f684199f5d
Move arch-dep kprobes stuff under arch/x86/kernel/kprobes. Link: http://lkml.kernel.org/r/20120928081522.3560.75469.stgit@ltc138.sdl.hitachi.co.jp Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> [ fixed whitespace and s/__attribute__((packed))/__packed/ ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
/*
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* Dynamic Ftrace based Kprobes Optimization
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright (C) Hitachi Ltd., 2012
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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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#include "common.h"
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static int __skip_singlestep(struct kprobe *p, struct pt_regs *regs,
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struct kprobe_ctlblk *kcb)
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{
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/*
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* Emulate singlestep (and also recover regs->ip)
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* as if there is a 5byte nop
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*/
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regs->ip = (unsigned long)p->addr + 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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__this_cpu_write(current_kprobe, NULL);
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return 1;
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}
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int __kprobes skip_singlestep(struct kprobe *p, struct pt_regs *regs,
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struct kprobe_ctlblk *kcb)
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{
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if (kprobe_ftrace(p))
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return __skip_singlestep(p, regs, kcb);
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else
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return 0;
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}
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/* Ftrace callback handler for kprobes */
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void __kprobes kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
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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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unsigned long flags;
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/* Disable irq for emulating a breakpoint and avoiding preempt */
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local_irq_save(flags);
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p = get_kprobe((kprobe_opcode_t *)ip);
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if (unlikely(!p) || kprobe_disabled(p))
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goto end;
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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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/* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */
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regs->ip = ip + sizeof(kprobe_opcode_t);
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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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__skip_singlestep(p, regs, kcb);
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/*
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* If pre_handler returns !0, it sets regs->ip and
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* resets current kprobe.
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*/
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}
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end:
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local_irq_restore(flags);
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}
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int __kprobes 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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