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Re: Re: Re: [PATCH v3 -tip] [BUGFIX] x86/kprobes: Fix to recover instructions on optimized path
* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> (2012/02/28 17:48), Ingo Molnar wrote:
> >
> > * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> >
> >> (2012/02/27 18:34), Ingo Molnar wrote:
> >>>
> >>> * 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?
> >>
> >> Would you mean that I should split all optprobe stuffs into
> >> new file?
> >
> > Yeah, that would be sensible I think - and it might help avoid
> > similar complications in the future.
> >
> > Could (and probably should) be done in a separate patch - to
> > keep the bits that you already fixed and tested intact.
>
> OK, I'll make a separate patch.
Could be done on top of your existing patch, to keep things
simpler for you - a split-up patch done before your fix would
create a lot of conflicts in the fix patch.
Thanks,
Ingo