[PATCH 3/4] perf bpf: Clone bpf stdout events in multiple bpf scripts
From: Wang Nan
Date: Fri Apr 08 2016 - 11:11:20 EST
This patch allows cloning bpf-output event configuration among multiple
bpf scripts. If there exist a map named '__bpf_output__' and not configured
using 'map:__bpf_output__.event=', this patch clones the configuration of
another '__bpf_stdout__' map. For example, following command:
# perf trace --ev bpf-output/no-inherit,name=evt/ \
--ev ./test_bpf_trace.c/map:__bpf_stdout__.event=evt/ \
--ev ./test_bpf_trace2.c usleep 100000
equals to:
# perf trace --ev bpf-output/no-inherit,name=evt/ \
--ev ./test_bpf_trace.c/map:__bpf_stdout__.event=evt/ \
--ev ./test_bpf_trace2.c/map:__bpf_stdout__.event=evt/ \
usleep 100000
Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
---
tools/perf/builtin-record.c | 8 +++
tools/perf/builtin-trace.c | 10 ++++
tools/perf/util/bpf-loader.c | 124 +++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/bpf-loader.h | 19 +++++++
4 files changed, 161 insertions(+)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 410035c..e64bd1e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1276,6 +1276,14 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
if (err)
return err;
+ err = bpf__setup_stdout(rec->evlist);
+ if (err) {
+ bpf__strerror_setup_stdout(rec->evlist, err, errbuf, sizeof(errbuf));
+ pr_err("ERROR: Setup BPF stdout failed: %s\n",
+ errbuf);
+ return err;
+ }
+
err = -ENOMEM;
symbol__init(NULL);
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index fb8257f..9d47bba 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -3289,6 +3289,16 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
argc = parse_options_subcommand(argc, argv, trace_options, trace_subcommands,
trace_usage, PARSE_OPT_STOP_AT_NON_OPTION);
+ err = bpf__setup_stdout(trace.evlist);
+ if (err) {
+ char errbuf[BUFSIZ];
+
+ bpf__strerror_setup_stdout(trace.evlist, err, errbuf, sizeof(errbuf));
+ pr_err("ERROR: Setup BPF stdout failed: %s\n",
+ errbuf);
+ goto out;
+ }
+
if (validate_evlist(trace.evlist, &has_bpf_output)) {
pr_err("Only support tracepoint and bpf-output events!\n");
return -EINVAL;
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 0967ce6..a0d2802 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -842,6 +842,58 @@ bpf_map_op__new(struct parse_events_term *term)
return op;
}
+static struct bpf_map_op *
+bpf_map_op__clone(struct bpf_map_op *op)
+{
+ struct bpf_map_op *newop;
+
+ newop = memdup(op, sizeof(*op));
+ if (!newop) {
+ pr_debug("Failed to alloc bpf_map_op\n");
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&newop->list);
+ if (op->key_type == BPF_MAP_KEY_RANGES) {
+ size_t memsz = op->k.array.nr_ranges *
+ sizeof(op->k.array.ranges[0]);
+
+ newop->k.array.ranges = memdup(op->k.array.ranges, memsz);
+ if (!newop->k.array.ranges) {
+ pr_debug("Failed to alloc indices for map\n");
+ free(newop);
+ return NULL;
+ }
+ }
+
+ return newop;
+}
+
+static struct bpf_map_priv *
+bpf_map_priv__clone(struct bpf_map_priv *priv)
+{
+ struct bpf_map_priv *newpriv;
+ struct bpf_map_op *pos, *newop;
+
+ newpriv = zalloc(sizeof(*newpriv));
+ if (!newpriv) {
+ pr_debug("No enough memory to alloc map private\n");
+ return NULL;
+ }
+ INIT_LIST_HEAD(&newpriv->ops_list);
+
+ list_for_each_entry(pos, &priv->ops_list, list) {
+ newop = bpf_map_op__clone(pos);
+ if (!newop) {
+ bpf_map_priv__purge(newpriv);
+ return NULL;
+ }
+ list_add_tail(&newop->list, &newpriv->ops_list);
+ }
+
+ return newpriv;
+}
+
static int
bpf_map__add_op(struct bpf_map *map, struct bpf_map_op *op)
{
@@ -1417,6 +1469,70 @@ int bpf__apply_obj_config(void)
return 0;
}
+#define bpf__for_each_map(pos, obj, objtmp) \
+ bpf_object__for_each_safe(obj, objtmp) \
+ bpf_map__for_each(pos, obj)
+
+#define bpf__for_each_stdout_map(pos, obj, objtmp) \
+ bpf__for_each_map(pos, obj, objtmp) \
+ if (bpf_map__get_name(pos) && \
+ (strcmp("__bpf_stdout__", \
+ bpf_map__get_name(pos)) == 0))
+
+int bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused)
+{
+ struct bpf_map_priv *tmpl_priv = NULL;
+ struct bpf_object *obj, *tmp;
+ struct bpf_map *map;
+ int err;
+ bool need_init = false;
+
+ bpf__for_each_stdout_map(map, obj, tmp) {
+ struct bpf_map_priv *priv;
+
+ err = bpf_map__get_private(map, (void **)&priv);
+ if (err)
+ return -BPF_LOADER_ERRNO__INTERNAL;
+
+ /*
+ * No need to check map type: type should have been
+ * verified by kernel.
+ */
+ if (!need_init && !priv)
+ need_init = !priv;
+ if (!tmpl_priv && priv)
+ tmpl_priv = priv;
+ }
+
+ if (!need_init)
+ return 0;
+
+ if (!tmpl_priv)
+ return 0;
+
+ bpf__for_each_stdout_map(map, obj, tmp) {
+ struct bpf_map_priv *priv;
+
+ err = bpf_map__get_private(map, (void **)&priv);
+ if (err)
+ return -BPF_LOADER_ERRNO__INTERNAL;
+ if (priv)
+ continue;
+
+ priv = bpf_map_priv__clone(tmpl_priv);
+ if (!priv)
+ return -ENOMEM;
+
+ err = bpf_map__set_private(map, priv, bpf_map_priv__clear);
+ if (err) {
+ bpf_map_priv__clear(map, priv);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
#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)
@@ -1590,3 +1706,11 @@ int bpf__strerror_apply_obj_config(int err, char *buf, size_t size)
bpf__strerror_end(buf, size);
return 0;
}
+
+int bpf__strerror_setup_stdout(struct perf_evlist *evlist __maybe_unused,
+ int err, char *buf, size_t size)
+{
+ bpf__strerror_head(err, buf, size);
+ bpf__strerror_end(buf, size);
+ return 0;
+}
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index be43119..941e172 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -79,6 +79,11 @@ int bpf__strerror_config_obj(struct bpf_object *obj,
size_t size);
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__strerror_setup_stdout(struct perf_evlist *evlist, int err,
+ char *buf, size_t size);
+
#else
static inline struct bpf_object *
bpf__prepare_load(const char *filename __maybe_unused,
@@ -125,6 +130,12 @@ bpf__apply_obj_config(void)
}
static inline int
+bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused)
+{
+ return 0;
+}
+
+static inline int
__bpf_strerror(char *buf, size_t size)
{
if (!size)
@@ -177,5 +188,13 @@ bpf__strerror_apply_obj_config(int err __maybe_unused,
{
return __bpf_strerror(buf, size);
}
+
+static inline int
+bpf__strerror_setup_stdout(struct perf_evlist *evlist __maybe_unused,
+ int err __maybe_unused, char *buf,
+ size_t size)
+{
+ return __bpf_strerror(buf, size);
+}
#endif
#endif
--
1.8.3.4