[RFC PATCH v4 28/29] perf tools: Add bpf_fd field to evsel and config it
From: Wang Nan
Date: Wed May 27 2015 - 01:22:06 EST
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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