(2013/12/23 13:51), Jovi Zhangwei wrote: > On Fri, Dec 20, 2013 at 5:21 PM, Masami Hiramatsu > <masami.hiramatsu.pt@xxxxxxxxxxx> wrote: >> (2013/12/20 17:31), Jovi Zhangwei wrote: >>> On Fri, Dec 20, 2013 at 12:42 PM, Masami Hiramatsu >>> <masami.hiramatsu.pt@xxxxxxxxxxx> wrote: >>>> (2013/12/20 12:07), Jovi Zhangwei wrote: >>>>> On Fri, Dec 20, 2013 at 10:37 AM, Masami Hiramatsu >>>>> <masami.hiramatsu.pt@xxxxxxxxxxx> wrote: >>>>>> Hi Jovi, >>>>>> >>>>>> (2013/12/19 18:37), Jovi Zhangwei wrote: >>>>>>> Hi Masami, >>>>>>> >>>>>>> On Thu, Dec 19, 2013 at 5:04 PM, Masami Hiramatsu >>>>>>> <masami.hiramatsu.pt@xxxxxxxxxxx> wrote: >>>>>>>> memcpy/memset functions are fundamental functions and >>>>>>>> those are involved in kprobe's exception handling. >>>>>>>> Prohibit probing on them to avoid kernel crash. >>>>>>>> >>>>>>> Would you please let me know the LKML link of that bugfix, I cannot >>>>>>> find it in my LKML fold. >>>>>> >>>>>> Yeah, that was found in my testing environment. >>>>>> >>>>>>> No objection on this patch. :) just want to know more, It seems there >>>>>>> have no problem to probe memcpy in my box, maybe I didn't hit the >>>>>>> crash code path. >>>>>> >>>>>> Ah, I see. Originally the problem happened when I put a probe on >>>>>> __memcpy. And it looks the instances of memcpy and __memcpy are >>>>>> same on x86-64. Thus I decided to blacklist both. (memset/__memset too) >>>>>> Have you ever tried to probe __memcpy on your box? >>>>>> >>>>> Hmm, still no crash, __memcpy and __memset are both tested. >>>>> >>>>> I use below kprobe related config: >>>>> >>>>> CONFIG_KPROBES=y >>>>> CONFIG_JUMP_LABEL=y >>>>> CONFIG_OPTPROBES=y >>>>> CONFIG_KPROBES_ON_FTRACE=y >>>> >>>> Hmm, I've added some debugging options. >>>> >>>> CONFIG_SLUB_DEBUG=y >>>> CONFIG_X86_DEBUGCTLMSR=y >>>> CONFIG_PNP_DEBUG_MESSAGES=y >>>> CONFIG_DEBUG_INFO=y >>>> CONFIG_DEBUG_FS=y >>>> CONFIG_DEBUG_KERNEL=y >>>> CONFIG_DEBUG_STACK_USAGE=y >>>> CONFIG_DEBUG_MEMORY_INIT=y >>>> CONFIG_DEBUG_STACKOVERFLOW=y >>>> CONFIG_DEBUG_SPINLOCK=y >>>> CONFIG_DEBUG_MUTEXES=y >>>> CONFIG_DEBUG_LOCK_ALLOC=y >>>> CONFIG_DEBUG_LOCKDEP=y >>>> CONFIG_DEBUG_BUGVERBOSE=y >>>> CONFIG_DEBUG_RODATA=y >>>> CONFIG_DEBUG_BOOT_PARAMS=y >>>> >>>> I guess some of them might cause it. >>>> >>> I recompiled the kernel with those config enabled, unfortunately still no crash, >>> I tested on 3.13.0-rc4, a fedora kvm box. >> >> Hmm, it's very odd. I'm running 3.13.0-rc4 x86-64 on the fedora >> kvm box too. here is the full of my kconfig. >> > That configuration is still working for me, no crash for memcpy kprobe test. Would you do __memcpy test? or memcpy test? I only had a crash on the __memcpy(__memset). Thank you, > > I also posted my kernel configration at: > https://gist.github.com/ktap/8091293 > > I compared two configs, no clue found yet. > > Thanks, > > Jovi > -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@xxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
