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. 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
