This patch adds a bpf_fd field to 'struct evsel' then introduces method
to config it. In bpf-loader, a bpf__for_each_program() function is added.
Which calls the callback function for each eBPF program with their names
and file descriptors. In evlist.c, perf_evlist__add_bpf()
is added to add all bpf events into evlist. 'perf record' calls
perf_evlist__add_bpf().

Since bpf-loader.c will not built if libelf not found, an empty
bpf__for_each_program() is defined in bpf-loader.h to avoid compiling
error.
---
 tools/perf/builtin-record.c  |  6 ++++++
 tools/perf/util/bpf-loader.c | 39 +++++++++++++++++++++++++++++++++++++++
 tools/perf/util/bpf-loader.h | 16 ++++++++++++++++
 tools/perf/util/evlist.c     | 32 ++++++++++++++++++++++++++++++++
 tools/perf/util/evlist.h     |  1 +
 tools/perf/util/evsel.c      |  1 +
 tools/perf/util/evsel.h      |  1 +
 7 files changed, 96 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 4b52399..692cfe5 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -982,6 +982,12 @@ 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 f9a1ab9..5d23346 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -243,3 +243,42 @@ errout:
                bpf_object__unload(obj);
        return err;
 }
+
+int
+bpf__for_each_program(bpf_prog_iter_callback_t func,
+                     void *arg)
+{
+       struct bpf_object *obj, *tmp;
+       struct bpf_program *prog;
+       int err;
+
+       bpf_object__for_each(obj, tmp) {
+               bpf_object__for_each_program(prog, obj) {
+                       struct bpf_prog_priv *priv;
+                       char *group, *event;
+                       int fd;
+
+                       err = bpf_program__get_private(prog,
+                                                      (void **)&priv);
+                       if (err || !priv) {
+                               pr_err("bpf: failed to get private field\n");
+                               return -EINVAL;
+                       }
+                       err = bpf_program__get_fd(prog, &fd);
+                       if (err || fd < 0) {
+                               pr_err("bpf: failed to get file descriptor\n");
+                               return -EINVAL;
+                       }
+
+                       group = priv->pev->group;
+                       event = priv->pev->event;
+                       err = func(group, event, 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 fcc775d..4d5eec2 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -5,6 +5,8 @@
 #ifndef __BPF_LOADER_H
 #define __BPF_LOADER_H
 
+#include <linux/compiler.h> // for __maybe_unused
+
 #define PERF_BPF_PROBE_GROUP "perf_bpf_probe"
 
 int bpf__prepare_load(const char *filename);
@@ -13,4 +15,18 @@ int bpf__unprobe(void);
 int bpf__load(void);
 
 void bpf__clear(void);
+
+typedef int (*bpf_prog_iter_callback_t)(char *group, char *event,
+                                       int fd, void *arg);
+
+#ifdef HAVE_LIBELF_SUPPORT
+int bpf__for_each_program(bpf_prog_iter_callback_t func, void *arg);
+#else
+static inline int
+bpf__for_each_program(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 080be93..2b997d1 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 +195,37 @@ error:
        return -ENOMEM;
 }
 
+static int add_bpf_event(char *group, char *event, 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",
+                group, event, fd);
+       INIT_LIST_HEAD(&list);
+       idx = evlist->nr_entries;
+       err = parse_events_add_tracepoint(&list, &idx, group, event);
+       
+       if (err) {
+               pr_err("Failed to add BPF event %s:%s\n",
+                      group, event);
+               return err;
+       }
+       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__for_each_program(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 b5cce95..032f04d 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -68,6 +68,7 @@ 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 33e3fd8..04d60a7 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -205,6 +205,7 @@ 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 e486151..ff1f634 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -100,6 +100,7 @@ struct perf_evsel {
        int                     sample_read;
        struct perf_evsel       *leader;
        char                    *group_name;
+       int                     bpf_fd;
 };
 
 union u64_swap {
-- 
1.8.3.4

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