Commit d7888573 authored by Wang Nan's avatar Wang Nan Committed by Arnaldo Carvalho de Melo
Browse files

perf bpf: Clone bpf stdout events in multiple bpf scripts 



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: default avatarWang Nan <wangnan0@huawei.com>
Suggested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1460128045-97310-4-git-send-email-wangnan0@huawei.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent f9383452

tools/perf/builtin-record.c

+8 −0
Original line number Diff line number Diff line
@@ -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);

tools/perf/builtin-trace.c

+7 −0
Original line number Diff line number Diff line
@@ -3273,6 +3273,13 @@ 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) {

		bpf__strerror_setup_stdout(trace.evlist, err, bf, sizeof(bf));

		pr_err("ERROR: Setup BPF stdout failed: %s\n", bf);

		goto out;

	}



	if (trace.trace_pgfaults) {

		trace.opts.sample_address = true;

		trace.opts.sample_time = true;

tools/perf/util/bpf-loader.c

+124 −0
Original line number Diff line number Diff line
@@ -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;

}

tools/perf/util/bpf-loader.h

+19 −0
Original line number Diff line number Diff line
@@ -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,
@@ -124,6 +129,12 @@ bpf__apply_obj_config(void) 
	return 0;

}



static inline int

bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused)

{

	return 0;

}



static inline int

__bpf_strerror(char *buf, size_t 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

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