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/zBackingFile_bsd.hpp"
26 #include "gc/z/zErrno.hpp"
27 #include "gc/z/zGlobals.hpp"
28 #include "gc/z/zLargePages.inline.hpp"
29 #include "gc/z/zPhysicalMemory.inline.hpp"
30 #include "logging/log.hpp"
31 #include "runtime/globals.hpp"
32 #include "runtime/os.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/debug.hpp"
35
36 #include <mach/mach.h>
37 #include <mach/mach_vm.h>
38 #include <sys/mman.h>
39 #include <sys/types.h>
40
41 static int vm_flags_superpage() {
42 if (!ZLargePages::is_explicit()) {
43 return 0;
44 }
45
46 const int page_size_in_megabytes = ZGranuleSize >> 20;
47 return page_size_in_megabytes << VM_FLAGS_SUPERPAGE_SHIFT;
48 }
49
50 static ZErrno mremap(uintptr_t from_addr, uintptr_t to_addr, size_t size) {
51 mach_vm_address_t remap_addr = to_addr;
52 vm_prot_t remap_cur_prot;
53 vm_prot_t remap_max_prot;
54
55 // Remap memory to an additional location
56 const kern_return_t res = mach_vm_remap(mach_task_self(),
57 &remap_addr,
58 size,
59 0 /* mask */,
60 VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE | vm_flags_superpage(),
61 mach_task_self(),
62 from_addr,
63 FALSE /* copy */,
64 &remap_cur_prot,
65 &remap_max_prot,
66 VM_INHERIT_COPY);
67
68 return (res == KERN_SUCCESS) ? ZErrno(0) : ZErrno(EINVAL);
69 }
70
71 ZBackingFile::ZBackingFile() :
72 _base(0),
73 _size(0),
74 _initialized(false) {
75
76 // Reserve address space for virtual backing file
77 _base = (uintptr_t)os::reserve_memory(MaxHeapSize);
78 if (_base == 0) {
79 // Failed
80 log_error(gc)("Failed to reserve address space for virtual backing file");
81 return;
82 }
83
84 // Successfully initialized
85 _initialized = true;
86 }
87
88 bool ZBackingFile::is_initialized() const {
89 return _initialized;
90 }
91
92 size_t ZBackingFile::size() const {
93 return _size;
94 }
95
96 bool ZBackingFile::commit_inner(size_t offset, size_t length) {
97 assert(is_aligned(offset, os::vm_page_size()), "Invalid offset");
98 assert(is_aligned(length, os::vm_page_size()), "Invalid length");
99
100 log_trace(gc, heap)("Committing memory: " SIZE_FORMAT "M-" SIZE_FORMAT "M (" SIZE_FORMAT "M)",
101 offset / M, (offset + length) / M, length / M);
102
103 const uintptr_t addr = _base + offset;
104 const void* const res = mmap((void*)addr, length, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
105 if (res == MAP_FAILED) {
106 ZErrno err;
107 log_error(gc)("Failed to commit memory (%s)", err.to_string());
108 return false;
109 }
110
111 const size_t end = offset + length;
112 if (end > _size) {
113 // Record new virtual file size
114 _size = end;
115 }
116
117 // Success
118 return true;
119 }
120
121 size_t ZBackingFile::commit(size_t offset, size_t length) {
122 // Try to commit the whole region
123 if (commit_inner(offset, length)) {
124 // Success
125 return length;
126 }
127
128 // Failed, try to commit as much as possible
129 size_t start = offset;
130 size_t end = offset + length;
131
132 for (;;) {
133 length = align_down((end - start) / 2, ZGranuleSize);
134 if (length == 0) {
135 // Done, don't commit more
136 return start - offset;
137 }
138
139 if (commit_inner(start, length)) {
140 // Success, try commit more
141 start += length;
142 } else {
143 // Failed, try commit less
144 end -= length;
145 }
146 }
147 }
148
149 size_t ZBackingFile::uncommit(size_t offset, size_t length) {
150 assert(is_aligned(offset, os::vm_page_size()), "Invalid offset");
151 assert(is_aligned(length, os::vm_page_size()), "Invalid length");
152
153 log_trace(gc, heap)("Uncommitting memory: " SIZE_FORMAT "M-" SIZE_FORMAT "M (" SIZE_FORMAT "M)",
154 offset / M, (offset + length) / M, length / M);
155
156 const uintptr_t start = _base + offset;
157 const void* const res = mmap((void*)start, length, PROT_NONE, MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, -1, 0);
158 if (res == MAP_FAILED) {
159 ZErrno err;
160 log_error(gc)("Failed to uncommit memory (%s)", err.to_string());
161 return 0;
162 }
163
164 return length;
165 }
166
167 void ZBackingFile::map(uintptr_t addr, size_t size, uintptr_t offset) const {
168 const ZErrno err = mremap(_base + offset, addr, size);
169 if (err) {
170 fatal("Failed to remap memory (%s)", err.to_string());
171 }
172 }
173
174 void ZBackingFile::unmap(uintptr_t addr, size_t size) const {
175 // Note that we must keep the address space reservation intact and just detach
176 // the backing memory. For this reason we map a new anonymous, non-accessible
177 // and non-reserved page over the mapping instead of actually unmapping.
178 const void* const res = mmap((void*)addr, size, PROT_NONE, MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, -1, 0);
179 if (res == MAP_FAILED) {
180 ZErrno err;
181 fatal("Failed to map memory (%s)", err.to_string());
182 }
183 }