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Commit e0a7cce5 authored by Wang Nan's avatar Wang Nan Committed by Arnaldo Carvalho de Melo
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perf data: Fix duplicate field names and avoid reserved keywords 

Some parameters of syscall tracepoints named as 'nr', 'event', etc.
When dealing with them, perf convert to ctf meets some problem:

 1. If a parameter with name 'nr', it will duplicate syscall's
    common field 'nr'. One such syscall is io_submit().

 2. If a parameter with name 'event', it is denied to be inserted
    because 'event' is a CTF spec keyword[1]. One such syscall is
    epoll_ctl.

This patch appends '_dupl_X' suffix to avoid problem 1, prepend a '_'
prefix to avoid problem 2.

[1] http://diamon.org/docs/ctf/v1.8.2/#specC.1.2



Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Link: http://lkml.kernel.org/r/1429372220-6406-7-git-send-email-jolsa@kernel.org


[ changed to use format_file::alias ]
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 8fa46753

tools/perf/util/data-convert-bt.c

+82 −4
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <babeltrace/ctf-writer/event.h>

#include <babeltrace/ctf-writer/event-types.h>

#include <babeltrace/ctf-writer/event-fields.h>

#include <babeltrace/ctf-ir/utils.h>

#include <babeltrace/ctf/events.h>

#include <traceevent/event-parse.h>

#include "asm/bug.h"
@@ -184,6 +185,7 @@ static int add_tracepoint_field_value(struct ctf_writer *cw, 
	unsigned int len;

	int ret;



	name = fmtf->alias;

	offset = fmtf->offset;

	len = fmtf->size;

	if (flags & FIELD_IS_STRING)
@@ -567,6 +569,82 @@ static int process_sample_event(struct perf_tool *tool, 
	return cs ? 0 : -1;

}



/* If dup < 0, add a prefix. Else, add _dupl_X suffix. */

static char *change_name(char *name, char *orig_name, int dup)

{

	char *new_name = NULL;

	size_t len;



	if (!name)

		name = orig_name;



	if (dup >= 10)

		goto out;

	/*

	 * Add '_' prefix to potential keywork.  According to

	 * Mathieu Desnoyers (https://lkml.org/lkml/2015/1/23/652),

	 * futher CTF spec updating may require us to use '$'.

	 */

	if (dup < 0)

		len = strlen(name) + sizeof("_");

	else

		len = strlen(orig_name) + sizeof("_dupl_X");



	new_name = malloc(len);

	if (!new_name)

		goto out;



	if (dup < 0)

		snprintf(new_name, len, "_%s", name);

	else

		snprintf(new_name, len, "%s_dupl_%d", orig_name, dup);



out:

	if (name != orig_name)

		free(name);

	return new_name;

}



static int event_class_add_field(struct bt_ctf_event_class *event_class,

		struct bt_ctf_field_type *type,

		struct format_field *field)

{

	struct bt_ctf_field_type *t = NULL;

	char *name;

	int dup = 1;

	int ret;



	/* alias was already assigned */

	if (field->alias != field->name)

		return bt_ctf_event_class_add_field(event_class, type,

				(char *)field->alias);



	name = field->name;



	/* If 'name' is a keywork, add prefix. */

	if (bt_ctf_validate_identifier(name))

		name = change_name(name, field->name, -1);



	if (!name) {

		pr_err("Failed to fix invalid identifier.");

		return -1;

	}

	while ((t = bt_ctf_event_class_get_field_by_name(event_class, name))) {

		bt_ctf_field_type_put(t);

		name = change_name(name, field->name, dup++);

		if (!name) {

			pr_err("Failed to create dup name for '%s'\n", field->name);

			return -1;

		}

	}



	ret = bt_ctf_event_class_add_field(event_class, type, name);

	if (!ret)

		field->alias = name;



	return ret;

}



static int add_tracepoint_fields_types(struct ctf_writer *cw,

				       struct format_field *fields,

				       struct bt_ctf_event_class *event_class)
@@ -595,14 +673,14 @@ static int add_tracepoint_fields_types(struct ctf_writer *cw, 
		if (flags & FIELD_IS_ARRAY)

			type = bt_ctf_field_type_array_create(type, field->arraylen);



		ret = bt_ctf_event_class_add_field(event_class, type,

				field->name);

		ret = event_class_add_field(event_class, type, field);



		if (flags & FIELD_IS_ARRAY)

			bt_ctf_field_type_put(type);



		if (ret) {

			pr_err("Failed to add field '%s\n", field->name);

			pr_err("Failed to add field '%s': %d\n",

					field->name, ret);

			return -1;

		}

	}
@@ -646,7 +724,7 @@ static int add_generic_types(struct ctf_writer *cw, struct perf_evsel *evsel, 
	do {								\

		pr2("  field '%s'\n", n);				\

		if (bt_ctf_event_class_add_field(cl, t, n)) {		\

			pr_err("Failed to add field '%s;\n", n);	\

			pr_err("Failed to add field '%s';\n", n);	\

			return -1;					\

		}							\

	} while (0)