42 lines
964 B
C
42 lines
964 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2013 Linaro Limited
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* Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
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* Copyright (C) 2017 Andes Technology Corporation
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*/
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#include <linux/ftrace.h>
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/*
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* Most of this file is copied from arm64.
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*/
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void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
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unsigned long frame_pointer)
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{
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unsigned long return_hooker = (unsigned long)&return_to_handler;
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unsigned long old;
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struct ftrace_graph_ent trace;
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int err;
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if (unlikely(atomic_read(¤t->tracing_graph_pause)))
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return;
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/*
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* We don't suffer access faults, so no extra fault-recovery assembly
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* is needed here.
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*/
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old = *parent;
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trace.func = self_addr;
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trace.depth = current->curr_ret_stack + 1;
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if (!ftrace_graph_entry(&trace))
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return;
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err = ftrace_push_return_trace(old, self_addr, &trace.depth,
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frame_pointer, NULL);
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if (err == -EBUSY)
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return;
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*parent = return_hooker;
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}
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