From: Ingo Molnar <mingo@elte.hu>
To: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: linux-kernel@vger.kernel.org, yrl.pp-manager.tt@hitachi.com,
systemtap@sourceware.org, anderson@redhat.com,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Subject: Re: [PATCH v3 -tip] [BUGFIX] x86/kprobes: Fix to recover instructions on optimized path
Date: Mon, 27 Feb 2012 09:34:00 -0000 [thread overview]
Message-ID: <20120227093421.GA10078@elte.hu> (raw)
In-Reply-To: <20120224095412.8462.55698.stgit@localhost.localdomain>
* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> +
> +#ifdef CONFIG_OPTPROBES
> +static unsigned long __recover_optprobed_insn(struct kprobe *kp,
> + kprobe_opcode_t *buf,
> + unsigned long addr)
> +{
> + long offs = addr - (unsigned long)kp->addr - 1;
> + struct optimized_kprobe *op = container_of(kp, struct optimized_kprobe, kp);
> +
> + /*
> + * If the kprobe can be optimized, original bytes which can be
> + * overwritten by jump destination address. In this case, original
> + * bytes must be recovered from op->optinsn.copied_insn buffer.
> + */
> + memcpy(buf, (void *)addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
> + if (addr == (unsigned long)kp->addr) {
> + buf[0] = kp->opcode;
> + memcpy(buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE);
> + } else
> + memcpy(buf, op->optinsn.copied_insn + offs, RELATIVE_ADDR_SIZE - offs);
> +
> + return (unsigned long)buf;
> +}
> +#endif
Why not stick this into a new kprobes-opt.c file?
> +
> +/*
> + * Recover the probed instruction at addr for further analysis.
> + * Caller must lock kprobes by kprobe_mutex, or disable preemption
> + * for preventing to release referencing kprobes.
> + */
> +static unsigned long recover_probed_instruction(kprobe_opcode_t *buf,
> + unsigned long addr)
> +{
> + struct kprobe *kp;
> +#ifdef CONFIG_OPTPROBES
> + int i;
> +
> + for (i = 0; i < RELATIVEJUMP_SIZE; i++) {
> + kp = get_kprobe((void *)addr - i);
> + if (kp && kprobe_optready(kp))
> + return __recover_optprobed_insn(kp, buf, addr);
> + }
> +#endif
This should be a separate, kprobes_recover_opt() method and be
inside kprobes-opt.c as well.
Thanks,
Ingo
next prev parent reply other threads:[~2012-02-27 9:34 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20120223083703.GA26781@elte.hu>
2012-02-24 9:54 ` Masami Hiramatsu
2012-02-27 9:34 ` Ingo Molnar [this message]
2012-02-28 2:53 ` Masami Hiramatsu
2012-02-28 8:49 ` Ingo Molnar
2012-02-28 9:52 ` Masami Hiramatsu
2012-02-28 10:00 ` Ingo Molnar
2012-02-29 13:21 ` Masami Hiramatsu
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