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linux/include/trace/ftrace.h
Steven Rostedt f5abaa1bfc tracing: Add DEFINE_EVENT_FN() macro 
Each TRACE_EVENT() adds several helper functions. If two or more trace events
share the same structure and print format, they can also share most of these
helper functions and save a lot of space from duplicate code. This is why the
DECLARE_EVENT_CLASS() and DEFINE_EVENT() were created.

Some events require a trigger to be called at registering and unregistering of
the event and to do so they use TRACE_EVENT_FN().

If multiple events require a trigger, they currently have no choice but to use
TRACE_EVENT_FN() as there's no DEFINE_EVENT_FN() available. This unfortunately
causes a lot of wasted duplicate code created.

By adding a DEFINE_EVENT_FN(), these events can still use a
DECLARE_EVENT_CLASS() and then define their own triggers.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/51C3236C.8030508@hds.com
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-06-20 22:24:32 -07:00

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/*
* Stage 1 of the trace events.
*
* Override the macros in <trace/trace_events.h> to include the following:
*
* struct ftrace_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/ftrace_event.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));
#undef __field
#define __field(type, item) type item;
#undef __field_ext
#define __field_ext(type, item, filter_type) type item;
#undef __array
#define __array(type, item, len) type item[len];
#undef __dynamic_array
#define __dynamic_array(type, item, len) u32 __data_loc_##item;
#undef __string
#define __string(item, src) __dynamic_array(char, item, -1)
#undef TP_STRUCT__entry
#define TP_STRUCT__entry(args...) args
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print) \
struct ftrace_raw_##name { \
struct trace_entry ent; \
tstruct \
char __data[0]; \
}; \
\
static struct ftrace_event_class event_class_##name;
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args) \
static struct ftrace_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_FLAGS
#define TRACE_EVENT_FLAGS(name, value) \
__TRACE_EVENT_FLAGS(name, value)
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
* Stage 2 of the trace events.
*
* Include the following:
*
* struct ftrace_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>.
*/
#undef __field
#define __field(type, item)
#undef __field_ext
#define __field_ext(type, item, filter_type)
#undef __array
#define __array(type, item, len)
#undef __dynamic_array
#define __dynamic_array(type, item, len) u32 item;
#undef __string
#define __string(item, src) __dynamic_array(char, item, -1)
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
struct ftrace_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) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
#undef TRACE_EVENT_FLAGS
#define TRACE_EVENT_FLAGS(event, flag)
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
* Stage 3 of the trace events.
*
* Override the macros in <trace/trace_events.h> to include the following:
*
* enum print_line_t
* ftrace_raw_output_<call>(struct trace_iterator *iter, int flags)
* {
* struct trace_seq *s = &iter->seq;
* struct ftrace_raw_<call> *field; <-- defined in stage 1
* struct trace_entry *entry;
* struct trace_seq *p = &iter->tmp_seq;
* int ret;
*
* 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);
* ret = trace_seq_printf(s, "%s: ", <call>);
* if (ret)
* ret = trace_seq_printf(s, <TP_printk> "\n");
* if (!ret)
* return TRACE_TYPE_PARTIAL_LINE;
*
* return TRACE_TYPE_HANDLED;
* }
*
* 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.
*/
#undef __entry
#define __entry field
#undef TP_printk
#define TP_printk(fmt, args...) fmt "\n", args
#undef __get_dynamic_array
#define __get_dynamic_array(field) \
((void *)__entry + (__entry->__data_loc_##field & 0xffff))
#undef __get_str
#define __get_str(field) (char *)__get_dynamic_array(field)
#undef __print_flags
#define __print_flags(flag, delim, flag_array...) \
({ \
static const struct trace_print_flags __flags[] = \
{ flag_array, { -1, NULL }}; \
ftrace_print_flags_seq(p, delim, flag, __flags); \
})
#undef __print_symbolic
#define __print_symbolic(value, symbol_array...) \
({ \
static const struct trace_print_flags symbols[] = \
{ symbol_array, { -1, NULL }}; \
ftrace_print_symbols_seq(p, value, symbols); \
})
#undef __print_symbolic_u64
#if BITS_PER_LONG == 32
#define __print_symbolic_u64(value, symbol_array...) \
({ \
static const struct trace_print_flags_u64 symbols[] = \
{ symbol_array, { -1, NULL } }; \
ftrace_print_symbols_seq_u64(p, value, symbols); \
})
#else
#define __print_symbolic_u64(value, symbol_array...) \
__print_symbolic(value, symbol_array)
#endif
#undef __print_hex
#define __print_hex(buf, buf_len) ftrace_print_hex_seq(p, buf, buf_len)
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace enum print_line_t \
ftrace_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 ftrace_raw_##call *field; \
int ret; \
\
field = (typeof(field))iter->ent; \
\
ret = ftrace_raw_output_prep(iter, trace_event); \
if (ret) \
return ret; \
\
ret = trace_seq_printf(s, print); \
if (!ret) \
return TRACE_TYPE_PARTIAL_LINE; \
\
return TRACE_TYPE_HANDLED; \
} \
static struct trace_event_functions ftrace_event_type_funcs_##call = { \
.trace = ftrace_raw_output_##call, \
};
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, call, proto, args, print) \
static notrace enum print_line_t \
ftrace_raw_output_##call(struct trace_iterator *iter, int flags, \
struct trace_event *event) \
{ \
struct trace_seq *s = &iter->seq; \
struct ftrace_raw_##template *field; \
struct trace_entry *entry; \
struct trace_seq *p = &iter->tmp_seq; \
int ret; \
\
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); \
ret = trace_seq_printf(s, "%s: ", #call); \
if (ret) \
ret = trace_seq_printf(s, print); \
if (!ret) \
return TRACE_TYPE_PARTIAL_LINE; \
\
return TRACE_TYPE_HANDLED; \
} \
static struct trace_event_functions ftrace_event_type_funcs_##call = { \
.trace = ftrace_raw_output_##call, \
};
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#undef __field_ext
#define __field_ext(type, item, filter_type) \
ret = trace_define_field(event_call, #type, #item, \
offsetof(typeof(field), item), \
sizeof(field.item), \
is_signed_type(type), filter_type); \
if (ret) \
return ret;
#undef __field
#define __field(type, item) __field_ext(type, item, FILTER_OTHER)
#undef __array
#define __array(type, item, len) \
do { \
mutex_lock(&event_storage_mutex); \
BUILD_BUG_ON(len > MAX_FILTER_STR_VAL); \
snprintf(event_storage, sizeof(event_storage), \
"%s[%d]", #type, len); \
ret = trace_define_field(event_call, event_storage, #item, \
offsetof(typeof(field), item), \
sizeof(field.item), \
is_signed_type(type), FILTER_OTHER); \
mutex_unlock(&event_storage_mutex); \
if (ret) \
return ret; \
} while (0);
#undef __dynamic_array
#define __dynamic_array(type, item, len) \
ret = trace_define_field(event_call, "__data_loc " #type "[]", #item, \
offsetof(typeof(field), __data_loc_##item), \
sizeof(field.__data_loc_##item), \
is_signed_type(type), FILTER_OTHER);
#undef __string
#define __string(item, src) __dynamic_array(char, item, -1)
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print) \
static int notrace __init \
ftrace_define_fields_##call(struct ftrace_event_call *event_call) \
{ \
struct ftrace_raw_##call field; \
int ret; \
\
tstruct; \
\
return ret; \
}
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args)
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
* remember the offset of each array from the beginning of the event.
*/
#undef __entry
#define __entry entry
#undef __field
#define __field(type, item)
#undef __field_ext
#define __field_ext(type, item, filter_type)
#undef __array
#define __array(type, item, len)
#undef __dynamic_array
#define __dynamic_array(type, item, len) \
__data_offsets->item = __data_size + \
offsetof(typeof(*entry), __data); \
__data_offsets->item |= (len * sizeof(type)) << 16; \
__data_size += (len) * sizeof(type);
#undef __string
#define __string(item, src) __dynamic_array(char, item, strlen(src) + 1)
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static inline notrace int ftrace_get_offsets_##call( \
struct ftrace_data_offsets_##call *__data_offsets, proto) \
{ \
int __data_size = 0; \
struct ftrace_raw_##call __maybe_unused *entry; \
\
tstruct; \
\
return __data_size; \
}
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args)
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
* Stage 4 of the trace events.
*
* Override the macros in <trace/trace_events.h> to include the following:
*
* For those macros defined with TRACE_EVENT:
*
* static struct ftrace_event_call event_<call>;
*
* static void ftrace_raw_event_<call>(void *__data, proto)
* {
* struct ftrace_event_file *ftrace_file = __data;
* struct ftrace_event_call *event_call = ftrace_file->event_call;
* struct ftrace_data_offsets_<call> __maybe_unused __data_offsets;
* struct ring_buffer_event *event;
* struct ftrace_raw_<call> *entry; <-- defined in stage 1
* struct ring_buffer *buffer;
* unsigned long irq_flags;
* int __data_size;
* int pc;
*
* if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT,
* &ftrace_file->flags))
* return;
*
* local_save_flags(irq_flags);
* pc = preempt_count();
*
* __data_size = ftrace_get_offsets_<call>(&__data_offsets, args);
*
* event = trace_event_buffer_lock_reserve(&buffer, ftrace_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 (!filter_current_check_discard(buffer, event_call, entry, event))
* trace_nowake_buffer_unlock_commit(buffer,
* event, irq_flags, pc);
* }
*
* static struct trace_event ftrace_event_type_<call> = {
* .trace = ftrace_raw_output_<call>, <-- stage 2
* };
*
* static const char print_fmt_<call>[] = <TP_printk>;
*
* static struct ftrace_event_class __used event_class_<template> = {
* .system = "<system>",
* .define_fields = ftrace_define_fields_<call>,
* .fields = LIST_HEAD_INIT(event_class_##call.fields),
* .raw_init = trace_event_raw_init,
* .probe = ftrace_raw_event_##call,
* .reg = ftrace_event_reg,
* };
*
* static struct ftrace_event_call event_<call> = {
* .name = "<call>",
* .class = event_class_<template>,
* .event = &ftrace_event_type_<call>,
* .print_fmt = print_fmt_<call>,
* };
* // its only safe to use pointers when doing linker tricks to
* // create an array.
* static struct ftrace_event_call __used
* __attribute__((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 */
#undef __entry
#define __entry entry
#undef __field
#define __field(type, item)
#undef __array
#define __array(type, item, len)
#undef __dynamic_array
#define __dynamic_array(type, item, len) \
__entry->__data_loc_##item = __data_offsets.item;
#undef __string
#define __string(item, src) __dynamic_array(char, item, -1) \
#undef __assign_str
#define __assign_str(dst, src) \
strcpy(__get_str(dst), src);
#undef TP_fast_assign
#define TP_fast_assign(args...) args
#undef TP_perf_assign
#define TP_perf_assign(args...)
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
\
static notrace void \
ftrace_raw_event_##call(void *__data, proto) \
{ \
struct ftrace_event_file *ftrace_file = __data; \
struct ftrace_event_call *event_call = ftrace_file->event_call; \
struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
struct ring_buffer_event *event; \
struct ftrace_raw_##call *entry; \
struct ring_buffer *buffer; \
unsigned long irq_flags; \
int __data_size; \
int pc; \
\
if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, \
&ftrace_file->flags)) \
return; \
\
local_save_flags(irq_flags); \
pc = preempt_count(); \
\
__data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
\
event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, \
event_call->event.type, \
sizeof(*entry) + __data_size, \
irq_flags, pc); \
if (!event) \
return; \
entry = ring_buffer_event_data(event); \
\
tstruct \
\
{ assign; } \
\
if (!filter_current_check_discard(buffer, event_call, entry, event)) \
trace_buffer_unlock_commit(buffer, event, irq_flags, pc); \
}
/*
* 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(ftrace_raw_event_##template); \
}
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print)
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#undef __entry
#define __entry REC
#undef __print_flags
#undef __print_symbolic
#undef __print_hex
#undef __get_dynamic_array
#undef __get_str
#undef TP_printk
#define TP_printk(fmt, args...) "\"" fmt "\", " __stringify(args)
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
_TRACE_PERF_PROTO(call, PARAMS(proto)); \
static const char print_fmt_##call[] = print; \
static struct ftrace_event_class __used __refdata event_class_##call = { \
.system = __stringify(TRACE_SYSTEM), \
.define_fields = ftrace_define_fields_##call, \
.fields = LIST_HEAD_INIT(event_class_##call.fields),\
.raw_init = trace_event_raw_init, \
.probe = ftrace_raw_event_##call, \
.reg = ftrace_event_reg, \
_TRACE_PERF_INIT(call) \
};
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, call, proto, args) \
\
static struct ftrace_event_call __used event_##call = { \
.name = #call, \
.class = &event_class_##template, \
.event.funcs = &ftrace_event_type_funcs_##template, \
.print_fmt = print_fmt_##template, \
}; \
static struct ftrace_event_call __used \
__attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, call, proto, args, print) \
\
static const char print_fmt_##call[] = print; \
\
static struct ftrace_event_call __used event_##call = { \
.name = #call, \
.class = &event_class_##template, \
.event.funcs = &ftrace_event_type_funcs_##call, \
.print_fmt = print_fmt_##call, \
}; \
static struct ftrace_event_call __used \
__attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#ifdef CONFIG_PERF_EVENTS
#undef __entry
#define __entry entry
#undef __get_dynamic_array
#define __get_dynamic_array(field) \
((void *)__entry + (__entry->__data_loc_##field & 0xffff))
#undef __get_str
#define __get_str(field) (char *)__get_dynamic_array(field)
#undef __perf_addr
#define __perf_addr(a) __addr = (a)
#undef __perf_count
#define __perf_count(c) __count = (c)
#undef __perf_task
#define __perf_task(t) __task = (t)
#undef TP_perf_assign
#define TP_perf_assign(args...) args
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace void \
perf_trace_##call(void *__data, proto) \
{ \
struct ftrace_event_call *event_call = __data; \
struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
struct ftrace_raw_##call *entry; \
struct pt_regs __regs; \
u64 __addr = 0, __count = 1; \
struct task_struct *__task = NULL; \
struct hlist_head *head; \
int __entry_size; \
int __data_size; \
int rctx; \
\
perf_fetch_caller_regs(&__regs); \
\
__data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
__entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\
sizeof(u64)); \
__entry_size -= sizeof(u32); \
\
if (WARN_ONCE(__entry_size > PERF_MAX_TRACE_SIZE, \
"profile buffer not large enough")) \
return; \
\
entry = (struct ftrace_raw_##call *)perf_trace_buf_prepare( \
__entry_size, event_call->event.type, &__regs, &rctx); \
if (!entry) \
return; \
\
tstruct \
\
{ assign; } \
\
head = this_cpu_ptr(event_call->perf_events); \
perf_trace_buf_submit(entry, __entry_size, rctx, __addr, \
__count, &__regs, head, __task); \
}
/*
* This part is compiled out, it is only here as a build time check
* to make sure that if the tracepoint handling changes, the
* perf probe will fail to compile unless it too is updated.
*/
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, call, proto, args) \
static inline void perf_test_probe_##call(void) \
{ \
check_trace_callback_type_##call(perf_trace_##template); \
}
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#endif /* CONFIG_PERF_EVENTS */
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