Commit 91729ef9 authored by Steven Rostedt's avatar Steven Rostedt
Browse files

tracing: add ftrace headers to event format files 



This patch includes the ftrace header to the event formats files:

 # cat /debug/tracing/events/sched/sched_switch/format
        field:unsigned char type;       offset:0;       size:1;
        field:unsigned char flags;      offset:1;       size:1;
        field:unsigned char preempt_count;      offset:2;       size:1;
        field:int pid;  offset:4;       size:4;
        field:int tgid; offset:8;       size:4;

        field:pid_t prev_pid;   offset:12;      size:4;
        field:int prev_prio;    offset:16;      size:4;
        field special:char next_comm[TASK_COMM_LEN];    offset:20;      size:16;
        field:pid_t next_pid;   offset:36;      size:4;
        field:int next_prio;    offset:40;      size:4;

A blank line is used as a deliminator between the ftrace header and the
trace point fields.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
parent 981d081e

kernel/trace/trace_events.c

+26 −1
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ 
#include <linux/module.h>

#include <linux/ctype.h>



#include "trace.h"

#include "trace_output.h"



#define TRACE_SYSTEM "TRACE_SYSTEM"
@@ -447,6 +447,28 @@ event_available_types_read(struct file *filp, char __user *ubuf, size_t cnt, 
	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);

}



#undef FIELD

#define FIELD(type, name) \

	#type, #name, offsetof(typeof(field), name), sizeof(field.name)



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:%lu;\tsize:%lu;\n"

				"\tfield:%s %s;\toffset:%lu;\tsize:%lu;\n"

				"\tfield:%s %s;\toffset:%lu;\tsize:%lu;\n"

				"\tfield:%s %s;\toffset:%lu;\tsize:%lu;\n"

				"\tfield:%s %s;\toffset:%lu;\tsize:%lu;\n"

				"\n",

				FIELD(unsigned char, type),

				FIELD(unsigned char, flags),

				FIELD(unsigned char, preempt_count),

				FIELD(int, pid),

				FIELD(int, tgid));

}

static ssize_t

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

		  loff_t *ppos)
@@ -465,6 +487,9 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt, 
	if (*ppos)

		return 0;



	/* If this fails, so will the show_format. */

	trace_write_header(s);



	r = call->show_format(s);

	if (!r) {

		/*

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