Commit 5a65e956 authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Steven Rostedt
Browse files

tracing: Use defined fields and print_fmt to print formats 



The calls ftrace_format_##call() and ftrace_define_fields_##call()
are almost duplicate in functionality. With the addition of the
print_fmt in previous patches, these two functions can be merged
into one.

The trace_define_field() defines the fields and links them into
the struct ftrace_event_call. The previous patches introduced
the print_fmt field and this can now be used with the trace_define_field()
to create the event format file fields and print_fmt field.

The struct ftrace_event_call->fields are used to print the fields
The struct ftrace_event_call->print_fmt is used to print
the "print fmt: XXXXXXXXXXX" line.

Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D49.5000006@cn.fujitsu.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent c7ef3a90

kernel/trace/trace_events.c

+41 −24
Original line number Diff line number Diff line
@@ -528,33 +528,16 @@ extern char *__bad_type_size(void); 
	#type, "common_" #name, offsetof(typeof(field), name),		\

		sizeof(field.name), is_signed_type(type)



static int trace_write_header(struct trace_seq *s)

{

	struct trace_entry field;



	/* struct trace_entry */

	return trace_seq_printf(s,

			"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"

			"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"

			"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"

			"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"

			"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n"

			"\n",

			FIELD(unsigned short, type),

			FIELD(unsigned char, flags),

			FIELD(unsigned char, preempt_count),

			FIELD(int, pid),

			FIELD(int, lock_depth));

}



static ssize_t

event_format_read(struct file *filp, char __user *ubuf, size_t cnt,

		  loff_t *ppos)

{

	struct ftrace_event_call *call = filp->private_data;

	struct ftrace_event_field *field;

	struct trace_seq *s;

	int common_field_count = 5;

	char *buf;

	int r;

	int r = 0;



	if (*ppos)

		return 0;
@@ -565,14 +548,48 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt, 


	trace_seq_init(s);



	/* If any of the first writes fail, so will the show_format. */



	trace_seq_printf(s, "name: %s\n", call->name);

	trace_seq_printf(s, "ID: %d\n", call->id);

	trace_seq_printf(s, "format:\n");

	trace_write_header(s);



	r = call->show_format(call, s);

	list_for_each_entry_reverse(field, &call->fields, link) {

		/*

		 * Smartly shows the array type(except dynamic array).

		 * Normal:

		 *	field:TYPE VAR

		 * If TYPE := TYPE[LEN], it is shown:

		 *	field:TYPE VAR[LEN]

		 */

		const char *array_descriptor = strchr(field->type, '[');



		if (!strncmp(field->type, "__data_loc", 10))

			array_descriptor = NULL;



		if (!array_descriptor) {

			r = trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"

					"\tsize:%u;\tsigned:%d;\n",

					field->type, field->name, field->offset,

					field->size, !!field->is_signed);

		} else {

			r = trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"

					"\tsize:%u;\tsigned:%d;\n",

					(int)(array_descriptor - field->type),

					field->type, field->name,

					array_descriptor, field->offset,

					field->size, !!field->is_signed);

		}



		if (--common_field_count == 0)

			r = trace_seq_printf(s, "\n");



		if (!r)

			break;

	}



	if (r)

		r = trace_seq_printf(s, "\nprint fmt: %s\n",

				call->print_fmt);



	if (!r) {

		/*

		 * ug!  The format output is bigger than a PAGE!!

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