Commit c3a057dc authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf inject: Fix output from a file to a pipe 



When the input is a regular file but the output is a pipe, it should
write a pipe header.  But just repiping would write a portion of the
existing header which is different in 'size' value.  So we need to
prevent it and write a new pipe header along with other information
like event attributes and features.

This can handle something like this:

  # perf record -a -B sleep 1

  # perf inject -b -i perf.data | perf report -i -

Factor out perf_event__synthesize_for_pipe() to be shared between perf
record and inject.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210719223153.1618812-5-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent fea20d66

tools/perf/builtin-inject.c

+26 −2
Original line number Diff line number Diff line
@@ -919,6 +919,7 @@ int cmd_inject(int argc, const char **argv) 
		.use_stdio = true,

	};

	int ret;

	bool repipe = true;



	struct option options[] = {

		OPT_BOOLEAN('b', "build-ids", &inject.build_ids,
@@ -993,10 +994,18 @@ int cmd_inject(int argc, const char **argv) 
	}



	data.path = inject.input_name;

	if (!strcmp(inject.input_name, "-") || inject.output.is_pipe)

	if (!strcmp(inject.input_name, "-") || inject.output.is_pipe) {

		inject.is_pipe = true;

		/*

		 * Do not repipe header when input is a regular file

		 * since either it can rewrite the header at the end

		 * or write a new pipe header.

		 */

		if (strcmp(inject.input_name, "-"))

			repipe = false;

	}



	inject.session = __perf_session__new(&data, inject.is_pipe,

	inject.session = __perf_session__new(&data, repipe,

					     perf_data__fd(&inject.output),

					     &inject.tool);

	if (IS_ERR(inject.session)) {
@@ -1007,6 +1016,21 @@ int cmd_inject(int argc, const char **argv) 
	if (zstd_init(&(inject.session->zstd_data), 0) < 0)

		pr_warning("Decompression initialization failed.\n");



	if (!data.is_pipe && inject.output.is_pipe) {

		ret = perf_header__write_pipe(perf_data__fd(&inject.output));

		if (ret < 0) {

			pr_err("Couldn't write a new pipe header.\n");

			goto out_delete;

		}



		ret = perf_event__synthesize_for_pipe(&inject.tool,

						      inject.session,

						      &inject.output,

						      perf_event__repipe);

		if (ret < 0)

			goto out_delete;

	}



	if (inject.build_ids && !inject.build_id_all) {

		/*

		 * to make sure the mmap records are ordered correctly

tools/perf/builtin-record.c

+4 −34
Original line number Diff line number Diff line
@@ -1387,7 +1387,6 @@ static int record__synthesize(struct record *rec, bool tail) 
	struct perf_data *data = &rec->data;

	struct record_opts *opts = &rec->opts;

	struct perf_tool *tool = &rec->tool;

	int fd = perf_data__fd(data);

	int err = 0;

	event_op f = process_synthesized_event;
@@ -1395,42 +1394,13 @@ static int record__synthesize(struct record *rec, bool tail) 
		return 0;



	if (data->is_pipe) {

		/*

		 * We need to synthesize events first, because some

		 * features works on top of them (on report side).

		 */

		err = perf_event__synthesize_attrs(tool, rec->evlist,

		err = perf_event__synthesize_for_pipe(tool, session, data,

						      process_synthesized_event);

		if (err < 0) {

			pr_err("Couldn't synthesize attrs.\n");

		if (err < 0)

			goto out;

		}



		err = perf_event__synthesize_features(tool, session, rec->evlist,

						      process_synthesized_event);

		if (err < 0) {

			pr_err("Couldn't synthesize features.\n");

			return err;

		}



		if (have_tracepoints(&rec->evlist->core.entries)) {

			/*

			 * FIXME err <= 0 here actually means that

			 * there were no tracepoints so its not really

			 * an error, just that we don't need to

			 * synthesize anything.  We really have to

			 * return this more properly and also

			 * propagate errors that now are calling die()

			 */

			err = perf_event__synthesize_tracing_data(tool,	fd, rec->evlist,

								  process_synthesized_event);

			if (err <= 0) {

				pr_err("Couldn't record tracing data.\n");

				goto out;

			}

		rec->bytes_written += err;

	}

	}



	err = perf_event__synth_time_conv(record__pick_pc(rec), tool,

					  process_synthesized_event, machine);

tools/perf/util/synthetic-events.c

+52 −1
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only 



#include "util/cgroup.h"

#include "util/data.h"

#include "util/debug.h"

#include "util/dso.h"

#include "util/event.h"
@@ -16,7 +18,6 @@ 
#include "util/synthetic-events.h"

#include "util/target.h"

#include "util/time-utils.h"

#include "util/cgroup.h"

#include <linux/bitops.h>

#include <linux/kernel.h>

#include <linux/string.h>
@@ -2179,3 +2180,53 @@ int perf_event__synthesize_features(struct perf_tool *tool, struct perf_session 
	free(ff.buf);

	return ret;

}



int perf_event__synthesize_for_pipe(struct perf_tool *tool,

				    struct perf_session *session,

				    struct perf_data *data,

				    perf_event__handler_t process)

{

	int err;

	int ret = 0;

	struct evlist *evlist = session->evlist;



	/*

	 * We need to synthesize events first, because some

	 * features works on top of them (on report side).

	 */

	err = perf_event__synthesize_attrs(tool, evlist, process);

	if (err < 0) {

		pr_err("Couldn't synthesize attrs.\n");

		return err;

	}

	ret += err;



	err = perf_event__synthesize_features(tool, session, evlist, process);

	if (err < 0) {

		pr_err("Couldn't synthesize features.\n");

		return err;

	}

	ret += err;



	if (have_tracepoints(&evlist->core.entries)) {

		int fd = perf_data__fd(data);



		/*

		 * FIXME err <= 0 here actually means that

		 * there were no tracepoints so its not really

		 * an error, just that we don't need to

		 * synthesize anything.  We really have to

		 * return this more properly and also

		 * propagate errors that now are calling die()

		 */

		err = perf_event__synthesize_tracing_data(tool,	fd, evlist,

							  process);

		if (err <= 0) {

			pr_err("Couldn't record tracing data.\n");

			return err;

		}

		ret += err;

	}



	return ret;

}

tools/perf/util/synthetic-events.h

+6 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ struct evsel; 
struct machine;

struct perf_counts_values;

struct perf_cpu_map;

struct perf_data;

struct perf_event_attr;

struct perf_event_mmap_page;

struct perf_sample;
@@ -101,4 +102,9 @@ static inline int perf_event__synthesize_bpf_events(struct perf_session *session 
}

#endif // HAVE_LIBBPF_SUPPORT



int perf_event__synthesize_for_pipe(struct perf_tool *tool,

				    struct perf_session *session,

				    struct perf_data *data,

				    perf_event__handler_t process);



#endif // __PERF_SYNTHETIC_EVENTS_H