Messages in this thread | | | Date | Wed, 29 Feb 2012 22:20:43 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v3 -tip] [BUGFIX] x86/kprobes: Fix to recover instructions on optimized path |
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(2012/02/28 18:59), Ingo Molnar wrote: > > * 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.
I see. And in the previous patch, I've just find a small racing bug. I'll update it too.
Thank you,
-- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
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