[PATCH 36/44] perf bpf: Generalize bpf__setup_stdout()

From: Arnaldo Carvalho de Melo
Date: Thu Aug 09 2018 - 11:01:32 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

We will use it to set up other bpf-output events, for instance to
generate augmented syscall entry tracepoints with pointer contents.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-4r7kw0nsyi4vyz6xm1tzx6a3@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/bpf-loader.c | 26 +++++++++++++++++---------
tools/perf/util/bpf-loader.h | 7 +++++++
2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index e864a7e0ff12..95a27bb6f1a1 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -1535,10 +1535,7 @@ int bpf__apply_obj_config(void)
(strcmp(name, \
bpf_map__name(pos)) == 0))

-#define bpf__for_each_stdout_map(pos, obj, objtmp) \
- bpf__for_each_map_named(pos, obj, objtmp, "__bpf_stdout__")
-
-int bpf__setup_stdout(struct perf_evlist *evlist)
+int bpf__setup_output_event(struct perf_evlist *evlist, const char *name)
{
struct bpf_map_priv *tmpl_priv = NULL;
struct bpf_object *obj, *tmp;
@@ -1547,7 +1544,7 @@ int bpf__setup_stdout(struct perf_evlist *evlist)
int err;
bool need_init = false;

- bpf__for_each_stdout_map(map, obj, tmp) {
+ bpf__for_each_map_named(map, obj, tmp, name) {
struct bpf_map_priv *priv = bpf_map__priv(map);

if (IS_ERR(priv))
@@ -1567,17 +1564,23 @@ int bpf__setup_stdout(struct perf_evlist *evlist)
return 0;

if (!tmpl_priv) {
- err = parse_events(evlist, "bpf-output/no-inherit=1,name=__bpf_stdout__/",
- NULL);
+ char *event_definition = NULL;
+
+ if (asprintf(&event_definition, "bpf-output/no-inherit=1,name=%s/", name) < 0)
+ return -ENOMEM;
+
+ err = parse_events(evlist, event_definition, NULL);
+ free(event_definition);
+
if (err) {
- pr_debug("ERROR: failed to create bpf-output event\n");
+ pr_debug("ERROR: failed to create the \"%s\" bpf-output event\n", name);
return -err;
}

evsel = perf_evlist__last(evlist);
}

- bpf__for_each_stdout_map(map, obj, tmp) {
+ bpf__for_each_map_named(map, obj, tmp, name) {
struct bpf_map_priv *priv = bpf_map__priv(map);

if (IS_ERR(priv))
@@ -1609,6 +1612,11 @@ int bpf__setup_stdout(struct perf_evlist *evlist)
return 0;
}

+int bpf__setup_stdout(struct perf_evlist *evlist)
+{
+ return bpf__setup_output_event(evlist, "__bpf_stdout__");
+}
+
#define ERRNO_OFFSET(e) ((e) - __BPF_LOADER_ERRNO__START)
#define ERRCODE_OFFSET(c) ERRNO_OFFSET(BPF_LOADER_ERRNO__##c)
#define NR_ERRNO (__BPF_LOADER_ERRNO__END - __BPF_LOADER_ERRNO__START)
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index 5d3aefd6fae7..6be0eec043c6 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -82,6 +82,7 @@ int bpf__apply_obj_config(void);
int bpf__strerror_apply_obj_config(int err, char *buf, size_t size);

int bpf__setup_stdout(struct perf_evlist *evlist);
+int bpf__setup_output_event(struct perf_evlist *evlist, const char *name);
int bpf__strerror_setup_stdout(struct perf_evlist *evlist, int err,
char *buf, size_t size);

@@ -138,6 +139,12 @@ bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused)
return 0;
}

+static inline int
+bpf__setup_output_event(struct perf_evlist *evlist __maybe_unused, const char *name __maybe_unused)
+{
+ return 0;
+}
+
static inline int
__bpf_strerror(char *buf, size_t size)
{
--
2.14.4