perf: Convert perf tracing data into a tracing_data event

Bypasses the tracing_data perf header code and replaces it with
a synthesized event and processing function that accomplishes
the same thing, used when reading/writing perf data to/from a
pipe.

The tracing data is pretty large, and this patch doesn't attempt
to break it down into component events.  The tracing_data event
itself doesn't actually contain the tracing data, rather it
arranges for the event processing code to skip over it after
it's read, using the skip return value added to the event
processing loop in a previous patch.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-8-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index c4c1322..3775abe 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -104,6 +104,11 @@
 	pc->data_tail = tail;
 }
 
+static void advance_output(size_t size)
+{
+	bytes_written += size;
+}
+
 static void write_output(void *buf, size_t size)
 {
 	while (size) {
@@ -599,6 +604,17 @@
 			pr_err("Couldn't synthesize event_types.\n");
 			return err;
 		}
+
+		err = event__synthesize_tracing_data(output, attrs,
+						     nr_counters,
+						     process_synthesized_event,
+						     session);
+		if (err <= 0) {
+			pr_err("Couldn't record tracing data.\n");
+			return err;
+		}
+
+		advance_output(err);
 	}
 
 	err = event__synthesize_kernel_mmap(process_synthesized_event,
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index e59d012..76f03a7 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -269,6 +269,7 @@
 	.read	= process_read_event,
 	.attr	= event__process_attr,
 	.event_type = event__process_event_type,
+	.tracing_data = event__process_tracing_data,
 };
 
 extern volatile int session_done;
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index eb884a7..1509744 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -106,6 +106,7 @@
 	.comm	= event__process_comm,
 	.attr	= event__process_attr,
 	.event_type = event__process_event_type,
+	.tracing_data = event__process_tracing_data,
 };
 
 extern volatile int session_done;
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index c720fe0..b896a17 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -86,6 +86,7 @@
 enum perf_header_event_type { /* above any possible kernel type */
 	PERF_RECORD_HEADER_ATTR			= 64,
 	PERF_RECORD_HEADER_EVENT_TYPE		= 65,
+	PERF_RECORD_HEADER_TRACING_DATA		= 66,
 	PERF_RECORD_HEADER_MAX
 };
 
@@ -107,6 +108,11 @@
 	struct perf_trace_event_type event_type;
 };
 
+struct tracing_data_event {
+	struct perf_event_header header;
+	u32 size;
+};
+
 typedef union event_union {
 	struct perf_event_header	header;
 	struct ip_event			ip;
@@ -118,6 +124,7 @@
 	struct sample_event		sample;
 	struct attr_event		attr;
 	struct event_type_event		event_type;
+	struct tracing_data_event	tracing_data;
 } event_t;
 
 struct events_stats {
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 4463799..c6874ec 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -934,3 +934,55 @@
 
 	return 0;
 }
+
+int event__synthesize_tracing_data(int fd, struct perf_event_attr *pattrs,
+				   int nb_events,
+				   event__handler_t process,
+				   struct perf_session *session __unused)
+{
+	event_t ev;
+	ssize_t size = 0, aligned_size = 0, padding;
+	int err = 0;
+
+	memset(&ev, 0, sizeof(ev));
+
+	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
+	size = read_tracing_data_size(fd, pattrs, nb_events);
+	if (size <= 0)
+		return size;
+	aligned_size = ALIGN(size, sizeof(u64));
+	padding = aligned_size - size;
+	ev.tracing_data.header.size = sizeof(ev.tracing_data);
+	ev.tracing_data.size = aligned_size;
+
+	process(&ev, session);
+
+	err = read_tracing_data(fd, pattrs, nb_events);
+	write_padded(fd, NULL, 0, padding);
+
+	return aligned_size;
+}
+
+int event__process_tracing_data(event_t *self,
+				struct perf_session *session)
+{
+	ssize_t size_read, padding, size = self->tracing_data.size;
+	off_t offset = lseek(session->fd, 0, SEEK_CUR);
+	char buf[BUFSIZ];
+
+	/* setup for reading amidst mmap */
+	lseek(session->fd, offset + sizeof(struct tracing_data_event),
+	      SEEK_SET);
+
+	size_read = trace_report(session->fd);
+
+	padding = ALIGN(size_read, sizeof(u64)) - size_read;
+
+	if (read(session->fd, buf, padding) < 0)
+		die("reading input file");
+
+	if (size_read + padding != size)
+		die("tracing data size mismatch");
+
+	return size_read + padding;
+}
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index afeb618..3ed3d98 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -111,5 +111,11 @@
 int event__process_event_type(event_t *self,
 			      struct perf_session *session);
 
+int event__synthesize_tracing_data(int fd, struct perf_event_attr *pattrs,
+				   int nb_events,
+				   event__handler_t process,
+				   struct perf_session *session);
+int event__process_tracing_data(event_t *self,
+				struct perf_session *session);
 
 #endif /* __PERF_HEADER_H */
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 96c4629..1516c40 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -204,6 +204,8 @@
 		handler->attr = process_event_stub;
 	if (handler->event_type == NULL)
 		handler->event_type = process_event_stub;
+	if (handler->tracing_data == NULL)
+		handler->tracing_data = process_event_stub;
 }
 
 static const char *event__name[] = {
@@ -219,6 +221,7 @@
 	[PERF_RECORD_SAMPLE]	 = "SAMPLE",
 	[PERF_RECORD_HEADER_ATTR]	 = "ATTR",
 	[PERF_RECORD_HEADER_EVENT_TYPE]	 = "EVENT_TYPE",
+	[PERF_RECORD_HEADER_TRACING_DATA]	 = "TRACING_DATA",
 };
 
 unsigned long event__total[PERF_RECORD_HEADER_MAX];
@@ -311,6 +314,11 @@
 		bswap_64(self->event_type.event_type.event_id);
 }
 
+static void event__tracing_data_swap(event_t *self)
+{
+	self->tracing_data.size = bswap_32(self->tracing_data.size);
+}
+
 typedef void (*event__swap_op)(event_t *self);
 
 static event__swap_op event__swap_ops[] = {
@@ -323,6 +331,7 @@
 	[PERF_RECORD_SAMPLE] = event__all64_swap,
 	[PERF_RECORD_HEADER_ATTR]   = event__attr_swap,
 	[PERF_RECORD_HEADER_EVENT_TYPE]   = event__event_type_swap,
+	[PERF_RECORD_HEADER_TRACING_DATA]   = event__tracing_data_swap,
 	[PERF_RECORD_HEADER_MAX]    = NULL,
 };
 
@@ -367,6 +376,10 @@
 		return ops->attr(event, self);
 	case PERF_RECORD_HEADER_EVENT_TYPE:
 		return ops->event_type(event, self);
+	case PERF_RECORD_HEADER_TRACING_DATA:
+		/* setup for reading amidst mmap */
+		lseek(self->fd, offset + head, SEEK_SET);
+		return ops->tracing_data(event, self);
 	default:
 		self->unknown_events++;
 		return -1;
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 0dac1f4..0739ebb 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -46,7 +46,8 @@
 		 throttle,
 		 unthrottle,
 		 attr,
-		 event_type;
+		 event_type,
+		 tracing_data;
 };
 
 struct perf_session *perf_session__new(const char *filename, int mode, bool force);
diff --git a/tools/perf/util/trace-event-info.c b/tools/perf/util/trace-event-info.c
index 5ea8973..30cd9b5 100644
--- a/tools/perf/util/trace-event-info.c
+++ b/tools/perf/util/trace-event-info.c
@@ -154,10 +154,17 @@
 	free(file);
 }
 
+static ssize_t calc_data_size;
+
 static ssize_t write_or_die(const void *buf, size_t len)
 {
 	int ret;
 
+	if (calc_data_size) {
+		calc_data_size += len;
+		return len;
+	}
+
 	ret = write(output_fd, buf, len);
 	if (ret < 0)
 		die("writing to '%s'", output_file);
@@ -526,3 +533,20 @@
 
 	return 0;
 }
+
+ssize_t read_tracing_data_size(int fd, struct perf_event_attr *pattrs,
+			       int nb_events)
+{
+	ssize_t size;
+	int err = 0;
+
+	calc_data_size = 1;
+	err = read_tracing_data(fd, pattrs, nb_events);
+	size = calc_data_size - 1;
+	calc_data_size = 0;
+
+	if (err < 0)
+		return err;
+
+	return size;
+}
diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index 7cd1193..44889c9 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -50,14 +50,37 @@
 
 static unsigned long	page_size;
 
+static ssize_t calc_data_size;
+
+static int do_read(int fd, void *buf, int size)
+{
+	int rsize = size;
+
+	while (size) {
+		int ret = read(fd, buf, size);
+
+		if (ret <= 0)
+			return -1;
+
+		size -= ret;
+		buf += ret;
+	}
+
+	return rsize;
+}
+
 static int read_or_die(void *data, int size)
 {
 	int r;
 
-	r = read(input_fd, data, size);
-	if (r != size)
+	r = do_read(input_fd, data, size);
+	if (r <= 0)
 		die("reading input file (size expected=%d received=%d)",
 		    size, r);
+
+	if (calc_data_size)
+		calc_data_size += r;
+
 	return r;
 }
 
@@ -82,56 +105,28 @@
 	char buf[BUFSIZ];
 	char *str = NULL;
 	int size = 0;
-	int i;
 	off_t r;
+	char c;
 
 	for (;;) {
-		r = read(input_fd, buf, BUFSIZ);
+		r = read(input_fd, &c, 1);
 		if (r < 0)
 			die("reading input file");
 
 		if (!r)
 			die("no data");
 
-		for (i = 0; i < r; i++) {
-			if (!buf[i])
-				break;
-		}
-		if (i < r)
+		buf[size++] = c;
+
+		if (!c)
 			break;
-
-		if (str) {
-			size += BUFSIZ;
-			str = realloc(str, size);
-			if (!str)
-				die("malloc of size %d", size);
-			memcpy(str + (size - BUFSIZ), buf, BUFSIZ);
-		} else {
-			size = BUFSIZ;
-			str = malloc_or_die(size);
-			memcpy(str, buf, size);
-		}
 	}
 
-	/* trailing \0: */
-	i++;
+	if (calc_data_size)
+		calc_data_size += size;
 
-	/* move the file descriptor to the end of the string */
-	r = lseek(input_fd, -(r - i), SEEK_CUR);
-	if (r == (off_t)-1)
-		die("lseek");
-
-	if (str) {
-		size += i;
-		str = realloc(str, size);
-		if (!str)
-			die("malloc of size %d", size);
-		memcpy(str + (size - i), buf, i);
-	} else {
-		size = i;
-		str = malloc_or_die(i);
-		memcpy(str, buf, i);
-	}
+	str = malloc_or_die(size);
+	memcpy(str, buf, size);
 
 	return str;
 }
@@ -459,7 +454,7 @@
 	return data;
 }
 
-void trace_report(int fd)
+ssize_t trace_report(int fd)
 {
 	char buf[BUFSIZ];
 	char test[] = { 23, 8, 68 };
@@ -467,6 +462,9 @@
 	int show_version = 0;
 	int show_funcs = 0;
 	int show_printk = 0;
+	ssize_t size;
+
+	calc_data_size = 1;
 
 	input_fd = fd;
 
@@ -499,14 +497,17 @@
 	read_proc_kallsyms();
 	read_ftrace_printk();
 
+	size = calc_data_size - 1;
+	calc_data_size = 0;
+
 	if (show_funcs) {
 		print_funcs();
-		return;
+		return size;
 	}
 	if (show_printk) {
 		print_printk();
-		return;
+		return size;
 	}
 
-	return;
+	return size;
 }
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index 81f2fd2..1f45d46 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -163,7 +163,7 @@
 
 void parse_set_info(int nr_cpus, int long_sz);
 
-void trace_report(int fd);
+ssize_t trace_report(int fd);
 
 void *malloc_or_die(unsigned int size);
 
@@ -259,6 +259,8 @@
 unsigned long long eval_flag(const char *flag);
 
 int read_tracing_data(int fd, struct perf_event_attr *pattrs, int nb_events);
+ssize_t read_tracing_data_size(int fd, struct perf_event_attr *pattrs,
+			       int nb_events);
 
 /* taken from kernel/trace/trace.h */
 enum trace_flag_type {