perf bpf: Rename bpf__foreach_tev() to bpf__foreach_event()

Following commit will allow BPF script attach to tracepoints.
bpf__foreach_tev() will iterate over all events, not only kprobes.
Rename it to bpf__foreach_event().

Since only group and event are used by caller, there's no need to pass
full 'struct probe_trace_event' to bpf_prog_iter_callback_t. Pass only
these two strings. After this patch bpf_prog_iter_callback_t natually
support tracepoints.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468406646-21642-5-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/bpf-loader.c

@@ -693,9 +693,9 @@ int bpf__load(struct bpf_object *obj)
 	return 0;
 }
 
-int bpf__foreach_tev(struct bpf_object *obj,
-		     bpf_prog_iter_callback_t func,
-		     void *arg)
+int bpf__foreach_event(struct bpf_object *obj,
+		       bpf_prog_iter_callback_t func,
+		       void *arg)
 {
 	struct bpf_program *prog;
 	int err;
@@ -728,7 +728,7 @@ int bpf__foreach_tev(struct bpf_object *obj,
 				return fd;
 			}
 
-			err = (*func)(tev, fd, arg);
+			err = (*func)(tev->group, tev->event, fd, arg);
 			if (err) {
 				pr_debug("bpf: call back failed, stop iterate\n");
 				return err;

tools/perf/util/bpf-loader.h

@@ -46,7 +46,7 @@ struct bpf_object;
 struct parse_events_term;
 #define PERF_BPF_PROBE_GROUP "perf_bpf_probe"
 
-typedef int (*bpf_prog_iter_callback_t)(struct probe_trace_event *tev,
+typedef int (*bpf_prog_iter_callback_t)(const char *group, const char *event,
 					int fd, void *arg);
 
 #ifdef HAVE_LIBBPF_SUPPORT
@@ -67,8 +67,8 @@ int bpf__strerror_probe(struct bpf_object *obj, int err,
 int bpf__load(struct bpf_object *obj);
 int bpf__strerror_load(struct bpf_object *obj, int err,
 		       char *buf, size_t size);
-int bpf__foreach_tev(struct bpf_object *obj,
-		     bpf_prog_iter_callback_t func, void *arg);
+int bpf__foreach_event(struct bpf_object *obj,
+		       bpf_prog_iter_callback_t func, void *arg);
 
 int bpf__config_obj(struct bpf_object *obj, struct parse_events_term *term,
 		    struct perf_evlist *evlist, int *error_pos);
@@ -107,9 +107,9 @@ static inline int bpf__unprobe(struct bpf_object *obj __maybe_unused) { return 0
 static inline int bpf__load(struct bpf_object *obj __maybe_unused) { return 0; }
 
 static inline int
-bpf__foreach_tev(struct bpf_object *obj __maybe_unused,
-		 bpf_prog_iter_callback_t func __maybe_unused,
-		 void *arg __maybe_unused)
+bpf__foreach_event(struct bpf_object *obj __maybe_unused,
+		   bpf_prog_iter_callback_t func __maybe_unused,
+		   void *arg __maybe_unused)
 {
 	return 0;
 }

tools/perf/util/parse-events.c

@@ -584,7 +584,7 @@ struct __add_bpf_event_param {
 	struct list_head *head_config;
 };
 
-static int add_bpf_event(struct probe_trace_event *tev, int fd,
+static int add_bpf_event(const char *group, const char *event, int fd,
 			 void *_param)
 {
 	LIST_HEAD(new_evsels);
@@ -595,27 +595,27 @@ static int add_bpf_event(struct probe_trace_event *tev, int fd,
 	int err;
 
 	pr_debug("add bpf event %s:%s and attach bpf program %d\n",
-		 tev->group, tev->event, fd);
+		 group, event, fd);
 
-	err = parse_events_add_tracepoint(&new_evsels, &evlist->idx, tev->group,
-					  tev->event, evlist->error,
+	err = parse_events_add_tracepoint(&new_evsels, &evlist->idx, group,
+					  event, evlist->error,
 					  param->head_config);
 	if (err) {
 		struct perf_evsel *evsel, *tmp;
 
 		pr_debug("Failed to add BPF event %s:%s\n",
-			 tev->group, tev->event);
+			 group, event);
 		list_for_each_entry_safe(evsel, tmp, &new_evsels, node) {
 			list_del(&evsel->node);
 			perf_evsel__delete(evsel);
 		}
 		return err;
 	}
-	pr_debug("adding %s:%s\n", tev->group, tev->event);
+	pr_debug("adding %s:%s\n", group, event);
 
 	list_for_each_entry(pos, &new_evsels, node) {
 		pr_debug("adding %s:%s to %p\n",
-			 tev->group, tev->event, pos);
+			 group, event, pos);
 		pos->bpf_fd = fd;
 	}
 	list_splice(&new_evsels, list);
@@ -661,7 +661,7 @@ int parse_events_load_bpf_obj(struct parse_events_evlist *data,
 		goto errout;
 	}
 
-	err = bpf__foreach_tev(obj, add_bpf_event, &param);
+	err = bpf__foreach_event(obj, add_bpf_event, &param);
 	if (err) {
 		snprintf(errbuf, sizeof(errbuf),
 			 "Attach events in BPF object failed");