[tip: perf/core] perf probe: Fix to probe an inline function which has no entry pc

[tip-bot2 for Masami Hiramatsu]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     eb6933b29d20bf2c3053883d409a53f462c1a3ac
Gitweb:        https://git.kernel.org/tip/eb6933b29d20bf2c3053883d409a53f462c1a3ac
Author:        Masami Hiramatsu <mhiramat@xxxxxxxxxx>
AuthorDate:    Fri, 25 Oct 2019 17:46:43 +09:00
Committer:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Wed, 06 Nov 2019 15:43:06 -03:00

perf probe: Fix to probe an inline function which has no entry pc

Fix perf probe to probe an inlne function which has no entry pc
or low pc but only has ranges attribute.

This seems very rare case, but I could find a few examples, as
same as probe_point_search_cb(), use die_entrypc() to get the
entry address in probe_point_inline_cb() too.

Without this patch:

  # perf probe -D __amd_put_nb_event_constraints
  Failed to get entry address of __amd_put_nb_event_constraints.
  Probe point '__amd_put_nb_event_constraints' not found.
    Error: Failed to add events.

With this patch:

  # perf probe -D __amd_put_nb_event_constraints
  p:probe/__amd_put_nb_event_constraints amd_put_event_constraints+43

Committer testing:

Before:

  [root@quaco ~]# perf probe -D __amd_put_nb_event_constraints
  Failed to get entry address of __amd_put_nb_event_constraints.
  Probe point '__amd_put_nb_event_constraints' not found.
    Error: Failed to add events.
  [root@quaco ~]#

After:

  [root@quaco ~]# perf probe -D __amd_put_nb_event_constraints
  p:probe/__amd_put_nb_event_constraints _text+33789
  [root@quaco ~]#

Fixes: 4ea42b181434 ("perf: Add perf probe subcommand, a kprobe-event setup helper")
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/157199320336.8075.16189530425277588587.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/probe-finder.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 71633f5..2fa932b 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -930,7 +930,7 @@ static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 		ret = find_probe_point_lazy(in_die, pf);
 	else {
 		/* Get probe address */
-		if (dwarf_entrypc(in_die, &addr) != 0) {
+		if (die_entrypc(in_die, &addr) != 0) {
 			pr_warning("Failed to get entry address of %s.\n",
 				   dwarf_diename(in_die));
 			return -ENOENT;