[PATCH 4.9 024/125] perf intel-pt: Use FUP always when scanning for an IP

From: Greg Kroah-Hartman
Date: Tue Jul 25 2017 - 15:21:14 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

commit 622b7a47b843c78626f40c1d1aeef8483383fba2 upstream.

The decoder will try to use branch packets to find an IP to start decoding
or to recover from errors. Currently the FUP packet is used only in the
case of an overflow, however there is no reason for that to be a special
case. So just use FUP always when scanning for an IP.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1495786658-18063-8-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1880,14 +1880,10 @@ static int intel_pt_walk_to_ip(struct in
break;

case INTEL_PT_FUP:
- if (decoder->overflow) {
- if (intel_pt_have_ip(decoder))
- intel_pt_set_ip(decoder);
- if (decoder->ip)
- return 0;
- }
- if (decoder->packet.count && decoder->have_last_ip)
- intel_pt_set_last_ip(decoder);
+ if (intel_pt_have_ip(decoder))
+ intel_pt_set_ip(decoder);
+ if (decoder->ip)
+ return 0;
break;

case INTEL_PT_MTC: