Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
		
			
				
	
	
		
			82 lines
		
	
	
	
		
			2.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
	
		
			2.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _ASM_X86_VM86_H
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#define _ASM_X86_VM86_H
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#include <asm/ptrace.h>
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#include <uapi/asm/vm86.h>
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/*
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 * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86
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 * mode - the main change is that the old segment descriptors aren't
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 * useful any more and are forced to be zero by the kernel (and the
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 * hardware when a trap occurs), and the real segment descriptors are
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 * at the end of the structure. Look at ptrace.h to see the "normal"
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 * setup. For user space layout see 'struct vm86_regs' above.
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 */
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struct kernel_vm86_regs {
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/*
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 * normal regs, with special meaning for the segment descriptors..
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 */
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	struct pt_regs pt;
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/*
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 * these are specific to v86 mode:
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 */
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	unsigned short es, __esh;
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	unsigned short ds, __dsh;
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	unsigned short fs, __fsh;
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	unsigned short gs, __gsh;
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};
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struct kernel_vm86_struct {
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	struct kernel_vm86_regs regs;
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/*
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 * the below part remains on the kernel stack while we are in VM86 mode.
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 * 'tss.esp0' then contains the address of VM86_TSS_ESP0 below, and when we
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 * get forced back from VM86, the CPU and "SAVE_ALL" will restore the above
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 * 'struct kernel_vm86_regs' with the then actual values.
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 * Therefore, pt_regs in fact points to a complete 'kernel_vm86_struct'
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 * in kernelspace, hence we need not reget the data from userspace.
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 */
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#define VM86_TSS_ESP0 flags
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	unsigned long flags;
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	unsigned long screen_bitmap;
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	unsigned long cpu_type;
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	struct revectored_struct int_revectored;
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	struct revectored_struct int21_revectored;
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	struct vm86plus_info_struct vm86plus;
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	struct pt_regs *regs32;   /* here we save the pointer to the old regs */
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/*
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 * The below is not part of the structure, but the stack layout continues
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 * this way. In front of 'return-eip' may be some data, depending on
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 * compilation, so we don't rely on this and save the pointer to 'oldregs'
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 * in 'regs32' above.
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 * However, with GCC-2.7.2 and the current CFLAGS you see exactly this:
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	long return-eip;        from call to vm86()
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	struct pt_regs oldregs;  user space registers as saved by syscall
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 */
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};
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#ifdef CONFIG_VM86
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void handle_vm86_fault(struct kernel_vm86_regs *, long);
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int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
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struct pt_regs *save_v86_state(struct kernel_vm86_regs *);
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struct task_struct;
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void release_vm86_irqs(struct task_struct *);
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#else
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#define handle_vm86_fault(a, b)
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#define release_vm86_irqs(a)
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static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c)
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{
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	return 0;
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}
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#endif /* CONFIG_VM86 */
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#endif /* _ASM_X86_VM86_H */
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