标准MDL方法修改Page、NonPage内存的属性

绝地灬酷狼 2022-08-18 14:25 118阅读 0赞

1.  **typedef****struct** \_REPROTECT\_CONTEXT 
2.  \{ 
3.   PMDL Mdl; 
4.  **PUCHAR** LockedVa; 
5.  \} REPROTECT\_CONTEXT, \* PREPROTECT\_CONTEXT; 
6.  
7.  NTSTATUS 
8.  MmLockVaForWrite( 
9.   \_\_in **PVOID** Va, 
10.  \_\_in **ULONG** Length, 
11.  \_\_out PREPROTECT\_CONTEXT ReprotectContext 
12.  ) 
13. \{ 
14.  NTSTATUS Status; 
15. 
16.  Status = STATUS\_SUCCESS; 
17. 
18.  ReprotectContext->Mdl = 0; 
19.  ReprotectContext->LockedVa = 0; 
20. 
21.  ReprotectContext->Mdl = IoAllocateMdl( 
22.  Va, 
23.  Length, 
24.  FALSE, 
25.  FALSE, 
26.  0 
27.  ); 
28. 
29. **if** (!ReprotectContext->Mdl) 
30.  \{ 
31. **return** STATUS\_INSUFFICIENT\_RESOURCES; 
32.  \} 
33. 
34. //
35. // Retrieve a locked VA mapping.
36. //
37. 
38. **\_\_try**
39.  \{ 
40.  MmProbeAndLockPages( 
41.  ReprotectContext->Mdl, 
42.  KernelMode, 
43.  IoModifyAccess 
44.  ); 
45.  \} 
46.  \_\_except (EXCEPTION\_EXECUTE\_HANDLER) 
47.  \{ 
48. **return** GetExceptionCode(); 
49.  \} 
50. 
51.  ReprotectContext->LockedVa = (**PUCHAR**)MmMapLockedPagesSpecifyCache( 
52.  ReprotectContext->Mdl, 
53.  KernelMode, 
54.  MmCached, 
55.  0, 
56.  FALSE, 
57.  NormalPagePriority 
58.  ); 
59. 
60. **if** (!ReprotectContext->LockedVa) 
61.  \{ 
62. 
63. 
64.  IoFreeMdl( 
65.  ReprotectContext->Mdl 
66.  ); 
67. 
68.  ReprotectContext->Mdl = 0; 
69. 
70. **return** STATUS\_ACCESS\_VIOLATION; 
71.  \} 
72. 
73. //
74. // Reprotect.
75. //
76. 
77.  Status = MmProtectMdlSystemAddress( 
78.  ReprotectContext->Mdl, 
79.  PAGE\_EXECUTE\_READWRITE 
80.  ); 
81. 
82. **if** (!NT\_SUCCESS(Status)) 
83.  \{ 
84. 
85. 
86.  MmUnmapLockedPages( 
87.  ReprotectContext->LockedVa, 
88.  ReprotectContext->Mdl 
89.  ); 
90.  MmUnlockPages( 
91.  ReprotectContext->Mdl 
92.  ); 
93.  IoFreeMdl( 
94.  ReprotectContext->Mdl 
95.  ); 
96. 
97.  ReprotectContext->LockedVa = 0; 
98.  ReprotectContext->Mdl = 0; 
99.  \} 
100. 
101. **return** Status; 
102. \} 
103. 
104. NTSTATUS 
105. MmUnlockVaForWrite( 
106.  \_\_in PREPROTECT\_CONTEXT ReprotectContext 
107.  ) 
108. \{ 
109. **if** (ReprotectContext->LockedVa) 
110.  \{ 
111.  MmUnmapLockedPages( 
112.  ReprotectContext->LockedVa, 
113.  ReprotectContext->Mdl 
114.  ); 
115.  MmUnlockPages( 
116.  ReprotectContext->Mdl 
117.  ); 
118.  IoFreeMdl( 
119.  ReprotectContext->Mdl 
120.  ); 
121. 
122.  ReprotectContext->LockedVa = 0; 
123.  ReprotectContext->Mdl = 0; 
124.  \} 
125. 
126. **return** STATUS\_SUCCESS; 
127. \}