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	Commit4c2de74cc8("powerpc/64: Interrupts save PPR on stack rather than thread_struct") changed sizeof(struct pt_regs) % 16 from 0 to 8, which causes the interrupt frame allocation on kernel entry to put the kernel stack out of alignment. Quadword (16-byte) alignment for the stack is required by both the 64-bit v1 ABI (v1.9 § 3.2.2) and the 64-bit v2 ABI (v1.1 § 2.2.2.1). Add a pad field to fix alignment, and add a BUILD_BUG_ON to catch this in future. Fixes:4c2de74cc8("powerpc/64: Interrupts save PPR on stack rather than thread_struct") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
		
			
				
	
	
		
			264 lines
		
	
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			264 lines
		
	
	
	
		
			7.8 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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#include <uapi/asm/ptrace.h>
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#include <asm/asm-const.h>
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#ifndef __ASSEMBLY__
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struct pt_regs
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{
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	union {
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		struct user_pt_regs user_regs;
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		struct {
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			unsigned long gpr[32];
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			unsigned long nip;
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			unsigned long msr;
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			unsigned long orig_gpr3;
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			unsigned long ctr;
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			unsigned long link;
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			unsigned long xer;
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			unsigned long ccr;
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#ifdef CONFIG_PPC64
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			unsigned long softe;
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#else
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			unsigned long mq;
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#endif
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			unsigned long trap;
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			unsigned long dar;
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			unsigned long dsisr;
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			unsigned long result;
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		};
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	};
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#ifdef CONFIG_PPC64
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	unsigned long ppr;
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	unsigned long __pad;	/* Maintain 16 byte interrupt stack alignment */
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#endif
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};
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#endif
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#ifdef __powerpc64__
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/*
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 * Size of redzone that userspace is allowed to use below the stack
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 * pointer.  This is 288 in the 64-bit big-endian ELF ABI, and 512 in
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 * the new ELFv2 little-endian ABI, so we allow the larger amount.
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 *
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 * For kernel code we allow a 288-byte redzone, in order to conserve
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 * kernel stack space; gcc currently only uses 288 bytes, and will
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 * hopefully allow explicit control of the redzone size in future.
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 */
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#define USER_REDZONE_SIZE	512
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#define KERNEL_REDZONE_SIZE	288
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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 + KERNEL_REDZONE_SIZE)
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#define STACK_FRAME_MARKER	12
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#ifdef PPC64_ELF_ABI_v2
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#define STACK_FRAME_MIN_SIZE	32
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#else
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#define STACK_FRAME_MIN_SIZE	STACK_FRAME_OVERHEAD
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#endif
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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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#else /* __powerpc64__ */
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#define USER_REDZONE_SIZE	0
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#define KERNEL_REDZONE_SIZE	0
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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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#define STACK_FRAME_MIN_SIZE	STACK_FRAME_OVERHEAD
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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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#endif /* __powerpc64__ */
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#ifndef __ASSEMBLY__
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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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#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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#include <asm-generic/ptrace.h>
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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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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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static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
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{
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	regs->gpr[3] = rc;
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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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#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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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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#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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#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_REPORT
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/*
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 * kprobe-based event tracer support
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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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 * 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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 * 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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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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 * 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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#endif /* __ASSEMBLY__ */
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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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