releases/4.4.129/perf-intel-pt-fix-error-recovery-from-missing-tip-packet.patch

   1 From 1c196a6c771c47a2faa63d38d913e03284f73a16 Mon Sep 17 00:00:00 2001
   2 From: Adrian Hunter <adrian.hunter@intel.com>
   3 Date: Wed, 7 Mar 2018 16:02:23 +0200
   4 Subject: perf intel-pt: Fix error recovery from missing TIP packet
   5
   6 From: Adrian Hunter <adrian.hunter@intel.com>
   7
   8 commit 1c196a6c771c47a2faa63d38d913e03284f73a16 upstream.
   9
  10 When a TIP packet is expected but there is a different packet, it is an
  11 error. However the unexpected packet might be something important like a
  12 TSC packet, so after the error, it is necessary to continue from there,
  13 rather than the next packet. That is achieved by setting pkt_step to
  14 zero.
  15
  16 Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
  17 Cc: Jiri Olsa <jolsa@redhat.com>
  18 Cc: stable@vger.kernel.org
  19 Link: http://lkml.kernel.org/r/1520431349-30689-4-git-send-email-adrian.hunter@intel.com
  20 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  tools/perf/util/intel-pt-decoder/intel-pt-decoder.c |    1 +
  25  1 file changed, 1 insertion(+)
  26
  27 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
  28 +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
  29 @@ -1492,6 +1492,7 @@ static int intel_pt_walk_fup_tip(struct
  30                 case INTEL_PT_PSBEND:
  31                         intel_pt_log("ERROR: Missing TIP after FUP\n");
  32                         decoder->pkt_state = INTEL_PT_STATE_ERR3;
  33 +                       decoder->pkt_step = 0;
  34                         return -ENOENT;
  35
  36                 case INTEL_PT_OVF: