MachVMMemory.cpp revision dc8ff30b6dbe28c851e99712e20c1358eca4709d 
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
55bool
56MachVMMemory::IsExecutable(task_t task, nub_addr_t address)
57{
58    MachVMRegion vmRegion(task);
59
60    if (vmRegion.GetRegionForAddress(address) && vmRegion.IsExecutable())
61       return true;
62    else
63       return false;
64}
65
66nub_size_t
67MachVMMemory::Read(task_t task, nub_addr_t address, void *data, nub_size_t data_count)
68{
69    if (data == NULL || data_count == 0)
70        return 0;
71
72    nub_size_t total_bytes_read = 0;
73    nub_addr_t curr_addr = address;
74    uint8_t *curr_data = (uint8_t*)data;
75    while (total_bytes_read < data_count)
76    {
77        mach_vm_size_t curr_size = MaxBytesLeftInPage(curr_addr, data_count - total_bytes_read);
78        mach_msg_type_number_t curr_bytes_read = 0;
79        vm_offset_t vm_memory = NULL;
80        m_err = ::mach_vm_read (task, curr_addr, curr_size, &vm_memory, &curr_bytes_read);
81        if (DNBLogCheckLogBit(LOG_MEMORY) || m_err.Fail())
82            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);
83
84        if (m_err.Success())
85        {
86            if (curr_bytes_read != curr_size)
87            {
88                if (DNBLogCheckLogBit(LOG_MEMORY))
89                    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);
90            }
91            ::memcpy (curr_data, (void *)vm_memory, curr_bytes_read);
92            ::vm_deallocate (mach_task_self (), vm_memory, curr_bytes_read);
93            total_bytes_read += curr_bytes_read;
94            curr_addr += curr_bytes_read;
95            curr_data += curr_bytes_read;
96        }
97        else
98        {
99            break;
100        }
101    }
102    return total_bytes_read;
103}
104
105
106nub_size_t
107MachVMMemory::Write(task_t task, nub_addr_t address, const void *data, nub_size_t data_count)
108{
109    MachVMRegion vmRegion(task);
110
111    nub_size_t total_bytes_written = 0;
112    nub_addr_t curr_addr = address;
113    const uint8_t *curr_data = (const uint8_t*)data;
114
115
116    while (total_bytes_written < data_count)
117    {
118        if (vmRegion.GetRegionForAddress(curr_addr))
119        {
120            mach_vm_size_t curr_data_count = data_count - total_bytes_written;
121            mach_vm_size_t region_bytes_left = vmRegion.BytesRemaining(curr_addr);
122            if (region_bytes_left == 0)
123            {
124                break;
125            }
126            if (curr_data_count > region_bytes_left)
127                curr_data_count = region_bytes_left;
128
129            if (vmRegion.SetProtections(curr_addr, curr_data_count, VM_PROT_READ | VM_PROT_WRITE))
130            {
131                nub_size_t bytes_written = WriteRegion(task, curr_addr, curr_data, curr_data_count);
132                if (bytes_written <= 0)
133                {
134                    // Error should have already be posted by WriteRegion...
135                    break;
136                }
137                else
138                {
139                    total_bytes_written += bytes_written;
140                    curr_addr += bytes_written;
141                    curr_data += bytes_written;
142                }
143            }
144            else
145            {
146                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));
147                break;
148            }
149        }
150        else
151        {
152            DNBLogThreadedIf(LOG_MEMORY_PROTECTIONS, "Failed to get region for address: 0x%8.8llx", (uint64_t)address);
153            break;
154        }
155    }
156
157    return total_bytes_written;
158}
159
160
161nub_size_t
162MachVMMemory::WriteRegion(task_t task, const nub_addr_t address, const void *data, const nub_size_t data_count)
163{
164    if (data == NULL || data_count == 0)
165        return 0;
166
167    nub_size_t total_bytes_written = 0;
168    nub_addr_t curr_addr = address;
169    const uint8_t *curr_data = (const uint8_t*)data;
170    while (total_bytes_written < data_count)
171    {
172        mach_msg_type_number_t curr_data_count = MaxBytesLeftInPage(curr_addr, data_count - total_bytes_written);
173        m_err = ::mach_vm_write (task, curr_addr, (pointer_t) curr_data, curr_data_count);
174        if (DNBLogCheckLogBit(LOG_MEMORY) || m_err.Fail())
175            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);
176
177#if !defined (__i386__) && !defined (__x86_64__)
178        vm_machine_attribute_val_t mattr_value = MATTR_VAL_CACHE_FLUSH;
179
180        m_err = ::vm_machine_attribute (task, curr_addr, curr_data_count, MATTR_CACHE, &mattr_value);
181        if (DNBLogCheckLogBit(LOG_MEMORY) || m_err.Fail())
182            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);
183#endif
184
185        if (m_err.Success())
186        {
187            total_bytes_written += curr_data_count;
188            curr_addr += curr_data_count;
189            curr_data += curr_data_count;
190        }
191        else
192        {
193            break;
194        }
195    }
196    return total_bytes_written;
197}
198