perf annotate: Add basic support for bpf_image

Add the DSO_BINARY_TYPE__BPF_IMAGE dso binary type to recognize BPF
images that carry trampoline or dispatcher.

Upcoming patches will add support to read the image data, store it
within the BPF feature in perf.data and display it for annotation
purposes.

Currently we only display following message:

  # ./perf annotate bpf_trampoline_24456 --stdio
   Percent |      Source code & Disassembly of . for cycles (504  ...
  --------------------------------------------------------------- ...
           :       to be implemented

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@redhat.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200312195610.346362-16-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 06aa4e4db63d..09845eae9c03 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -736,6 +736,12 @@ int machine__process_switch_event(struct machine *machine __maybe_unused,
 	return 0;
 }
 
+static int is_bpf_image(const char *name)
+{
+	return strncmp(name, "bpf_trampoline_", sizeof("bpf_trampoline_") - 1) ||
+	       strncmp(name, "bpf_dispatcher_", sizeof("bpf_dispatcher_") - 1);
+}
+
 static int machine__process_ksymbol_register(struct machine *machine,
 					     union perf_event *event,
 					     struct perf_sample *sample __maybe_unused)
@@ -760,6 +766,11 @@ static int machine__process_ksymbol_register(struct machine *machine,
 		map->end = map->start + event->ksymbol.len;
 		maps__insert(&machine->kmaps, map);
 		dso__set_loaded(dso);
+
+		if (is_bpf_image(event->ksymbol.name)) {
+			dso->binary_type = DSO_BINARY_TYPE__BPF_IMAGE;
+			dso__set_long_name(dso, "", false);
+		}
 	}
 
 	sym = symbol__new(map->map_ip(map, map->start),