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Brian Carlstrom27ec9612011-09-19 20:20:38 -07001/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "mem_map.h"
18
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070019#include <corkscrew/map_info.h>
20
Elliott Hughese222ee02012-12-13 14:41:43 -080021#include "base/stringprintf.h"
22#include "ScopedFd.h"
23#include "utils.h"
24
Elliott Hughes6c9c06d2011-11-07 16:43:47 -080025#define USE_ASHMEM 1
26
27#ifdef USE_ASHMEM
28#include <cutils/ashmem.h>
29#endif
30
Brian Carlstrom27ec9612011-09-19 20:20:38 -070031namespace art {
32
Elliott Hughes96970cd2012-03-13 15:46:31 -070033#if !defined(NDEBUG)
34
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070035static std::ostream& operator<<(std::ostream& os, map_info_t* rhs) {
36 for (map_info_t* m = rhs; m != NULL; m = m->next) {
Elliott Hughes7bda1582012-06-07 11:00:54 -070037 os << StringPrintf("0x%08x-0x%08x %c%c %s\n",
38 static_cast<uint32_t>(m->start),
39 static_cast<uint32_t>(m->end),
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070040 m->is_readable ? 'r' : '-', m->is_executable ? 'x' : '-', m->name);
41 }
42 return os;
Brian Carlstrom27ec9612011-09-19 20:20:38 -070043}
44
Ian Rogers10c5b782013-01-10 10:40:53 -080045static void CheckMapRequest(byte* addr, size_t byte_count) {
Brian Carlstrom27ec9612011-09-19 20:20:38 -070046 if (addr == NULL) {
47 return;
48 }
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070049
Elliott Hughes96970cd2012-03-13 15:46:31 -070050 uint32_t base = reinterpret_cast<size_t>(addr);
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070051 uint32_t limit = base + byte_count;
Brian Carlstrom27ec9612011-09-19 20:20:38 -070052
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070053 map_info_t* map_info_list = load_map_info_list(getpid());
54 for (map_info_t* m = map_info_list; m != NULL; m = m->next) {
Brian Carlstrom7934ac22013-07-26 10:54:15 -070055 CHECK(!(base >= m->start && base < m->end) // start of new within old
56 && !(limit > m->start && limit < m->end) // end of new within old
57 && !(base <= m->start && limit > m->end)) // start/end of new includes all of old
Elliott Hughes7bda1582012-06-07 11:00:54 -070058 << StringPrintf("Requested region 0x%08x-0x%08x overlaps with existing map 0x%08x-0x%08x (%s)\n",
59 base, limit,
60 static_cast<uint32_t>(m->start), static_cast<uint32_t>(m->end), m->name)
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070061 << map_info_list;
Elliott Hughes96970cd2012-03-13 15:46:31 -070062 }
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070063 free_map_info_list(map_info_list);
Brian Carlstrom27ec9612011-09-19 20:20:38 -070064}
65
Elliott Hughes96970cd2012-03-13 15:46:31 -070066#else
Elliott Hughes1bac54f2012-03-16 12:48:31 -070067static void CheckMapRequest(byte*, size_t) { }
Elliott Hughes96970cd2012-03-13 15:46:31 -070068#endif
69
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070070MemMap* MemMap::MapAnonymous(const char* name, byte* addr, size_t byte_count, int prot) {
Brian Carlstrom9004cb62013-07-26 15:48:31 -070071 if (byte_count == 0) {
72 return new MemMap(name, NULL, 0, NULL, 0, prot);
73 }
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070074 size_t page_aligned_byte_count = RoundUp(byte_count, kPageSize);
75 CheckMapRequest(addr, page_aligned_byte_count);
Elliott Hughes6c9c06d2011-11-07 16:43:47 -080076
77#ifdef USE_ASHMEM
Ian Rogersa40307e2013-02-22 11:32:44 -080078 // android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are
79 // prefixed "dalvik-".
80 std::string debug_friendly_name("dalvik-");
81 debug_friendly_name += name;
82 ScopedFd fd(ashmem_create_region(debug_friendly_name.c_str(), page_aligned_byte_count));
Elliott Hughes6c9c06d2011-11-07 16:43:47 -080083 int flags = MAP_PRIVATE;
84 if (fd.get() == -1) {
85 PLOG(ERROR) << "ashmem_create_region failed (" << name << ")";
86 return NULL;
87 }
88#else
89 ScopedFd fd(-1);
90 int flags = MAP_PRIVATE | MAP_ANONYMOUS;
91#endif
92
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070093 byte* actual = reinterpret_cast<byte*>(mmap(addr, page_aligned_byte_count, prot, flags, fd.get(), 0));
Brian Carlstrom27ec9612011-09-19 20:20:38 -070094 if (actual == MAP_FAILED) {
jeffhao8161c032012-10-31 15:50:00 -070095 std::string maps;
96 ReadFileToString("/proc/self/maps", &maps);
Elliott Hughesecd3a6f2012-06-06 18:16:37 -070097 PLOG(ERROR) << "mmap(" << reinterpret_cast<void*>(addr) << ", " << page_aligned_byte_count
jeffhao8161c032012-10-31 15:50:00 -070098 << ", " << prot << ", " << flags << ", " << fd.get() << ", 0) failed for " << name
99 << "\n" << maps;
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700100 return NULL;
101 }
Mathieu Chartier1c23e1e2012-10-12 14:14:11 -0700102 return new MemMap(name, actual, byte_count, actual, page_aligned_byte_count, prot);
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700103}
104
Brian Carlstrom700c8d32012-11-05 10:42:02 -0800105MemMap* MemMap::MapFileAtAddress(byte* addr, size_t byte_count,
106 int prot, int flags, int fd, off_t start, bool reuse) {
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700107 CHECK_NE(0, prot);
108 CHECK_NE(0, flags & (MAP_SHARED | MAP_PRIVATE));
Brian Carlstrom9004cb62013-07-26 15:48:31 -0700109 if (byte_count == 0) {
110 return new MemMap("file", NULL, 0, NULL, 0, prot);
111 }
Ian Rogersf8adc602013-04-18 17:06:19 -0700112 // Adjust 'offset' to be page-aligned as required by mmap.
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700113 int page_offset = start % kPageSize;
114 off_t page_aligned_offset = start - page_offset;
Ian Rogersf8adc602013-04-18 17:06:19 -0700115 // Adjust 'byte_count' to be page-aligned as we will map this anyway.
Elliott Hughesecd3a6f2012-06-06 18:16:37 -0700116 size_t page_aligned_byte_count = RoundUp(byte_count + page_offset, kPageSize);
Ian Rogersf8adc602013-04-18 17:06:19 -0700117 // The 'addr' is modified (if specified, ie non-null) to be page aligned to the file but not
118 // necessarily to virtual memory. mmap will page align 'addr' for us.
119 byte* page_aligned_addr = (addr == NULL) ? NULL : (addr - page_offset);
Brian Carlstrom700c8d32012-11-05 10:42:02 -0800120 if (!reuse) {
121 // reuse means it is okay that it overlaps an existing page mapping.
122 // Only use this if you actually made the page reservation yourself.
123 CheckMapRequest(page_aligned_addr, page_aligned_byte_count);
Ian Rogersf8adc602013-04-18 17:06:19 -0700124 } else {
125 CHECK(addr != NULL);
Brian Carlstrom700c8d32012-11-05 10:42:02 -0800126 }
127 byte* actual = reinterpret_cast<byte*>(mmap(page_aligned_addr,
Elliott Hughesecd3a6f2012-06-06 18:16:37 -0700128 page_aligned_byte_count,
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700129 prot,
130 flags,
131 fd,
132 page_aligned_offset));
133 if (actual == MAP_FAILED) {
jeffhao8161c032012-10-31 15:50:00 -0700134 std::string maps;
135 ReadFileToString("/proc/self/maps", &maps);
Brian Carlstrom700c8d32012-11-05 10:42:02 -0800136 PLOG(ERROR) << "mmap(" << reinterpret_cast<void*>(page_aligned_addr)
137 << ", " << page_aligned_byte_count
jeffhao8161c032012-10-31 15:50:00 -0700138 << ", " << prot << ", " << flags << ", " << fd << ", " << page_aligned_offset
139 << ") failed\n" << maps;
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700140 return NULL;
141 }
Mathieu Chartier1c23e1e2012-10-12 14:14:11 -0700142 return new MemMap("file", actual + page_offset, byte_count, actual, page_aligned_byte_count,
143 prot);
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700144}
145
146MemMap::~MemMap() {
Ian Rogers30fab402012-01-23 15:43:46 -0800147 if (base_begin_ == NULL && base_size_ == 0) {
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700148 return;
149 }
Ian Rogers30fab402012-01-23 15:43:46 -0800150 int result = munmap(base_begin_, base_size_);
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700151 if (result == -1) {
152 PLOG(FATAL) << "munmap failed";
153 }
154}
155
Mathieu Chartier1c23e1e2012-10-12 14:14:11 -0700156MemMap::MemMap(const std::string& name, byte* begin, size_t size, void* base_begin,
157 size_t base_size, int prot)
158 : name_(name), begin_(begin), size_(size), base_begin_(base_begin), base_size_(base_size),
159 prot_(prot) {
Brian Carlstrom9004cb62013-07-26 15:48:31 -0700160 if (size_ == 0) {
161 CHECK(begin_ == NULL);
162 CHECK(base_begin_ == NULL);
163 CHECK_EQ(base_size_, 0U);
164 } else {
165 CHECK(begin_ != NULL);
166 CHECK(base_begin_ != NULL);
167 CHECK_NE(base_size_, 0U);
168 }
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700169};
170
Mathieu Chartiercc236d72012-07-20 10:29:05 -0700171void MemMap::UnMapAtEnd(byte* new_end) {
172 DCHECK_GE(new_end, Begin());
173 DCHECK_LE(new_end, End());
174 size_t unmap_size = End() - new_end;
175 munmap(new_end, unmap_size);
176 size_ -= unmap_size;
177}
Logan Chiend88fa262012-06-06 15:23:32 +0800178
179bool MemMap::Protect(int prot) {
180 if (base_begin_ == NULL && base_size_ == 0) {
Ian Rogers1c849e52012-06-28 14:00:33 -0700181 prot_ = prot;
Logan Chiend88fa262012-06-06 15:23:32 +0800182 return true;
183 }
184
185 if (mprotect(base_begin_, base_size_, prot) == 0) {
Ian Rogers1c849e52012-06-28 14:00:33 -0700186 prot_ = prot;
Logan Chiend88fa262012-06-06 15:23:32 +0800187 return true;
188 }
189
Shih-wei Liaoa060ed92012-06-07 09:25:28 -0700190 PLOG(ERROR) << "mprotect(" << reinterpret_cast<void*>(base_begin_) << ", " << base_size_ << ", "
191 << prot << ") failed";
Logan Chiend88fa262012-06-06 15:23:32 +0800192 return false;
193}
194
Sebastien Hertz2d6ba512013-05-17 11:31:37 +0200195bool MemMap::ProtectRegion(uint8_t* addr, size_t length, int prot) {
196 CHECK_GE(addr, base_begin_);
197 CHECK_LT(addr + length, reinterpret_cast<const uint8_t*>(base_begin_) + base_size_);
198
199 /*
200 * Align "addr" to a page boundary and adjust "length" appropriately.
201 * (The address must be page-aligned, the length doesn't need to be,
202 * but we do need to ensure we cover the same range.)
203 */
Brian Carlstrom2d888622013-07-18 17:02:00 -0700204 uint8_t* alignAddr = reinterpret_cast<uint8_t*>(RoundDown(reinterpret_cast<uintptr_t>(addr),
205 kPageSize));
Sebastien Hertz2d6ba512013-05-17 11:31:37 +0200206 size_t alignLength = length + (addr - alignAddr);
207
208 if (mprotect(alignAddr, alignLength, prot) == 0) {
209 prot_ = prot;
210 return true;
211 }
212
213 PLOG(ERROR) << "mprotect(" << reinterpret_cast<void*>(alignAddr) << ", " << alignLength << ", "
214 << prot << ") failed";
215 return false;
216}
217
Brian Carlstrom27ec9612011-09-19 20:20:38 -0700218} // namespace art