OK (re-adding lttng-dev) ----- On Jul 17, 2015, at 9:09 AM, Dilong Zheng <[email protected]> wrote:
> I was using lttng-ust 2.5.4 but now I'm moving up to lttng-ust 2.5.5 (which > should be the latest 2.5 version) > Thanks, > Dilong > From: Mathieu Desnoyers <[email protected]> > Sent: Thursday, July 16, 2015 12:00 AM > To: Dilong Zheng > Cc: lttng-dev > Subject: Re: [lttng-dev] SIGSEGV __event_probe, C++ application (static > linking) > ----- On Jul 13, 2015, at 4:37 PM, Dilong Zheng <[email protected]> > wrote: >> Hi, >> I have instrumented a C++ application with user space tracepoints. When I run >> the application and do a: "lttng list -u" command, I am able to see all my >> available tracepoints for the application. However when I enable those user >> space tracepoints and then start the trace, a core gets dumped and examining >> the core file in gdb I see the following error: >> Program terminated with signal SIGSEGV, Segmentation fault. >> #0 0x00000000 in ?? () >> ... >> (gdb) bt >> #0 0x00000000 in ?? () >> #1 0x08dd1088 in __event_probe__mike___sem_wait_entry (__tp_data=0xef92d818) >> at /localhome/zhengd/override_mcd/System/SS_Inc/./sem_wrapper.h:67 >> #2 0x08dd44d9 in __tracepoint_cb_mike___sem_wait_entry () at >> /localhome/zhengd/override_mc /System/SS_Inc/sem_wrapper.h:67 >> #3 __wrap_sem_wait (sem=0xf43014c8) at >> /localhome/zhengd/override_mcd/System/System_Services/SysServices_Linux/SystemLinux.cpp:1877 >> Contextual Information: I would like to trace all calls to sem_wait() in my >> application. I am simply using a wrapper sem_wait function where I can place >> tracepoint() calls. Here's what the sem_wait wrapper looks like: >> extern "C" int __real_sem_wait(sem_t*); >> extern "C" int __wrap_sem_wait(sem_t* sem) >> { >> tracepoint(mike, sem_wait_entry); >> int ret = __real_sem_wait(sem); >> tracepoint(mike, sem_wait_exit, ret); >> return ret; >> } >> Here is the TRACEPOINT_EVENT macro found in my tracepoint provider header >> file >> (which was generated using lttng-gen-tp command line utility): >> TRACEPOINT_EVENT(mike, >> sem_wait_entry, >> TP_ARGS(), >> TP_FIELDS() >> ) >> And I am statically linking by using an existing CPP file (file with the >> __wrap_sem_wait() function) to create probes. I would just like to know any >> possible reasons why this error may be happening given the above mentioned >> circumstances and what I may be able to try in order to fix this. > Which UST version do you use ? Make sure you upgrade to latest, > since we have fixed a similar segfault issue with probes compiled in > C++ not so long ago. > Thanks, > Mathieu >> Thanks, >> Dilong >> _______________________________________________ >> lttng-dev mailing list >> [email protected] >> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > -- > Mathieu Desnoyers > EfficiOS Inc. > http://www.efficios.com -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
_______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
