1 /*
2 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 #include "precompiled.hpp"
25 #include "gc/z/zMapper_windows.hpp"
26 #include "gc/z/zSyscall_windows.hpp"
27 #include "logging/log.hpp"
28 #include "utilities/debug.hpp"
29
30 #include <Windows.h>
31
32 // Memory reservation, commit, views, and placeholders.
33 //
34 // To be able to up-front reserve address space for the heap views, and later
35 // multi-map the heap views to the same physical memory, without ever losing the
36 // reservation of the reserved address space, we use "placeholders".
37 //
38 // These placeholders block out the address space from being used by other parts
39 // of the process. To commit memory in this address space, the placeholder must
40 // be replaced by anonymous memory, or replaced by mapping a view against a
41 // paging file mapping. We use the later to support multi-mapping.
42 //
43 // We want to be able to dynamically commit and uncommit the physical memory of
44 // the heap (and also unmap ZPages), in granules of ZGranuleSize bytes. There is
45 // no way to grow and shrink the committed memory of a paging file mapping.
46 // Therefore, we create multiple granule-sized page file mappings. The memory is
47 // committed by creating a page file mapping, map a view against it, commit the
48 // memory, unmap the view. The memory will stay committed until all views are
49 // unmapped, and the paging file mapping handle is closed.
50 //
51 // When replacing a placeholder address space reservation with a mapped view
52 // against a paging file mapping, the virtual address space must exactly match
53 // an existing placeholder's address and size. Therefore we only deal with
54 // granule-sized placeholders at this layer. Higher layers that keep track of
55 // reserved available address space can (and will) coalesce placeholders, but
56 // they will be split before being used.
57
58 #define fatal_error(msg, addr, size) \
59 fatal(msg ": " PTR_FORMAT " " SIZE_FORMAT "M (%d)", \
60 (addr), (size) / M, GetLastError())
61
62 uintptr_t ZMapper::reserve(uintptr_t addr, size_t size) {
63 void* const res = ZSyscall::VirtualAlloc2(
64 GetCurrentProcess(), // Process
65 (void*)addr, // BaseAddress
66 size, // Size
67 MEM_RESERVE | MEM_RESERVE_PLACEHOLDER, // AllocationType
68 PAGE_NOACCESS, // PageProtection
69 NULL, // ExtendedParameters
70 0 // ParameterCount
71 );
72
73 // Caller responsible for error handling
74 return (uintptr_t)res;
75 }
76
77 void ZMapper::unreserve(uintptr_t addr, size_t size) {
78 const bool res = ZSyscall::VirtualFreeEx(
79 GetCurrentProcess(), // hProcess
80 (void*)addr, // lpAddress
81 size, // dwSize
82 MEM_RELEASE // dwFreeType
83 );
84
85 if (!res) {
86 fatal_error("Failed to unreserve memory", addr, size);
87 }
88 }
89
90 HANDLE ZMapper::create_paging_file_mapping(size_t size) {
91 // Create mapping with SEC_RESERVE instead of SEC_COMMIT.
92 //
93 // We use MapViewOfFile3 for two different reasons:
94 // 1) When commiting memory for the created paging file
95 // 2) When mapping a view of the memory created in (2)
96 //
97 // The non-platform code is only setup to deal with out-of-memory
98 // errors in (1). By using SEC_RESERVE, we prevent MapViewOfFile3
99 // from failing because of "commit limit" checks. To actually commit
100 // memory in (1), a call to VirtualAlloc2 is done.
101
102 HANDLE const res = ZSyscall::CreateFileMappingW(
103 INVALID_HANDLE_VALUE, // hFile
104 NULL, // lpFileMappingAttribute
105 PAGE_READWRITE | SEC_RESERVE, // flProtect
106 size >> 32, // dwMaximumSizeHigh
107 size & 0xFFFFFFFF, // dwMaximumSizeLow
108 NULL // lpName
109 );
110
111 // Caller responsible for error handling
112 return res;
113 }
114
115 bool ZMapper::commit_paging_file_mapping(HANDLE file_handle, uintptr_t file_offset, size_t size) {
116 const uintptr_t addr = map_view_no_placeholder(file_handle, file_offset, size);
117 if (addr == 0) {
118 log_error(gc)("Failed to map view of paging file mapping (%d)", GetLastError());
119 return false;
120 }
121
122 const uintptr_t res = commit(addr, size);
123 if (res != addr) {
124 log_error(gc)("Failed to commit memory (%d)", GetLastError());
125 }
126
127 unmap_view_no_placeholder(addr, size);
128
129 return res == addr;
130 }
131
132 uintptr_t ZMapper::map_view_no_placeholder(HANDLE file_handle, uintptr_t file_offset, size_t size) {
133 void* const res = ZSyscall::MapViewOfFile3(
134 file_handle, // FileMapping
135 GetCurrentProcess(), // ProcessHandle
136 NULL, // BaseAddress
137 file_offset, // Offset
138 size, // ViewSize
139 0, // AllocationType
140 PAGE_NOACCESS, // PageProtection
141 NULL, // ExtendedParameters
142 0 // ParameterCount
143 );
144
145 // Caller responsible for error handling
146 return (uintptr_t)res;
147 }
148
149 void ZMapper::unmap_view_no_placeholder(uintptr_t addr, size_t size) {
150 const bool res = ZSyscall::UnmapViewOfFile2(
151 GetCurrentProcess(), // ProcessHandle
152 (void*)addr, // BaseAddress
153 0 // UnmapFlags
154 );
155
156 if (!res) {
157 fatal_error("Failed to unmap memory", addr, size);
158 }
159 }
160
161 uintptr_t ZMapper::commit(uintptr_t addr, size_t size) {
162 void* const res = ZSyscall::VirtualAlloc2(
163 GetCurrentProcess(), // Process
164 (void*)addr, // BaseAddress
165 size, // Size
166 MEM_COMMIT, // AllocationType
167 PAGE_NOACCESS, // PageProtection
168 NULL, // ExtendedParameters
169 0 // ParameterCount
170 );
171
172 // Caller responsible for error handling
173 return (uintptr_t)res;
174 }
175
176 HANDLE ZMapper::create_and_commit_paging_file_mapping(size_t size) {
177 HANDLE const file_handle = create_paging_file_mapping(size);
178 if (file_handle == 0) {
179 log_error(gc)("Failed to create paging file mapping (%d)", GetLastError());
180 return 0;
181 }
182
183 const bool res = commit_paging_file_mapping(file_handle, 0 /* file_offset */, size);
184 if (!res) {
185 close_paging_file_mapping(file_handle);
186 return 0;
187 }
188
189 return file_handle;
190 }
191
192 void ZMapper::close_paging_file_mapping(HANDLE file_handle) {
193 const bool res = CloseHandle(
194 file_handle // hObject
195 );
196
197 if (!res) {
198 fatal("Failed to close paging file handle (%d)", GetLastError());
199 }
200 }
201
202 void ZMapper::split_placeholder(uintptr_t addr, size_t size) {
203 const bool res = VirtualFree(
204 (void*)addr, // lpAddress
205 size, // dwSize
206 MEM_RELEASE | MEM_PRESERVE_PLACEHOLDER // dwFreeType
207 );
208
209 if (!res) {
210 fatal_error("Failed to split placeholder", addr, size);
211 }
212 }
213
214 void ZMapper::coalesce_placeholders(uintptr_t addr, size_t size) {
215 const bool res = VirtualFree(
216 (void*)addr, // lpAddress
217 size, // dwSize
218 MEM_RELEASE | MEM_COALESCE_PLACEHOLDERS // dwFreeType
219 );
220
221 if (!res) {
222 fatal_error("Failed to coalesce placeholders", addr, size);
223 }
224 }
225
226 void ZMapper::map_view_replace_placeholder(HANDLE file_handle, uintptr_t file_offset, uintptr_t addr, size_t size) {
227 void* const res = ZSyscall::MapViewOfFile3(
228 file_handle, // FileMapping
229 GetCurrentProcess(), // ProcessHandle
230 (void*)addr, // BaseAddress
231 file_offset, // Offset
232 size, // ViewSize
233 MEM_REPLACE_PLACEHOLDER, // AllocationType
234 PAGE_READWRITE, // PageProtection
235 NULL, // ExtendedParameters
236 0 // ParameterCount
237 );
238
239 if (res == NULL) {
240 fatal_error("Failed to map memory", addr, size);
241 }
242 }
243
244 void ZMapper::unmap_view_preserve_placeholder(uintptr_t addr, size_t size) {
245 const bool res = ZSyscall::UnmapViewOfFile2(
246 GetCurrentProcess(), // ProcessHandle
247 (void*)addr, // BaseAddress
248 MEM_PRESERVE_PLACEHOLDER // UnmapFlags
249 );
250
251 if (!res) {
252 fatal_error("Failed to unmap memory", addr, size);
253 }
254 }