/* * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ #include "precompiled.hpp" #include "gc/z/zMapper_windows.hpp" #include "gc/z/zSyscall_windows.hpp" #include "logging/log.hpp" #include "utilities/debug.hpp" #include // Memory reservation, commit, views, and placeholders. // // To be able to up-front reserve address space for the heap views, and later // multi-map the heap views to the same physical memory, without ever losing the // reservation of the reserved address space, we use "placeholders". // // These placeholders block out the address space from being used by other parts // of the process. To commit memory in this address space, the placeholder must // be replaced by anonymous memory, or replaced by mapping a view against a // paging file mapping. We use the later to support multi-mapping. // // We want to be able to dynamically commit and uncommit the physical memory of // the heap (and also unmap ZPages), in granules of ZGranuleSize bytes. There is // no way to grow and shrink the committed memory of a paging file mapping. // Therefore, we create multiple granule-sized page file mappings. The memory is // committed by creating a page file mapping, map a view against it, commit the // memory, unmap the view. The memory will stay committed until all views are // unmapped, and the paging file mapping handle is closed. // // When replacing a placeholder address space reservation with a mapped view // against a paging file mapping, the virtual address space must exactly match // an existing placeholder's address and size. Therefore we only deal with // granule-sized placeholders at this layer. Higher layers that keep track of // reserved available address space can (and will) coalesce placeholders, but // they will be split before being used. #define fatal_error(msg, addr, size) \ fatal(msg ": " PTR_FORMAT " " SIZE_FORMAT "M (%d)", \ (addr), (size) / M, GetLastError()) uintptr_t ZMapper::reserve(uintptr_t addr, size_t size) { void* const res = ZSyscall::VirtualAlloc2( GetCurrentProcess(), // Process (void*)addr, // BaseAddress size, // Size MEM_RESERVE | MEM_RESERVE_PLACEHOLDER, // AllocationType PAGE_NOACCESS, // PageProtection NULL, // ExtendedParameters 0 // ParameterCount ); // Caller responsible for error handling return (uintptr_t)res; } void ZMapper::unreserve(uintptr_t addr, size_t size) { const bool res = ZSyscall::VirtualFreeEx( GetCurrentProcess(), // hProcess (void*)addr, // lpAddress size, // dwSize MEM_RELEASE // dwFreeType ); if (!res) { fatal_error("Failed to unreserve memory", addr, size); } } HANDLE ZMapper::create_paging_file_mapping(size_t size) { // Create mapping with SEC_RESERVE instead of SEC_COMMIT. // // We use MapViewOfFile3 for two different reasons: // 1) When commiting memory for the created paging file // 2) When mapping a view of the memory created in (2) // // The non-platform code is only setup to deal with out-of-memory // errors in (1). By using SEC_RESERVE, we prevent MapViewOfFile3 // from failing because of "commit limit" checks. To actually commit // memory in (1), a call to VirtualAlloc2 is done. HANDLE const res = ZSyscall::CreateFileMappingW( INVALID_HANDLE_VALUE, // hFile NULL, // lpFileMappingAttribute PAGE_READWRITE | SEC_RESERVE, // flProtect size >> 32, // dwMaximumSizeHigh size & 0xFFFFFFFF, // dwMaximumSizeLow NULL // lpName ); // Caller responsible for error handling return res; } bool ZMapper::commit_paging_file_mapping(HANDLE file_handle, uintptr_t file_offset, size_t size) { const uintptr_t addr = map_view_no_placeholder(file_handle, file_offset, size); if (addr == 0) { log_error(gc)("Failed to map view of paging file mapping (%d)", GetLastError()); return false; } const uintptr_t res = commit(addr, size); if (res != addr) { log_error(gc)("Failed to commit memory (%d)", GetLastError()); } unmap_view_no_placeholder(addr, size); return res == addr; } uintptr_t ZMapper::map_view_no_placeholder(HANDLE file_handle, uintptr_t file_offset, size_t size) { void* const res = ZSyscall::MapViewOfFile3( file_handle, // FileMapping GetCurrentProcess(), // ProcessHandle NULL, // BaseAddress file_offset, // Offset size, // ViewSize 0, // AllocationType PAGE_NOACCESS, // PageProtection NULL, // ExtendedParameters 0 // ParameterCount ); // Caller responsible for error handling return (uintptr_t)res; } void ZMapper::unmap_view_no_placeholder(uintptr_t addr, size_t size) { const bool res = ZSyscall::UnmapViewOfFile2( GetCurrentProcess(), // ProcessHandle (void*)addr, // BaseAddress 0 // UnmapFlags ); if (!res) { fatal_error("Failed to unmap memory", addr, size); } } uintptr_t ZMapper::commit(uintptr_t addr, size_t size) { void* const res = ZSyscall::VirtualAlloc2( GetCurrentProcess(), // Process (void*)addr, // BaseAddress size, // Size MEM_COMMIT, // AllocationType PAGE_NOACCESS, // PageProtection NULL, // ExtendedParameters 0 // ParameterCount ); // Caller responsible for error handling return (uintptr_t)res; } HANDLE ZMapper::create_and_commit_paging_file_mapping(size_t size) { HANDLE const file_handle = create_paging_file_mapping(size); if (file_handle == 0) { log_error(gc)("Failed to create paging file mapping (%d)", GetLastError()); return 0; } const bool res = commit_paging_file_mapping(file_handle, 0 /* file_offset */, size); if (!res) { close_paging_file_mapping(file_handle); return 0; } return file_handle; } void ZMapper::close_paging_file_mapping(HANDLE file_handle) { const bool res = CloseHandle( file_handle // hObject ); if (!res) { fatal("Failed to close paging file handle (%d)", GetLastError()); } } void ZMapper::split_placeholder(uintptr_t addr, size_t size) { const bool res = VirtualFree( (void*)addr, // lpAddress size, // dwSize MEM_RELEASE | MEM_PRESERVE_PLACEHOLDER // dwFreeType ); if (!res) { fatal_error("Failed to split placeholder", addr, size); } } void ZMapper::coalesce_placeholders(uintptr_t addr, size_t size) { const bool res = VirtualFree( (void*)addr, // lpAddress size, // dwSize MEM_RELEASE | MEM_COALESCE_PLACEHOLDERS // dwFreeType ); if (!res) { fatal_error("Failed to coalesce placeholders", addr, size); } } void ZMapper::map_view_replace_placeholder(HANDLE file_handle, uintptr_t file_offset, uintptr_t addr, size_t size) { void* const res = ZSyscall::MapViewOfFile3( file_handle, // FileMapping GetCurrentProcess(), // ProcessHandle (void*)addr, // BaseAddress file_offset, // Offset size, // ViewSize MEM_REPLACE_PLACEHOLDER, // AllocationType PAGE_READWRITE, // PageProtection NULL, // ExtendedParameters 0 // ParameterCount ); if (res == NULL) { fatal_error("Failed to map memory", addr, size); } } void ZMapper::unmap_view_preserve_placeholder(uintptr_t addr, size_t size) { const bool res = ZSyscall::UnmapViewOfFile2( GetCurrentProcess(), // ProcessHandle (void*)addr, // BaseAddress MEM_PRESERVE_PLACEHOLDER // UnmapFlags ); if (!res) { fatal_error("Failed to unmap memory", addr, size); } }