* tarek slaymia ([email protected]) wrote: > Hi, > > can we retrieve kernel data structures addresses or contents using LTTng ?
With "--probe", not yet. With static tracepoints, yes, but the instrumentation needs to be either already in or added to the kernel code. Thanks, Mathieu > > regards. > > > 2013/6/23 Mathieu Desnoyers <[email protected]> > > > * Jessica Foest ([email protected]) wrote: > > > Hi, > > > i tried to apply kprobe to a system call , so i used probe and function > > > option : > > > > > > lttng enable-event aname -k --probe sys_open+0x0 > > > this command returns ip value > > > > > > lttng enable-event aname -k --function sys_open > > > this command returns ip and parent_ip values . > > > > > > what does these values ip and parent_ip means ? > > > > ip: instruction pointer of the function, > > parent_ip: instruction pointer of the caller. > > > > > > > > I try to apply probe and function options to some kernel symbols like > > > initialized date (like xen_vcpu_info symbol), read only data (like > > > linux_prob_banner symbol) and code (like reserve_ebda_region symbol) it > > > displays to me : Enable kernel event failed ,warning some command went(s) > > > wrong. > > > Did i make a mistake or it's a limitation in LTTng ? > > > > It's kprobes: you can only add breakpoints to code, not data. > > > > Thanks, > > > > Mathieu > > > > > regards. > > > > > _______________________________________________ > > > lttng-dev mailing list > > > [email protected] > > > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > > > > > > -- > > Mathieu Desnoyers > > EfficiOS Inc. > > http://www.efficios.com > > > > _______________________________________________ > > lttng-dev mailing list > > [email protected] > > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
