[PATCH 5.7 091/204] perf intel-pt: Fix FUP packet state

Greg Kroah-Hartman
2020-08-20T09:40:02Z

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

commit 401136bb084fd021acd9f8c51b52fe0a25e326b2 upstream.

While walking code towards a FUP ip, the packet state is
INTEL_PT_STATE_FUP or INTEL_PT_STATE_FUP_NO_TIP. That was mishandled
resulting in the state becoming INTEL_PT_STATE_IN_SYNC prematurely. The
result was an occasional lost EXSTOP event.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200710151104.15137-2-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 | 21 ++++++--------------
1 file changed, 7 insertions(+), 14 deletions(-)

--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1164,6 +1164,7 @@ static int intel_pt_walk_fup(struct inte
return 0;
if (err == -EAGAIN ||
intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
+ decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
if (intel_pt_fup_event(decoder))
return 0;
return -EAGAIN;
@@ -1942,17 +1943,13 @@ next:
}
if (decoder->set_fup_mwait)
no_tip = true;
+ if (no_tip)
+ decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;
+ else
+ decoder->pkt_state = INTEL_PT_STATE_FUP;
err = intel_pt_walk_fup(decoder);
- if (err != -EAGAIN) {
- if (err)
- return err;
- if (no_tip)
- decoder->pkt_state =
- INTEL_PT_STATE_FUP_NO_TIP;
- else
- decoder->pkt_state = INTEL_PT_STATE_FUP;
- return 0;
- }
+ if (err != -EAGAIN)
+ return err;
if (no_tip) {
no_tip = false;
break;
@@ -2599,15 +2596,11 @@ const struct intel_pt_state *intel_pt_de
err = intel_pt_walk_tip(decoder);
break;
case INTEL_PT_STATE_FUP:
- decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
err = intel_pt_walk_fup(decoder);
if (err == -EAGAIN)
err = intel_pt_walk_fup_tip(decoder);
- else if (!err)
- decoder->pkt_state = INTEL_PT_STATE_FUP;
break;
case INTEL_PT_STATE_FUP_NO_TIP:
- decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
err = intel_pt_walk_fup(decoder);
if (err == -EAGAIN)
err = intel_pt_walk_trace(decoder);