[PATCH 31/57] perf trace: Hide evsel->access further, simplify code

Arnaldo Carvalho de Melo
2019-10-21T13:40:25Z

From: Arnaldo Carvalho de Melo <acme@redhat.com>

Next step will be to have a 'struct evsel_trace' to allow for handling
the syscalls tracepoints via the strace-like code while reusing parts of
that code with the other tracepoints, where we don't have things like
the 'syscall_nr' or 'ret' ((raw_)?syscalls:sys_{enter,exit}(_SYSCALL)?)
args that we want to cache offsets and have been using evsel->priv for
that, while for the other tracepoints we'll have just an array of
'struct syscall_arg_fmt' (i.e. ->scnprint() for number->string and
->strtoul() string->number conversions and other state those functions
need).

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-fre21jbyoqxmmquxcho7oa0x@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-trace.c | 57 +++++++++++++++++++++-----------------
1 file changed, 31 insertions(+), 26 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index e0be1df555a2..1d2ed2823202 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -296,6 +296,15 @@ static inline struct syscall_tp *__evsel__syscall_tp(struct evsel *evsel)
return sc;
}

+static struct syscall_tp *evsel__syscall_tp(struct evsel *evsel)
+{
+ if (evsel->priv == NULL) {
+ evsel->priv = zalloc(sizeof(struct syscall_tp));
+ }
+
+ return __evsel__syscall_tp(evsel);
+}
+
/*
* Used with all the other tracepoints.
*/
@@ -306,6 +315,15 @@ static inline struct syscall_arg_fmt *__evsel__syscall_arg_fmt(struct evsel *evs
return fmt;
}

+static struct syscall_arg_fmt *evsel__syscall_arg_fmt(struct evsel *evsel)
+{
+ if (evsel->priv == NULL) {
+ evsel->priv = calloc(evsel->tp_format->format.nr_fields, sizeof(struct syscall_arg_fmt));
+ }
+
+ return __evsel__syscall_arg_fmt(evsel);
+}
+
static int perf_evsel__init_tp_uint_field(struct evsel *evsel,
struct tp_field *field,
const char *name)
@@ -346,41 +364,34 @@ static void evsel__delete_priv(struct evsel *evsel)

static int perf_evsel__init_syscall_tp(struct evsel *evsel)
{
- struct syscall_tp *sc = evsel->priv = malloc(sizeof(struct syscall_tp));
+ struct syscall_tp *sc = evsel__syscall_tp(evsel);

- if (evsel->priv != NULL) {
+ if (sc != NULL) {
if (perf_evsel__init_tp_uint_field(evsel, &sc->id, "__syscall_nr") &&
perf_evsel__init_tp_uint_field(evsel, &sc->id, "nr"))
- goto out_delete;
+ return -ENOENT;
return 0;
}

return -ENOMEM;
-out_delete:
- zfree(&evsel->priv);
- return -ENOENT;
}

static int perf_evsel__init_augmented_syscall_tp(struct evsel *evsel, struct evsel *tp)
{
- struct syscall_tp *sc = evsel->priv = malloc(sizeof(struct syscall_tp));
+ struct syscall_tp *sc = evsel__syscall_tp(evsel);

- if (evsel->priv != NULL) {
+ if (sc != NULL) {
struct tep_format_field *syscall_id = perf_evsel__field(tp, "id");
if (syscall_id == NULL)
syscall_id = perf_evsel__field(tp, "__syscall_nr");
- if (syscall_id == NULL)
- goto out_delete;
- if (__tp_field__init_uint(&sc->id, syscall_id->size, syscall_id->offset, evsel->needs_swap))
- goto out_delete;
+ if (syscall_id == NULL ||
+ __tp_field__init_uint(&sc->id, syscall_id->size, syscall_id->offset, evsel->needs_swap))
+ return -EINVAL;

return 0;
}

return -ENOMEM;
-out_delete:
- zfree(&evsel->priv);
- return -EINVAL;
}

static int perf_evsel__init_augmented_syscall_tp_args(struct evsel *evsel)
@@ -399,20 +410,15 @@ static int perf_evsel__init_augmented_syscall_tp_ret(struct evsel *evsel)

static int perf_evsel__init_raw_syscall_tp(struct evsel *evsel, void *handler)
{
- evsel->priv = malloc(sizeof(struct syscall_tp));
- if (evsel->priv != NULL) {
+ if (evsel__syscall_tp(evsel) != NULL) {
if (perf_evsel__init_sc_tp_uint_field(evsel, id))
- goto out_delete;
+ return -ENOENT;

evsel->handler = handler;
return 0;
}

return -ENOMEM;
-
-out_delete:
- zfree(&evsel->priv);
- return -ENOENT;
}

static struct evsel *perf_evsel__raw_syscall_newtp(const char *direction, void *handler)
@@ -1690,11 +1696,10 @@ static int trace__read_syscall_info(struct trace *trace, int id)

static int perf_evsel__init_tp_arg_scnprintf(struct evsel *evsel)
{
- int nr_args = evsel->tp_format->format.nr_fields;
+ struct syscall_arg_fmt *fmt = evsel__syscall_arg_fmt(evsel);

- evsel->priv = calloc(nr_args, sizeof(struct syscall_arg_fmt));
- if (evsel->priv != NULL) {
- syscall_arg_fmt__init_array(evsel->priv, evsel->tp_format->format.fields);
+ if (fmt != NULL) {
+ syscall_arg_fmt__init_array(fmt, evsel->tp_format->format.fields);
return 0;
}

--
2.21.0