MachVMMemory.cpp revision d906b1b24a6c838d78039b399ee43dc57598ab52 
1//===-- MachVMMemory.cpp ----------------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  Created by Greg Clayton on 6/26/07.
11//
12//===----------------------------------------------------------------------===//
13
14#include "MachVMMemory.h"
15#include "MachVMRegion.h"
16#include "DNBLog.h"
17#include <mach/mach_vm.h>
18
19MachVMMemory::MachVMMemory() :
20    m_page_size    (kInvalidPageSize),
21    m_err        (0)
22{
23}
24
25MachVMMemory::~MachVMMemory()
26{
27}
28
29nub_size_t
30MachVMMemory::PageSize()
31{
32    if (m_page_size == kInvalidPageSize)
33    {
34        m_err = ::host_page_size( ::mach_host_self(), &m_page_size);
35        if (m_err.Fail())
36            m_page_size = 0;
37    }
38    return m_page_size;
39}
40
41nub_size_t
42MachVMMemory::MaxBytesLeftInPage(nub_addr_t addr, nub_size_t count)
43{
44    const nub_size_t page_size = PageSize();
45    if (page_size > 0)
46    {
47        nub_size_t page_offset = (addr % page_size);
48        nub_size_t bytes_left_in_page = page_size - page_offset;
49        if (count > bytes_left_in_page)
50            count = bytes_left_in_page;
51    }
52    return count;
53}
54
55int
56MachVMMemory::GetMemoryRegionInfo(task_t task, nub_addr_t address, DNBRegionInfo *region_info)
57{
58    MachVMRegion vmRegion(task);
59
60    if (vmRegion.GetRegionForAddress(address))
61    {
62        region_info->addr = vmRegion.StartAddress();
63        region_info->size = vmRegion.GetByteSize();
64        region_info->permissions = vmRegion.GetDNBPermissions();
65        return 1;
66    }
67    region_info->addr = 0;
68    region_info->size = 0;
69    region_info->permissions = 0;
70    return 0;
71}
72
73nub_size_t
74MachVMMemory::Read(task_t task, nub_addr_t address, void *data, nub_size_t data_count)
75{
76    if (data == NULL || data_count == 0)
77        return 0;
78
79    nub_size_t total_bytes_read = 0;
80    nub_addr_t curr_addr = address;
81    uint8_t *curr_data = (uint8_t*)data;
82    while (total_bytes_read < data_count)
83    {
84        mach_vm_size_t curr_size = MaxBytesLeftInPage(curr_addr, data_count - total_bytes_read);
85        mach_msg_type_number_t curr_bytes_read = 0;
86        vm_offset_t vm_memory = NULL;
87        m_err = ::mach_vm_read (task, curr_addr, curr_size, &vm_memory, &curr_bytes_read);
88
89        // We end up being asked to read memory at 0x0 a lot without that being a real error, so that ends up just
90        // causing a lot of useless log spam.  Only complain on failing reads if the address is not 0x0.
91        if (DNBLogCheckLogBit(LOG_MEMORY) || (m_err.Fail() && curr_addr != 0))
92            m_err.LogThreaded("::mach_vm_read ( task = 0x%4.4x, addr = 0x%8.8llx, size = %llu, data => %8.8p, dataCnt => %i )", task, (uint64_t)curr_addr, (uint64_t)curr_size, vm_memory, curr_bytes_read);
93
94        if (m_err.Success())
95        {
96            if (curr_bytes_read != curr_size)
97            {
98                if (DNBLogCheckLogBit(LOG_MEMORY))
99                    m_err.LogThreaded("::mach_vm_read ( task = 0x%4.4x, addr = 0x%8.8llx, size = %llu, data => %8.8p, dataCnt=>%i ) only read %u of %llu bytes", task, (uint64_t)curr_addr, (uint64_t)curr_size, vm_memory, curr_bytes_read, curr_bytes_read, (uint64_t)curr_size);
100            }
101            ::memcpy (curr_data, (void *)vm_memory, curr_bytes_read);
102            ::vm_deallocate (mach_task_self (), vm_memory, curr_bytes_read);
103            total_bytes_read += curr_bytes_read;
104            curr_addr += curr_bytes_read;
105            curr_data += curr_bytes_read;
106        }
107        else
108        {
109            break;
110        }
111    }
112    return total_bytes_read;
113}
114
115
116nub_size_t
117MachVMMemory::Write(task_t task, nub_addr_t address, const void *data, nub_size_t data_count)
118{
119    MachVMRegion vmRegion(task);
120
121    nub_size_t total_bytes_written = 0;
122    nub_addr_t curr_addr = address;
123    const uint8_t *curr_data = (const uint8_t*)data;
124
125
126    while (total_bytes_written < data_count)
127    {
128        if (vmRegion.GetRegionForAddress(curr_addr))
129        {
130            mach_vm_size_t curr_data_count = data_count - total_bytes_written;
131            mach_vm_size_t region_bytes_left = vmRegion.BytesRemaining(curr_addr);
132            if (region_bytes_left == 0)
133            {
134                break;
135            }
136            if (curr_data_count > region_bytes_left)
137                curr_data_count = region_bytes_left;
138
139            if (vmRegion.SetProtections(curr_addr, curr_data_count, VM_PROT_READ | VM_PROT_WRITE))
140            {
141                nub_size_t bytes_written = WriteRegion(task, curr_addr, curr_data, curr_data_count);
142                if (bytes_written <= 0)
143                {
144                    // Error should have already be posted by WriteRegion...
145                    break;
146                }
147                else
148                {
149                    total_bytes_written += bytes_written;
150                    curr_addr += bytes_written;
151                    curr_data += bytes_written;
152                }
153            }
154            else
155            {
156                DNBLogThreadedIf(LOG_MEMORY_PROTECTIONS, "Failed to set read/write protections on region for address: [0x%8.8llx-0x%8.8llx)", (uint64_t)curr_addr, (uint64_t)(curr_addr + curr_data_count));
157                break;
158            }
159        }
160        else
161        {
162            DNBLogThreadedIf(LOG_MEMORY_PROTECTIONS, "Failed to get region for address: 0x%8.8llx", (uint64_t)address);
163            break;
164        }
165    }
166
167    return total_bytes_written;
168}
169
170
171nub_size_t
172MachVMMemory::WriteRegion(task_t task, const nub_addr_t address, const void *data, const nub_size_t data_count)
173{
174    if (data == NULL || data_count == 0)
175        return 0;
176
177    nub_size_t total_bytes_written = 0;
178    nub_addr_t curr_addr = address;
179    const uint8_t *curr_data = (const uint8_t*)data;
180    while (total_bytes_written < data_count)
181    {
182        mach_msg_type_number_t curr_data_count = MaxBytesLeftInPage(curr_addr, data_count - total_bytes_written);
183        m_err = ::mach_vm_write (task, curr_addr, (pointer_t) curr_data, curr_data_count);
184        if (DNBLogCheckLogBit(LOG_MEMORY) || m_err.Fail())
185            m_err.LogThreaded("::mach_vm_write ( task = 0x%4.4x, addr = 0x%8.8llx, data = %8.8p, dataCnt = %u )", task, (uint64_t)curr_addr, curr_data, curr_data_count);
186
187#if !defined (__i386__) && !defined (__x86_64__)
188        vm_machine_attribute_val_t mattr_value = MATTR_VAL_CACHE_FLUSH;
189
190        m_err = ::vm_machine_attribute (task, curr_addr, curr_data_count, MATTR_CACHE, &mattr_value);
191        if (DNBLogCheckLogBit(LOG_MEMORY) || m_err.Fail())
192            m_err.LogThreaded("::vm_machine_attribute ( task = 0x%4.4x, addr = 0x%8.8llx, size = %u, attr = MATTR_CACHE, mattr_value => MATTR_VAL_CACHE_FLUSH )", task, (uint64_t)curr_addr, curr_data_count);
193#endif
194
195        if (m_err.Success())
196        {
197            total_bytes_written += curr_data_count;
198            curr_addr += curr_data_count;
199            curr_data += curr_data_count;
200        }
201        else
202        {
203            break;
204        }
205    }
206    return total_bytes_written;
207}
208