[PATCH 3.16 069/148] perf probe: Fix to show inlined function callsite without entry_pc

[Ben Hutchings]

3.16.82-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

commit 18e21eb671dc87a4f0546ba505a89ea93598a634 upstream.

Fix 'perf probe --line' option to show inlined function callsite lines
even if the function DIE has only ranges.

Without this:

  # perf probe -L amd_put_event_constraints
  ...
      2  {
      3         if (amd_has_nb(cpuc) && amd_is_nb_event(&event->hw))
                        __amd_put_nb_event_constraints(cpuc, event);
      5  }

With this patch:

  # perf probe -L amd_put_event_constraints
  ...
      2  {
      3         if (amd_has_nb(cpuc) && amd_is_nb_event(&event->hw))
      4                 __amd_put_nb_event_constraints(cpuc, event);
      5  }

Committer testing:

Before:

  [root@quaco ~]# perf probe -L amd_put_event_constraints
  <amd_put_event_constraints@/usr/src/debug/kernel-5.2.fc30/linux-5.2.18-200.fc30.x86_64/arch/x86/events/amd/core.c:0>
        0  static void amd_put_event_constraints(struct cpu_hw_events *cpuc,
                                                struct perf_event *event)
        2  {
        3         if (amd_has_nb(cpuc) && amd_is_nb_event(&event->hw))
                          __amd_put_nb_event_constraints(cpuc, event);
        5  }

           PMU_FORMAT_ATTR(event, "config:0-7,32-35");
           PMU_FORMAT_ATTR(umask, "config:8-15"   );

  [root@quaco ~]#

After:

  [root@quaco ~]# perf probe -L amd_put_event_constraints
  <amd_put_event_constraints@/usr/src/debug/kernel-5.2.fc30/linux-5.2.18-200.fc30.x86_64/arch/x86/events/amd/core.c:0>
        0  static void amd_put_event_constraints(struct cpu_hw_events *cpuc,
                                                struct perf_event *event)
        2  {
        3         if (amd_has_nb(cpuc) && amd_is_nb_event(&event->hw))
        4                 __amd_put_nb_event_constraints(cpuc, event);
        5  }

           PMU_FORMAT_ATTR(event, "config:0-7,32-35");
           PMU_FORMAT_ATTR(umask, "config:8-15"   );

  [root@quaco ~]# perf probe amd_put_event_constraints:4
  Added new event:
    probe:amd_put_event_constraints (on amd_put_event_constraints:4)

  You can now use it in all perf tools, such as:

  	perf record -e probe:amd_put_event_constraints -aR sleep 1

  [root@quaco ~]#

  [root@quaco ~]# perf probe -l
    probe:amd_put_event_constraints (on amd_put_event_constraints:4@arch/x86/events/amd/core.c)
    probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask@kernel/cpu.c)
  [root@quaco ~]#

Using it:

  [root@quaco ~]# perf trace -e probe:*
  ^C[root@quaco ~]#

Ok, Intel system here... :-)

Fixes: 4cc9cec636e7 ("perf probe: Introduce lines walker interface")
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: http://lore.kernel.org/lkml/157199322107.8075.12659099000567865708.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 tools/perf/util/dwarf-aux.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -628,7 +628,7 @@ static int __die_walk_funclines_cb(Dwarf
 	if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
 		fname = die_get_call_file(in_die);
 		lineno = die_get_call_lineno(in_die);
-		if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
+		if (fname && lineno > 0 && die_entrypc(in_die, &addr) == 0) {
 			lw->retval = lw->callback(fname, lineno, addr, lw->data);
 			if (lw->retval != 0)
 				return DIE_FIND_CB_END;