[PATCH 29/35] perf intel-pt: Add some more logging to intel_pt_walk_next_insn()

Adrian Hunter
2022-07-11T10:14:53Z

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

Signed-off-by: Adrian Hunter <adrian.hunter@intel.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