[PATCH 1/8] trace: add new DECLARE_EVENT_CLASS_PRINT_INIT class type

[Linyu Yuan <quic_linyyuan@quicinc.com>]

This class almost same as DECLARE_EVENT_CLASS, it allow user add some
init operation before print at output stage.

Add a new macro TP_printk_init(), user can add operation in it.

Also add a new TRACE_EVENT_PRINT_INIT() macro.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
---
 include/linux/tracepoint.h                 |  22 ++++
 include/trace/bpf_probe.h                  |   4 +
 include/trace/perf.h                       |  43 ++++++++
 include/trace/stages/stage3_trace_output.h |   3 +
 include/trace/trace_events.h               | 118 +++++++++++++++++++++
 5 files changed, 190 insertions(+)

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 88c0ba623ee6..3fd42640236a 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -551,6 +551,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
  */
 
 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
+#define DECLARE_EVENT_CLASS_PRINT_INIT(name, proto, args, tstruct, assign, print, init)
 #define DEFINE_EVENT(template, name, proto, args)		\
 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 #define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
@@ -576,6 +577,20 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 	DECLARE_TRACE_CONDITION(name, PARAMS(proto),		\
 				PARAMS(args), PARAMS(cond))
 
+#define TRACE_EVENT_PRINT_INIT(name, proto, args, struct, assign, print, init)	\
+	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define TRACE_EVENT_FN_PRINT_INIT(name, proto, args, struct,		\
+		assign, print, reg, unreg, init)			\
+	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define TRACE_EVENT_FN_COND_PRINT_INIT(name, proto, args, cond, struct,		\
+		assign, print, reg, unreg, init)			\
+	DECLARE_TRACE_CONDITION(name, PARAMS(proto),	\
+			PARAMS(args), PARAMS(cond))
+#define TRACE_EVENT_CONDITION_PRINT_INIT(name, proto, args, cond,		\
+			      struct, assign, print, init)		\
+	DECLARE_TRACE_CONDITION(name, PARAMS(proto),		\
+				PARAMS(args), PARAMS(cond))
+
 #define TRACE_EVENT_FLAGS(event, flag)
 
 #define TRACE_EVENT_PERF_PERM(event, expr...)
@@ -595,4 +610,11 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 #define DEFINE_EVENT_NOP(template, name, proto, args)			\
 	DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
 
+#define TRACE_EVENT_NOP_PRINT_INIT(name, proto, args, struct, assign, print, init)	\
+	DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
+
+#define DECLARE_EVENT_CLASS_NOP_PRINT_INIT(name, proto, args, tstruct, assign, print, init)
+#define DEFINE_EVENT_NOP(template, name, proto, args)			\
+	DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
+
 #endif /* ifdef TRACE_EVENT (see note above) */
diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h
index e609cd7da47e..99b5594a4a8e 100644
--- a/include/trace/bpf_probe.h
+++ b/include/trace/bpf_probe.h
@@ -54,6 +54,10 @@ __bpf_trace_##call(void *__data, proto)					\
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
 	__BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
 
+#undef DECLARE_EVENT_CLASS_PRINT_INIT
+#define DECLARE_EVENT_CLASS_PRINT_INIT(call, proto, args, tstruct, assign, print, init)	\
+	__BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
+
 /*
  * This part is compiled out, it is only here as a build time check
  * to make sure that if the tracepoint handling changes, the
diff --git a/include/trace/perf.h b/include/trace/perf.h
index 2c11181c82e0..bee78e8eef5d 100644
--- a/include/trace/perf.h
+++ b/include/trace/perf.h
@@ -55,6 +55,49 @@ perf_trace_##call(void *__data, proto)					\
 				  head, __task);			\
 }
 
+#undef DECLARE_EVENT_CLASS_PRINT_INIT
+#define DECLARE_EVENT_CLASS_PRINT_INIT(call, proto, args, tstruct, assign, print, init)	\
+static notrace void							\
+perf_trace_##call(void *__data, proto)					\
+{									\
+	struct trace_event_call *event_call = __data;			\
+	struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
+	struct trace_event_raw_##call *entry;				\
+	struct pt_regs *__regs;						\
+	u64 __count = 1;						\
+	struct task_struct *__task = NULL;				\
+	struct hlist_head *head;					\
+	int __entry_size;						\
+	int __data_size;						\
+	int rctx;							\
+									\
+	__data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
+									\
+	head = this_cpu_ptr(event_call->perf_events);			\
+	if (!bpf_prog_array_valid(event_call) &&			\
+	    __builtin_constant_p(!__task) && !__task &&			\
+	    hlist_empty(head))						\
+		return;							\
+									\
+	__entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\
+			     sizeof(u64));				\
+	__entry_size -= sizeof(u32);					\
+									\
+	entry = perf_trace_buf_alloc(__entry_size, &__regs, &rctx);	\
+	if (!entry)							\
+		return;							\
+									\
+	perf_fetch_caller_regs(__regs);					\
+									\
+	tstruct								\
+									\
+	{ assign; }							\
+									\
+	perf_trace_run_bpf_submit(entry, __entry_size, rctx,		\
+				  event_call, __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
diff --git a/include/trace/stages/stage3_trace_output.h b/include/trace/stages/stage3_trace_output.h
index c1fb1355d309..121425e695f5 100644
--- a/include/trace/stages/stage3_trace_output.h
+++ b/include/trace/stages/stage3_trace_output.h
@@ -142,3 +142,6 @@
 
 #undef __get_buf
 #define __get_buf(len)		trace_seq_acquire(p, (len))
+
+#undef TP_printk_init
+#define TP_printk_init(args...) args
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index c2f9cabf154d..9a8872544a8b 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -45,6 +45,17 @@
 			     PARAMS(print));		       \
 	DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
 
+#undef TRACE_EVENT_PRINT_INIT
+#define TRACE_EVENT_PRINT_INIT(name, proto, args, tstruct, assign, print, init) \
+	DECLARE_EVENT_CLASS_PRINT_INIT(name,			       \
+			     PARAMS(proto),		       \
+			     PARAMS(args),		       \
+			     PARAMS(tstruct),		       \
+			     PARAMS(assign),		       \
+			     PARAMS(print),			\
+			     PARAMS(init));		       \
+	DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
+
 #include "stages/stage1_struct_define.h"
 
 #undef DECLARE_EVENT_CLASS
@@ -57,6 +68,16 @@
 									\
 	static struct trace_event_class event_class_##name;
 
+#undef DECLARE_EVENT_CLASS_PRINT_INIT
+#define DECLARE_EVENT_CLASS_PRINT_INIT(name, proto, args, tstruct, assign, print, init)	\
+	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		\
@@ -117,6 +138,12 @@
 		tstruct;						\
 	};
 
+#undef DECLARE_EVENT_CLASS_PRINT_INIT
+#define DECLARE_EVENT_CLASS_PRINT_INIT(call, proto, args, tstruct, assign, print, init)	\
+	struct trace_event_data_offsets_##call {			\
+		tstruct;						\
+	};
+
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args)
 
@@ -208,6 +235,32 @@ static struct trace_event_functions trace_event_type_funcs_##call = {	\
 	.trace			= trace_raw_output_##call,		\
 };
 
+#undef DECLARE_EVENT_CLASS_PRINT_INIT
+#define DECLARE_EVENT_CLASS_PRINT_INIT(call, proto, args, tstruct, assign, print, init)	\
+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;						\
+									\
+	init								\
+	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					\
@@ -244,6 +297,12 @@ static struct trace_event_fields trace_event_fields_##call[] = {	\
 	tstruct								\
 	{} };
 
+#undef DECLARE_EVENT_CLASS_PRINT_INIT
+#define DECLARE_EVENT_CLASS_PRINT_INIT(call, proto, args, tstruct, func, print, init)	\
+static struct trace_event_fields trace_event_fields_##call[] = {	\
+	tstruct								\
+	{} };
+
 #undef DEFINE_EVENT_PRINT
 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)
 
@@ -265,6 +324,20 @@ static inline notrace int trace_event_get_offsets_##call(		\
 	return __data_size;						\
 }
 
+#undef DECLARE_EVENT_CLASS_PRINT_INIT
+#define DECLARE_EVENT_CLASS_PRINT_INIT(call, proto, args, tstruct, assign, print, init)	\
+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)
 
 /*
@@ -403,6 +476,37 @@ trace_event_raw_event_##call(void *__data, proto)			\
 									\
 	trace_event_buffer_commit(&fbuffer);				\
 }
+
+#undef DECLARE_EVENT_CLASS_PRINT_INIT
+#define DECLARE_EVENT_CLASS_PRINT_INIT(call, proto, args, tstruct, assign, print, init)	\
+									\
+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
@@ -434,6 +538,20 @@ static struct trace_event_class __used __refdata event_class_##call = { \
 	_TRACE_PERF_INIT(call)						\
 };
 
+#undef DECLARE_EVENT_CLASS_PRINT_INIT
+#define DECLARE_EVENT_CLASS_PRINT_INIT(call, proto, args, tstruct, assign, print, init)	\
+_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)			\
 									\
-- 
2.17.1