Kernel crash when using systemtap

[Frank Ch. Eigler]

Padmanabhan S N <paddusn@yahoo.com> writes:

> While using systemtap to do function call tracing (.call,
> .inline. .return probes) on one of our proprietary kernel modules,
> the system crashes. [...]

OK.

> The environment is RHEL 5.5 64-bit. I've tried to look at the crash
> dump, and it does point to the generated systemtap module. But I
> couldn't proceed beyond that. Here is a bt from one of the crash dumps.
>
> [...]
> #4 [ffff8100956f1af0] add_to_page_cache at ffffffff8000c722
> #5 [ffff8100956f1b48] _stp_map_get_ii at ffffffff889d8459 [stap_44a2f6019f0e29a88c9470c55950ae1a_14041197]
> [...]

How big is this module?  That _14041197 string makes it sound large.
Can you share the script source?  Consider removing the .inline
probes, or narrow the wildcards and/or pretty-printing.  Consider
testing out an updated kernel; IIRC there have been kprobes robustness
improvements.

- FChE