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Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
64 lines
1.5 KiB
C
64 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Dynamic Ftrace based Kprobes Optimization
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*
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* Copyright (C) Hitachi Ltd., 2012
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* Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
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* IBM Corporation
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*/
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#include <linux/kprobes.h>
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#include <linux/ptrace.h>
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#include <linux/hardirq.h>
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#include <linux/preempt.h>
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#include <linux/ftrace.h>
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/* Ftrace callback handler for kprobes */
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void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip,
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struct ftrace_ops *ops, struct pt_regs *regs)
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{
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struct kprobe *p;
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struct kprobe_ctlblk *kcb;
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p = get_kprobe((kprobe_opcode_t *)nip);
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if (unlikely(!p) || kprobe_disabled(p))
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return;
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kcb = get_kprobe_ctlblk();
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if (kprobe_running()) {
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kprobes_inc_nmissed_count(p);
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} else {
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/*
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* On powerpc, NIP is *before* this instruction for the
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* pre handler
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*/
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regs->nip -= MCOUNT_INSN_SIZE;
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__this_cpu_write(current_kprobe, p);
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kcb->kprobe_status = KPROBE_HIT_ACTIVE;
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if (!p->pre_handler || !p->pre_handler(p, regs)) {
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/*
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* Emulate singlestep (and also recover regs->nip)
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* as if there is a nop
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*/
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regs->nip += MCOUNT_INSN_SIZE;
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if (unlikely(p->post_handler)) {
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kcb->kprobe_status = KPROBE_HIT_SSDONE;
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p->post_handler(p, regs, 0);
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}
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}
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/*
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* If pre_handler returns !0, it changes regs->nip. We have to
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* skip emulating post_handler.
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*/
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__this_cpu_write(current_kprobe, NULL);
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}
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}
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NOKPROBE_SYMBOL(kprobe_ftrace_handler);
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int arch_prepare_kprobe_ftrace(struct kprobe *p)
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{
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p->ainsn.insn = NULL;
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p->ainsn.boostable = -1;
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return 0;
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}
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