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linux/include/trace/trace_events.h
Steven Rostedt (Google) af6b9668e8 tracing: Move the defines to create TRACE_EVENTS into their own files 
In an effort to add custom event macros that can be used to create your
own custom events based on existing tracepoints, move the defines of the
special macros used in TRACE_EVENT() into their own files such that they
can be reused for TRACE_CUSTOM_EVENT().

Link: https://lkml.kernel.org/r/20220303220625.553406495@goodmis.org

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-11 11:49:23 -05:00

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Stage 1 of the trace events.
*
* Override the macros in the event tracepoint header <trace/events/XXX.h>
* to include the following:
*
* struct trace_event_raw_<call> {
* struct trace_entry ent;
* <type> <item>;
* <type2> <item2>[<len>];
* [...]
* };
*
* The <type> <item> is created by the __field(type, item) macro or
* the __array(type2, item2, len) macro.
* We simply do "type item;", and that will create the fields
* in the structure.
*/
#include <linux/trace_events.h>
#ifndef TRACE_SYSTEM_VAR
#define TRACE_SYSTEM_VAR TRACE_SYSTEM
#endif
#include "stages/init.h"
/*
* DECLARE_EVENT_CLASS can be used to add a generic function
* handlers for events. That is, if all events have the same
* parameters and just have distinct trace points.
* Each tracepoint can be defined with DEFINE_EVENT and that
* will map the DECLARE_EVENT_CLASS to the tracepoint.
*
* TRACE_EVENT is a one to one mapping between tracepoint and template.
*/
#undef TRACE_EVENT
#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
DECLARE_EVENT_CLASS(name, \
PARAMS(proto), \
PARAMS(args), \
PARAMS(tstruct), \
PARAMS(assign), \
PARAMS(print)); \
DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
#include "stages/stage1_defines.h"
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print) \
struct trace_event_raw_##name { \
struct trace_entry ent; \
tstruct \
char __data[]; \
}; \
\
static struct trace_event_class event_class_##name;
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args) \
static struct trace_event_call __used \
__attribute__((__aligned__(4))) event_##name
#undef DEFINE_EVENT_FN
#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
/* Callbacks are meaningless to ftrace. */
#undef TRACE_EVENT_FN
#define TRACE_EVENT_FN(name, proto, args, tstruct, \
assign, print, reg, unreg) \
TRACE_EVENT(name, PARAMS(proto), PARAMS(args), \
PARAMS(tstruct), PARAMS(assign), PARAMS(print)) \
#undef TRACE_EVENT_FN_COND
#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct, \
assign, print, reg, unreg) \
TRACE_EVENT_CONDITION(name, PARAMS(proto), PARAMS(args), PARAMS(cond), \
PARAMS(tstruct), PARAMS(assign), PARAMS(print)) \
#undef TRACE_EVENT_FLAGS
#define TRACE_EVENT_FLAGS(name, value) \
__TRACE_EVENT_FLAGS(name, value)
#undef TRACE_EVENT_PERF_PERM
#define TRACE_EVENT_PERF_PERM(name, expr...) \
__TRACE_EVENT_PERF_PERM(name, expr)
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
* Stage 2 of the trace events.
*
* Include the following:
*
* struct trace_event_data_offsets_<call> {
* u32 <item1>;
* u32 <item2>;
* [...]
* };
*
* The __dynamic_array() macro will create each u32 <item>, this is
* to keep the offset of each array from the beginning of the event.
* The size of an array is also encoded, in the higher 16 bits of <item>.
*/
#include "stages/stage2_defines.h"
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
struct trace_event_data_offsets_##call { \
tstruct; \
};
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args)
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print)
#undef TRACE_EVENT_FLAGS
#define TRACE_EVENT_FLAGS(event, flag)
#undef TRACE_EVENT_PERF_PERM
#define TRACE_EVENT_PERF_PERM(event, expr...)
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
* Stage 3 of the trace events.
*
* Override the macros in the event tracepoint header <trace/events/XXX.h>
* to include the following:
*
* enum print_line_t
* trace_raw_output_<call>(struct trace_iterator *iter, int flags)
* {
* struct trace_seq *s = &iter->seq;
* struct trace_event_raw_<call> *field; <-- defined in stage 1
* struct trace_seq *p = &iter->tmp_seq;
*
* -------(for event)-------
*
* struct trace_entry *entry;
*
* entry = iter->ent;
*
* if (entry->type != event_<call>->event.type) {
* WARN_ON_ONCE(1);
* return TRACE_TYPE_UNHANDLED;
* }
*
* field = (typeof(field))entry;
*
* trace_seq_init(p);
* return trace_output_call(iter, <call>, <TP_printk> "\n");
*
* ------(or, for event class)------
*
* int ret;
*
* field = (typeof(field))iter->ent;
*
* ret = trace_raw_output_prep(iter, trace_event);
* if (ret != TRACE_TYPE_HANDLED)
* return ret;
*
* trace_event_printf(iter, <TP_printk> "\n");
*
* return trace_handle_return(s);
* -------
* }
*
* This is the method used to print the raw event to the trace
* output format. Note, this is not needed if the data is read
* in binary.
*/
#include "stages/stage3_defines.h"
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace enum print_line_t \
trace_raw_output_##call(struct trace_iterator *iter, int flags, \
struct trace_event *trace_event) \
{ \
struct trace_seq *s = &iter->seq; \
struct trace_seq __maybe_unused *p = &iter->tmp_seq; \
struct trace_event_raw_##call *field; \
int ret; \
\
field = (typeof(field))iter->ent; \
\
ret = trace_raw_output_prep(iter, trace_event); \
if (ret != TRACE_TYPE_HANDLED) \
return ret; \
\
trace_event_printf(iter, print); \
\
return trace_handle_return(s); \
} \
static struct trace_event_functions trace_event_type_funcs_##call = { \
.trace = trace_raw_output_##call, \
};
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, call, proto, args, print) \
static notrace enum print_line_t \
trace_raw_output_##call(struct trace_iterator *iter, int flags, \
struct trace_event *event) \
{ \
struct trace_event_raw_##template *field; \
struct trace_entry *entry; \
struct trace_seq *p = &iter->tmp_seq; \
\
entry = iter->ent; \
\
if (entry->type != event_##call.event.type) { \
WARN_ON_ONCE(1); \
return TRACE_TYPE_UNHANDLED; \
} \
\
field = (typeof(field))entry; \
\
trace_seq_init(p); \
return trace_output_call(iter, #call, print); \
} \
static struct trace_event_functions trace_event_type_funcs_##call = { \
.trace = trace_raw_output_##call, \
};
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#include "stages/stage4_defines.h"
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print) \
static struct trace_event_fields trace_event_fields_##call[] = { \
tstruct \
{} };
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print)
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#include "stages/stage5_defines.h"
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static inline notrace int trace_event_get_offsets_##call( \
struct trace_event_data_offsets_##call *__data_offsets, proto) \
{ \
int __data_size = 0; \
int __maybe_unused __item_length; \
struct trace_event_raw_##call __maybe_unused *entry; \
\
tstruct; \
\
return __data_size; \
}
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
* Stage 4 of the trace events.
*
* Override the macros in the event tracepoint header <trace/events/XXX.h>
* to include the following:
*
* For those macros defined with TRACE_EVENT:
*
* static struct trace_event_call event_<call>;
*
* static void trace_event_raw_event_<call>(void *__data, proto)
* {
* struct trace_event_file *trace_file = __data;
* struct trace_event_call *event_call = trace_file->event_call;
* struct trace_event_data_offsets_<call> __maybe_unused __data_offsets;
* unsigned long eflags = trace_file->flags;
* enum event_trigger_type __tt = ETT_NONE;
* struct ring_buffer_event *event;
* struct trace_event_raw_<call> *entry; <-- defined in stage 1
* struct trace_buffer *buffer;
* unsigned long irq_flags;
* int __data_size;
* int pc;
*
* if (!(eflags & EVENT_FILE_FL_TRIGGER_COND)) {
* if (eflags & EVENT_FILE_FL_TRIGGER_MODE)
* event_triggers_call(trace_file, NULL);
* if (eflags & EVENT_FILE_FL_SOFT_DISABLED)
* return;
* }
*
* local_save_flags(irq_flags);
* pc = preempt_count();
*
* __data_size = trace_event_get_offsets_<call>(&__data_offsets, args);
*
* event = trace_event_buffer_lock_reserve(&buffer, trace_file,
* event_<call>->event.type,
* sizeof(*entry) + __data_size,
* irq_flags, pc);
* if (!event)
* return;
* entry = ring_buffer_event_data(event);
*
* { <assign>; } <-- Here we assign the entries by the __field and
* __array macros.
*
* if (eflags & EVENT_FILE_FL_TRIGGER_COND)
* __tt = event_triggers_call(trace_file, entry);
*
* if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT,
* &trace_file->flags))
* ring_buffer_discard_commit(buffer, event);
* else if (!filter_check_discard(trace_file, entry, buffer, event))
* trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
*
* if (__tt)
* event_triggers_post_call(trace_file, __tt);
* }
*
* static struct trace_event ftrace_event_type_<call> = {
* .trace = trace_raw_output_<call>, <-- stage 2
* };
*
* static char print_fmt_<call>[] = <TP_printk>;
*
* static struct trace_event_class __used event_class_<template> = {
* .system = "<system>",
* .fields_array = trace_event_fields_<call>,
* .fields = LIST_HEAD_INIT(event_class_##call.fields),
* .raw_init = trace_event_raw_init,
* .probe = trace_event_raw_event_##call,
* .reg = trace_event_reg,
* };
*
* static struct trace_event_call event_<call> = {
* .class = event_class_<template>,
* {
* .tp = &__tracepoint_<call>,
* },
* .event = &ftrace_event_type_<call>,
* .print_fmt = print_fmt_<call>,
* .flags = TRACE_EVENT_FL_TRACEPOINT,
* };
* // its only safe to use pointers when doing linker tricks to
* // create an array.
* static struct trace_event_call __used
* __section("_ftrace_events") *__event_<call> = &event_<call>;
*
*/
#ifdef CONFIG_PERF_EVENTS
#define _TRACE_PERF_PROTO(call, proto) \
static notrace void \
perf_trace_##call(void *__data, proto);
#define _TRACE_PERF_INIT(call) \
.perf_probe = perf_trace_##call,
#else
#define _TRACE_PERF_PROTO(call, proto)
#define _TRACE_PERF_INIT(call)
#endif /* CONFIG_PERF_EVENTS */
#include "stages/stage6_defines.h"
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
\
static notrace void \
trace_event_raw_event_##call(void *__data, proto) \
{ \
struct trace_event_file *trace_file = __data; \
struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
struct trace_event_buffer fbuffer; \
struct trace_event_raw_##call *entry; \
int __data_size; \
\
if (trace_trigger_soft_disabled(trace_file)) \
return; \
\
__data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
\
entry = trace_event_buffer_reserve(&fbuffer, trace_file, \
sizeof(*entry) + __data_size); \
\
if (!entry) \
return; \
\
tstruct \
\
{ assign; } \
\
trace_event_buffer_commit(&fbuffer); \
}
/*
* The ftrace_test_probe is compiled out, it is only here as a build time check
* to make sure that if the tracepoint handling changes, the ftrace probe will
* fail to compile unless it too is updated.
*/
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, call, proto, args) \
static inline void ftrace_test_probe_##call(void) \
{ \
check_trace_callback_type_##call(trace_event_raw_event_##template); \
}
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#include "stages/stage7_defines.h"
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
_TRACE_PERF_PROTO(call, PARAMS(proto)); \
static char print_fmt_##call[] = print; \
static struct trace_event_class __used __refdata event_class_##call = { \
.system = TRACE_SYSTEM_STRING, \
.fields_array = trace_event_fields_##call, \
.fields = LIST_HEAD_INIT(event_class_##call.fields),\
.raw_init = trace_event_raw_init, \
.probe = trace_event_raw_event_##call, \
.reg = trace_event_reg, \
_TRACE_PERF_INIT(call) \
};
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, call, proto, args) \
\
static struct trace_event_call __used event_##call = { \
.class = &event_class_##template, \
{ \
.tp = &__tracepoint_##call, \
}, \
.event.funcs = &trace_event_type_funcs_##template, \
.print_fmt = print_fmt_##template, \
.flags = TRACE_EVENT_FL_TRACEPOINT, \
}; \
static struct trace_event_call __used \
__section("_ftrace_events") *__event_##call = &event_##call
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, call, proto, args, print) \
\
static char print_fmt_##call[] = print; \
\
static struct trace_event_call __used event_##call = { \
.class = &event_class_##template, \
{ \
.tp = &__tracepoint_##call, \
}, \
.event.funcs = &trace_event_type_funcs_##call, \
.print_fmt = print_fmt_##call, \
.flags = TRACE_EVENT_FL_TRACEPOINT, \
}; \
static struct trace_event_call __used \
__section("_ftrace_events") *__event_##call = &event_##call
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
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