tracing/events: move the ftrace event tracing code to core
This patch moves the ftrace creation into include/trace/ftrace.h and
simplifies the work of developers in adding new tracepoints.
Just the act of creating the trace points in include/trace and including
define_trace.h will create the events in the debugfs/tracing/events
directory.
This patch removes the need of include/trace/trace_events.h
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index de9dc7d..980eb66 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -56,6 +56,10 @@
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+#ifdef CONFIG_EVENT_TRACER
+#include <trace/ftrace.h>
+#endif
+
#undef TRACE_HEADER_MULTI_READ
/* Only undef what we defined in this file */
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
new file mode 100644
index 0000000..955b967
--- /dev/null
+++ b/include/trace/ftrace.h
@@ -0,0 +1,492 @@
+/*
+ * 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>
+
+#undef TRACE_FORMAT
+#define TRACE_FORMAT(call, proto, args, fmt)
+
+#undef __array
+#define __array(type, item, len) type item[len];
+
+#undef __field
+#define __field(type, item) type item;
+
+#undef TP_STRUCT__entry
+#define TP_STRUCT__entry(args...) args
+
+#undef TRACE_EVENT
+#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
+ struct ftrace_raw_##name { \
+ struct trace_entry ent; \
+ tstruct \
+ }; \
+ static struct ftrace_event_call event_##name
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+/*
+ * Stage 2 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;
+ * int ret;
+ *
+ * entry = iter->ent;
+ *
+ * if (entry->type != event_<call>.id) {
+ * WARN_ON_ONCE(1);
+ * return TRACE_TYPE_UNHANDLED;
+ * }
+ *
+ * field = (typeof(field))entry;
+ *
+ * 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 TRACE_EVENT
+#define TRACE_EVENT(call, proto, args, tstruct, assign, print) \
+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; \
+ struct trace_entry *entry; \
+ int ret; \
+ \
+ entry = iter->ent; \
+ \
+ if (entry->type != event_##call.id) { \
+ WARN_ON_ONCE(1); \
+ return TRACE_TYPE_UNHANDLED; \
+ } \
+ \
+ field = (typeof(field))entry; \
+ \
+ ret = trace_seq_printf(s, #call ": " print); \
+ if (!ret) \
+ return TRACE_TYPE_PARTIAL_LINE; \
+ \
+ return TRACE_TYPE_HANDLED; \
+}
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+/*
+ * Setup the showing format of trace point.
+ *
+ * int
+ * ftrace_format_##call(struct trace_seq *s)
+ * {
+ * struct ftrace_raw_##call field;
+ * int ret;
+ *
+ * ret = trace_seq_printf(s, #type " " #item ";"
+ * " offset:%u; size:%u;\n",
+ * offsetof(struct ftrace_raw_##call, item),
+ * sizeof(field.type));
+ *
+ * }
+ */
+
+#undef TP_STRUCT__entry
+#define TP_STRUCT__entry(args...) args
+
+#undef __field
+#define __field(type, item) \
+ ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \
+ "offset:%u;\tsize:%u;\n", \
+ (unsigned int)offsetof(typeof(field), item), \
+ (unsigned int)sizeof(field.item)); \
+ if (!ret) \
+ return 0;
+
+#undef __array
+#define __array(type, item, len) \
+ ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \
+ "offset:%u;\tsize:%u;\n", \
+ (unsigned int)offsetof(typeof(field), item), \
+ (unsigned int)sizeof(field.item)); \
+ if (!ret) \
+ return 0;
+
+#undef __entry
+#define __entry REC
+
+#undef TP_printk
+#define TP_printk(fmt, args...) "%s, %s\n", #fmt, __stringify(args)
+
+#undef TP_fast_assign
+#define TP_fast_assign(args...) args
+
+#undef TRACE_EVENT
+#define TRACE_EVENT(call, proto, args, tstruct, func, print) \
+static int \
+ftrace_format_##call(struct trace_seq *s) \
+{ \
+ struct ftrace_raw_##call field; \
+ int ret; \
+ \
+ tstruct; \
+ \
+ trace_seq_printf(s, "\nprint fmt: " print); \
+ \
+ return ret; \
+}
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+#undef __field
+#define __field(type, item) \
+ ret = trace_define_field(event_call, #type, #item, \
+ offsetof(typeof(field), item), \
+ sizeof(field.item)); \
+ if (ret) \
+ return ret;
+
+#undef __array
+#define __array(type, item, len) \
+ BUILD_BUG_ON(len > MAX_FILTER_STR_VAL); \
+ ret = trace_define_field(event_call, #type "[" #len "]", #item, \
+ offsetof(typeof(field), item), \
+ sizeof(field.item)); \
+ if (ret) \
+ return ret;
+
+#undef TRACE_EVENT
+#define TRACE_EVENT(call, proto, args, tstruct, func, print) \
+int \
+ftrace_define_fields_##call(void) \
+{ \
+ struct ftrace_raw_##call field; \
+ struct ftrace_event_call *event_call = &event_##call; \
+ int ret; \
+ \
+ __common_field(unsigned char, type); \
+ __common_field(unsigned char, flags); \
+ __common_field(unsigned char, preempt_count); \
+ __common_field(int, pid); \
+ __common_field(int, tgid); \
+ \
+ tstruct; \
+ \
+ return ret; \
+}
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+/*
+ * Stage 3 of the trace events.
+ *
+ * Override the macros in <trace/trace_events.h> to include the following:
+ *
+ * static void ftrace_event_<call>(proto)
+ * {
+ * event_trace_printk(_RET_IP_, "<call>: " <fmt>);
+ * }
+ *
+ * static int ftrace_reg_event_<call>(void)
+ * {
+ * int ret;
+ *
+ * ret = register_trace_<call>(ftrace_event_<call>);
+ * if (!ret)
+ * pr_info("event trace: Could not activate trace point "
+ * "probe to <call>");
+ * return ret;
+ * }
+ *
+ * static void ftrace_unreg_event_<call>(void)
+ * {
+ * unregister_trace_<call>(ftrace_event_<call>);
+ * }
+ *
+ * For those macros defined with TRACE_FORMAT:
+ *
+ * static struct ftrace_event_call __used
+ * __attribute__((__aligned__(4)))
+ * __attribute__((section("_ftrace_events"))) event_<call> = {
+ * .name = "<call>",
+ * .regfunc = ftrace_reg_event_<call>,
+ * .unregfunc = ftrace_unreg_event_<call>,
+ * }
+ *
+ *
+ * For those macros defined with TRACE_EVENT:
+ *
+ * static struct ftrace_event_call event_<call>;
+ *
+ * static void ftrace_raw_event_<call>(proto)
+ * {
+ * struct ring_buffer_event *event;
+ * struct ftrace_raw_<call> *entry; <-- defined in stage 1
+ * unsigned long irq_flags;
+ * int pc;
+ *
+ * local_save_flags(irq_flags);
+ * pc = preempt_count();
+ *
+ * event = trace_current_buffer_lock_reserve(event_<call>.id,
+ * sizeof(struct ftrace_raw_<call>),
+ * irq_flags, pc);
+ * if (!event)
+ * return;
+ * entry = ring_buffer_event_data(event);
+ *
+ * <assign>; <-- Here we assign the entries by the __field and
+ * __array macros.
+ *
+ * trace_current_buffer_unlock_commit(event, irq_flags, pc);
+ * }
+ *
+ * static int ftrace_raw_reg_event_<call>(void)
+ * {
+ * int ret;
+ *
+ * ret = register_trace_<call>(ftrace_raw_event_<call>);
+ * if (!ret)
+ * pr_info("event trace: Could not activate trace point "
+ * "probe to <call>");
+ * return ret;
+ * }
+ *
+ * static void ftrace_unreg_event_<call>(void)
+ * {
+ * unregister_trace_<call>(ftrace_raw_event_<call>);
+ * }
+ *
+ * static struct trace_event ftrace_event_type_<call> = {
+ * .trace = ftrace_raw_output_<call>, <-- stage 2
+ * };
+ *
+ * static int ftrace_raw_init_event_<call>(void)
+ * {
+ * int id;
+ *
+ * id = register_ftrace_event(&ftrace_event_type_<call>);
+ * if (!id)
+ * return -ENODEV;
+ * event_<call>.id = id;
+ * return 0;
+ * }
+ *
+ * static struct ftrace_event_call __used
+ * __attribute__((__aligned__(4)))
+ * __attribute__((section("_ftrace_events"))) event_<call> = {
+ * .name = "<call>",
+ * .system = "<system>",
+ * .raw_init = ftrace_raw_init_event_<call>,
+ * .regfunc = ftrace_reg_event_<call>,
+ * .unregfunc = ftrace_unreg_event_<call>,
+ * .show_format = ftrace_format_<call>,
+ * }
+ *
+ */
+
+#undef TP_FMT
+#define TP_FMT(fmt, args...) fmt "\n", ##args
+
+#ifdef CONFIG_EVENT_PROFILE
+#define _TRACE_PROFILE(call, proto, args) \
+static void ftrace_profile_##call(proto) \
+{ \
+ extern void perf_tpcounter_event(int); \
+ perf_tpcounter_event(event_##call.id); \
+} \
+ \
+static int ftrace_profile_enable_##call(struct ftrace_event_call *call) \
+{ \
+ int ret = 0; \
+ \
+ if (!atomic_inc_return(&call->profile_count)) \
+ ret = register_trace_##call(ftrace_profile_##call); \
+ \
+ return ret; \
+} \
+ \
+static void ftrace_profile_disable_##call(struct ftrace_event_call *call) \
+{ \
+ if (atomic_add_negative(-1, &call->profile_count)) \
+ unregister_trace_##call(ftrace_profile_##call); \
+}
+
+#define _TRACE_PROFILE_INIT(call) \
+ .profile_count = ATOMIC_INIT(-1), \
+ .profile_enable = ftrace_profile_enable_##call, \
+ .profile_disable = ftrace_profile_disable_##call,
+
+#else
+#define _TRACE_PROFILE(call, proto, args)
+#define _TRACE_PROFILE_INIT(call)
+#endif
+
+#define _TRACE_FORMAT(call, proto, args, fmt) \
+static void ftrace_event_##call(proto) \
+{ \
+ event_trace_printk(_RET_IP_, #call ": " fmt); \
+} \
+ \
+static int ftrace_reg_event_##call(void) \
+{ \
+ int ret; \
+ \
+ ret = register_trace_##call(ftrace_event_##call); \
+ if (ret) \
+ pr_info("event trace: Could not activate trace point " \
+ "probe to " #call "\n"); \
+ return ret; \
+} \
+ \
+static void ftrace_unreg_event_##call(void) \
+{ \
+ unregister_trace_##call(ftrace_event_##call); \
+} \
+ \
+static struct ftrace_event_call event_##call; \
+ \
+static int ftrace_init_event_##call(void) \
+{ \
+ int id; \
+ \
+ id = register_ftrace_event(NULL); \
+ if (!id) \
+ return -ENODEV; \
+ event_##call.id = id; \
+ return 0; \
+}
+
+#undef TRACE_FORMAT
+#define TRACE_FORMAT(call, proto, args, fmt) \
+_TRACE_FORMAT(call, PARAMS(proto), PARAMS(args), PARAMS(fmt)) \
+_TRACE_PROFILE(call, PARAMS(proto), PARAMS(args)) \
+static struct ftrace_event_call __used \
+__attribute__((__aligned__(4))) \
+__attribute__((section("_ftrace_events"))) event_##call = { \
+ .name = #call, \
+ .system = __stringify(TRACE_SYSTEM), \
+ .raw_init = ftrace_init_event_##call, \
+ .regfunc = ftrace_reg_event_##call, \
+ .unregfunc = ftrace_unreg_event_##call, \
+ _TRACE_PROFILE_INIT(call) \
+}
+
+#undef __entry
+#define __entry entry
+
+#undef TRACE_EVENT
+#define TRACE_EVENT(call, proto, args, tstruct, assign, print) \
+_TRACE_PROFILE(call, PARAMS(proto), PARAMS(args)) \
+ \
+static struct ftrace_event_call event_##call; \
+ \
+static void ftrace_raw_event_##call(proto) \
+{ \
+ struct ftrace_event_call *call = &event_##call; \
+ struct ring_buffer_event *event; \
+ struct ftrace_raw_##call *entry; \
+ unsigned long irq_flags; \
+ int pc; \
+ \
+ local_save_flags(irq_flags); \
+ pc = preempt_count(); \
+ \
+ event = trace_current_buffer_lock_reserve(event_##call.id, \
+ sizeof(struct ftrace_raw_##call), \
+ irq_flags, pc); \
+ if (!event) \
+ return; \
+ entry = ring_buffer_event_data(event); \
+ \
+ assign; \
+ \
+ if (!filter_current_check_discard(call, entry, event)) \
+ trace_nowake_buffer_unlock_commit(event, irq_flags, pc); \
+} \
+ \
+static int ftrace_raw_reg_event_##call(void) \
+{ \
+ int ret; \
+ \
+ ret = register_trace_##call(ftrace_raw_event_##call); \
+ if (ret) \
+ pr_info("event trace: Could not activate trace point " \
+ "probe to " #call "\n"); \
+ return ret; \
+} \
+ \
+static void ftrace_raw_unreg_event_##call(void) \
+{ \
+ unregister_trace_##call(ftrace_raw_event_##call); \
+} \
+ \
+static struct trace_event ftrace_event_type_##call = { \
+ .trace = ftrace_raw_output_##call, \
+}; \
+ \
+static int ftrace_raw_init_event_##call(void) \
+{ \
+ int id; \
+ \
+ id = register_ftrace_event(&ftrace_event_type_##call); \
+ if (!id) \
+ return -ENODEV; \
+ event_##call.id = id; \
+ INIT_LIST_HEAD(&event_##call.fields); \
+ init_preds(&event_##call); \
+ return 0; \
+} \
+ \
+static struct ftrace_event_call __used \
+__attribute__((__aligned__(4))) \
+__attribute__((section("_ftrace_events"))) event_##call = { \
+ .name = #call, \
+ .system = __stringify(TRACE_SYSTEM), \
+ .raw_init = ftrace_raw_init_event_##call, \
+ .regfunc = ftrace_raw_reg_event_##call, \
+ .unregfunc = ftrace_raw_unreg_event_##call, \
+ .show_format = ftrace_format_##call, \
+ .define_fields = ftrace_define_fields_##call, \
+ _TRACE_PROFILE_INIT(call) \
+}
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+#undef _TRACE_PROFILE
+#undef _TRACE_PROFILE_INIT
+
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
deleted file mode 100644
index 13d6b85..0000000
--- a/include/trace/trace_events.h
+++ /dev/null
@@ -1,7 +0,0 @@
-/* trace/<type>.h here */
-
-#include <trace/sched.h>
-#include <trace/irq.h>
-#include <trace/lockdep.h>
-#include <trace/skb.h>
-#include <trace/kmem.h>