On Mon, Dec 23, 2013 at 6:59 PM, Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx> wrote: > (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). > Still no crash, use your kernel config. memcpy and __memcpy have same address in /proc/kallsyms. Looks like a interesting problem. Thanks, Jovi. -- 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
