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Viewing changes to arch/blackfin/kernel/ftrace.c

  • Committer: Bazaar Package Importer
  • Author(s): Luke Yelavich
  • Date: 2009-08-05 23:00:52 UTC
  • Revision ID: james.westby@ubuntu.com-20090805230052-7xedvqcyk9dnnxb2
Tags: 2.6.31-1.1
New upstream release

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arch/blackfin/kernel/ftrace.c
 
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/*
 
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 * ftrace graph code
 
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 *
 
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 * Copyright (C) 2009 Analog Devices Inc.
 
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 * Licensed under the GPL-2 or later.
 
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 */
 
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#include <linux/ftrace.h>
 
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#include <linux/kernel.h>
 
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#include <linux/sched.h>
 
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#include <asm/atomic.h>
 
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
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/*
 
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 * Hook the return address and push it in the stack of return addrs
 
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 * in current thread info.
 
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 */
 
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void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 
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{
 
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        struct ftrace_graph_ent trace;
 
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        unsigned long return_hooker = (unsigned long)&return_to_handler;
 
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        if (unlikely(atomic_read(&current->tracing_graph_pause)))
 
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                return;
 
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        if (ftrace_push_return_trace(*parent, self_addr, &trace.depth) == -EBUSY)
 
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                return;
 
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        trace.func = self_addr;
 
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        /* Only trace if the calling function expects to */
 
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        if (!ftrace_graph_entry(&trace)) {
 
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                current->curr_ret_stack--;
 
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                return;
 
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        }
 
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        /* all is well in the world !  hijack RETS ... */
 
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        *parent = return_hooker;
 
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}
 
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#endif