Re: Unknown symbol error using stap in 2.6.31 on ARM

[Cipher Chen <cipher dot chen2012 at gmail dot com>]

Hi, Alexander

On Sun, Dec 30, 2012 at 5:23 PM, Alexander Lochmann
<alexander.lochmann@tu-dortmund.de> wrote:
> Hi,
>
> try to run stap with "--compatible=1.8".
> Stap needs uprobe support for some builtin functions as weel. Using this
> option it will use old fashion builtin function.



    I'm not sure this would help, since I've already tried version 1.8
and snapshot 20122222(?), too(I mean re-install the whole systemtap).
And it didn't work either.(current used is 2.0)
    Anyway, I'll try that again tomorrow.

    Thanks.







>
> Greetings
> Alex
>
>
> On 12/30/2012 02:55 AM, Cipher Chen wrote:
>>
>> Hi,
>>     I met the same problem descripted here:
>>
>> http://sourceware-org.1504.n7.nabble.com/Unknown-symbol-error-using-stap-in-RHEL-5-4-td176251.html
>>
>>     What's different is that it's an ARM target. After i got
>> ntfs_watching.ko, "staprun ntfs_watching.ko" on that, it told me:
>> dmesg here:
>> ntfs_watching: Unknown symbol utrace_control
>> ntfs_watching: Unknown symbol utrace_barrier
>> ntfs_watching: Unknown symbol __utrace_engine_release
>> ntfs_watching: Unknown symbol unregister_uretprobe
>> ntfs_watching: Unknown symbol register_uprobe
>> ntfs_watching: Unknown symbol unmap_uretprobe
>> ntfs_watching: Unknown symbol utrace_attach_task
>> ntfs_watching: Unknown symbol register_uretprobe
>> ntfs_watching: Unknown symbol unmap_uprobe
>> ntfs_watching: Unknown symbol utrace_set_events
>> ntfs_watching: Unknown symbol unregister_uprobe
>>
>>   So i tried something mentioned in that thread, it didnt work since
>> it's linux-2.6.31.5 without CONFIG_UPROBES.
>>   It doesnt have any modules running.
>>   Can we say that staprun ran with its own uprobes.ko?
>>
>>   Then I also copied the uprobes.ko in /tmp/stap**** generated on host
>> to the ARM target, and "insmod uprobes.ko"
>> dmesg here:
>> uprobes: Unknown symbol utrace_control
>> uprobes: Unknown symbol utrace_attach_pid
>> uprobes: Unknown symbol utrace_set_events
>> ("staprun ntfs_watching -u" told me these too)
>>
>> Any thoughts on what might be causing this problem?
>>
>>
>>
>> Thanks!
>
>