-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Daniel,
On 12-01-18 02:12 PM, Thibault, Daniel wrote: > > Well, the good news is that the new head (lttng-tools-2.0-pre16+-76150f6 > 2012-01-18 17:21) compiles correctly (no warnings, no errors in bootstrap, > configure, make and install logs). The bad news is that it still misbehaves. > Here's my session log, edited for brevity: > Hmmmm... this is really unusual. I'll try to test this issue on a 2.6.38 kernel because apart from that, I have no idea what can cause this. We can't reproduce it here... Some of my dev. is on Lucid 10.04 and Debian testing so I doubt that the Ubuntu version makes difference here. I'll let you know for sure. > $ sudo lttng list -k > Spawning a session daemon > Kernel events: > ------------- > sched_kthread_stop (type: tracepoint) > sched_kthread_stop_ret (type: tracepoint) > [...] > kvm_ioapic_set_irq (type: tracepoint) > kvm_msi_set_irq (type: tracepoint) > (type: tracepoint) [disabled] > (type: tracepoint) [disabled] > [... 27 more instances ...] > (type: tracepoint) [disabled] > (type: tracepoint) [disabled] > > $ sudo lttng list -k > Kernel events: > ------------- > sched_kthread_stop (type: tracepoint) > sched_kthread_stop_ret (type: tracepoint) > [...] > kvm_ioapic_set_irq (type: tracepoint) > kvm_msi_set_irq (type: tracepoint) > kvm_ack_irq (type: tracepoint) > kvm_mmio (type: tracepoint) > [...] > block_bio_remap (type: tracepoint) > block_rq_remap (type: tracepoint) > > When I kill the lttng-sessiond daemon, all 17 lttng-modules are unloaded. > > I tried doing 'sudo modprobe lttng_probe_block' before calling 'sudo lttng > list -k' to see if that wouldn't un-anonymise the block_* tracepoints (which > I think are serviced by the lttng_probe_block module). The module loaded > along with a handful of other modules it depends on (ltt_relay, > lttng_kretprobes, lttng_kprobes, lttng_ftrace, lib_ring_buffer) but 'sudo > lttng list -k' yielded precisely the same output. > > ----- > > I'd like to take this opportunity to point out a problem when running > lttng from an unelevated account: > > $ lttng list -k > Spawning a session daemon > FATAL: Error inserting lttng_ftrace > (/lib/modules/2.6.38-020638-generic/extra/probes/lttng-ftrace.ko): Operation > not permitted > FATAL: Error inserting lttng_kprobes > (/lib/modules/2.6.38-020638-generic/extra/probes/lttng-kprobes.ko): Operation > not permitted > [... 14 more FATAL errors interleaved with 30 WARNINGs ...] > WARNING: Error inserting ltt_relay > (/lib/modules/2.6.38-020638-generic/extra/ltt-relay.ko): Operation not > permitted > FATAL: Error inserting lttng_probe_sched > (/lib/modules/2.6.38-020638-generic/extra/probes/lttng-probe-sched.ko): > Operation not permitted > Error: Unable to list kernel events > Error: Kernel tracer not available > > If the error is FATAL, why does lttng keep going? The final error message > could be improved to read something like "Error: Kernel tracer not available > or not accessible at your privilege level", in order to at least hint at what > the source of the problem is. > I did fix that with latest commit : Author: David Goulet <[email protected]> Date: Thu Jan 19 13:43:57 2012 -0500 Don't init kernel tracer if not root (UID=0) No point of trying to init kernel tracer if the session daemon is not root. At this time, only UID=0 can load kernel modules and interact with the lttng kernel tracer. Reported-by: Daniel Thibault <[email protected]> Signed-off-by: David Goulet <[email protected]> Thanks of the report! Note that after this commit, I'll release lttng-tools pre17 and completely feature freeze it until February 16th 2012. We are going into stable mode aiming at the stable packages for Ubuntu next LTS. Cheers! David > Daniel U. Thibault > R & D pour la défense Canada - Valcartier (RDDC Valcartier) / Defence R&D > Canada - Valcartier (DRDC Valcartier) > Système de systèmes (SdS) / System of Systems (SoS) > Solutions informatiques et expérimentations (SIE) / Computing Solutions and > Experimentations (CSE) > 2459 Boul. Pie XI Nord > Québec, QC G3J 1X5 > CANADA > Vox : (418) 844-4000 x4245 > Fax : (418) 844-4538 > NAC: 918V QSDJ > Gouvernement du Canada / Government of Canada > <http://www.valcartier.drdc-rddc.gc.ca/> > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQEcBAEBAgAGBQJPGGcaAAoJEELoaioR9I028EgH/217mx6gMoPm07ylxWwUBbg1 J5FfpdIGCFiuspT38zUXhlM3+J+W4oMY8giONGTlVuBkdK34PWNflXf0QyBfg3XW i1ZmBBLGg/3vVbjGA74MGrYDVIUUr7Cpm+cycM2XD9k7xhe3RWbPdzP7JY8RWmzH IqKDUxSvPHp9GnbNaRHdZ1G6nF89w6xXIHO5gaMJP4087AhGvDo8m52nCHBXIEJA +uaB49NhvoOES5LPTxOJbaYPEpLgzEdGGjx1uriDX3BGGnfPRMmAS27Nf+4iiusI H7B6Oye104hTZFqR4a/15T0v+FKR3dlGZvJga2MBHqiNoDRX5CuIohHBG0YDsvk= =lD76 -----END PGP SIGNATURE----- _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
