CONTEXT structure
原文链接：http://msdn.microsoft.com/en-us/library/windows/desktop/ms679284%28v=vs.85%29.aspx
本文链接：http://blog.csdn.net/wlsgzl/article/details/18714021
参考资料：1、来自互联网http://www.bitscn.com/plus/view.php?aid=48915中的部分内容。
2、微软的WinNT.h头文件。
Contains processor-specific register data. 包含了特定处理器的寄存器数据。The system uses CONTEXT structures to perform various internal operations.系统使用CONTEXT结构体执行各种中间操作。 Refer to the header file WinNT.h for definitions of this structure for each processor architecture.参考WinNT.h文件中各种处理器架构的所对应的本结构体。
大致的看下下面的三个结构体：
typedef struct DECLSPEC_ALIGN(16) _CONTEXT {
//
// Register parameter home addresses.
//
// N.B. These fields are for convience - they could be used to extend the
// context record in the future.
//
DWORD64 P1Home;
DWORD64 P2Home;
DWORD64 P3Home;
DWORD64 P4Home;
DWORD64 P5Home;
DWORD64 P6Home;
//
// Control flags.
//
DWORD ContextFlags;
DWORD MxCsr;
//
// Segment Registers and processor flags.
//
WORD SegCs;
WORD SegDs;
WORD SegEs;
WORD SegFs;
WORD SegGs;
WORD SegSs;
DWORD EFlags;
//
// Debug registers
//
DWORD64 Dr0;
DWORD64 Dr1;
DWORD64 Dr2;
DWORD64 Dr3;
DWORD64 Dr6;
DWORD64 Dr7;
//
// Integer registers.
//
DWORD64 Rax;
DWORD64 Rcx;
DWORD64 Rdx;
DWORD64 Rbx;
DWORD64 Rsp;
DWORD64 Rbp;
DWORD64 Rsi;
DWORD64 Rdi;
DWORD64 R8;
DWORD64 R9;
DWORD64 R10;
DWORD64 R11;
DWORD64 R12;
DWORD64 R13;
DWORD64 R14;
DWORD64 R15;
//
// Program counter.
//
DWORD64 Rip;
//
// Floating point state.
//
union {
XMM_SAVE_AREA32 FltSave;
struct {
M128A Header[2];
M128A Legacy[8];
M128A Xmm0;
M128A Xmm1;
M128A Xmm2;
M128A Xmm3;
M128A Xmm4;
M128A Xmm5;
M128A Xmm6;
M128A Xmm7;
M128A Xmm8;
M128A Xmm9;
M128A Xmm10;
M128A Xmm11;
M128A Xmm12;
M128A Xmm13;
M128A Xmm14;
M128A Xmm15;
} DUMMYSTRUCTNAME;
} DUMMYUNIONNAME;
//
// Vector registers.
//
M128A VectorRegister[26];
DWORD64 VectorControl;
//
// Special debug control registers.
//
DWORD64 DebugControl;
DWORD64 LastBranchToRip;
DWORD64 LastBranchFromRip;
DWORD64 LastExceptionToRip;
DWORD64 LastExceptionFromRip;
} CONTEXT, *PCONTEXT; |
typedef struct _CONTEXT {
//
// The flags values within this flag control the contents of
// a CONTEXT record.
//
// If the context record is used as an input parameter, then
// for each portion of the context record controlled by a flag
// whose value is set, it is assumed that that portion of the
// context record contains valid context. If the context record
// is being used to modify a threads context, then only that
// portion of the threads context will be modified.
//
// If the context record is used as an IN OUT parameter to capture
// the context of a thread, then only those portions of the thread's
// context corresponding to set flags will be returned.
//
// The context record is never used as an OUT only parameter.
//
DWORD ContextFlags;
//
// This section is specified/returned if CONTEXT_DEBUG_REGISTERS is
// set in ContextFlags. Note that CONTEXT_DEBUG_REGISTERS is NOT
// included in CONTEXT_FULL.
//
DWORD Dr0;
DWORD Dr1;
DWORD Dr2;
DWORD Dr3;
DWORD Dr6;
DWORD Dr7;
//
// This section is specified/returned if the
// ContextFlags word contians the flag CONTEXT_FLOATING_POINT.
//
FLOATING_SAVE_AREA FloatSave;
//
// This section is specified/returned if the
// ContextFlags word contians the flag CONTEXT_SEGMENTS.
//
DWORD SegGs;
DWORD SegFs;
DWORD SegEs;
DWORD SegDs;
//
// This section is specified/returned if the
// ContextFlags word contians the flag CONTEXT_INTEGER.
//
DWORD Edi;
DWORD Esi;
DWORD Ebx;
DWORD Edx;
DWORD Ecx;
DWORD Eax;
//
// This section is specified/returned if the
// ContextFlags word contians the flag CONTEXT_CONTROL.
//
DWORD Ebp;
DWORD Eip;
DWORD SegCs; // MUST BE SANITIZED
DWORD EFlags; // MUST BE SANITIZED
DWORD Esp;
DWORD SegSs;
//
// This section is specified/returned if the ContextFlags word
// contains the flag CONTEXT_EXTENDED_REGISTERS.
// The format and contexts are processor specific
//
BYTE ExtendedRegisters[MAXIMUM_SUPPORTED_EXTENSION];
} CONTEXT; |
typedef struct _CONTEXT {
//
// The flags values within this flag control the contents of
// a CONTEXT record.
//
// If the context record is used as an input parameter, then
// for each portion of the context record controlled by a flag
// whose value is set, it is assumed that that portion of the
// context record contains valid context. If the context record
// is being used to modify a thread's context, then only that
// portion of the threads context will be modified.
//
// If the context record is used as an __inout parameter to capture
// the context of a thread, then only those portions of the thread's
// context corresponding to set flags will be returned.
//
// The context record is never used as an __out only parameter.
//
DWORD ContextFlags;
DWORD Fill1[3]; // for alignment of following on 16-byte boundary
//
// This section is specified/returned if the ContextFlags word contains
// the flag CONTEXT_DEBUG.
//
// N.B. CONTEXT_DEBUG is *not* part of CONTEXT_FULL.
//
ULONGLONG DbI0;
ULONGLONG DbI1;
ULONGLONG DbI2;
ULONGLONG DbI3;
ULONGLONG DbI4;
ULONGLONG DbI5;
ULONGLONG DbI6;
ULONGLONG DbI7;
ULONGLONG DbD0;
ULONGLONG DbD1;
ULONGLONG DbD2;
ULONGLONG DbD3;
ULONGLONG DbD4;
ULONGLONG DbD5;
ULONGLONG DbD6;
ULONGLONG DbD7;
//
// This section is specified/returned if the ContextFlags word contains
// the flag CONTEXT_LOWER_FLOATING_POINT.
//
FLOAT128 FltS0;
FLOAT128 FltS1;
FLOAT128 FltS2;
FLOAT128 FltS3;
FLOAT128 FltT0;
FLOAT128 FltT1;
FLOAT128 FltT2;
FLOAT128 FltT3;
FLOAT128 FltT4;
FLOAT128 FltT5;
FLOAT128 FltT6;
FLOAT128 FltT7;
FLOAT128 FltT8;
FLOAT128 FltT9;
//
// This section is specified/returned if the ContextFlags word contains
// the flag CONTEXT_HIGHER_FLOATING_POINT.
//
FLOAT128 FltS4;
FLOAT128 FltS5;
FLOAT128 FltS6;
FLOAT128 FltS7;
FLOAT128 FltS8;
FLOAT128 FltS9;
FLOAT128 FltS10;
FLOAT128 FltS11;
FLOAT128 FltS12;
FLOAT128 FltS13;
FLOAT128 FltS14;
FLOAT128 FltS15;
FLOAT128 FltS16;
FLOAT128 FltS17;
FLOAT128 FltS18;
FLOAT128 FltS19;
FLOAT128 FltF32;
FLOAT128 FltF33;
FLOAT128 FltF34;
FLOAT128 FltF35;
FLOAT128 FltF36;
FLOAT128 FltF37;
FLOAT128 FltF38;
FLOAT128 FltF39;
FLOAT128 FltF40;
FLOAT128 FltF41;
FLOAT128 FltF42;
FLOAT128 FltF43;
FLOAT128 FltF44;
FLOAT128 FltF45;
FLOAT128 FltF46;
FLOAT128 FltF47;
FLOAT128 FltF48;
FLOAT128 FltF49;
FLOAT128 FltF50;
FLOAT128 FltF51;
FLOAT128 FltF52;
FLOAT128 FltF53;
FLOAT128 FltF54;
FLOAT128 FltF55;
FLOAT128 FltF56;
FLOAT128 FltF57;
FLOAT128 FltF58;
FLOAT128 FltF59;
FLOAT128 FltF60;
FLOAT128 FltF61;
FLOAT128 FltF62;
FLOAT128 FltF63;
FLOAT128 FltF64;
FLOAT128 FltF65;
FLOAT128 FltF66;
FLOAT128 FltF67;
FLOAT128 FltF68;
FLOAT128 FltF69;
FLOAT128 FltF70;
FLOAT128 FltF71;
FLOAT128 FltF72;
FLOAT128 FltF73;
FLOAT128 FltF74;
FLOAT128 FltF75;
FLOAT128 FltF76;
FLOAT128 FltF77;
FLOAT128 FltF78;
FLOAT128 FltF79;
FLOAT128 FltF80;
FLOAT128 FltF81;
FLOAT128 FltF82;
FLOAT128 FltF83;
FLOAT128 FltF84;
FLOAT128 FltF85;
FLOAT128 FltF86;
FLOAT128 FltF87;
FLOAT128 FltF88;
FLOAT128 FltF89;
FLOAT128 FltF90;
FLOAT128 FltF91;
FLOAT128 FltF92;
FLOAT128 FltF93;
FLOAT128 FltF94;
FLOAT128 FltF95;
FLOAT128 FltF96;
FLOAT128 FltF97;
FLOAT128 FltF98;
FLOAT128 FltF99;
FLOAT128 FltF100;
FLOAT128 FltF101;
FLOAT128 FltF102;
FLOAT128 FltF103;
FLOAT128 FltF104;
FLOAT128 FltF105;
FLOAT128 FltF106;
FLOAT128 FltF107;
FLOAT128 FltF108;
FLOAT128 FltF109;
FLOAT128 FltF110;
FLOAT128 FltF111;
FLOAT128 FltF112;
FLOAT128 FltF113;
FLOAT128 FltF114;
FLOAT128 FltF115;
FLOAT128 FltF116;
FLOAT128 FltF117;
FLOAT128 FltF118;
FLOAT128 FltF119;
FLOAT128 FltF120;
FLOAT128 FltF121;
FLOAT128 FltF122;
FLOAT128 FltF123;
FLOAT128 FltF124;
FLOAT128 FltF125;
FLOAT128 FltF126;
FLOAT128 FltF127;
//
// This section is specified/returned if the ContextFlags word contains
// the flag CONTEXT_LOWER_FLOATING_POINT | CONTEXT_HIGHER_FLOATING_POINT | CONTEXT_CONTROL.
//
ULONGLONG StFPSR; // FP status
//
// This section is specified/returned if the ContextFlags word contains
// the flag CONTEXT_INTEGER.
//
// N.B. The registers gp, sp, rp are part of the control context
//
ULONGLONG IntGp; // r1, volatile
ULONGLONG IntT0; // r2-r3, volatile
ULONGLONG IntT1; //
ULONGLONG IntS0; // r4-r7, preserved
ULONGLONG IntS1;
ULONGLONG IntS2;
ULONGLONG IntS3;
ULONGLONG IntV0; // r8, volatile
ULONGLONG IntT2; // r9-r11, volatile
ULONGLONG IntT3;
ULONGLONG IntT4;
ULONGLONG IntSp; // stack pointer (r12), special
ULONGLONG IntTeb; // teb (r13), special
ULONGLONG IntT5; // r14-r31, volatile
ULONGLONG IntT6;
ULONGLONG IntT7;
ULONGLONG IntT8;
ULONGLONG IntT9;
ULONGLONG IntT10;
ULONGLONG IntT11;
ULONGLONG IntT12;
ULONGLONG IntT13;
ULONGLONG IntT14;
ULONGLONG IntT15;
ULONGLONG IntT16;
ULONGLONG IntT17;
ULONGLONG IntT18;
ULONGLONG IntT19;
ULONGLONG IntT20;
ULONGLONG IntT21;
ULONGLONG IntT22;
ULONGLONG IntNats; // Nat bits for r1-r31
// r1-r31 in bits 1 thru 31.
ULONGLONG Preds; // predicates, preserved
ULONGLONG BrRp; // return pointer, b0, preserved
ULONGLONG BrS0; // b1-b5, preserved
ULONGLONG BrS1;
ULONGLONG BrS2;
ULONGLONG BrS3;
ULONGLONG BrS4;
ULONGLONG BrT0; // b6-b7, volatile
ULONGLONG BrT1;
//
// This section is specified/returned if the ContextFlags word contains
// the flag CONTEXT_CONTROL.
//
// Other application registers
ULONGLONG ApUNAT; // User Nat collection register, preserved
ULONGLONG ApLC; // Loop counter register, preserved
ULONGLONG ApEC; // Epilog counter register, preserved
ULONGLONG ApCCV; // CMPXCHG value register, volatile
ULONGLONG ApDCR; // Default control register (TBD)
// Register stack info
ULONGLONG RsPFS; // Previous function state, preserved
ULONGLONG RsBSP; // Backing store pointer, preserved
ULONGLONG RsBSPSTORE;
ULONGLONG RsRSC; // RSE configuration, volatile
ULONGLONG RsRNAT; // RSE Nat collection register, preserved
// Trap Status Information
ULONGLONG StIPSR; // Interruption Processor Status
ULONGLONG StIIP; // Interruption IP
ULONGLONG StIFS; // Interruption Function State
// iA32 related control registers
ULONGLONG StFCR; // copy of Ar21
ULONGLONG Eflag; // Eflag copy of Ar24
ULONGLONG SegCSD; // iA32 CSDescriptor (Ar25)
ULONGLONG SegSSD; // iA32 SSDescriptor (Ar26)
ULONGLONG Cflag; // Cr0+Cr4 copy of Ar27
ULONGLONG StFSR; // x86 FP status (copy of AR28)
ULONGLONG StFIR; // x86 FP status (copy of AR29)
ULONGLONG StFDR; // x86 FP status (copy of AR30)
ULONGLONG UNUSEDPACK; // added to pack StFDR to 16-bytes
} CONTEXT, *PCONTEXT; |
可以看出，该结构中的成员是对实际处理器的寄存器的模仿。在使用该结构之前 要在ContextFlags 中指定哪些寄存器组用来读写。如要访问所有的寄存器， 你可以置ContextFlags 为CONTEXT_FULL 。或者只访问regEbp, regEip, regCs, regFlag, regEsp 或 regSs, 应置ContextFlags 为 CONTEXT_CONTROL 。
在使用结构CONTEXT 时还应记住: 它必须是双字对齐的，否则在NT下将得 到奇怪的结果。可以在定义前加上"align dword"。例如:
align dword
MyContext CONTEXT <>