Em Thu, Jan 23, 2014 at 02:29:55AM +0000, Masami Hiramatsu escreveu: > Since several local symbols can have same name (e.g. t_show), > we need to use the actual address instead of symbol name for > those points. Note that this works only with debuginfo. > > E.g. without this change; > ----
Please use spaces after dashed lines, this is even as (or more) important as prefixing # lines, as this makes everything after the --- line and the patch itself to be ignored. I'm fixing this up this time, please add the spaces next time, - Arnaldo > # ./perf probe -a t_show \$vars > Added new events: > probe:t_show (on t_show with $vars) > probe:t_show_1 (on t_show with $vars) > probe:t_show_2 (on t_show with $vars) > probe:t_show_3 (on t_show with $vars) > > You can now use it in all perf tools, such as: > > perf record -e probe:t_show_3 -aR sleep 1 > ---- > OK, we have 4 different t_show()s. All functions have > different arguments as below; > ---- > # cat /sys/kernel/debug/tracing/kprobe_events > p:probe/t_show t_show m=%di:u64 v=%si:u64 > p:probe/t_show_1 t_show m=%di:u64 v=%si:u64 t=%si:u64 > p:probe/t_show_2 t_show m=%di:u64 v=%si:u64 fmt=%si:u64 > p:probe/t_show_3 t_show m=%di:u64 v=%si:u64 file=%si:u64 > ---- > However, all of them have been put on the *same* address. > ---- > # cat /sys/kernel/debug/kprobes/list > ffffffff810d9720 k t_show+0x0 [DISABLED] > ffffffff810d9720 k t_show+0x0 [DISABLED] > ffffffff810d9720 k t_show+0x0 [DISABLED] > ffffffff810d9720 k t_show+0x0 [DISABLED] > ---- > > With this change; > ---- > # ./perf probe -a t_show \$vars > Added new events: > probe:t_show (on t_show with $vars) > probe:t_show_1 (on t_show with $vars) > probe:t_show_2 (on t_show with $vars) > probe:t_show_3 (on t_show with $vars) > > You can now use it in all perf tools, such as: > > perf record -e probe:t_show_3 -aR sleep 1 > > # cat /sys/kernel/debug/tracing/kprobe_events > p:probe/t_show 0xffffffff810d9720 m=%di:u64 v=%si:u64 > p:probe/t_show_1 0xffffffff810e2e40 m=%di:u64 v=%si:u64 t=%si:u64 > p:probe/t_show_2 0xffffffff810ece30 m=%di:u64 v=%si:u64 fmt=%si:u64 > p:probe/t_show_3 0xffffffff810f4ad0 m=%di:u64 v=%si:u64 file=%si:u64 > > # cat /sys/kernel/debug/kprobes/list > ffffffff810e2e40 k t_show+0x0 [DISABLED] > ffffffff810ece30 k t_show+0x0 [DISABLED] > ffffffff810f4ad0 k t_show+0x0 [DISABLED] > ffffffff810d9720 k t_show+0x0 [DISABLED] > ---- > This time, each event is put in different address > correctly. > > Note that currently this doesn't support address-based > probe on modules (thus the probes on modules are symbol > based), since it requires relative address probe syntax > for kprobe-tracer, and it doesn't implemented yet. > > One more note, this allows us to put events on correct > address, but --list option should be updated to show > correct corresponding source code. > > Signed-off-by: Masami Hiramatsu <[email protected]> > --- > tools/perf/util/probe-event.c | 23 +++++++++++++++-------- > 1 file changed, 15 insertions(+), 8 deletions(-) > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index 2fb4486..92ab688 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -1529,20 +1529,27 @@ char *synthesize_probe_trace_command(struct > probe_trace_event *tev) > if (buf == NULL) > return NULL; > > - if (tev->uprobes) > - len = e_snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s:%s", > - tp->retprobe ? 'r' : 'p', > - tev->group, tev->event, > + len = e_snprintf(buf, MAX_CMDLEN, "%c:%s/%s ", tp->retprobe ? 'r' : 'p', > + tev->group, tev->event); > + if (len <= 0) > + goto error; > + > + /* Use the real address, except for kernel modules */ > + if (tp->address && !(tp->module && !tev->uprobes)) > + ret = e_snprintf(buf + len, MAX_CMDLEN, "%s%s0x%lx", > + tp->module ?: "", tp->module ? ":" : "", > + tp->address); > + else if (tev->uprobes) > + ret = e_snprintf(buf + len, MAX_CMDLEN, "%s:%s", > tp->module, tp->symbol); > else > - len = e_snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s%s%s+%lu", > - tp->retprobe ? 'r' : 'p', > - tev->group, tev->event, > + ret = e_snprintf(buf + len, MAX_CMDLEN, "%s%s%s+%lu", > tp->module ?: "", tp->module ? ":" : "", > tp->symbol, tp->offset); > > - if (len <= 0) > + if (ret <= 0) > goto error; > + len += ret; > > for (i = 0; i < tev->nargs; i++) { > ret = synthesize_probe_trace_arg(&tev->args[i], buf + len, > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
