Commit 5f3efd1d authored by Vincent Donnefort's avatar Vincent Donnefort Committed by Steven Rostedt (Google)
Browse files

tracing: Add helpers to create trace remote events 

Declaring remote events can be cumbersome let's add a set of macros to
simplify developers life. The declaration of a remote event is very
similar to kernel's events:

 REMOTE_EVENT(name, id,
     RE_STRUCT(
        re_field(u64 foo)
     ),
     RE_PRINTK("foo=%llu", __entry->foo)
 )

Link: https://patch.msgid.link/20260309162516.2623589-12-vdonnefort@google.com


Reviewed-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarVincent Donnefort <vdonnefort@google.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 775cb093

include/linux/trace_remote_event.h

+10 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 


struct trace_remote;

struct trace_event_fields;

struct trace_seq;



struct remote_event_hdr {

	unsigned short	id;
@@ -20,4 +21,13 @@ struct remote_event { 
	char				*print_fmt;

	void				(*print)(void *evt, struct trace_seq *seq);

};



#define RE_STRUCT(__args...) __args

#define re_field(__type, __field) __type __field;



#define REMOTE_EVENT_FORMAT(__name, __struct)	\

	struct remote_event_format_##__name {	\

		struct remote_event_hdr hdr;	\

		__struct			\

	}

#endif

include/trace/define_remote_events.h

0 → 100644
+73 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */



#include <linux/trace_events.h>

#include <linux/trace_remote_event.h>

#include <linux/trace_seq.h>

#include <linux/stringify.h>



#define REMOTE_EVENT_INCLUDE(__file) __stringify(../../__file)



#ifdef REMOTE_EVENT_SECTION

# define __REMOTE_EVENT_SECTION(__name) __used __section(REMOTE_EVENT_SECTION"."#__name)

#else

# define __REMOTE_EVENT_SECTION(__name)

#endif



#define REMOTE_PRINTK_COUNT_ARGS(__args...) \

	__COUNT_ARGS(, ##__args, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 0)



#define __remote_printk0()								\

	trace_seq_putc(seq, '\n')



#define __remote_printk1(__fmt)								\

	trace_seq_puts(seq, " " __fmt "\n")						\



#define __remote_printk2(__fmt, __args...)						\

do {											\

	trace_seq_putc(seq, ' ');							\

	trace_seq_printf(seq, __fmt, __args);						\

	trace_seq_putc(seq, '\n');							\

} while (0)



/* Apply the appropriate trace_seq sequence according to the number of arguments */

#define remote_printk(__args...)							\

	CONCATENATE(__remote_printk, REMOTE_PRINTK_COUNT_ARGS(__args))(__args)



#define RE_PRINTK(__args...) __args



#define REMOTE_EVENT(__name, __id, __struct, __printk)					\

	REMOTE_EVENT_FORMAT(__name, __struct);						\

	static void remote_event_print_##__name(void *evt, struct trace_seq *seq)	\

	{										\

		struct remote_event_format_##__name __maybe_unused *__entry = evt;	\

		trace_seq_puts(seq, #__name);						\

		remote_printk(__printk);						\

	}

#include REMOTE_EVENT_INCLUDE(REMOTE_EVENT_INCLUDE_FILE)



#undef REMOTE_EVENT

#undef RE_PRINTK

#undef re_field

#define re_field(__type, __field)							\

	{										\

		.type = #__type, .name = #__field,					\

		.size = sizeof(__type), .align = __alignof__(__type),			\

		.is_signed = is_signed_type(__type),					\

	},

#define __entry REC

#define RE_PRINTK(__fmt, __args...) "\"" __fmt "\", " __stringify(__args)

#define REMOTE_EVENT(__name, __id, __struct, __printk)					\

	static struct trace_event_fields remote_event_fields_##__name[] = {		\

		__struct								\

		{}									\

	};										\

	static char remote_event_print_fmt_##__name[] = __printk;			\

	static struct remote_event __REMOTE_EVENT_SECTION(__name)			\

	remote_event_##__name = {							\

		.name		= #__name,						\

		.id		= __id,							\

		.fields		= remote_event_fields_##__name,				\

		.print_fmt	= remote_event_print_fmt_##__name,			\

		.print		= remote_event_print_##__name,				\

	}

#include REMOTE_EVENT_INCLUDE(REMOTE_EVENT_INCLUDE_FILE)