perf probe: Ignore vmlinux buildid if offline kernel is given

Ignore the buildid of running kernel when both of --definition and
--vmlinux is given because that kernel should be off-line.

This also skips post-processing of kprobe event for relocating symbol
and checking blacklist, because it can not be done on off-line kernel.

E.g. without this fix perf shows an error as below
  ----
  $ perf probe --vmlinux=./vmlinux-arm --definition do_sys_open
  ./vmlinux-arm with build id 7a1f76dd56e9c4da707cd3d6333f50748141434b not found, continuing without symbols
  Failed to find symbol do_sys_open in kernel
    Error: Failed to add events.
  ----
with this fix, we can get the definition
  ----
  $ perf probe --vmlinux=./vmlinux-arm --definition do_sys_open
  p:probe/do_sys_open do_sys_open+0
  ----

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147214228193.23638.12581984840822162131.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 4a49cb8ce7ab..8a1e9e67614f 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -674,6 +674,10 @@ post_process_kernel_probe_trace_events(struct probe_trace_event *tevs,
 	char *tmp;
 	int i, skipped = 0;
 
+	/* Skip post process if the target is an offline kernel */
+	if (symbol_conf.ignore_vmlinux_buildid)
+		return 0;
+
 	reloc_sym = kernel_get_ref_reloc_sym();
 	if (!reloc_sym) {
 		pr_warning("Relocated base symbol is not found!\n");