Commit 401136bb authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf intel-pt: Fix FUP packet state 



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: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarAndi 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 94fb1afb

tools/perf/util/intel-pt-decoder/intel-pt-decoder.c

+7 −14
Original line number Diff line number Diff line
@@ -1164,6 +1164,7 @@ static int intel_pt_walk_fup(struct intel_pt_decoder *decoder) 
			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 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder) 
			}

			if (decoder->set_fup_mwait)

				no_tip = true;

			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;

				decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;

			else

				decoder->pkt_state = INTEL_PT_STATE_FUP;

				return 0;

			}

			err = intel_pt_walk_fup(decoder);

			if (err != -EAGAIN)

				return err;

			if (no_tip) {

				no_tip = false;

				break;
@@ -2599,15 +2596,11 @@ const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder) 
			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);