1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
#ifndef _LINUX_VM86_H
#define _LINUX_VM86_H
/*
* I'm guessing at the VIF/VIP flag usage, but hope that this is how
* the Pentium uses them. Linux will return from vm86 mode when both
* VIF and VIP is set.
*
* On a Pentium, we could probably optimize the virtual flags directly
* in the eflags register instead of doing it "by hand" in vflags...
*
* Linus
*/
#define TF_MASK 0x00000100
#define IF_MASK 0x00000200
#define IOPL_MASK 0x00003000
#define NT_MASK 0x00004000
#ifdef CONFIG_VM86
#define VM_MASK 0x00020000
#else
#define VM_MASK 0 /* ignored */
#endif
#define AC_MASK 0x00040000
#define VIF_MASK 0x00080000 /* virtual interrupt flag */
#define VIP_MASK 0x00100000 /* virtual interrupt pending */
#define ID_MASK 0x00200000
#define BIOSSEG 0x0f000
#define CPU_086 0
#define CPU_186 1
#define CPU_286 2
#define CPU_386 3
#define CPU_486 4
#define CPU_586 5
/*
* Return values for the 'vm86()' system call
*/
#define VM86_TYPE(retval) ((retval) & 0xff)
#define VM86_ARG(retval) ((retval) >> 8)
#define VM86_SIGNAL 0 /* return due to signal */
#define VM86_UNKNOWN 1 /* unhandled GP fault - IO-instruction or similar */
#define VM86_INTx 2 /* int3/int x instruction (ARG = x) */
#define VM86_STI 3 /* sti/popf/iret instruction enabled virtual interrupts */
/*
* Additional return values when invoking new vm86()
*/
#define VM86_PICRETURN 4 /* return due to pending PIC request */
#define VM86_TRAP 6 /* return due to DOS-debugger request */
/*
* function codes when invoking new vm86()
*/
#define VM86_PLUS_INSTALL_CHECK 0
#define VM86_ENTER 1
#define VM86_ENTER_NO_BYPASS 2
#define VM86_REQUEST_IRQ 3
#define VM86_FREE_IRQ 4
#define VM86_GET_IRQ_BITS 5
#define VM86_GET_AND_RESET_IRQ 6
/*
* This is the stack-layout seen by the user space program when we have
* done a translation of "SAVE_ALL" from vm86 mode. The real kernel layout
* is 'kernel_vm86_regs' (see below).
*/
struct vm86_regs {
/*
* normal regs, with special meaning for the segment descriptors..
*/
long ebx;
long ecx;
long edx;
long esi;
long edi;
long ebp;
long eax;
long __null_ds;
long __null_es;
long __null_fs;
long __null_gs;
long orig_eax;
long eip;
unsigned short cs, __csh;
long eflags;
long esp;
unsigned short ss, __ssh;
/*
* these are specific to v86 mode:
*/
unsigned short es, __esh;
unsigned short ds, __dsh;
unsigned short fs, __fsh;
unsigned short gs, __gsh;
};
struct revectored_struct {
unsigned long __map[8]; /* 256 bits */
};
struct vm86_struct {
struct vm86_regs regs;
unsigned long flags;
unsigned long screen_bitmap;
unsigned long cpu_type;
struct revectored_struct int_revectored;
struct revectored_struct int21_revectored;
};
/*
* flags masks
*/
#define VM86_SCREEN_BITMAP 0x0001
struct vm86plus_info_struct {
unsigned long force_return_for_pic:1;
unsigned long vm86dbg_active:1; /* for debugger */
unsigned long vm86dbg_TFpendig:1; /* for debugger */
unsigned long unused:28;
unsigned long is_vm86pus:1; /* for vm86 internal use */
unsigned char vm86dbg_intxxtab[32]; /* for debugger */
};
struct vm86plus_struct {
struct vm86_regs regs;
unsigned long flags;
unsigned long screen_bitmap;
unsigned long cpu_type;
struct revectored_struct int_revectored;
struct revectored_struct int21_revectored;
struct vm86plus_info_struct vm86plus;
};
#ifdef __KERNEL__
/*
* This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86
* mode - the main change is that the old segment descriptors aren't
* useful any more and are forced to be zero by the kernel (and the
* hardware when a trap occurs), and the real segment descriptors are
* at the end of the structure. Look at ptrace.h to see the "normal"
* setup. For user space layout see 'struct vm86_regs' above.
*/
#include <asm/ptrace.h>
struct kernel_vm86_regs {
/*
* normal regs, with special meaning for the segment descriptors..
*/
struct pt_regs pt;
/*
* these are specific to v86 mode:
*/
unsigned short es, __esh;
unsigned short ds, __dsh;
unsigned short fs, __fsh;
unsigned short gs, __gsh;
};
struct kernel_vm86_struct {
struct kernel_vm86_regs regs;
/*
* the below part remains on the kernel stack while we are in VM86 mode.
* 'tss.esp0' then contains the address of VM86_TSS_ESP0 below, and when we
* get forced back from VM86, the CPU and "SAVE_ALL" will restore the above
* 'struct kernel_vm86_regs' with the then actual values.
* Therefore, pt_regs in fact points to a complete 'kernel_vm86_struct'
* in kernelspace, hence we need not reget the data from userspace.
*/
#define VM86_TSS_ESP0 flags
unsigned long flags;
unsigned long screen_bitmap;
unsigned long cpu_type;
struct revectored_struct int_revectored;
struct revectored_struct int21_revectored;
struct vm86plus_info_struct vm86plus;
struct pt_regs *regs32; /* here we save the pointer to the old regs */
/*
* The below is not part of the structure, but the stack layout continues
* this way. In front of 'return-eip' may be some data, depending on
* compilation, so we don't rely on this and save the pointer to 'oldregs'
* in 'regs32' above.
* However, with GCC-2.7.2 and the current CFLAGS you see exactly this:
long return-eip; from call to vm86()
struct pt_regs oldregs; user space registers as saved by syscall
*/
};
#ifdef CONFIG_VM86
void handle_vm86_fault(struct kernel_vm86_regs *, long);
int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
struct pt_regs *save_v86_state(struct kernel_vm86_regs *);
struct task_struct;
void release_vm86_irqs(struct task_struct *);
#else
#define handle_vm86_fault(a, b)
#define release_vm86_irqs(a)
static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c) {
return 0;
}
#endif /* CONFIG_VM86 */
#endif /* __KERNEL__ */
#endif
|
