<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><br></div><div><br></div><span id="zwchr" data-marker="__DIVIDER__">----- On Feb 12, 2016, at 3:21 PM, Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:<br></span><div data-marker="__QUOTED_TEXT__"><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><span id="zwchr">----- On Feb 12, 2016, at 12:02 PM, Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:<br></span></div><div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><span id="zwchr">---- On Feb 11, 2016, at 9:01 AM, Sean Heelan <seanheelan@gmail.com> wrote:<br></span></div><div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div dir="ltr">Hi all,<br><div>I am running a target within a Docker instance, and tracing function execution using the latest LTTng release (2.7). The commands I am issuing look as follows:</div><br><div>----<br></div><div><div>lttng create cc_session -o bla</div><div>lttng enable-event --userspace lttng_ust_cyg_profile:func_entry</div><div>lttng start</div><br><div>LD_PRELOAD=liblttng-ust-cyg-profile.so target</div><br><div>lttng stop</div><div>lttng destroy</div><div>----</div></div><br><div>When the target is executed it aborts with the following error:</div><br><div>----</div><div>php: lttng-ust-comm.c:1582: lttng_ust_init: Assertion `!ret' failed.<br></div><div>----</div><br><div>If I rerun the command it then works fine. In fact, simply doing the following within the Docker container demonstrates the issue:</div><br><div>----</div><div><div>LD_PRELOAD=liblttng-ust-cyg-profile.so ls</div><div>LD_PRELOAD=liblttng-ust-cyg-profile.so ls</div></div><div>----</div><br><div>The first 'ls' will fail at the same point mentioned above, while the second will succeed. Off the top of my head I'm struggling to come up with an explanation as to what impact the first execution using LD_PRELOAD would have on the second. Does it impact a shared lib cache in some way, which I'm unaware of?</div><br><div>Any assistance would be appreciated!</div></div></blockquote><div>It appears that sem_timedwait() returns an unexpected error.<br></div><br><div>Can you add a ERROR("sem_timedwait"); just before the assert at line 1582 in your liblttng-ust/lttng-ust-comm.c<br></div><div>and show us the output ?<br></div><br><div>Also, what is the value of your LTTNG_UST_REGISTER_TIMEOUT env. var. ?</div></div></div></blockquote><br><div>Also, what architecture, Linux distribution, and kernel<br></div><div>version are you using ?</div></div></div></blockquote><div><br></div><div>I pushed the following fix in lttng-ust:<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>commit 5cf81d53e305c81517e48e0dc91620a916cdc0cc<br>Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com><br>Date: Fri Feb 12 15:44:10 2016 -0500<br><br> Fix: handle negative range for LTTNG_UST_REGISTER_TIMEOUT<br> <br> We should not consider values below -1 as valid timeout values, this is<br> is unexpected and could lead to EINVAL errors returned by sem_timedwait.<br> <br> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com><br></div><div><br data-mce-bogus="1"></div><div>Let me know if it helps,<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>Thanks,<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>Mathieu<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><div><br></div><br><div>Thanks,<br></div><br><div>Mathieu<br></div><br><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><br><br><div>Thanks,<br></div><br><div>Mathieu<br></div><br><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div dir="ltr"><div><br>Sean</div><br><br></div><br>_______________________________________________<br>lttng-dev mailing list<br>lttng-dev@lists.lttng.org<br>http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev<br></blockquote></div><br><div>-- <br></div><div>Mathieu Desnoyers<br>EfficiOS Inc.<br>http://www.efficios.com</div></div><br>_______________________________________________<br>lttng-dev mailing list<br>lttng-dev@lists.lttng.org<br>http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev<br></blockquote></div><br><div>-- <br></div><div>Mathieu Desnoyers<br>EfficiOS Inc.<br>http://www.efficios.com</div></div><br>_______________________________________________<br>lttng-dev mailing list<br>lttng-dev@lists.lttng.org<br>http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev<br></blockquote></div><br><div data-marker="__SIG_POST__">-- <br></div><div>Mathieu Desnoyers<br>EfficiOS Inc.<br>http://www.efficios.com</div></div></body></html>