1 #ifndef _ASM_X86_VM86_H 2 #define _ASM_X86_VM86_H 3 4 5 #include <asm/ptrace.h> 6 #include <uapi/asm/vm86.h> 7 8 /* 9 * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86 10 * mode - the main change is that the old segment descriptors aren't 11 * useful any more and are forced to be zero by the kernel (and the 12 * hardware when a trap occurs), and the real segment descriptors are 13 * at the end of the structure. Look at ptrace.h to see the "normal" 14 * setup. For user space layout see 'struct vm86_regs' above. 15 */ 16 17 struct kernel_vm86_regs { 18 /* 19 * normal regs, with special meaning for the segment descriptors.. 20 */ 21 struct pt_regs pt; 22 /* 23 * these are specific to v86 mode: 24 */ 25 unsigned short es, __esh; 26 unsigned short ds, __dsh; 27 unsigned short fs, __fsh; 28 unsigned short gs, __gsh; 29 }; 30 31 struct kernel_vm86_struct { 32 struct kernel_vm86_regs regs; 33 /* 34 * the below part remains on the kernel stack while we are in VM86 mode. 35 * 'tss.esp0' then contains the address of VM86_TSS_ESP0 below, and when we 36 * get forced back from VM86, the CPU and "SAVE_ALL" will restore the above 37 * 'struct kernel_vm86_regs' with the then actual values. 38 * Therefore, pt_regs in fact points to a complete 'kernel_vm86_struct' 39 * in kernelspace, hence we need not reget the data from userspace. 40 */ 41 #define VM86_TSS_ESP0 flags 42 unsigned long flags; 43 unsigned long screen_bitmap; 44 unsigned long cpu_type; 45 struct revectored_struct int_revectored; 46 struct revectored_struct int21_revectored; 47 struct vm86plus_info_struct vm86plus; 48 struct pt_regs *regs32; /* here we save the pointer to the old regs */ 49 /* 50 * The below is not part of the structure, but the stack layout continues 51 * this way. In front of 'return-eip' may be some data, depending on 52 * compilation, so we don't rely on this and save the pointer to 'oldregs' 53 * in 'regs32' above. 54 * However, with GCC-2.7.2 and the current CFLAGS you see exactly this: 55 56 long return-eip; from call to vm86() 57 struct pt_regs oldregs; user space registers as saved by syscall 58 */ 59 }; 60 61 #ifdef CONFIG_VM86 62 63 void handle_vm86_fault(struct kernel_vm86_regs *, long); 64 int handle_vm86_trap(struct kernel_vm86_regs *, long, int); 65 struct pt_regs *save_v86_state(struct kernel_vm86_regs *); 66 67 struct task_struct; 68 void release_vm86_irqs(struct task_struct *); 69 70 #else 71 72 #define handle_vm86_fault(a, b) 73 #define release_vm86_irqs(a) 74 75 static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c) 76 { 77 return 0; 78 } 79 80 #endif /* CONFIG_VM86 */ 81 82 #endif /* _ASM_X86_VM86_H */ 83