ftrace: Rework event_create_dir()

Rework event_create_dir() to use an array of static data instead of
function pointers where possible.

The problem is that it would call the function pointer on module load
before parse_args(), possibly even before jump_labels were initialized.
Luckily the generated functions don't use jump_labels but it still seems
fragile. It also gets in the way of changing when we make the module map
executable.

The generated function are basically calling trace_define_field() with a
bunch of static arguments. So instead of a function, capture these
arguments in a static array, avoiding the function call.

Now there are a number of cases where the fields are dynamic (syscall
arguments, kprobes and uprobes), in which case a static array does not
work, for these we preserve the function call. Luckily all these cases
are not related to modules and so we can retain the function call for
them.

Also fix up all broken tracepoint definitions that now generate a
compile error.

Tested-by: Alexei Starovoitov <[email protected]>
Tested-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Steven Rostedt (VMware) <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: Peter Zijlstra

drivers/infiniband/hw/hfi1/trace_tid.h

@@ -138,10 +138,10 @@ TRACE_EVENT(/* put_tid */
 	TP_ARGS(dd, index, type, pa, order),
 	TP_STRUCT__entry(/* entry */
 		DD_DEV_ENTRY(dd)
-		__field(unsigned long, pa);
-		__field(u32, index);
-		__field(u32, type);
-		__field(u16, order);
+		__field(unsigned long, pa)
+		__field(u32, index)
+		__field(u32, type)
+		__field(u16, order)
 	),
 	TP_fast_assign(/* assign */
 		DD_DEV_ASSIGN(dd);

drivers/infiniband/hw/hfi1/trace_tx.h

@@ -588,7 +588,7 @@ TRACE_EVENT(hfi1_sdma_user_reqinfo,
 	    TP_PROTO(struct hfi1_devdata *dd, u16 ctxt, u8 subctxt, u16 *i),
 	    TP_ARGS(dd, ctxt, subctxt, i),
 	    TP_STRUCT__entry(
-		    DD_DEV_ENTRY(dd);
+		    DD_DEV_ENTRY(dd)
 		    __field(u16, ctxt)
 		    __field(u8, subctxt)
 		    __field(u8, ver_opcode)

drivers/lightnvm/pblk-trace.h

@@ -46,7 +46,7 @@ TRACE_EVENT(pblk_chunk_reset,
 	TP_STRUCT__entry(
 		__string(name, name)
 		__field(u64, ppa)
-		__field(int, state);
+		__field(int, state)
 	),
 
 	TP_fast_assign(
@@ -72,7 +72,7 @@ TRACE_EVENT(pblk_chunk_state,
 	TP_STRUCT__entry(
 		__string(name, name)
 		__field(u64, ppa)
-		__field(int, state);
+		__field(int, state)
 	),
 
 	TP_fast_assign(
@@ -98,7 +98,7 @@ TRACE_EVENT(pblk_line_state,
 	TP_STRUCT__entry(
 		__string(name, name)
 		__field(int, line)
-		__field(int, state);
+		__field(int, state)
 	),
 
 	TP_fast_assign(
@@ -121,7 +121,7 @@ TRACE_EVENT(pblk_state,
 
 	TP_STRUCT__entry(
 		__string(name, name)
-		__field(int, state);
+		__field(int, state)
 	),
 
 	TP_fast_assign(

drivers/net/fjes/fjes_trace.h

@@ -28,7 +28,7 @@ TRACE_EVENT(fjes_hw_issue_request_command,
 		__field(u8, cs_busy)
 		__field(u8, cs_complete)
 		__field(int, timeout)
-		__field(int, ret);
+		__field(int, ret)
 	),
 	TP_fast_assign(
 		__entry->cr_req = cr->bits.req_code;

drivers/net/wireless/ath/ath10k/trace.h

@@ -239,7 +239,7 @@ TRACE_EVENT(ath10k_wmi_dbglog,
 	TP_STRUCT__entry(
 		__string(device, dev_name(ar->dev))
 		__string(driver, dev_driver_string(ar->dev))
-		__field(u8, hw_type);
+		__field(u8, hw_type)
 		__field(size_t, buf_len)
 		__dynamic_array(u8, buf, buf_len)
 	),
@@ -269,7 +269,7 @@ TRACE_EVENT(ath10k_htt_pktlog,
 	TP_STRUCT__entry(
 		__string(device, dev_name(ar->dev))
 		__string(driver, dev_driver_string(ar->dev))
-		__field(u8, hw_type);
+		__field(u8, hw_type)
 		__field(u16, buf_len)
 		__dynamic_array(u8, pktlog, buf_len)
 	),
@@ -435,7 +435,7 @@ TRACE_EVENT(ath10k_htt_rx_desc,
 	TP_STRUCT__entry(
 		__string(device, dev_name(ar->dev))
 		__string(driver, dev_driver_string(ar->dev))
-		__field(u8, hw_type);
+		__field(u8, hw_type)
 		__field(u16, len)
 		__dynamic_array(u8, rxdesc, len)
 	),

fs/xfs/scrub/trace.h

@@ -329,7 +329,7 @@ TRACE_EVENT(xchk_btree_op_error,
 		__field(int, level)
 		__field(xfs_agnumber_t, agno)
 		__field(xfs_agblock_t, bno)
-		__field(int, ptr);
+		__field(int, ptr)
 		__field(int, error)
 		__field(void *, ret_ip)
 	),
@@ -414,7 +414,7 @@ TRACE_EVENT(xchk_btree_error,
 		__field(int, level)
 		__field(xfs_agnumber_t, agno)
 		__field(xfs_agblock_t, bno)
-		__field(int, ptr);
+		__field(int, ptr)
 		__field(void *, ret_ip)
 	),
 	TP_fast_assign(
@@ -452,7 +452,7 @@ TRACE_EVENT(xchk_ifork_btree_error,
 		__field(int, level)
 		__field(xfs_agnumber_t, agno)
 		__field(xfs_agblock_t, bno)
-		__field(int, ptr);
+		__field(int, ptr)
 		__field(void *, ret_ip)
 	),
 	TP_fast_assign(

fs/xfs/xfs_trace.h

@@ -218,8 +218,8 @@ DECLARE_EVENT_CLASS(xfs_bmap_class,
 	TP_STRUCT__entry(
 		__field(dev_t, dev)
 		__field(xfs_ino_t, ino)
-		__field(void *, leaf);
-		__field(int, pos);
+		__field(void *, leaf)
+		__field(int, pos)
 		__field(xfs_fileoff_t, startoff)
 		__field(xfs_fsblock_t, startblock)
 		__field(xfs_filblks_t, blockcount)

include/linux/trace_events.h

@@ -187,6 +187,22 @@ enum trace_reg {
 
 struct trace_event_call;
 
+#define TRACE_FUNCTION_TYPE ((const char *)~0UL)
+
+struct trace_event_fields {
+	const char *type;
+	union {
+		struct {
+			const char *name;
+			const int  size;
+			const int  align;
+			const int  is_signed;
+			const int  filter_type;
+		};
+		int (*define_fields)(struct trace_event_call *);
+	};
+};
+
 struct trace_event_class {
 	const char		*system;
 	void			*probe;
@@ -195,7 +211,7 @@ struct trace_event_class {
 #endif
 	int			(*reg)(struct trace_event_call *event,
 				       enum trace_reg type, void *data);
-	int			(*define_fields)(struct trace_event_call *);
+	struct trace_event_fields *fields_array;
 	struct list_head	*(*get_fields)(struct trace_event_call *);
 	struct list_head	fields;
 	int			(*raw_init)(struct trace_event_call *);

include/trace/events/filemap.h

@@ -85,7 +85,7 @@ TRACE_EVENT(file_check_and_advance_wb_err,
 		TP_ARGS(file, old),
 
 		TP_STRUCT__entry(
-			__field(struct file *, file);
+			__field(struct file *, file)
 			__field(unsigned long, i_ino)
 			__field(dev_t, s_dev)
 			__field(errseq_t, old)

include/trace/events/rpcrdma.h

@@ -1507,7 +1507,7 @@ TRACE_EVENT(svcrdma_dma_map_page,
 	TP_ARGS(rdma, page),
 
 	TP_STRUCT__entry(
-		__field(const void *, page);
+		__field(const void *, page)
 		__string(device, rdma->sc_cm_id->device->name)
 		__string(addr, rdma->sc_xprt.xpt_remotebuf)
 	),

include/trace/trace_events.h

@@ -394,22 +394,16 @@ static struct trace_event_functions trace_event_type_funcs_##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;
+#define __field_ext(_type, _item, _filter_type) {			\
+	.type = #_type, .name = #_item,					\
+	.size = sizeof(_type), .align = __alignof__(_type),		\
+	.is_signed = is_signed_type(_type), .filter_type = _filter_type },
 
 #undef __field_struct_ext
-#define __field_struct_ext(type, item, filter_type)			\
-	ret = trace_define_field(event_call, #type, #item,		\
-				 offsetof(typeof(field), item),		\
-				 sizeof(field.item),			\
-				 0, filter_type);			\
-	if (ret)							\
-		return ret;
+#define __field_struct_ext(_type, _item, _filter_type) {		\
+	.type = #_type, .name = #_item,					\
+	.size = sizeof(_type), .align = __alignof__(_type),		\
+	0, .filter_type = _filter_type },
 
 #undef __field
 #define __field(type, item)	__field_ext(type, item, FILTER_OTHER)
@@ -418,25 +412,16 @@ static struct trace_event_functions trace_event_type_funcs_##call = {	\
 #define __field_struct(type, item) __field_struct_ext(type, item, FILTER_OTHER)
 
 #undef __array
-#define __array(type, item, len)					\
-	do {								\
-		char *type_str = #type"["__stringify(len)"]";		\
-		BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);			\
-		BUILD_BUG_ON(len <= 0);					\
-		ret = trace_define_field(event_call, type_str, #item,	\
-				 offsetof(typeof(field), item),		\
-				 sizeof(field.item),			\
-				 is_signed_type(type), FILTER_OTHER);	\
-		if (ret)						\
-			return ret;					\
-	} while (0);
+#define __array(_type, _item, _len) {					\
+	.type = #_type"["__stringify(_len)"]", .name = #_item,		\
+	.size = sizeof(_type[_len]), .align = __alignof__(_type),	\
+	.is_signed = is_signed_type(_type), .filter_type = FILTER_OTHER },
 
 #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);
+#define __dynamic_array(_type, _item, _len) {				\
+	.type = "__data_loc " #_type "[]", .name = #_item,		\
+	.size = 4, .align = 4,						\
+	.is_signed = is_signed_type(_type), .filter_type = FILTER_OTHER },
 
 #undef __string
 #define __string(item, src) __dynamic_array(char, item, -1)
@@ -446,16 +431,9 @@ static struct trace_event_functions trace_event_type_funcs_##call = {	\
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print)	\
-static int notrace __init						\
-trace_event_define_fields_##call(struct trace_event_call *event_call)	\
-{									\
-	struct trace_event_raw_##call field;				\
-	int ret;							\
-									\
-	tstruct;							\
-									\
-	return ret;							\
-}
+static struct trace_event_fields trace_event_fields_##call[] = {	\
+	tstruct								\
+	{} };
 
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args)
@@ -613,7 +591,7 @@ static inline notrace int trace_event_get_offsets_##call(		\
  *
  * static struct trace_event_class __used event_class_<template> = {
  *	.system			= "<system>",
- *	.define_fields		= trace_event_define_fields_<call>,
+ *	.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,
@@ -761,7 +739,7 @@ _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,			\
-	.define_fields		= trace_event_define_fields_##call,	\
+	.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,		\

kernel/trace/trace.h

@@ -49,6 +49,9 @@ enum trace_type {
 #undef __field
 #define __field(type, item)		type	item;
 
+#undef __field_fn
+#define __field_fn(type, item)		type	item;
+
 #undef __field_struct
 #define __field_struct(type, item)	__field(type, item)
 
@@ -68,26 +71,22 @@ enum trace_type {
 #define F_STRUCT(args...)		args
 
 #undef FTRACE_ENTRY
-#define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
+#define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
 	struct struct_name {						\
 		struct trace_entry	ent;				\
 		tstruct							\
 	}
 
 #undef FTRACE_ENTRY_DUP
-#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
+#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
 
 #undef FTRACE_ENTRY_REG
-#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
-			 filter, regfn) \
-	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter)
+#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	regfn)	\
+	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
 
 #undef FTRACE_ENTRY_PACKED
-#define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,	\
-			    filter)					\
-	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter) __packed
+#define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)	\
+	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
 
 #include "trace_entries.h"
 
@@ -1899,17 +1898,15 @@ extern void tracing_log_err(struct trace_array *tr,
 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
 
 #undef FTRACE_ENTRY
-#define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
+#define FTRACE_ENTRY(call, struct_name, id, tstruct, print)	\
 	extern struct trace_event_call					\
 	__aligned(4) event_##call;
 #undef FTRACE_ENTRY_DUP
-#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
-	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter)
+#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)	\
+	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 #undef FTRACE_ENTRY_PACKED
-#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
-	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
-		     filter)
+#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
+	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 
 #include "trace_entries.h"