From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/x86/include/asm/vm86.h | 82 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 arch/x86/include/asm/vm86.h (limited to 'arch/x86/include/asm/vm86.h') diff --git a/arch/x86/include/asm/vm86.h b/arch/x86/include/asm/vm86.h new file mode 100644 index 000000000..1d8de3f3f --- /dev/null +++ b/arch/x86/include/asm/vm86.h @@ -0,0 +1,82 @@ +#ifndef _ASM_X86_VM86_H +#define _ASM_X86_VM86_H + + +#include +#include + +/* + * 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. + */ + +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 /* _ASM_X86_VM86_H */ -- cgit v1.2.3-54-g00ecf