linux-kernel - [PATCH 29/35] perf intel-pt: Add some more logging to intel_pt_walk_next

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Message-Id: <20220711093218.10967-30-adrian.hunter@intel.com>
Date:   Mon, 11 Jul 2022 12:32:12 +0300
From:   Adrian Hunter <adrian.hunter@...el.com>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:     Jiri Olsa <jolsa@...hat.com>, Namhyung Kim <namhyung@...nel.org>,
        Ian Rogers <irogers@...gle.com>,
        Andi Kleen <ak@...ux.intel.com>, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Subject: [PATCH 29/35] perf intel-pt: Add some more logging to intel_pt_walk_next_insn()

To aid debugging, add some more logging to intel_pt_walk_next_insn().

Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
---
 tools/perf/util/intel-pt.c | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index 014f9f73cc49..a8798b5bb311 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -758,27 +758,38 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
 
 	if (nr) {
 		if ((!symbol_conf.guest_code && cpumode != PERF_RECORD_MISC_GUEST_KERNEL) ||
-		    intel_pt_get_guest(ptq))
+		    intel_pt_get_guest(ptq)) {
+			intel_pt_log("ERROR: no guest machine\n");
 			return -EINVAL;
+		}
 		machine = ptq->guest_machine;
 		thread = ptq->guest_thread;
 		if (!thread) {
-			if (cpumode != PERF_RECORD_MISC_GUEST_KERNEL)
+			if (cpumode != PERF_RECORD_MISC_GUEST_KERNEL) {
+				intel_pt_log("ERROR: no guest thread\n");
 				return -EINVAL;
+			}
 			thread = ptq->unknown_guest_thread;
 		}
 	} else {
 		thread = ptq->thread;
 		if (!thread) {
-			if (cpumode != PERF_RECORD_MISC_KERNEL)
+			if (cpumode != PERF_RECORD_MISC_KERNEL) {
+				intel_pt_log("ERROR: no thread\n");
 				return -EINVAL;
+			}
 			thread = ptq->pt->unknown_thread;
 		}
 	}
 
 	while (1) {
-		if (!thread__find_map(thread, cpumode, *ip, &al) || !al.map->dso)
+		if (!thread__find_map(thread, cpumode, *ip, &al) || !al.map->dso) {
+			if (al.map)
+				intel_pt_log("ERROR: thread has no dso for %#" PRIx64 "\n", *ip);
+			else
+				intel_pt_log("ERROR: thread has no map for %#" PRIx64 "\n", *ip);
 			return -EINVAL;
+		}
 
 		if (al.map->dso->data.status == DSO_DATA_STATUS_ERROR &&
 		    dso__data_status_seen(al.map->dso,
@@ -819,8 +830,12 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
 			len = dso__data_read_offset(al.map->dso, machine,
 						    offset, buf,
 						    INTEL_PT_INSN_BUF_SZ);
-			if (len <= 0)
+			if (len <= 0) {
+				intel_pt_log("ERROR: failed to read at %" PRIu64 " ", offset);
+				if (intel_pt_enable_logging)
+					dso__fprintf(al.map->dso, intel_pt_log_fp());
 				return -EINVAL;
+			}
 
 			if (intel_pt_get_insn(buf, len, x86_64, intel_pt_insn))
 				return -EINVAL;
-- 
2.25.1