[PATCH 6/7] perf intel-pt: Fix missing 'instruction' events with 'q' option

From: Adrian Hunter
Date: Fri Dec 10 2021 - 11:23:37 EST


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")
Cc: stable@xxxxxxxxxxxxxxx # v5.15+
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index 75b504aed7f4..0e013c2d9eb4 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -2683,6 +2683,8 @@ static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);
/* 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);
@@ -2723,18 +2725,21 @@ static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, in
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;

--
2.25.1