Project

General

Profile

Actions
Copy link

Bug #615

closed

consumerd crashes during buffer snapshot

Added by Stanislav Vovk over 11 years ago. Updated over 11 years ago.

Status:
Resolved
Priority:
High
Assignee:
-
Target version:
LTTng - 2.3
Start date:
08/13/2013
Due date:
% Done:

0%

Estimated time:

Description

Commit IDs

tools: 81ea21bfd975bdf60dd30229a4caece7c98a2912
ust:   42f209e98d68936df04ec947a12e684155ce7cfe
rcu:   a5bae03d59c22e57263b8610b9fed99738303cf0

Problem description
consumerd crashes when 'lttng snapshot record' is executed. The crash only happens when an instrumented program is/has been run as non-privileged user.

System setup
sessiond is started as root and configured with following commands,

lttng create s1 --snapshot -o /trace/
lttng enable-channel ch -u -s s1
lttng enable-event -u -a -c ch
lttng start

There is a user Bob, member in groups 'users' and 'tracing'.
Instrumented program is run as Bob, program can be killed or continue running, does not matter for fault reproduction.

Crash happens when 'lttng snapshot record -s s1' is executed. Crash is always reproducible.

A snapshot is dumped to output but is not readable. Seems like 'metadata' is missing.

root@du1:~# l /trace/snapshot-1-20130813-122306-2/ust/uid/1000/32-bit/      
total 4
drwxrwx--- 2 root root    0 Aug 13 12:23 ./
drwxrwx--- 3 root root    0 Aug 13 12:23 ../
-rw-rw---- 1 root root 4096 Aug 13 12:23 c_tri_0
-rw-rw---- 1 root root 4096 Aug 13 12:23 c_tri_1
-rw-rw---- 1 root root 4096 Aug 13 12:23 c_tri_2
-rw-rw---- 1 root root 4096 Aug 13 12:23 c_tri_3

Attaching debug info!

Files

Download all files
lttng_dbg.txt (499 KB) lttng_dbg.txt sessiond debug output Stanislav Vovk, 08/13/2013 06:52 AM
consumerd-bt.txt (7.21 KB) consumerd-bt.txt gdb bt Stanislav Vovk, 08/13/2013 06:52 AM
ust-dbg.txt (47.2 KB) ust-dbg.txt Stanislav Vovk, 08/13/2013 06:52 AM
sesd-dbg.txt (6.44 KB) sesd-dbg.txt Stanislav Vovk, 08/19/2013 08:18 AM
Actions
Copy link

Also available in: Atom PDF