 ee4a391661
			
		
	
	
	ee4a391661
	
	
	
		
			
			Currently ptrace_get_reg returns error as a value what make impossible to tell whether it is a correct value or error code. The patch adds a parameter which points to the real return data and returns an error code. As get_user_msr() never fails and it is used in multiple places so it has not been changed by this patch. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
		
			
				
	
	
		
			205 lines
		
	
	
	
		
			6.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			205 lines
		
	
	
	
		
			6.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (C) 2001 PPC64 Team, IBM Corp
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|  *
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|  * This struct defines the way the registers are stored on the
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|  * kernel stack during a system call or other kernel entry.
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|  *
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|  * this should only contain volatile regs
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|  * since we can keep non-volatile in the thread_struct
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|  * should set this up when only volatiles are saved
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|  * by intr code.
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|  *
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|  * Since this is going on the stack, *CARE MUST BE TAKEN* to insure
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|  * that the overall structure is a multiple of 16 bytes in length.
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|  *
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|  * Note that the offsets of the fields in this struct correspond with
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|  * the PT_* values below.  This simplifies arch/powerpc/kernel/ptrace.c.
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|  *
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|  * This program is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU General Public License
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|  * as published by the Free Software Foundation; either version
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|  * 2 of the License, or (at your option) any later version.
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|  */
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| #ifndef _ASM_POWERPC_PTRACE_H
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| #define _ASM_POWERPC_PTRACE_H
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| 
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| #include <uapi/asm/ptrace.h>
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| 
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| 
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| #ifdef __powerpc64__
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| 
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| #define STACK_FRAME_OVERHEAD	112	/* size of minimum stack frame */
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| #define STACK_FRAME_LR_SAVE	2	/* Location of LR in stack frame */
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| #define STACK_FRAME_REGS_MARKER	ASM_CONST(0x7265677368657265)
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| #define STACK_INT_FRAME_SIZE	(sizeof(struct pt_regs) + \
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| 					STACK_FRAME_OVERHEAD + 288)
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| #define STACK_FRAME_MARKER	12
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| 
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| /* Size of dummy stack frame allocated when calling signal handler. */
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| #define __SIGNAL_FRAMESIZE	128
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| #define __SIGNAL_FRAMESIZE32	64
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| 
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| #else /* __powerpc64__ */
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| 
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| #define STACK_FRAME_OVERHEAD	16	/* size of minimum stack frame */
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| #define STACK_FRAME_LR_SAVE	1	/* Location of LR in stack frame */
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| #define STACK_FRAME_REGS_MARKER	ASM_CONST(0x72656773)
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| #define STACK_INT_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
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| #define STACK_FRAME_MARKER	2
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| 
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| /* Size of stack frame allocated when calling signal handler. */
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| #define __SIGNAL_FRAMESIZE	64
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| 
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| #endif /* __powerpc64__ */
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| 
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| #ifndef __ASSEMBLY__
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| 
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| #define GET_IP(regs)		((regs)->nip)
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| #define GET_USP(regs)		((regs)->gpr[1])
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| #define GET_FP(regs)		(0)
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| #define SET_FP(regs, val)
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| 
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| #ifdef CONFIG_SMP
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| extern unsigned long profile_pc(struct pt_regs *regs);
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| #define profile_pc profile_pc
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| #endif
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| 
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| #include <asm-generic/ptrace.h>
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| 
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| #define kernel_stack_pointer(regs) ((regs)->gpr[1])
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| static inline int is_syscall_success(struct pt_regs *regs)
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| {
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| 	return !(regs->ccr & 0x10000000);
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| }
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| 
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| static inline long regs_return_value(struct pt_regs *regs)
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| {
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| 	if (is_syscall_success(regs))
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| 		return regs->gpr[3];
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| 	else
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| 		return -regs->gpr[3];
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| }
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| 
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| #ifdef __powerpc64__
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| #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
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| #else
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| #define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
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| #endif
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| 
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| #define force_successful_syscall_return()   \
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| 	do { \
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| 		set_thread_flag(TIF_NOERROR); \
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| 	} while(0)
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| 
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| struct task_struct;
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| extern int ptrace_get_reg(struct task_struct *task, int regno,
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| 			  unsigned long *data);
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| extern int ptrace_put_reg(struct task_struct *task, int regno,
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| 			  unsigned long data);
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| 
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| #define current_pt_regs() \
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| 	((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1)
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| /*
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|  * We use the least-significant bit of the trap field to indicate
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|  * whether we have saved the full set of registers, or only a
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|  * partial set.  A 1 there means the partial set.
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|  * On 4xx we use the next bit to indicate whether the exception
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|  * is a critical exception (1 means it is).
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|  */
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| #define FULL_REGS(regs)		(((regs)->trap & 1) == 0)
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| #ifndef __powerpc64__
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| #define IS_CRITICAL_EXC(regs)	(((regs)->trap & 2) != 0)
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| #define IS_MCHECK_EXC(regs)	(((regs)->trap & 4) != 0)
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| #define IS_DEBUG_EXC(regs)	(((regs)->trap & 8) != 0)
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| #endif /* ! __powerpc64__ */
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| #define TRAP(regs)		((regs)->trap & ~0xF)
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| #ifdef __powerpc64__
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| #define NV_REG_POISON		0xdeadbeefdeadbeefUL
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| #define CHECK_FULL_REGS(regs)	BUG_ON(regs->trap & 1)
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| #else
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| #define NV_REG_POISON		0xdeadbeef
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| #define CHECK_FULL_REGS(regs)						      \
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| do {									      \
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| 	if ((regs)->trap & 1)						      \
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| 		printk(KERN_CRIT "%s: partial register set\n", __func__); \
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| } while (0)
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| #endif /* __powerpc64__ */
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| 
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| #define arch_has_single_step()	(1)
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| #define arch_has_block_step()	(!cpu_has_feature(CPU_FTR_601))
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| #define ARCH_HAS_USER_SINGLE_STEP_INFO
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| 
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| /*
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|  * kprobe-based event tracer support
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|  */
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| 
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| #include <linux/stddef.h>
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| #include <linux/thread_info.h>
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| extern int regs_query_register_offset(const char *name);
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| extern const char *regs_query_register_name(unsigned int offset);
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| #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
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| 
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| /**
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|  * regs_get_register() - get register value from its offset
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|  * @regs:	   pt_regs from which register value is gotten
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|  * @offset:    offset number of the register.
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|  *
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|  * regs_get_register returns the value of a register whose offset from @regs.
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|  * The @offset is the offset of the register in struct pt_regs.
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|  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
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|  */
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| static inline unsigned long regs_get_register(struct pt_regs *regs,
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| 						unsigned int offset)
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| {
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| 	if (unlikely(offset > MAX_REG_OFFSET))
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| 		return 0;
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| 	return *(unsigned long *)((unsigned long)regs + offset);
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| }
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| 
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| /**
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|  * regs_within_kernel_stack() - check the address in the stack
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|  * @regs:      pt_regs which contains kernel stack pointer.
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|  * @addr:      address which is checked.
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|  *
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|  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
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|  * If @addr is within the kernel stack, it returns true. If not, returns false.
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|  */
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| 
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| static inline bool regs_within_kernel_stack(struct pt_regs *regs,
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| 						unsigned long addr)
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| {
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| 	return ((addr & ~(THREAD_SIZE - 1))  ==
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| 		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
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| }
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| 
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| /**
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|  * regs_get_kernel_stack_nth() - get Nth entry of the stack
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|  * @regs:	pt_regs which contains kernel stack pointer.
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|  * @n:		stack entry number.
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|  *
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|  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
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|  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
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|  * this returns 0.
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|  */
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| static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
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| 						      unsigned int n)
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| {
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| 	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
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| 	addr += n;
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| 	if (regs_within_kernel_stack(regs, (unsigned long)addr))
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| 		return *addr;
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| 	else
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| 		return 0;
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| }
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| 
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| #endif /* __ASSEMBLY__ */
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| 
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| #ifndef __powerpc64__
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| #else /* __powerpc64__ */
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| #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1)	/* each FP reg occupies 2 32-bit userspace slots */
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| #define PT_VR0_32 164	/* each Vector reg occupies 4 slots in 32-bit */
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| #define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
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| #define PT_VRSAVE_32 (PT_VR0 + 33*4)
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| #define PT_VSR0_32 300 	/* each VSR reg occupies 4 slots in 32-bit */
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| #endif /* __powerpc64__ */
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| #endif /* _ASM_POWERPC_PTRACE_H */
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