This patch adds a bpf_fd field to 'struct evsel' then introduces method
to config it. In bpf-loader, a bpf__foreach_tev() function is added,
Which calls the callback function for each 'struct probe_trace_event'
events for each bpf program with their file descriptors. In evlist.c,
perf_evlist__add_bpf() is introduced to add all bpf events into evlist.
The event names are found from probe_trace_event structure.
'perf record' calls perf_evlist__add_bpf().

Since bpf-loader.c will not be built if libbpf is turned off, an empty
bpf__foreach_tev() is defined in bpf-loader.h to avoid compiling
error.

This patch iterates over 'struct probe_trace_event' instead of
'struct probe_trace_event' during the loop for further patches, which
will generate multiple instances form one BPF program and install then
onto different 'struct probe_trace_event'.

Signed-off-by: Wang Nan <wangn...@huawei.com>
---
 tools/perf/builtin-record.c  |  6 ++++++
 tools/perf/util/bpf-loader.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/bpf-loader.h | 13 +++++++++++++
 tools/perf/util/evlist.c     | 41 +++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/evlist.h     |  1 +
 tools/perf/util/evsel.c      |  1 +
 tools/perf/util/evsel.h      |  1 +
 7 files changed, 105 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 6d943a7..bd189b1 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1140,6 +1140,12 @@ int cmd_record(int argc, const char **argv, const char 
*prefix __maybe_unused)
                goto out_symbol_exit;
        }
 
+       err = perf_evlist__add_bpf(rec->evlist);
+       if (err < 0) {
+               pr_err("Failed to add events from BPF object(s)\n");
+               goto out_symbol_exit;
+       }
+
        symbol__init(NULL);
 
        if (symbol_conf.kptr_restrict)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index f68ba33..63077b9 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -260,3 +260,45 @@ errout:
                bpf_object__unload(obj);
        return err;
 }
+
+int bpf__foreach_tev(bpf_prog_iter_callback_t func, void *arg)
+{
+       struct bpf_object *obj, *tmp;
+       struct bpf_program *prog;
+       int err;
+
+       bpf_object__for_each_safe(obj, tmp) {
+               bpf_object__for_each_program(prog, obj) {
+                       struct probe_trace_event *tev;
+                       struct perf_probe_event *pev;
+                       struct bpf_prog_priv *priv;
+                       int i, fd;
+
+                       err = bpf_program__get_private(prog,
+                                                      (void **)&priv);
+                       if (err || !priv) {
+                               pr_err("bpf: failed to get private field\n");
+                               return -EINVAL;
+                       }
+
+                       pev = priv->pev;
+                       for (i = 0; i < pev->ntevs; i++) {
+                               tev = &pev->tevs[i];
+
+                               err = bpf_program__get_fd(prog, &fd);
+
+                               if (err || fd < 0) {
+                                       pr_err("bpf: failed to get file 
descriptor\n");
+                                       return -EINVAL;
+                               }
+                               err = func(tev, fd, arg);
+                               if (err) {
+                                       pr_err("bpf: call back failed, stop 
iterate\n");
+                                       return err;
+                               }
+                       }
+               }
+       }
+
+       return 0;
+}
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index ae0dc9b..ef9b3bb 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -6,10 +6,14 @@
 #define __BPF_LOADER_H
 
 #include <linux/compiler.h>
+#include "probe-event.h"
 #include "debug.h"
 
 #define PERF_BPF_PROBE_GROUP "perf_bpf_probe"
 
+typedef int (*bpf_prog_iter_callback_t)(struct probe_trace_event *tev,
+                                       int fd, void *arg);
+
 #ifdef HAVE_LIBBPF_SUPPORT
 int bpf__prepare_load(const char *filename, bool source);
 int bpf__probe(void);
@@ -17,6 +21,8 @@ int bpf__unprobe(void);
 int bpf__load(void);
 
 void bpf__clear(void);
+
+int bpf__foreach_tev(bpf_prog_iter_callback_t func, void *arg);
 #else
 static inline int bpf__prepare_load(const char *filename __maybe_unused,
                                    bool source __maybe_unused)
@@ -29,5 +35,12 @@ static inline int bpf__probe(void) { return 0; }
 static inline int bpf__unprobe(void) { return 0; }
 static inline int bpf__load(void) { return 0; }
 static inline void bpf__clear(void) { }
+
+static inline int
+bpf__foreach_tev(bpf_prog_iter_callback_t func __maybe_unused,
+                void *arg __maybe_unused)
+{
+       return 0;
+}
 #endif
 #endif
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index f7d9c77..5a01c7f 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -14,6 +14,7 @@
 #include "target.h"
 #include "evlist.h"
 #include "evsel.h"
+#include "bpf-loader.h"
 #include "debug.h"
 #include <unistd.h>
 
@@ -194,6 +195,46 @@ error:
        return -ENOMEM;
 }
 
+static int add_bpf_event(struct probe_trace_event *tev, int fd,
+                        void *arg)
+{
+       struct perf_evlist *evlist = arg;
+       struct perf_evsel *pos;
+       struct list_head list;
+       int err, idx, entries;
+
+       pr_debug("add bpf event %s:%s and attach bpf program %d\n",
+                       tev->group, tev->event, fd);
+       INIT_LIST_HEAD(&list);
+       idx = evlist->nr_entries;
+
+       pr_debug("adding %s:%s\n", tev->group, tev->event);
+       err = parse_events_add_tracepoint(&list, &idx, tev->group,
+                                         tev->event);
+       if (err) {
+               struct perf_evsel *evsel, *tmp;
+
+               pr_err("Failed to add BPF event %s:%s\n",
+                               tev->group, tev->event);
+               list_for_each_entry_safe(evsel, tmp, &list, node) {
+                       list_del(&evsel->node);
+                       perf_evsel__delete(evsel);
+               }
+               return -EINVAL;
+       }
+
+       list_for_each_entry(pos, &list, node)
+               pos->bpf_fd = fd;
+       entries = idx - evlist->nr_entries;
+       perf_evlist__splice_list_tail(evlist, &list, entries);
+       return 0;
+}
+
+int perf_evlist__add_bpf(struct perf_evlist *evlist)
+{
+       return bpf__foreach_tev(add_bpf_event, evlist);
+}
+
 static int perf_evlist__add_attrs(struct perf_evlist *evlist,
                                  struct perf_event_attr *attrs, size_t 
nr_attrs)
 {
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 037633c..4e3b6b0 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -72,6 +72,7 @@ void perf_evlist__delete(struct perf_evlist *evlist);
 
 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry);
 int perf_evlist__add_default(struct perf_evlist *evlist);
+int perf_evlist__add_bpf(struct perf_evlist *evlist);
 int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
                                     struct perf_event_attr *attrs, size_t 
nr_attrs);
 
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 83c0803..fe80047 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -206,6 +206,7 @@ void perf_evsel__init(struct perf_evsel *evsel,
        evsel->leader      = evsel;
        evsel->unit        = "";
        evsel->scale       = 1.0;
+       evsel->bpf_fd      = -1;
        INIT_LIST_HEAD(&evsel->node);
        perf_evsel__object.init(evsel);
        evsel->sample_size = __perf_evsel__sample_size(attr->sample_type);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index fe9f327..4bcd629 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -86,6 +86,7 @@ struct perf_evsel {
        unsigned long           *per_pkg_mask;
        struct perf_evsel       *leader;
        char                    *group_name;
+       int                     bpf_fd;
 };
 
 union u64_swap {
-- 
1.8.3.4

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