[PATCH 1/7] perf intel-pt: Fix some PGE usage

From: Adrian Hunter
Date: Fri Dec 10 2021 - 11:23:32 EST


Packet generation enable (PGE) refers to whether control flow (COFI)
packets are being produced. PGE may be false even when branch-tracing is
enabled, due to being out-of-context, or outside a filter address range.
Fix some missing PGE usage.

Fixes: 839598176b0554 ("perf intel-pt: Allow decoding with branch tracing disabled")
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 | 7 ++++---
1 file changed, 4 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 5f83937bf8f3..6f6f163161a9 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -2678,6 +2678,7 @@ static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, in
return HOP_IGNORE;

case INTEL_PT_TIP_PGD:
+ decoder->pge = false;
if (!decoder->packet.count) {
intel_pt_set_nr(decoder);
return HOP_IGNORE;
@@ -2707,7 +2708,7 @@ static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, in
intel_pt_set_ip(decoder);
if (intel_pt_fup_event(decoder))
return HOP_RETURN;
- if (!decoder->branch_enable)
+ if (!decoder->branch_enable || !decoder->pge)
*no_tip = true;
if (*no_tip) {
decoder->state.type = INTEL_PT_INSTRUCTION;
@@ -2897,7 +2898,7 @@ static bool intel_pt_psb_with_fup(struct intel_pt_decoder *decoder, int *err)
{
struct intel_pt_psb_info data = { .fup = false };

- if (!decoder->branch_enable || !decoder->pge)
+ if (!decoder->branch_enable)
return false;

intel_pt_pkt_lookahead(decoder, intel_pt_psb_lookahead_cb, &data);
@@ -2999,7 +3000,7 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
break;
}
intel_pt_set_last_ip(decoder);
- if (!decoder->branch_enable) {
+ if (!decoder->branch_enable || !decoder->pge) {
decoder->ip = decoder->last_ip;
if (intel_pt_fup_event(decoder))
return 0;
--
2.25.1