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    SubjectRe: [BUG] perf: intel_pt won't display kernel function
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    > On Apr 3, 2019, at 11:55 AM, Song Liu <songliubraving@fb.com> wrote:
    >
    >
    >
    >> On Apr 3, 2019, at 11:50 AM, Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> wrote:
    >>
    >> Em Wed, Apr 03, 2019 at 04:27:56PM +0000, Song Liu escreveu:
    >>>
    >>>
    >>>> On Apr 3, 2019, at 8:15 AM, Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> wrote:
    >>>>
    >>>> Em Wed, Apr 03, 2019 at 11:53:53AM -0300, Arnaldo Carvalho de Melo escreveu:
    >>>>> Em Wed, Apr 03, 2019 at 04:37:38PM +0200, Jiri Olsa escreveu:
    >>>>>> hi,
    >>>>>> perf script --call-trace stop working for me recently,
    >>>>>> and displays only user space functions
    >>>>>>
    >>>>>> I bisected that to:
    >>>>>> 7b612e291a5a perf tools: Synthesize PERF_RECORD_* for loaded BPF programs
    >>>>>>
    >>>>>> data from following comands will display user space functions only:
    >>>>>> # perf-with-kcore record pt -e intel_pt// -- ls
    >>>>>> # perf-with-kcore script pt --call-trace
    >>>>>>
    >>>>>> when I disable the bpf synthesizing (patch below), kernel functions are back
    >>>>>>
    >>>>>> I guess the new events mess up with intel_pt decoder somehow
    >>>>>
    >>>>> I.e. I'm adding the patch below to my perf/urgent branch.
    >>>>
    >>>> Song, that is what I have, can I have your Acked-by and please consider
    >>>> taking a look at the bug Jiri reported,
    >>>>
    >>>> Thanks,
    >>>>
    >>>> - Arnaldo
    >>>
    >>> Current logic with --no-bpf-event is to generate PERF_RECORD_KSYMBOL, but not
    >>> PERF_RECORD_BPF_EVENT:
    >>
    >> I see... The opts is done later, after querying the kernel for existing
    >> BPF programs so that at least the KSYMBOL ones can be generated. So I'll
    >> keep it as is, no need for this patch.
    >>
    >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__elixir.bootlin.com_linux_v5.1-2Drc3_source_tools_perf_util_bpf-2Devent.c-23L254&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=dR8692q0_uaizy0jkrBJQM5k2hfm4CiFxYT8KaysFrg&m=8ITYgIrqFBIy1uQFQPHrsX5kBX5RlmhwcknKYJa2eGs&s=MdB2zA9JstwC93qKEonsfTQeQYiw-yeOLbPxm3QMRo8&e=
    >>>
    >>> I will look into the intel_pt problem.
    >>
    >> Ok.
    >>
    >>> In the meanwhile, let's fix it for now.
    >>
    >> I'll wait a bit.
    >
    > I guess something like this might be a better fix? (Sorry for missing
    > commit message):
    >
    > diff --git i/tools/perf/util/map.c w/tools/perf/util/map.c
    > index e32628cd20a7..741430a35dca 100644
    > --- i/tools/perf/util/map.c
    > +++ w/tools/perf/util/map.c
    > @@ -261,6 +261,12 @@ bool __map__is_extra_kernel_map(const struct map *map)
    > return kmap && kmap->name[0];
    > }
    >
    > +bool __map__is_bpf_prog(const struct map *map)
    > +{
    > + const char *name = map->dso->short_name;
    > + return name && (strstr(name, "bpf_prog_") == name);
    > +}
    > +
    > bool map__has_symbols(const struct map *map)
    > {
    > return dso__has_symbols(map->dso);
    > diff --git i/tools/perf/util/map.h w/tools/perf/util/map.h
    > index 0e20749f2c55..01079f1f4375 100644
    > --- i/tools/perf/util/map.h
    > +++ w/tools/perf/util/map.h
    > @@ -159,10 +159,12 @@ int map__set_kallsyms_ref_reloc_sym(struct map *map, const char *symbol_name,
    >
    > bool __map__is_kernel(const struct map *map);
    > bool __map__is_extra_kernel_map(const struct map *map);
    > +bool __map__is_bpf_prog(const struct map *map);
    >
    > static inline bool __map__is_kmodule(const struct map *map)
    > {
    > - return !__map__is_kernel(map) && !__map__is_extra_kernel_map(map);
    > + return !__map__is_kernel(map) && !__map__is_extra_kernel_map(map) &&
    > + !__map__is_bpf_prog(map);
    > }
    >
    > bool map__has_symbols(const struct map *map);
    >
    > Thanks,
    > Song

    Actually, it should be something like this:

    diff --git i/tools/perf/util/map.c w/tools/perf/util/map.c
    index e32628cd20a7..31cd23612529 100644
    --- i/tools/perf/util/map.c
    +++ w/tools/perf/util/map.c
    @@ -261,6 +261,11 @@ bool __map__is_extra_kernel_map(const struct map *map)
    return kmap && kmap->name[0];
    }

    +bool __map__is_bpf_prog(const struct map *map)
    +{
    + return map->dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO;
    +}
    +
    bool map__has_symbols(const struct map *map)
    {
    return dso__has_symbols(map->dso);
    diff --git i/tools/perf/util/map.h w/tools/perf/util/map.h
    index 0e20749f2c55..01079f1f4375 100644
    --- i/tools/perf/util/map.h
    +++ w/tools/perf/util/map.h
    @@ -159,10 +159,12 @@ int map__set_kallsyms_ref_reloc_sym(struct map *map, const char *symbol_name,

    bool __map__is_kernel(const struct map *map);
    bool __map__is_extra_kernel_map(const struct map *map);
    +bool __map__is_bpf_prog(const struct map *map);

    static inline bool __map__is_kmodule(const struct map *map)
    {
    - return !__map__is_kernel(map) && !__map__is_extra_kernel_map(map);
    + return !__map__is_kernel(map) && !__map__is_extra_kernel_map(map) &&
    + !__map__is_bpf_prog(map);
    }

    bool map__has_symbols(const struct map *map);

    >
    >>
    >>> Acked-by: Song Liu <songliubraving@fb.com>
    >>>
    >>> Thanks,
    >>> Song
    >>>
    >>>
    >>>> commit 011318ccc2024ba03e96c32a06f74ca5d6ab5503
    >>>> Author: Arnaldo Carvalho de Melo <acme@redhat.com>
    >>>> Date: Wed Apr 3 12:05:15 2019 -0300
    >>>>
    >>>> perf record: Do not synthesize BPF records when --no-bpf-event is used
    >>>>
    >>>> By default we synthesize and ask the kernel for BPF events, having a
    >>>> --no-bpf-event option to disable that, which can be useful, for
    >>>> instance, if there are still bugs in that code, which seems to be the
    >>>> case as reported by Jiri Olsa in:
    >>>>
    >>>> "[BUG] perf: intel_pt won't display kernel function"
    >>>> https://lore.kernel.org/lkml/20190403143738.GB32001@krava
    >>>>
    >>>> So add the check for record_opts.no_bpf_event when considering
    >>>> synthesizing BPF events for pre-existing BPF programs in 'perf record'.
    >>>>
    >>>> The reported bug needs further analysis and is a separate matter.
    >>>>
    >>>> Cc: Adrian Hunter <adrian.hunter@intel.com>
    >>>> Cc: Alexei Starovoitov <ast@kernel.org>
    >>>> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
    >>>> Cc: Daniel Borkmann <daniel@iogearbox.net>
    >>>> Cc: Jiri Olsa <jolsa@kernel.org>
    >>>> Cc: Martin KaFai Lau <kafai@fb.com>
    >>>> Cc: Namhyung Kim <namhyung@kernel.org>
    >>>> Cc: Peter Zijlstra <peterz@infradead.org>
    >>>> Cc: Song Liu <songliubraving@fb.com>
    >>>> Cc: Yonghong Song <yhs@fb.com>
    >>>> Fixes: 7b612e291a5a ("perf tools: Synthesize PERF_RECORD_* for loaded BPF programs")
    >>>> Link: https://lore.kernel.org/lkml/20190403145353.GE32553@kernel.org
    >>>> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    >>>>
    >>>> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
    >>>> index 4e2d953d4bc5..17d772f192ad 100644
    >>>> --- a/tools/perf/builtin-record.c
    >>>> +++ b/tools/perf/builtin-record.c
    >>>> @@ -1114,10 +1114,11 @@ static int record__synthesize(struct record *rec, bool tail)
    >>>> return err;
    >>>> }
    >>>>
    >>>> - err = perf_event__synthesize_bpf_events(session, process_synthesized_event,
    >>>> - machine, opts);
    >>>> - if (err < 0)
    >>>> - pr_warning("Couldn't synthesize bpf events.\n");
    >>>> + if (!opts->no_bpf_event) {
    >>>> + err = perf_event__synthesize_bpf_events(session, process_synthesized_event, machine, opts);
    >>>> + if (err < 0)
    >>>> + pr_warning("Couldn't synthesize bpf events.\n");
    >>>> + }
    >>>>
    >>>> err = __machine__synthesize_threads(machine, tool, &opts->target, rec->evlist->threads,
    >>>> process_synthesized_event, opts->sample_address,
    >>
    >> --
    >>
    >> - Arnaldo

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