Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Paul Mackerras <paulus@samba.org>
		
			
				
	
	
		
			127 lines
		
	
	
	
		
			2.9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			127 lines
		
	
	
	
		
			2.9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/**
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 * Copyright (C) 2005 Brian Rogan <bcr6@cornell.edu>, IBM
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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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#include <linux/oprofile.h>
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#include <linux/sched.h>
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#include <asm/processor.h>
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#include <asm/uaccess.h>
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#include <asm/compat.h>
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#define STACK_SP(STACK)		*(STACK)
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#define STACK_LR64(STACK)	*((unsigned long *)(STACK) + 2)
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#define STACK_LR32(STACK)	*((unsigned int *)(STACK) + 1)
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#ifdef CONFIG_PPC64
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#define STACK_LR(STACK)		STACK_LR64(STACK)
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#else
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#define STACK_LR(STACK)		STACK_LR32(STACK)
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#endif
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static unsigned int user_getsp32(unsigned int sp, int is_first)
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{
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	unsigned int stack_frame[2];
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	void __user *p = compat_ptr(sp);
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	if (!access_ok(VERIFY_READ, p, sizeof(stack_frame)))
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		return 0;
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	/*
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	 * The most likely reason for this is that we returned -EFAULT,
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	 * which means that we've done all that we can do from
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	 * interrupt context.
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	 */
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	if (__copy_from_user_inatomic(stack_frame, p, sizeof(stack_frame)))
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		return 0;
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	if (!is_first)
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		oprofile_add_trace(STACK_LR32(stack_frame));
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	/*
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	 * We do not enforce increasing stack addresses here because
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	 * we may transition to a different stack, eg a signal handler.
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	 */
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	return STACK_SP(stack_frame);
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}
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#ifdef CONFIG_PPC64
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static unsigned long user_getsp64(unsigned long sp, int is_first)
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{
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	unsigned long stack_frame[3];
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	if (!access_ok(VERIFY_READ, (void __user *)sp, sizeof(stack_frame)))
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		return 0;
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	if (__copy_from_user_inatomic(stack_frame, (void __user *)sp,
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					sizeof(stack_frame)))
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		return 0;
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	if (!is_first)
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		oprofile_add_trace(STACK_LR64(stack_frame));
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	return STACK_SP(stack_frame);
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}
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#endif
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static unsigned long kernel_getsp(unsigned long sp, int is_first)
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{
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	unsigned long *stack_frame = (unsigned long *)sp;
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	if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
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		return 0;
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	if (!is_first)
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		oprofile_add_trace(STACK_LR(stack_frame));
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	/*
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	 * We do not enforce increasing stack addresses here because
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	 * we might be transitioning from an interrupt stack to a kernel
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	 * stack. validate_sp() is designed to understand this, so just
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	 * use it.
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	 */
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	return STACK_SP(stack_frame);
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}
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void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth)
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{
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	unsigned long sp = regs->gpr[1];
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	int first_frame = 1;
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	/* We ditch the top stackframe so need to loop through an extra time */
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	depth += 1;
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	if (!user_mode(regs)) {
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		while (depth--) {
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			sp = kernel_getsp(sp, first_frame);
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			if (!sp)
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				break;
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			first_frame = 0;
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		}
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	} else {
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#ifdef CONFIG_PPC64
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		if (!test_thread_flag(TIF_32BIT)) {
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			while (depth--) {
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				sp = user_getsp64(sp, first_frame);
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				if (!sp)
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					break;
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				first_frame = 0;
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			}
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			return;
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		}
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#endif
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		while (depth--) {
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			sp = user_getsp32(sp, first_frame);
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			if (!sp)
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				break;
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			first_frame = 0;
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		}
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	}
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}
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