* Rui Han ([email protected]) wrote: > Hi, > > I try to modified the lttng2.0 source code for my research. For example, I > try to log the "comm" for the write system call, I add the following filed > in the file x86-64-syscalls-3.0.4_pointers.h located at the path > lttng-modules-2.0.3/instrumentation/syscalls/headers. I modify the > TRACE_EVENTS() macro from the original one: > > #ifndef OVERRIDE_64_sys_write > SC_TRACE_EVENT(sys_write, > TP_PROTO(unsigned int fd, const char * buf, size_t count), > TP_ARGS(fd, buf, count), > TP_STRUCT__entry(__field(unsigned int, fd) __field_hex(const char *, buf) > __field(size_t, count)), > TP_fast_assign(tp_assign(fd, fd) tp_assign(buf, buf) tp_assign(count, > count)), > TP_printk() > ) > #endif > > to the following one: > > #ifndef OVERRIDE_64_sys_write > SC_TRACE_EVENT(sys_write, > TP_PROTO(unsigned int fd, const char * buf, size_t count, struct > task_struct *p), > TP_ARGS(fd, buf, count, p), > TP_STRUCT__entry( __field(unsigned int, fd) __field_hex(const char *, > buf) __field(size_t, > count) __array_text(char, comm, TASK_COMM_LEN)), > TP_fast_assign( tp_assign(fd, fd) tp_assign(buf, buf) tp_assign(count, > 2064) tp_memcpy(comm, > p->comm, TASK_COMM_LEN)), > TP_printk() > ) > #endif > > I add one argument *p and one filed "comm" for the macro. It was able to > be compiled, however, after reload the lttng modules, It will show the > following error messages when I start lttng. > > PERROR: ioctl start session: No buffer space available [in > kernel_start_session() at kernel.c:397] > Error: Starting kernel trace failed
I don't see how modifying the system call tracing macro would trigger this error at start. Try restarting lttng-sessiond. Try unloading the lttng modules, and, maybe, as last resort, rebooting your system. Thanks, Mathieu > > It won't work. Please help me out with this. My next step is try to add > extra fields in the sys_connect macros to enable the logging of the > connected IP/port from the socket. Is this method right? what are other > possible solutions in order to logging the details of the socket > information? > > Thank you very much. > > Regards, > Rui -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
