perf script: Display off-cpu samples correctly

No PERF_SAMPLE_CALLCHAIN in sample_type, but 'perf script' needs to
display a callchain, have to specify manually.

Also, prefer displaying a callchain:

 gvfs-afc-volume    2267 [001] 3829232.955656: 1001115340 offcpu-time:
            77f05292603f __pselect+0xbf (/usr/lib/x86_64-linux-gnu/libc.so.6)
            77f052a1801c [unknown] (/usr/lib/x86_64-linux-gnu/libusbmuxd-2.0.so.6.0.0)
            77f052a18d45 [unknown] (/usr/lib/x86_64-linux-gnu/libusbmuxd-2.0.so.6.0.0)
            77f05289ca94 start_thread+0x384 (/usr/lib/x86_64-linux-gnu/libc.so.6)
            77f052929c3c clone3+0x2c (/usr/lib/x86_64-linux-gnu/libc.so.6)

to a raw binary BPF output:

  BPF output: 0000: dd 08 00 00 db 08 00 00  <DD>...<DB>...
	  0008: cc ce ab 3b 00 00 00 00  <CC>Ϋ;....
	  0010: 06 00 00 00 00 00 00 00  ........
	  0018: 00 fe ff ff ff ff ff ff  .<FE><FF><FF><FF><FF><FF><FF>
	  0020: 3f 60 92 52 f0 77 00 00  ?`.R<F0>w..
	  0028: 1c 80 a1 52 f0 77 00 00  ..<A1>R<F0>w..
	  0030: 45 8d a1 52 f0 77 00 00  E.<A1>R<F0>w..
	  0038: 94 ca 89 52 f0 77 00 00  .<CA>.R<F0>w..
	  0040: 3c 9c 92 52 f0 77 00 00  <..R<F0>w..
	  0048: 00 00 00 00 00 00 00 00  ........
	  0050: 00 00 00 00              ....

Reviewed-by: Ian Rogers <[email protected]>
Signed-off-by: Howard Chu <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Tested-by: Gautam Menghani <[email protected]>
Tested-by: Ian Rogers <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: Sberm

tools/perf/builtin-script.c

@@ -680,7 +680,7 @@ static int perf_session__check_output_opt(struct perf_session *session)
 
 		evlist__for_each_entry(session->evlist, evsel) {
 			not_pipe = true;
-			if (evsel__has_callchain(evsel)) {
+			if (evsel__has_callchain(evsel) || evsel__is_offcpu_event(evsel)) {
 				use_callchain = true;
 				break;
 			}
@@ -2295,7 +2295,7 @@ static void process_event(struct perf_script *script,
 	else if (PRINT_FIELD(BRSTACKOFF))
 		perf_sample__fprintf_brstackoff(sample, thread, evsel, fp);
 
-	if (evsel__is_bpf_output(evsel) && PRINT_FIELD(BPF_OUTPUT))
+	if (evsel__is_bpf_output(evsel) && !evsel__is_offcpu_event(evsel) && PRINT_FIELD(BPF_OUTPUT))
 		perf_sample__fprintf_bpf_output(sample, fp);
 	perf_sample__fprintf_insn(sample, evsel, attr, thread, machine, fp, al);