Quelle  trace_events.h   Sprache: C

/* 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));

#undef TRACE_EVENT_SYSCALL
#define TRACE_EVENT_SYSCALL(name, proto, args, tstruct, assign, print, reg, unreg) \
 DECLARE_EVENT_SYSCALL_CLASS(name,         \
        PARAMS(proto),         \
        PARAMS(args),         \
        PARAMS(tstruct),         \
        PARAMS(assign),         \
        PARAMS(print));         \
 DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));

#include "stages/stage1_struct_define.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 DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS

#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_data_offsets.h"

#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
 struct trace_event_data_offsets_##call {   \
  tstruct;      \
 };

#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS

#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_trace_output.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 DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS

#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_event_fields.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 DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS

#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print)

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

#include "stages/stage5_get_offsets.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;      \
}

#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS

#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_event_callback.h"


#undef __DECLARE_EVENT_CLASS
#define __DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace void       \
do_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);    \
}

#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
        PARAMS(assign), PARAMS(print))   \
static notrace void       \
trace_event_raw_event_##call(void *__data, proto)   \
{         \
 do_trace_event_raw_event_##call(__data, args);   \
}

#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \
__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
        PARAMS(assign), PARAMS(print))   \
static notrace void       \
trace_event_raw_event_##call(void *__data, proto)   \
{         \
 might_fault();       \
 preempt_disable_notrace();     \
 do_trace_event_raw_event_##call(__data, args);   \
 preempt_enable_notrace();     \
}

/*
 * 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)

#undef __DECLARE_EVENT_CLASS

#include "stages/stage7_class_define.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 DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS

#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)