[PATCH 5.15 081/171] perf intel-pt: Fix missing instruction events with q option

Greg Kroah-Hartman
2021-12-13T10:21:30Z

From: Adrian Hunter <adrian.hunter@intel.com>

commit a882cc94971093e146ffa1163b140ad956236754 upstream.

FUP packets contain IP information, which makes them also an 'instruction'
event in 'hop' mode i.e. the itrace 'q' option. That wasn't happening, so
restructure the logic so that FUP events are added along with appropriate
'instruction' and 'branch' events.

Fixes: 7c1b16ba0e26e6 ("perf intel-pt: Add support for decoding FUP/TIP only")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org # v5.15+
Link: https://lore.kernel.org/r/20211210162303.2288710-7-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -2682,6 +2682,8 @@ static int intel_pt_scan_for_psb(struct
/* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */
static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err)
{
+ *err = 0;
+
/* Leap from PSB to PSB, getting ip from FUP within PSB+ */
if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
*err = intel_pt_scan_for_psb(decoder);
@@ -2722,18 +2724,21 @@ static int intel_pt_hop_trace(struct int
if (!decoder->packet.count)
return HOP_IGNORE;
intel_pt_set_ip(decoder);
- if (intel_pt_fup_event(decoder))
- return HOP_RETURN;
+ if (decoder->set_fup_mwait || decoder->set_fup_pwre)
+ *no_tip = true;
if (!decoder->branch_enable || !decoder->pge)
*no_tip = true;
if (*no_tip) {
decoder->state.type = INTEL_PT_INSTRUCTION;
decoder->state.from_ip = decoder->ip;
decoder->state.to_ip = 0;
+ intel_pt_fup_event(decoder);
return HOP_RETURN;
}
+ intel_pt_fup_event(decoder);
+ decoder->state.type |= INTEL_PT_INSTRUCTION | INTEL_PT_BRANCH;
*err = intel_pt_walk_fup_tip(decoder);
- if (!*err)
+ if (!*err && decoder->state.to_ip)
decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
return HOP_RETURN;