start() const { return memory_->start() + ObjectStartOffset(); } uword object_end() const { return object_end_; } @@ -71,8 +70,7 @@ class HeapPage { } // Warning: This does not work for objects on image pages because image pages - // are not aligned. However, it works for objects on large pages, because - // only one object is allocated per large page. + // are not aligned. static HeapPage* Of(RawObject* obj) { ASSERT(obj->IsHeapObject()); ASSERT(obj->IsOldObject()); @@ -80,45 +78,10 @@ class HeapPage { kPageMask); } - // Warning: This does not work for addresses on image pages or on large pages. - static HeapPage* Of(uword addr) { + static HeapPage* Of(uintptr_t addr) { return reinterpret_cast(addr & kPageMask); } - // Warning: This does not work for objects on image pages. - static RawObject* ToExecutable(RawObject* obj) { - HeapPage* page = Of(obj); - VirtualMemory* memory = page->memory_; - const intptr_t alias_offset = memory->AliasOffset(); - if (alias_offset == 0) { - return obj; // Not aliased. - } - uword addr = RawObject::ToAddr(obj); - if (memory->Contains(addr)) { - return RawObject::FromAddr(addr + alias_offset); - } - // obj is executable. - ASSERT(memory->ContainsAlias(addr)); - return obj; - } - - // Warning: This does not work for objects on image pages. - static RawObject* ToWritable(RawObject* obj) { - HeapPage* page = Of(obj); - VirtualMemory* memory = page->memory_; - const intptr_t alias_offset = memory->AliasOffset(); - if (alias_offset == 0) { - return obj; // Not aliased. - } - uword addr = RawObject::ToAddr(obj); - if (memory->ContainsAlias(addr)) { - return RawObject::FromAddr(addr - alias_offset); - } - // obj is writable. - ASSERT(memory->Contains(addr)); - return obj; - } - // 1 card = 128 slots. static const intptr_t kSlotsPerCardLog2 = 7; static const intptr_t kBytesPerCardLog2 = kWordSizeLog2 + kSlotsPerCardLog2; diff --git a/runtime/vm/heap/verifier.cc b/runtime/vm/heap/verifier.cc index 237777e440c..8ea2fdb5e93 100644 --- a/runtime/vm/heap/verifier.cc +++ b/runtime/vm/heap/verifier.cc @@ -49,10 +49,6 @@ void VerifyPointersVisitor::VisitPointers(RawObject** first, RawObject** last) { RawObject* raw_obj = *current; if (raw_obj->IsHeapObject()) { if (!allocated_set_->Contains(raw_obj)) { - if (raw_obj->IsInstructions() && - allocated_set_->Contains(HeapPage::ToWritable(raw_obj))) { - continue; - } uword raw_addr = RawObject::ToAddr(raw_obj); FATAL1("Invalid object pointer encountered %#" Px "\n", raw_addr); } diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc index 70145783140..864555df691 100644 --- a/runtime/vm/object.cc +++ b/runtime/vm/object.cc @@ -2015,12 +2015,7 @@ RawError* Object::Init(Isolate* isolate, bool Object::IsReadOnly() const { if (FLAG_verify_handles && raw()->IsReadOnly()) { Heap* vm_isolate_heap = Dart::vm_isolate()->heap(); - uword addr = RawObject::ToAddr(raw()); - if (!vm_isolate_heap->Contains(addr)) { - ASSERT(FLAG_write_protect_code); - addr = RawObject::ToAddr(HeapPage::ToWritable(raw())); - ASSERT(vm_isolate_heap->Contains(addr)); - } + ASSERT(vm_isolate_heap->Contains(RawObject::ToAddr(raw()))); } return raw()->IsReadOnly(); } @@ -2077,12 +2072,8 @@ void Object::CheckHandle() const { Isolate* isolate = Isolate::Current(); Heap* isolate_heap = isolate->heap(); Heap* vm_isolate_heap = Dart::vm_isolate()->heap(); - uword addr = RawObject::ToAddr(raw_); - if (!isolate_heap->Contains(addr) && !vm_isolate_heap->Contains(addr)) { - ASSERT(FLAG_write_protect_code); - addr = RawObject::ToAddr(HeapPage::ToWritable(raw_)); - ASSERT(isolate_heap->Contains(addr) || vm_isolate_heap->Contains(addr)); - } + ASSERT(isolate_heap->Contains(RawObject::ToAddr(raw_)) || + vm_isolate_heap->Contains(RawObject::ToAddr(raw_))); } } #endif @@ -14571,24 +14562,6 @@ RawCode* Code::FinalizeCode(FlowGraphCompiler* compiler, object->raw()); } - // Write protect instructions and, if supported by OS, use dual mapping - // for execution. - if (FLAG_write_protect_code) { - uword address = RawObject::ToAddr(instrs.raw()); - // Check if a dual mapping exists. - instrs = Instructions::RawCast(HeapPage::ToExecutable(instrs.raw())); - uword exec_address = RawObject::ToAddr(instrs.raw()); - if (exec_address != address) { - VirtualMemory::Protect(reinterpret_cast(address), - instrs.raw()->HeapSize(), - VirtualMemory::kReadOnly); - address = exec_address; - } - VirtualMemory::Protect(reinterpret_cast(address), - instrs.raw()->HeapSize(), - VirtualMemory::kReadExecute); - } - // Hook up Code and Instructions objects. code.SetActiveInstructions(instrs); code.set_instructions(instrs); @@ -14599,6 +14572,13 @@ RawCode* Code::FinalizeCode(FlowGraphCompiler* compiler, code.set_object_pool(object_pool->raw()); } + if (FLAG_write_protect_code) { + uword address = RawObject::ToAddr(instrs.raw()); + VirtualMemory::Protect(reinterpret_cast(address), + instrs.raw()->HeapSize(), + VirtualMemory::kReadExecute); + } + #if defined(DART_PRECOMPILER) if (stats != nullptr) { stats->Finalize(); diff --git a/runtime/vm/object.h b/runtime/vm/object.h index 05ba3eb0b07..e19f35718a5 100644 --- a/runtime/vm/object.h +++ b/runtime/vm/object.h @@ -4651,7 +4651,6 @@ class ExceptionHandlers : public Object { class Code : public Object { public: - // When dual mapping, this returns the executable view. RawInstructions* active_instructions() const { #if defined(DART_PRECOMPILED_RUNTIME) UNREACHABLE(); @@ -4661,7 +4660,6 @@ class Code : public Object { #endif } - // When dual mapping, these return the executable view. RawInstructions* instructions() const { return raw_ptr()->instructions_; } static RawInstructions* InstructionsOf(const RawCode* code) { return code->ptr()->instructions_; @@ -5142,7 +5140,6 @@ class Code : public Object { FINAL_HEAP_OBJECT_IMPLEMENTATION(Code, Object); friend class Class; - friend class CodeTestHelper; friend class SnapshotWriter; friend class StubCode; // for set_object_pool friend class Precompiler; // for set_object_pool @@ -9143,12 +9140,8 @@ DART_FORCE_INLINE void Object::SetRaw(RawObject* value) { Isolate* isolate = Isolate::Current(); Heap* isolate_heap = isolate->heap(); Heap* vm_isolate_heap = Dart::vm_isolate()->heap(); - uword addr = RawObject::ToAddr(raw_); - if (!isolate_heap->Contains(addr) && !vm_isolate_heap->Contains(addr)) { - ASSERT(FLAG_write_protect_code); - addr = RawObject::ToAddr(HeapPage::ToWritable(raw_)); - ASSERT(isolate_heap->Contains(addr) || vm_isolate_heap->Contains(addr)); - } + ASSERT(isolate_heap->Contains(RawObject::ToAddr(raw_)) || + vm_isolate_heap->Contains(RawObject::ToAddr(raw_))); } #endif } diff --git a/runtime/vm/object_graph.cc b/runtime/vm/object_graph.cc index 3e52f53ba2b..5a5e740e878 100644 --- a/runtime/vm/object_graph.cc +++ b/runtime/vm/object_graph.cc @@ -44,12 +44,7 @@ class ObjectGraph::Stack : public ObjectPointerVisitor { if (!include_vm_objects_ && !IsUserClass((*current)->GetClassId())) { continue; } - if (FLAG_write_protect_code && (*current)->IsInstructions()) { - // A non-writable alias mapping may exist for instruction pages. - HeapPage::ToWritable(*current)->SetGraphMarked(); - } else { - (*current)->SetGraphMarked(); - } + (*current)->SetGraphMarked(); Node node; node.ptr = current; node.obj = *current; diff --git a/runtime/vm/object_test.cc b/runtime/vm/object_test.cc index 4664ee7ae9a..c0d95266bfd 100644 --- a/runtime/vm/object_test.cc +++ b/runtime/vm/object_test.cc @@ -23,7 +23,6 @@ namespace dart { -DECLARE_FLAG(bool, dual_map_code); DECLARE_FLAG(bool, write_protect_code); static RawClass* CreateDummyClass(const String& class_name, @@ -2508,56 +2507,8 @@ ISOLATE_UNIT_TEST_CASE(CodeImmutability) { if (!FLAG_write_protect_code) { // Since this test is expected to crash, crash if write protection of code // is switched off. - FATAL("Test requires --write-protect-code; skip by forcing expected crash"); - } - MallocHooks::set_stack_trace_collection_enabled( - stack_trace_collection_enabled); -} - -class CodeTestHelper { - public: - static void SetInstructions(const Code& code, - const Instructions& instructions) { - code.SetActiveInstructions(instructions); - code.set_instructions(instructions); - } -}; - -// Test for executability of generated instructions. The test crashes with a -// segmentation fault when executing the writeable view. -ISOLATE_UNIT_TEST_CASE(CodeExecutability) { - bool stack_trace_collection_enabled = - MallocHooks::stack_trace_collection_enabled(); - MallocHooks::set_stack_trace_collection_enabled(false); - extern void GenerateIncrement(Assembler * assembler); - ObjectPoolBuilder object_pool_builder; - Assembler _assembler_(&object_pool_builder); - GenerateIncrement(&_assembler_); - const Function& function = Function::Handle(CreateFunction("Test_Code")); - Code& code = Code::Handle(Code::FinalizeCodeAndNotify( - function, nullptr, &_assembler_, Code::PoolAttachment::kAttachPool)); - function.AttachCode(code); - Instructions& instructions = Instructions::Handle(code.instructions()); - uword payload_start = instructions.PayloadStart(); - EXPECT_EQ(instructions.raw(), Instructions::FromPayloadStart(payload_start)); - // Execute the executable view of the instructions (default). - Object& result = - Object::Handle(DartEntry::InvokeFunction(function, Array::empty_array())); - EXPECT_EQ(1, Smi::Cast(result).Value()); - // Switch to the writeable but non-executable view of the instructions. - instructions ^= HeapPage::ToWritable(instructions.raw()); - payload_start = instructions.PayloadStart(); - EXPECT_EQ(instructions.raw(), Instructions::FromPayloadStart(payload_start)); - // Hook up Code and Instructions objects. - CodeTestHelper::SetInstructions(code, instructions); - function.AttachCode(code); - // Try executing the generated code, expected to crash. - result = DartEntry::InvokeFunction(function, Array::empty_array()); - EXPECT_EQ(1, Smi::Cast(result).Value()); - if (!FLAG_dual_map_code) { - // Since this test is expected to crash, crash if dual mapping of code - // is switched off. - FATAL("Test requires --dual-map-code; skip by forcing expected crash"); + // TODO(regis, fschneider): Should this be FATAL() instead? + OS::DebugBreak(); } MallocHooks::set_stack_trace_collection_enabled( stack_trace_collection_enabled); diff --git a/runtime/vm/os_linux.cc b/runtime/vm/os_linux.cc index 20db94d89fd..1079bdbc421 100644 --- a/runtime/vm/os_linux.cc +++ b/runtime/vm/os_linux.cc @@ -558,7 +558,9 @@ void OS::SleepMicros(int64_t micros) { } } -// TODO(regis): Function called only from the simulator. +// TODO(regis, iposva): When this function is no longer called from the +// CodeImmutability test in object_test.cc, it will be called only from the +// simulator, which means that only the Intel implementation is needed. void OS::DebugBreak() { __builtin_trap(); } diff --git a/runtime/vm/virtual_memory.cc b/runtime/vm/virtual_memory.cc index 48ba86735d7..6d73ba05022 100644 --- a/runtime/vm/virtual_memory.cc +++ b/runtime/vm/virtual_memory.cc @@ -17,18 +17,12 @@ bool VirtualMemory::InSamePage(uword address0, uword address1) { void VirtualMemory::Truncate(intptr_t new_size) { ASSERT(Utils::IsAligned(new_size, PageSize())); ASSERT(new_size <= size()); - if (reserved_.size() == - region_.size()) { // Don't create holes in reservation. + if (reserved_.size() == region_.size()) { // Don't create holes in reservation. FreeSubSegment(reinterpret_cast(start() + new_size), size() - new_size); reserved_.set_size(new_size); - if (AliasOffset() != 0) { - FreeSubSegment(reinterpret_cast(alias_.start() + new_size), - alias_.size() - new_size); - } } region_.Subregion(region_, 0, new_size); - alias_.Subregion(alias_, 0, new_size); } VirtualMemory* VirtualMemory::ForImagePage(void* pointer, uword size) { @@ -37,7 +31,7 @@ VirtualMemory* VirtualMemory::ForImagePage(void* pointer, uword size) { MemoryRegion region(pointer, size); MemoryRegion reserved(0, 0); // NULL reservation indicates VM should not // attempt to free this memory. - VirtualMemory* memory = new VirtualMemory(region, region, reserved); + VirtualMemory* memory = new VirtualMemory(region, reserved); ASSERT(!memory->vm_owns_region()); return memory; } diff --git a/runtime/vm/virtual_memory.h b/runtime/vm/virtual_memory.h index 496e63c35bf..6d745411029 100644 --- a/runtime/vm/virtual_memory.h +++ b/runtime/vm/virtual_memory.h @@ -28,14 +28,10 @@ class VirtualMemory { uword end() const { return region_.end(); } void* address() const { return region_.pointer(); } intptr_t size() const { return region_.size(); } - intptr_t AliasOffset() const { return alias_.start() - region_.start(); } static void Init(); bool Contains(uword addr) const { return region_.Contains(addr); } - bool ContainsAlias(uword addr) const { - return (AliasOffset() != 0) && alias_.Contains(addr); - } // Changes the protection of the virtual memory area. static void Protect(void* address, intptr_t size, Protection mode); @@ -76,22 +72,14 @@ class VirtualMemory { // can give back the virtual memory to the system. Returns true on success. static void FreeSubSegment(void* address, intptr_t size); - // These constructors are only used internally when reserving new virtual - // spaces. They do not reserve any virtual address space on their own. + // This constructor is only used internally when reserving new virtual spaces. + // It does not reserve any virtual address space on its own. VirtualMemory(const MemoryRegion& region, - const MemoryRegion& alias, const MemoryRegion& reserved) - : region_(region), alias_(alias), reserved_(reserved) {} - - VirtualMemory(const MemoryRegion& region, const MemoryRegion& reserved) - : region_(region), alias_(region), reserved_(reserved) {} + : region_(region), reserved_(reserved) {} MemoryRegion region_; - // Optional secondary mapping of region_ to a virtual space with different - // protection, e.g. allowing code execution. - MemoryRegion alias_; - // The underlying reservation not yet given back to the OS. // Its address might disagree with region_ due to aligned allocations. // Its size might disagree with region_ due to Truncate. @@ -99,10 +87,6 @@ class VirtualMemory { static uword page_size_; -#if defined(HOST_OS_FUCHSIA) - static uword base_; // Cached base of root vmar. -#endif - DISALLOW_IMPLICIT_CONSTRUCTORS(VirtualMemory); }; diff --git a/runtime/vm/virtual_memory_fuchsia.cc b/runtime/vm/virtual_memory_fuchsia.cc index b627ddf124a..63c47ae5ab1 100644 --- a/runtime/vm/virtual_memory_fuchsia.cc +++ b/runtime/vm/virtual_memory_fuchsia.cc @@ -35,29 +35,15 @@ namespace dart { -DECLARE_FLAG(bool, dual_map_code); DECLARE_FLAG(bool, write_protect_code); uword VirtualMemory::page_size_ = 0; -uword VirtualMemory::base_ = 0; void VirtualMemory::Init() { page_size_ = getpagesize(); - - // Cache the base of zx_vmar_root_self() which is used to align mappings. - zx_info_vmar_t buf[1]; - size_t actual; - size_t avail; - zx_status_t status = - zx_object_get_info(zx_vmar_root_self(), ZX_INFO_VMAR, buf, - sizeof(zx_info_vmar_t), &actual, &avail); - if (status != ZX_OK) { - FATAL1("zx_object_get_info failed: %s\n", zx_status_get_string(status)); - } - base_ = buf[0].base; } -static void Unmap(zx_handle_t vmar, uword start, uword end) { +static void unmap(zx_handle_t vmar, uword start, uword end) { ASSERT(start <= end); const uword size = end - start; if (size == 0) { @@ -70,61 +56,28 @@ static void Unmap(zx_handle_t vmar, uword start, uword end) { } } -static void* MapAligned(zx_handle_t vmar, - zx_handle_t vmo, - zx_vm_option_t options, - uword size, - uword alignment, - uword vmar_base, - uword padded_size) { - uword base; - zx_status_t status = - zx_vmar_map(vmar, options, 0, vmo, 0u, padded_size, &base); - LOG_INFO("zx_vmar_map(%u, 0x%lx, 0x%lx)\n", options, base, padded_size); - - if (status != ZX_OK) { - LOG_ERR("zx_vmar_map(%u, 0x%lx, 0x%lx) failed: %s\n", options, base, - padded_size, zx_status_get_string(status)); - return NULL; - } - const uword aligned_base = Utils::RoundUp(base, alignment); - const zx_vm_option_t overwrite_options = options | ZX_VM_SPECIFIC_OVERWRITE; - status = zx_vmar_map(vmar, overwrite_options, aligned_base - vmar_base, vmo, - 0u, size, &base); - LOG_INFO("zx_vmar_map(%u, 0x%lx, 0x%lx)\n", overwrite_options, - aligned_base - vmar_base, size); - - if (status != ZX_OK) { - LOG_ERR("zx_vmar_map(%u, 0x%lx, 0x%lx) failed: %s\n", overwrite_options, - aligned_base - vmar_base, size, zx_status_get_string(status)); - return NULL; - } - ASSERT(base == aligned_base); - return reinterpret_cast(base); -} - VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size, intptr_t alignment, bool is_executable, const char* name) { - // When FLAG_write_protect_code is active, code memory (indicated by - // is_executable = true) is allocated as non-executable and later - // changed to executable via VirtualMemory::Protect, which requires - // ZX_RIGHT_EXECUTE on the underlying VMO. - // In addition, dual mapping of the same underlying code memory is provided. - const bool dual_mapping = - is_executable && FLAG_write_protect_code && FLAG_dual_map_code; + // When FLAG_write_protect_code is active, the VM allocates code + // memory with !is_executable, and later changes to executable via + // VirtualMemory::Protect, which requires ZX_RIGHT_EXECUTE on the + // underlying VMO. Conservatively assume all memory needs to be + // executable in this mode. + // TODO(mdempsky): Make into parameter. + const bool can_prot_exec = FLAG_write_protect_code; ASSERT(Utils::IsAligned(size, page_size_)); ASSERT(Utils::IsPowerOfTwo(alignment)); ASSERT(Utils::IsAligned(alignment, page_size_)); - const intptr_t padded_size = size + alignment - page_size_; + const intptr_t allocated_size = size + alignment - page_size_; zx_handle_t vmar = zx_vmar_root_self(); zx_handle_t vmo = ZX_HANDLE_INVALID; - zx_status_t status = zx_vmo_create(size, 0u, &vmo); + zx_status_t status = zx_vmo_create(allocated_size, 0u, &vmo); if (status != ZX_OK) { - LOG_ERR("zx_vmo_create(0x%lx) failed: %s\n", size, + LOG_ERR("zx_vmo_create(%ld) failed: %s\n", size, zx_status_get_string(status)); return NULL; } @@ -133,9 +86,9 @@ VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size, zx_object_set_property(vmo, ZX_PROP_NAME, name, strlen(name)); } - if (is_executable) { + if (is_executable || can_prot_exec) { // Add ZX_RIGHT_EXECUTE permission to VMO, so it can be mapped - // into memory as executable (now or later). + // into memory as executable. status = zx_vmo_replace_as_executable(vmo, ZX_HANDLE_INVALID, &vmo); if (status != ZX_OK) { LOG_ERR("zx_vmo_replace_as_executable() failed: %s\n", @@ -144,59 +97,39 @@ VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size, } } - const zx_vm_option_t region_options = - ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | - ((is_executable && !FLAG_write_protect_code) ? ZX_VM_PERM_EXECUTE : 0); - void* region_ptr = MapAligned(vmar, vmo, region_options, size, alignment, - base_, padded_size); - if (region_ptr == NULL) { + const zx_vm_option_t options = ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | + (is_executable ? ZX_VM_PERM_EXECUTE : 0); + uword base; + status = zx_vmar_map(vmar, options, 0u, vmo, 0u, allocated_size, &base); + zx_handle_close(vmo); + if (status != ZX_OK) { + LOG_ERR("zx_vmar_map(%u, %ld) failed: %s\n", flags, size, + zx_status_get_string(status)); return NULL; } - MemoryRegion region(region_ptr, size); - VirtualMemory* result; + const uword aligned_base = Utils::RoundUp(base, alignment); - if (dual_mapping) { - // ZX_VM_PERM_EXECUTE is added later via VirtualMemory::Protect. - const zx_vm_option_t alias_options = ZX_VM_PERM_READ; - void* alias_ptr = MapAligned(vmar, vmo, alias_options, size, alignment, - base_, padded_size); - if (alias_ptr == NULL) { - const uword region_base = reinterpret_cast(region_ptr); - Unmap(vmar, region_base, region_base + size); - return NULL; - } - ASSERT(region_ptr != alias_ptr); - MemoryRegion alias(alias_ptr, size); - result = new VirtualMemory(region, alias, region); - } else { - result = new VirtualMemory(region, region, region); - } - zx_handle_close(vmo); - return result; + unmap(vmar, base, aligned_base); + unmap(vmar, aligned_base + size, base + allocated_size); + + MemoryRegion region(reinterpret_cast(aligned_base), size); + return new VirtualMemory(region, region); } VirtualMemory::~VirtualMemory() { // Reserved region may be empty due to VirtualMemory::Truncate. if (vm_owns_region() && reserved_.size() != 0) { - Unmap(zx_vmar_root_self(), reserved_.start(), reserved_.end()); - LOG_INFO("zx_vmar_unmap(0x%lx, 0x%lx) success\n", reserved_.start(), + unmap(zx_vmar_root_self(), reserved_.start(), reserved_.end()); + LOG_INFO("zx_vmar_unmap(%lx, %lx) success\n", reserved_.start(), reserved_.size()); - - const intptr_t alias_offset = AliasOffset(); - if (alias_offset != 0) { - Unmap(zx_vmar_root_self(), reserved_.start() + alias_offset, - reserved_.end() + alias_offset); - LOG_INFO("zx_vmar_unmap(0x%lx, 0x%lx) success\n", - reserved_.start() + alias_offset, reserved_.size()); - } } } void VirtualMemory::FreeSubSegment(void* address, intptr_t size) { const uword start = reinterpret_cast(address); - Unmap(zx_vmar_root_self(), start, start + size); - LOG_INFO("zx_vmar_unmap(0x%p, 0x%lx) success\n", address, size); + unmap(zx_vmar_root_self(), start, start + size); + LOG_INFO("zx_vmar_unmap(%p, %lx) success\n", address, size); } void VirtualMemory::Protect(void* address, intptr_t size, Protection mode) { @@ -228,12 +161,12 @@ void VirtualMemory::Protect(void* address, intptr_t size, Protection mode) { } zx_status_t status = zx_vmar_protect(zx_vmar_root_self(), prot, page_address, end_address - page_address); - LOG_INFO("zx_vmar_protect(%u, 0x%lx, 0x%lx)\n", prot, page_address, - end_address - page_address); if (status != ZX_OK) { - FATAL3("zx_vmar_protect(0x%lx, 0x%lx) failed: %s\n", page_address, + FATAL3("zx_vmar_protect(%lx, %lx) failed: %s\n", page_address, end_address - page_address, zx_status_get_string(status)); } + LOG_INFO("zx_vmar_protect(%lx, %lx, %x) success\n", page_address, + end_address - page_address, prot); } } // namespace dart diff --git a/runtime/vm/virtual_memory_posix.cc b/runtime/vm/virtual_memory_posix.cc index 87672503dfb..31c7f156f60 100644 --- a/runtime/vm/virtual_memory_posix.cc +++ b/runtime/vm/virtual_memory_posix.cc @@ -9,7 +9,6 @@ #include #include -#include #include #include "platform/assert.h" @@ -17,13 +16,6 @@ #include "vm/isolate.h" -// #define VIRTUAL_MEMORY_LOGGING 1 -#if defined(VIRTUAL_MEMORY_LOGGING) -#define LOG_INFO(msg, ...) OS::PrintErr(msg, ##__VA_ARGS__) -#else -#define LOG_INFO(msg, ...) -#endif // defined(VIRTUAL_MEMORY_LOGGING) - namespace dart { // standard MAP_FAILED causes "error: use of old-style cast" as it @@ -31,9 +23,6 @@ namespace dart { #undef MAP_FAILED #define MAP_FAILED reinterpret_cast(-1) -DECLARE_FLAG(bool, dual_map_code); -DECLARE_FLAG(bool, write_protect_code); - uword VirtualMemory::page_size_ = 0; void VirtualMemory::Init() { @@ -56,97 +45,17 @@ static void unmap(uword start, uword end) { } } -#if defined(DUAL_MAPPING_SUPPORTED) -// Wrapper to call memfd_create syscall. -static inline int memfd_create(const char* name, unsigned int flags) { - return syscall(__NR_memfd_create, name, flags); -} - -static void* MapAligned(int fd, - int prot, - intptr_t size, - intptr_t alignment, - intptr_t allocated_size) { - void* address = - mmap(NULL, allocated_size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - LOG_INFO("mmap(NULL, 0x%" Px ", PROT_NONE, ...): %p\n", allocated_size, - address); - if (address == MAP_FAILED) { - return NULL; - } - - const uword base = reinterpret_cast(address); - const uword aligned_base = Utils::RoundUp(base, alignment); - - // Guarantee the alignment by mapping at a fixed address inside the above - // mapping. Overlapping region will be automatically discarded in the above - // mapping. Manually discard non-overlapping regions. - address = mmap(reinterpret_cast(aligned_base), size, prot, - MAP_SHARED | MAP_FIXED, fd, 0); - LOG_INFO("mmap(0x%" Px ", 0x%" Px ", %u, ...): %p\n", aligned_base, size, - prot, address); - if (address == MAP_FAILED) { - unmap(base, base + allocated_size); - return NULL; - } - ASSERT(address == reinterpret_cast(aligned_base)); - unmap(base, aligned_base); - unmap(aligned_base + size, base + allocated_size); - return address; -} -#endif // defined(DUAL_MAPPING_SUPPORTED) - VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size, intptr_t alignment, bool is_executable, const char* name) { - // When FLAG_write_protect_code is active, code memory (indicated by - // is_executable = true) is allocated as non-executable and later - // changed to executable via VirtualMemory::Protect. ASSERT(Utils::IsAligned(size, page_size_)); ASSERT(Utils::IsPowerOfTwo(alignment)); ASSERT(Utils::IsAligned(alignment, page_size_)); const intptr_t allocated_size = size + alignment - page_size_; -#if defined(DUAL_MAPPING_SUPPORTED) - int fd = -1; - const bool dual_mapping = - is_executable && FLAG_write_protect_code && FLAG_dual_map_code; - if (dual_mapping) { - fd = memfd_create("/dual_mapping", 0); - if ((fd == -1) || (ftruncate(fd, size) == -1)) { - close(fd); - return NULL; - } - const int region_prot = PROT_READ | PROT_WRITE; - void* region_ptr = - MapAligned(fd, region_prot, size, alignment, allocated_size); - if (region_ptr == NULL) { - close(fd); - return NULL; - } - MemoryRegion region(region_ptr, size); - // PROT_EXEC is added later via VirtualMemory::Protect. - const int alias_prot = PROT_READ; - void* alias_ptr = - MapAligned(fd, alias_prot, size, alignment, allocated_size); - close(fd); - if (alias_ptr == NULL) { - const uword region_base = reinterpret_cast(region_ptr); - unmap(region_base, region_base + size); - return NULL; - } - ASSERT(region_ptr != alias_ptr); - MemoryRegion alias(alias_ptr, size); - return new VirtualMemory(region, alias, region); - } -#endif // defined(DUAL_MAPPING_SUPPORTED) - const int prot = - PROT_READ | PROT_WRITE | - ((is_executable && !FLAG_write_protect_code) ? PROT_EXEC : 0); + const int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); void* address = - mmap(NULL, allocated_size, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - LOG_INFO("mmap(NULL, 0x%" Px ", %u, ...): %p\n", allocated_size, prot, - address); + mmap(NULL, allocated_size, prot, MAP_PRIVATE | MAP_ANON, -1, 0); if (address == MAP_FAILED) { return NULL; } @@ -164,10 +73,6 @@ VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size, VirtualMemory::~VirtualMemory() { if (vm_owns_region()) { unmap(reserved_.start(), reserved_.end()); - const intptr_t alias_offset = AliasOffset(); - if (alias_offset != 0) { - unmap(reserved_.start() + alias_offset, reserved_.end() + alias_offset); - } } } @@ -209,15 +114,11 @@ void VirtualMemory::Protect(void* address, intptr_t size, Protection mode) { int error = errno; const int kBufferSize = 1024; char error_buf[kBufferSize]; - LOG_INFO("mprotect(0x%" Px ", 0x%" Px ", %u) failed\n", page_address, - end_address - page_address, prot); FATAL2("mprotect error: %d (%s)", error, Utils::StrError(error, error_buf, kBufferSize)); } - LOG_INFO("mprotect(0x%" Px ", 0x%" Px ", %u) ok\n", page_address, - end_address - page_address, prot); } } // namespace dart -#endif // defined(HOST_OS_ANDROID ... HOST_OS_LINUX ... HOST_OS_MACOS) +#endif // defined(HOST_OS_ANDROID) || defined(HOST_OS_LINUX) || defined(HOST_OS_MACOS) diff --git a/runtime/vm/virtual_memory_win.cc b/runtime/vm/virtual_memory_win.cc index 3ec743f04e0..9c917b30d6a 100644 --- a/runtime/vm/virtual_memory_win.cc +++ b/runtime/vm/virtual_memory_win.cc @@ -14,8 +14,6 @@ namespace dart { -DECLARE_FLAG(bool, write_protect_code); - uword VirtualMemory::page_size_ = 0; void VirtualMemory::Init() { @@ -28,16 +26,11 @@ VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size, intptr_t alignment, bool is_executable, const char* name) { - // When FLAG_write_protect_code is active, code memory (indicated by - // is_executable = true) is allocated as non-executable and later - // changed to executable via VirtualMemory::Protect. ASSERT(Utils::IsAligned(size, page_size_)); ASSERT(Utils::IsPowerOfTwo(alignment)); ASSERT(Utils::IsAligned(alignment, page_size_)); intptr_t reserved_size = size + alignment - page_size_; - int prot = (is_executable && !FLAG_write_protect_code) - ? PAGE_EXECUTE_READWRITE - : PAGE_READWRITE; + int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE; void* address = VirtualAlloc(NULL, reserved_size, MEM_RESERVE, prot); if (address == NULL) { return NULL;