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

Ian Rogers
2022-07-20T01:15:41Z

On Mon, Jul 11, 2022 at 2:33 AM Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> To aid debugging, add some more logging to intel_pt_walk_next_insn().
>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>

Acked-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

> ---
> 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
>