1//===-- MachVMRegion.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 "MachVMRegion.h"
15#include <mach/mach_vm.h>
16#include "DNBLog.h"
17#include <assert.h>
18
19MachVMRegion::MachVMRegion(task_t task) :
20    m_task(task),
21    m_addr(INVALID_NUB_ADDRESS),
22    m_err(),
23    m_start(INVALID_NUB_ADDRESS),
24    m_size(0),
25    m_depth(-1),
26    m_curr_protection(0),
27    m_protection_addr(INVALID_NUB_ADDRESS),
28    m_protection_size(0)
29{
30    memset(&m_data, 0, sizeof(m_data));
31}
32
33MachVMRegion::~MachVMRegion()
34{
35    // Restore any original protections and clear our vars
36    Clear();
37}
38
39void
40MachVMRegion::Clear()
41{
42    RestoreProtections();
43    m_addr = INVALID_NUB_ADDRESS;
44    m_err.Clear();
45    m_start = INVALID_NUB_ADDRESS;
46    m_size = 0;
47    m_depth = -1;
48    memset(&m_data, 0, sizeof(m_data));
49    m_curr_protection = 0;
50    m_protection_addr = INVALID_NUB_ADDRESS;
51    m_protection_size = 0;
52}
53
54bool
55MachVMRegion::SetProtections(mach_vm_address_t addr, mach_vm_size_t size, vm_prot_t prot)
56{
57    if (ContainsAddress(addr))
58    {
59        mach_vm_size_t prot_size = size;
60        mach_vm_address_t end_addr = EndAddress();
61        if (prot_size > (end_addr - addr))
62            prot_size = end_addr - addr;
63
64        if (prot_size > 0)
65        {
66            if (prot == (m_curr_protection & VM_PROT_ALL))
67            {
68                DNBLogThreadedIf(LOG_MEMORY_PROTECTIONS | LOG_VERBOSE, "MachVMRegion::%s: protections (%u) already sufficient for task 0x%4.4x at address 0x%8.8llx) ", __FUNCTION__, prot, m_task, (uint64_t)addr);
69                // Protections are already set as requested...
70                return true;
71            }
72            else
73            {
74                m_err = ::mach_vm_protect (m_task, addr, prot_size, 0, prot);
75                if (DNBLogCheckLogBit(LOG_MEMORY_PROTECTIONS))
76                    m_err.LogThreaded("::mach_vm_protect ( task = 0x%4.4x, addr = 0x%8.8llx, size = %llu, set_max = %i, prot = %u )", m_task, (uint64_t)addr, (uint64_t)prot_size, 0, prot);
77                if (m_err.Fail())
78                {
79                    // Try again with the ability to create a copy on write region
80                    m_err = ::mach_vm_protect (m_task, addr, prot_size, 0, prot | VM_PROT_COPY);
81                    if (DNBLogCheckLogBit(LOG_MEMORY_PROTECTIONS) || m_err.Fail())
82                        m_err.LogThreaded("::mach_vm_protect ( task = 0x%4.4x, addr = 0x%8.8llx, size = %llu, set_max = %i, prot = %u )", m_task, (uint64_t)addr, (uint64_t)prot_size, 0, prot | VM_PROT_COPY);
83                }
84                if (m_err.Success())
85                {
86                    m_curr_protection = prot;
87                    m_protection_addr = addr;
88                    m_protection_size = prot_size;
89                    return true;
90                }
91            }
92        }
93        else
94        {
95            DNBLogThreadedIf(LOG_MEMORY_PROTECTIONS | LOG_VERBOSE, "%s: Zero size for task 0x%4.4x at address 0x%8.8llx) ", __FUNCTION__, m_task, (uint64_t)addr);
96        }
97    }
98    return false;
99}
100
101bool
102MachVMRegion::RestoreProtections()
103{
104    if (m_curr_protection != m_data.protection && m_protection_size > 0)
105    {
106        m_err = ::mach_vm_protect (m_task, m_protection_addr, m_protection_size, 0, m_data.protection);
107        if (DNBLogCheckLogBit(LOG_MEMORY_PROTECTIONS) || m_err.Fail())
108            m_err.LogThreaded("::mach_vm_protect ( task = 0x%4.4x, addr = 0x%8.8llx, size = %llu, set_max = %i, prot = %u )", m_task, (uint64_t)m_protection_addr, (uint64_t)m_protection_size, 0, m_data.protection);
109        if (m_err.Success())
110        {
111            m_protection_size = 0;
112            m_protection_addr = INVALID_NUB_ADDRESS;
113            m_curr_protection = m_data.protection;
114            return true;
115        }
116    }
117    else
118    {
119        m_err.Clear();
120        return true;
121    }
122
123    return false;
124}
125
126bool
127MachVMRegion::GetRegionForAddress(nub_addr_t addr)
128{
129    // Restore any original protections and clear our vars
130    Clear();
131    m_err.Clear();
132    m_addr = addr;
133    m_start = addr;
134    m_depth = 1024;
135    mach_msg_type_number_t info_size = kRegionInfoSize;
136    assert(sizeof(info_size) == 4);
137    m_err = ::mach_vm_region_recurse (m_task, &m_start, &m_size, &m_depth, (vm_region_recurse_info_t)&m_data, &info_size);
138
139    const bool failed = m_err.Fail();
140    const bool log_protections = DNBLogCheckLogBit(LOG_MEMORY_PROTECTIONS);
141
142    if (log_protections || failed)
143        m_err.LogThreaded("::mach_vm_region_recurse ( task = 0x%4.4x, address => 0x%8.8llx, size => %llu, nesting_depth => %d, info => %p, infoCnt => %d) addr = 0x%8.8llx ", m_task, (uint64_t)m_start, (uint64_t)m_size, m_depth, &m_data, info_size, (uint64_t)addr);
144
145    if (failed)
146        return false;
147    if (log_protections)
148    {
149        DNBLogThreaded("info = { prot = %u, "
150                         "max_prot = %u, "
151                         "inheritance = 0x%8.8x, "
152                         "offset = 0x%8.8llx, "
153                         "user_tag = 0x%8.8x, "
154                         "ref_count = %u, "
155                         "shadow_depth = %u, "
156                         "ext_pager = %u, "
157                         "share_mode = %u, "
158                         "is_submap = %d, "
159                         "behavior = %d, "
160                         "object_id = 0x%8.8x, "
161                         "user_wired_count = 0x%4.4x }",
162                         m_data.protection,
163                         m_data.max_protection,
164                         m_data.inheritance,
165                         (uint64_t)m_data.offset,
166                         m_data.user_tag,
167                         m_data.ref_count,
168                         m_data.shadow_depth,
169                         m_data.external_pager,
170                         m_data.share_mode,
171                         m_data.is_submap,
172                         m_data.behavior,
173                         m_data.object_id,
174                         m_data.user_wired_count);
175    }
176    m_curr_protection = m_data.protection;
177
178    // We make a request for an address and got no error back, but this
179    // doesn't mean that "addr" is in the range. The data in this object will
180    // be valid though, so you could see where the next region begins. So we
181    // return false, yet leave "m_err" with a successfull return code.
182    if ((addr < m_start) || (addr >= (m_start + m_size)))
183        return false;
184
185    return true;
186}
187
188uint32_t
189MachVMRegion::GetDNBPermissions () const
190{
191    if (m_addr == INVALID_NUB_ADDRESS || m_start == INVALID_NUB_ADDRESS || m_size == 0)
192      return 0;
193    uint32_t dnb_permissions = 0;
194
195    if ((m_data.protection & VM_PROT_READ) == VM_PROT_READ)
196        dnb_permissions |= eMemoryPermissionsReadable;
197    if ((m_data.protection & VM_PROT_WRITE) == VM_PROT_WRITE)
198        dnb_permissions |= eMemoryPermissionsWritable;
199    if ((m_data.protection & VM_PROT_EXECUTE) == VM_PROT_EXECUTE)
200        dnb_permissions |= eMemoryPermissionsExecutable;
201    return dnb_permissions;
202}
203