LTTng » LTTng-tools

on ctrl+c with snapshots enabled, the cleanup mechanism tries to contact the consumer even when it is already gone.

steps to reproduce :
start lttng-sessiond in a console (not in daemon mode)
in a separate console :
lttng create --snapshot
lttng enable-event -k sched_switch
lttng start

then ctrl+c in the console with the session

This should appear :
PERROR [15884/15884]: sendmsg: Bad file descriptor (in lttcomm_send_unix_sock() at unix.c:218)

Backtrace leading to this bug :
#4 0x000000000042f5a5 in lttcomm_send_unix_sock (sock=<optimized out>, buf=<optimized out>,
len=<optimized out>) at unix.c:219
#5 0x000000000040ec0c in consumer_send_msg (sock=0x7f3b8c003eb0, msg=<optimized out>)
at consumer.c:676
#6 0x0000000000412253 in kernel_consumer_destroy_channel (socket=0x7f3b8c003eb0,
channel=<optimized out>) at kernel-consumer.c:384
#7 0x000000000040ac6b in kernel_destroy_session (ksess=0x7f3b8c003cb0) at kernel.c:774
#8 0x000000000041524b in cmd_destroy_session (session=0x7f3b8c005cd0, wpipe=-1) at cmd.c:1828
#9 0x000000000040552e in cleanup () at main.c:486
#10 main (argc=<optimized out>, argv=<optimized out>) at main.c:4769

Log starting at the ctrl+c :
^CDEBUG1 [19560/19560]: SIGINT caught (in sighandler() at main.c:4229)
DEBUG1 [19560/19560]: Terminating all threads (in stop_threads() at main.c:382)
DEBUG1 [19701/19701]: ignoring first SIGINT (in sighandler() at lttng-consumerd.c:81)
DEBUG1 [19560/19560]: Futex n to 1 wake done (in futex_nto1_wake() at futex.c:104)
DEBUG1 [19560/19659]: [ust-thread] cleanup complete. (in thread_ht_cleanup() at ht-cleanup.c:130)
DEBUG1 [19560/19662]: Futex n to 1 wait done (in futex_nto1_wait() at futex.c:90)
DEBUG1 [19560/19662]: Dispatch thread dying (in thread_dispatch_ust_registration() at main.c:1684)
DEBUG1 [19560/19702]: consumer thread cleanup completed (in thread_manage_consumer() at main.c:1191)
DEBUG1 [19701/19706]: Incoming command on sock (in consumer_thread_sessiond_poll() at consumer.c:2948)
DEBUG1 [19560/19665]: Application notify communication apps thread cleanup complete (in ust_thread_manage_notify() at ust-thread.c:174)
DEBUG1 [19701/19706]: Communication interrupted on command socket (in consumer_thread_sessiond_poll() at consumer.c:2959)
DEBUG1 [19701/19706]: Consumer thread sessiond poll exiting (in consumer_thread_sessiond_poll() at consumer.c:2969)
DEBUG1 [19560/19660]: Health check thread dying (in thread_manage_health() at main.c:3553)
DEBUG1 [19701/19705]: poll num_rdy : 1 (in consumer_thread_data_poll() at consumer.c:2387)
DEBUG1 [19701/19705]: consumer_data_pipe wake up (in consumer_thread_data_poll() at consumer.c:2411)
DEBUG1 [19560/19663]: Notifying applications of session daemon state: 0 (in notify_ust_apps() at main.c:555)
DEBUG1 [19701/19705]: Consumer delete flagged data stream (in validate_endpoint_status_data_stream() at consumer.c:2059)
DEBUG1 [19701/19705]: polling thread exiting (in consumer_thread_data_poll() at consumer.c:2541)
DEBUG1 [19560/19663]: Got the wait shm fd 5 (in get_wait_shm() at shm.c:119)
DEBUG1 [19701/19703]: Channel event catched in thread (in consumer_thread_channel_poll() at consumer.c:2681)
DEBUG1 [19560/19663]: Futex wait update active 0 (in futex_wait_update() at futex.c:63)
DEBUG1 [19701/19703]: Channel poll thread exiting (in consumer_thread_channel_poll() at consumer.c:2837)
DEBUG1 [19560/19663]: UST Registration thread cleanup complete (in thread_registration_apps() at main.c:1888)
DEBUG1 [19701/19704]: Metadata event catched in thread (in consumer_thread_metadata_poll() at consumer.c:2154)
DEBUG1 [19701/19704]: Metadata thread pipe hung up (in consumer_thread_metadata_poll() at consumer.c:2177)
DEBUG1 [19560/19664]: Application communication apps thread cleanup complete (in thread_manage_apps() at main.c:1351)
DEBUG1 [19701/19704]: Metadata poll thread exiting (in consumer_thread_metadata_poll() at consumer.c:2295)
DEBUG1 [19560/19666]: Kernel thread dying (in thread_manage_kernel() at main.c:881)
PERROR [19701/19701]: sendmsg: Broken pipe (in lttcomm_send_unix_sock() at unix.c:218)
DEBUG1 [19560/19661]: Clean command context structure (in clean_command_ctx() at main.c:535)
lttng-consumerd: unix.c:219: lttcomm_send_unix_sock: Assertion `0' failed.
DEBUG1 [19560/19661]: Client thread dying (in thread_manage_clients() at main.c:3810)
DEBUG1 [19560/19560]: Cleaning up (in cleanup() at main.c:447)
DEBUG1 [19560/19560]: Removing /var/run/lttng directory (in cleanup() at main.c:463)
DEBUG1 [19560/19560]: Cleaning up all sessions (in cleanup() at main.c:477)
DEBUG1 [19560/19560]: Tearing down kernel session (in kernel_destroy_session() at kernel.c:755)
DEBUG1 [19560/19560]: Sending kernel consumer destroy channel key 33 (in kernel_consumer_destroy_channel() at kernel-consumer.c:376)
PERROR [19560/19560]: sendmsg: Bad file descriptor (in lttcomm_send_unix_sock() at unix.c:218)