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authorAdrian Hunter <adrian.hunter@intel.com>2017-05-26 11:17:07 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-27 15:10:05 -0700
commitc68f8e30d7be490fabfcb9c4201af0ef1691b1fa (patch)
tree05b400b249545fd6d4a76f0f6c5d44419764bcd5 /tools
parentd7cccb4b6cffd31c6fce4c980776ff94a6c0bd47 (diff)
perf intel-pt: Ensure never to set 'last_ip' when packet 'count' is zero
commit f952eaceb089b691eba7c4e13686e742a8f26bf5 upstream. Intel PT uses IP compression based on the last IP. For decoding purposes, 'last IP' is not updated when a branch target has been suppressed, which is indicated by IPBytes == 0. IPBytes is stored in the packet 'count', so ensure never to set 'last_ip' when packet 'count' is zero. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1495786658-18063-7-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/intel-pt-decoder/intel-pt-decoder.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index 62e2c2ad3f1d..72b9dc8135a2 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1470,7 +1470,8 @@ static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
case INTEL_PT_FUP:
decoder->pge = true;
- intel_pt_set_last_ip(decoder);
+ if (decoder->packet.count)
+ intel_pt_set_last_ip(decoder);
break;
case INTEL_PT_MODE_TSX:
@@ -1756,8 +1757,9 @@ next:
static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
{
- return decoder->have_last_ip || decoder->packet.count == 0 ||
- decoder->packet.count == 3 || decoder->packet.count == 6;
+ return decoder->packet.count &&
+ (decoder->have_last_ip || decoder->packet.count == 3 ||
+ decoder->packet.count == 6);
}
/* Walk PSB+ packets to get in sync. */