linux/kernel/trace/trace_entries.h

// SPDX-License-Identifier: GPL-2.0
/*
 * This file defines the trace event structures that go into the ring
 * buffer directly. They are created via macros so that changes for them
 * appear in the format file. Using macros will automate this process.
 *
 * The macro used to create a ftrace data structure is:
 *
 * FTRACE_ENTRY( name, struct_name, id, structure, print )
 *
 * @name: the name used the event name, as well as the name of
 *   the directory that holds the format file.
 *
 * @struct_name: the name of the structure that is created.
 *
 * @id: The event identifier that is used to detect what event
 *    this is from the ring buffer.
 *
 * @structure: the structure layout
 *
 *  - __field(	type,	item	)
 *	  This is equivalent to declaring
 *		type	item;
 *	  in the structure.
 *  - __array(	type,	item,	size	)
 *	  This is equivalent to declaring
 *		type	item[size];
 *	  in the structure.
 *
 *   * for structures within structures, the format of the internal
 *	structure is laid out. This allows the internal structure
 *	to be deciphered for the format file. Although these macros
 *	may become out of sync with the internal structure, they
 *	will create a compile error if it happens. Since the
 *	internal structures are just tracing helpers, this is not
 *	an issue.
 *
 *	When an internal structure is used, it should use:
 *
 *	__field_struct(	type,	item	)
 *
 *	instead of __field. This will prevent it from being shown in
 *	the output file. The fields in the structure should use.
 *
 *	__field_desc(	type,	container,	item		)
 *	__array_desc(	type,	container,	item,	len	)
 *
 *	type, item and len are the same as __field and __array, but
 *	container is added. This is the name of the item in
 *	__field_struct that this is describing.
 *
 *
 * @print: the print format shown to users in the format file.
 */

/*
 * Function trace entry - function address and parent function address:
 */
FTRACE_ENTRY_REG(function, ftrace_entry,

	TRACE_FN,

	F_STRUCT(
		__field_fn(	 … } ;

/* Function call entry */
FTRACE_ENTRY_PACKED(funcgraph_entry, ftrace_graph_ent_entry,

	TRACE_GRAPH_ENT,

	F_STRUCT(
		__field_struct(	 … } ;

/* Function return entry */
#ifdef CONFIG_FUNCTION_GRAPH_RETVAL

FTRACE_ENTRY_PACKED(funcgraph_exit, ftrace_graph_ret_entry,

	TRACE_GRAPH_RET,

	F_STRUCT(
		__field_struct(	 … } ;

#else

FTRACE_ENTRY_PACKED(funcgraph_exit, ftrace_graph_ret_entry,

	TRACE_GRAPH_RET,

	F_STRUCT(
		__field_struct(	struct ftrace_graph_ret,	ret	)
		__field_packed(	unsigned long,	ret,		func	)
		__field_packed(	int,		ret,		depth	)
		__field_packed(	unsigned int,	ret,		overrun	)
		__field_packed(	unsigned long long, ret,	calltime)
		__field_packed(	unsigned long long, ret,	rettime	)
	),

	F_printk("<-- %ps (%d) (start: %llx  end: %llx) over: %d",
		 (void *)__entry->func, __entry->depth,
		 __entry->calltime, __entry->rettime,
		 __entry->depth)
);

#endif

/*
 * Context switch trace entry - which task (and prio) we switched from/to:
 *
 * This is used for both wakeup and context switches. We only want
 * to create one structure, but we need two outputs for it.
 */
#define FTRACE_CTX_FIELDS …

FTRACE_ENTRY(context_switch, ctx_switch_entry,

	TRACE_CTX,

	F_STRUCT(
		FTRACE_CTX_FIELDS
	),

	F_printk("%u:%u:%u  ==> %u:%u:%u [%03u]",
		 __entry->prev_pid, __entry->prev_prio, __entry->prev_state,
		 __entry->next_pid, __entry->next_prio, __entry->next_state,
		 __entry->next_cpu)
);

/*
 * FTRACE_ENTRY_DUP only creates the format file, it will not
 *  create another structure.
 */
FTRACE_ENTRY_DUP(wakeup, ctx_switch_entry,

	TRACE_WAKE,

	F_STRUCT(
		FTRACE_CTX_FIELDS
	),

	F_printk("%u:%u:%u  ==+ %u:%u:%u [%03u]",
		 __entry->prev_pid, __entry->prev_prio, __entry->prev_state,
		 __entry->next_pid, __entry->next_prio, __entry->next_state,
		 __entry->next_cpu)
);

/*
 * Stack-trace entry:
 */

#define FTRACE_STACK_ENTRIES …

FTRACE_ENTRY(kernel_stack, stack_entry,

	TRACE_STACK,

	F_STRUCT(
		__field(	 … } ;

FTRACE_ENTRY(user_stack, userstack_entry,

	TRACE_USER_STACK,

	F_STRUCT(
		__field(	 … } ;

/*
 * trace_printk entry:
 */
FTRACE_ENTRY(bprint, bprint_entry,

	TRACE_BPRINT,

	F_STRUCT(
		__field(	 … } ;

FTRACE_ENTRY_REG(print, print_entry,

	TRACE_PRINT,

	F_STRUCT(
		__field(	 … } ;

FTRACE_ENTRY(raw_data, raw_data_entry,

	TRACE_RAW_DATA,

	F_STRUCT(
		__field(	 … } ;

FTRACE_ENTRY(bputs, bputs_entry,

	TRACE_BPUTS,

	F_STRUCT(
		__field(	 … } ;

FTRACE_ENTRY(mmiotrace_rw, trace_mmiotrace_rw,

	TRACE_MMIO_RW,

	F_STRUCT(
		__field_struct(	 … } ;

FTRACE_ENTRY(mmiotrace_map, trace_mmiotrace_map,

	TRACE_MMIO_MAP,

	F_STRUCT(
		__field_struct(	 … } ;


#define TRACE_FUNC_SIZE …
#define TRACE_FILE_SIZE …

FTRACE_ENTRY(branch, trace_branch,

	TRACE_BRANCH,

	F_STRUCT(
		__field(	 … } ;


FTRACE_ENTRY(hwlat, hwlat_entry,

	TRACE_HWLAT,

	F_STRUCT(
		__field(	u64,			 … } ;

#define FUNC_REPEATS_GET_DELTA_TS(entry) …	\

FTRACE_ENTRY(func_repeats, func_repeats_entry,

	TRACE_FUNC_REPEATS,

	F_STRUCT(
		__field(	 … } ;

FTRACE_ENTRY(osnoise, osnoise_entry,

	TRACE_OSNOISE,

	F_STRUCT(
		__field(	u64,			 … } ;

FTRACE_ENTRY(timerlat, timerlat_entry,

	TRACE_TIMERLAT,

	F_STRUCT(
		__field(	 … } ;