Re: Kernel panics during execution of timeouts.stp example when booted with kgdboc=kms,kbd

[Mark Wielaard <mjw at redhat dot com>]

Hi,

On Tue, 2011-12-06 at 03:39 -0500, dmitry.krivenok@emc.com wrote:
> The problem is that kernel panics if you run it with "kgdboc=kms,kbd"
> parameter and then run standard timeout.stp example as follows:
> 
> $ sudo stap -v `locate timeout.stp`
> Pass 1: parsed user script and 77 library script(s) using 78192virt/22076res/2376shr kb, in 190usr/60sys/689real ms.
> Pass 2: analyzed script: 12 probe(s), 7 function(s), 5 embed(s), 10 global(s) using 202032virt/44892res/3256shr kb, in 790usr/4810sys/10056real ms.
> Pass 3: using cached /root/.systemtap/cache/dd/stap_ddd8c5ac8daf0d8644742908043722b3_12685.c
> Pass 4: using cached /root/.systemtap/cache/dd/stap_ddd8c5ac8daf0d8644742908043722b3_12685.ko
> Pass 5: starting run.
> 
> I also tried to run stap with -vvv options and the last lines I saw were:
> ...
> ...
> execing: /usr/local/libexec/systemtap/stapio -v -v -R stap_ddd8c5ac8daf0d8644742908043722b3_1_777
> stapio:parse_modpath:368 modpath="/lib/modules/3.1.1/systemtap/stap_ddd8c5ac8daf0d8644742908043722b3_1_777.ko"
> stapio:main:41 modpath="/lib/modules/3.1.1/systemtap/stap_ddd8c5ac8daf0d8644742908043722b3_1_777.ko", modname="stap_ddd8c5ac8daf0d8644742908043722b3_1_777"
> stapio:init_stapio:338 init_stapio
> stapio:init_ctl_channel:31 Opened /sys/kernel/debug/systemtap/stap_ddd8c5ac8daf0d8644742908043722b3_1_777/.cmd (3)
> stapio:stp_main_loop:529 in main loop
> stapio:init_relayfs:239 initializing relayfs
> stapio:init_relayfs:263 attempting to open /sys/kernel/debug/systemtap/stap_ddd8c5ac8daf0d8644742908043722b3_1_777/trace0
> stapio:init_relayfs:263 attempting to open /sys/kernel/debug/systemtap/stap_ddd8c5ac8daf0d8644742908043722b3_1_777/trace1
> stapio:init_relayfs:269 ncpus=1, bulkmode = 0
> stapio:init_relayfs:352 starting threads
> 
> The problem is 100% reproducible on both systems.
> I'm not sure if it's a bug in Systemtap or kernel, because I could misconfigure something.
> 
> Could someone please try to reproduce the problem and post results here?

I don't have the above setup here handy atm. But it would be helpful if
you could post the results of 'stap-report' somewhere. And even better
if you could try and get a serial console dump of the kernel panic you
are getting, see http://sourceware.org/systemtap/wiki/HowToReportBugs
and here http://sourceware.org/systemtap/wiki/DeveloperSetupTips for
some guides on setting that up.

Thanks,

Mark