This is the mail archive of the systemtap@sourceware.org mailing list for the systemtap project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[Bug runtime/6030] stap, staprun, stapio interaction quirks: stale module left unloaded


------- Additional Comments From fche at redhat dot com  2008-04-08 14:12 -------
(In reply to comment #3)
> cron wouldn't work well. If you wanted to run the same script you would
> not be able to until cron had triggered the cleanup.  As a user, I find
> stuff like that extremely annoying.

Remember, the scenario here is that the user killed his own stap*
processes with kill -9.  Such extreme annoyance is self-induced.

I recall we came across some runes that perform pseudo-renaming of a
compiled module before insmod time.  If that can be made to work
(as a part of staprun presumably), then reexecuting the same probe
several times concurrently would be possible.

Another simple possibility is for staprun to attempt to *unload* a
module with the same name that it's about to load - to clean up an
orphaned zombie.  (It'd use sys_delete_module(2) with O_NONBLOCK.)


> I still prefer the solution I described here
> http://sources.redhat.com/bugzilla/show_bug.cgi?id=5716
> 
> "I think a simpler, more secure approach would be to simply separate the
> module removal and build it as a standalone suid program.   [...]

Perhaps, but is it useful & necessary enough to overcome the natural
skepticism toward adding anything setuid?


-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=6030

------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]