[PATCH 5.10 22/33] perf intel-pt: Fix some PGE (packet generation enable/control flow packets) usage

From: Greg Kroah-Hartman
Date: Wed Dec 15 2021 - 12:26:40 EST


From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

commit 057ae59f5a1d924511beb1b09f395bdb316cfd03 upstream.

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: 7c1b16ba0e26e6 ("perf intel-pt: Add support for decoding FUP/TIP only")
Fixes: 839598176b0554 ("perf intel-pt: Allow decoding with branch tracing disabled")
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.15+
Link: https://lore.kernel.org/r/20211210162303.2288710-2-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
[Adrian: Backport to v5.10]
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1949,6 +1949,7 @@ static int intel_pt_hop_trace(struct int
return HOP_IGNORE;

case INTEL_PT_TIP_PGD:
+ decoder->pge = false;
if (!decoder->packet.count)
return HOP_IGNORE;
intel_pt_set_ip(decoder);
@@ -1972,7 +1973,7 @@ static int intel_pt_hop_trace(struct int
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;
@@ -2124,7 +2125,7 @@ next:
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;