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perf intel-pt: Fix state setting when receiving overflow (OVF) packet

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commit c79ee2b2160909889df67c8801352d3e69d43a1a upstream.

An overflow (OVF packet) is treated as an error because it represents a
loss of trace data, but there is no loss of synchronization, so the packet
state should be INTEL_PT_STATE_IN_SYNC not INTEL_PT_STATE_ERR_RESYNC.

To support that, some additional variables must be reset, and the FUP
packet that may follow OVF is treated as an FUP event.

Fixes: f4aa081949 ("perf tools: Add Intel PT decoder")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org # v5.15+
Link: https://lore.kernel.org/r/20211210162303.2288710-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
[Adrian: Backport to v5.10]
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Adrian Hunter
2021-12-13 17:45:45 +02:00
committed by Greg Kroah-Hartman
parent cbed09b44c
commit 02681dd178
1 changed files with 28 additions and 4 deletions
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30
tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
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@@ -1158,6 +1158,20 @@ static bool intel_pt_fup_event(struct intel_pt_decoder *decoder)
decoder->state.type |= INTEL_PT_BLK_ITEMS;
ret = true;
}
if (decoder->overflow) {
decoder->overflow = false;
if (!ret && !decoder->pge) {
if (decoder->hop) {
decoder->state.type = 0;
decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
}
decoder->pge = true;
decoder->state.type |= INTEL_PT_BRANCH | INTEL_PT_TRACE_BEGIN;
decoder->state.from_ip = 0;
decoder->state.to_ip = decoder->ip;
return true;
}
}
if (ret) {
decoder->state.from_ip = decoder->ip;
decoder->state.to_ip = 0;
@@ -1480,7 +1494,16 @@ static int intel_pt_overflow(struct intel_pt_decoder *decoder)
intel_pt_log("ERROR: Buffer overflow\n");
intel_pt_clear_tx_flags(decoder);
decoder->timestamp_insn_cnt = 0;
decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
decoder->state.from_ip = decoder->ip;
decoder->ip = 0;
decoder->pge = false;
decoder->set_fup_tx_flags = false;
decoder->set_fup_ptw = false;
decoder->set_fup_mwait = false;
decoder->set_fup_pwre = false;
decoder->set_fup_exstop = false;
decoder->set_fup_bep = false;
decoder->overflow = true;
return -EOVERFLOW;
}
@@ -2083,6 +2106,7 @@ next:
case INTEL_PT_TIP_PGE: {
decoder->pge = true;
decoder->overflow = false;
intel_pt_mtc_cyc_cnt_pge(decoder);
if (decoder->packet.count == 0) {
intel_pt_log_at("Skipping zero TIP.PGE",
@@ -2596,10 +2620,10 @@ static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
decoder->set_fup_pwre = false;
decoder->set_fup_exstop = false;
decoder->set_fup_bep = false;
decoder->overflow = false;
if (!decoder->branch_enable) {
decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
decoder->overflow = false;
decoder->state.type = 0; /* Do not have a sample */
return 0;
}
@@ -2614,7 +2638,6 @@ static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
else
decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
decoder->overflow = false;
decoder->state.from_ip = 0;
decoder->state.to_ip = decoder->ip;
@@ -2823,6 +2846,7 @@ const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
if (err) {
decoder->state.err = intel_pt_ext_err(err);
if (err != -EOVERFLOW)
decoder->state.from_ip = decoder->ip;
intel_pt_update_sample_time(decoder);
decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;