Merge remote-tracking branch 'ftrace/ftrace/core' into HEAD

 Conflicts:
	include/trace/trace_events.h

Conflicts with:

  sched/tracing: Don't re-read p->state when emitting sched_switch event
  tracing: Introduce helpers to safely handle dynamic-sized sockaddrs

Documentation/admin-guide/kernel-parameters.txt

@@ -1465,6 +1465,14 @@
 			as early as possible in order to facilitate early
 			boot debugging.
 
+	ftrace_boot_snapshot
+			[FTRACE] On boot up, a snapshot will be taken of the
+			ftrace ring buffer that can be read at:
+			/sys/kernel/tracing/snapshot.
+			This is useful if you need tracing information from kernel
+			boot up that is likely to be overridden by user space
+			start up functionality.
+
 	ftrace_dump_on_oops[=orig_cpu]
 			[FTRACE] will dump the trace buffers on oops.
 			If no parameter is passed, ftrace will dump

include/linux/ftrace.h

@@ -30,6 +30,12 @@
 #define ARCH_SUPPORTS_FTRACE_OPS 0
 #endif
 
+#ifdef CONFIG_TRACING
+extern void ftrace_boot_snapshot(void);
+#else
+static inline void ftrace_boot_snapshot(void) { }
+#endif
+
 #ifdef CONFIG_FUNCTION_TRACER
 struct ftrace_ops;
 struct ftrace_regs;
@@ -215,7 +221,10 @@ struct ftrace_ops_hash {
 void ftrace_free_init_mem(void);
 void ftrace_free_mem(struct module *mod, void *start, void *end);
 #else
-static inline void ftrace_free_init_mem(void) { }
+static inline void ftrace_free_init_mem(void)
+{
+	ftrace_boot_snapshot();
+}
 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
 #endif
 

include/linux/trace_events.h

@@ -315,6 +315,7 @@ enum {
 	TRACE_EVENT_FL_KPROBE_BIT,
 	TRACE_EVENT_FL_UPROBE_BIT,
 	TRACE_EVENT_FL_EPROBE_BIT,
+	TRACE_EVENT_FL_CUSTOM_BIT,
 };
 
 /*
@@ -328,6 +329,9 @@ enum {
  *  KPROBE        - Event is a kprobe
  *  UPROBE        - Event is a uprobe
  *  EPROBE        - Event is an event probe
+ *  CUSTOM        - Event is a custom event (to be attached to an exsiting tracepoint)
+ *                   This is set when the custom event has not been attached
+ *                   to a tracepoint yet, then it is cleared when it is.
  */
 enum {
 	TRACE_EVENT_FL_FILTERED		= (1 << TRACE_EVENT_FL_FILTERED_BIT),
@@ -339,6 +343,7 @@ enum {
 	TRACE_EVENT_FL_KPROBE		= (1 << TRACE_EVENT_FL_KPROBE_BIT),
 	TRACE_EVENT_FL_UPROBE		= (1 << TRACE_EVENT_FL_UPROBE_BIT),
 	TRACE_EVENT_FL_EPROBE		= (1 << TRACE_EVENT_FL_EPROBE_BIT),
+	TRACE_EVENT_FL_CUSTOM		= (1 << TRACE_EVENT_FL_CUSTOM_BIT),
 };
 
 #define TRACE_EVENT_FL_UKPROBE (TRACE_EVENT_FL_KPROBE | TRACE_EVENT_FL_UPROBE)
@@ -440,7 +445,9 @@ static inline bool bpf_prog_array_valid(struct trace_event_call *call)
 static inline const char *
 trace_event_name(struct trace_event_call *call)
 {
-	if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
+	if (call->flags & TRACE_EVENT_FL_CUSTOM)
+		return call->name;
+	else if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
 		return call->tp ? call->tp->name : NULL;
 	else
 		return call->name;
@@ -903,3 +910,18 @@ perf_trace_buf_submit(void *raw_data, int size, int rctx, u16 type,
 #endif
 
 #endif /* _LINUX_TRACE_EVENT_H */
+
+/*
+ * Note: we keep the TRACE_CUSTOM_EVENT outside the include file ifdef protection.
+ *  This is due to the way trace custom events work. If a file includes two
+ *  trace event headers under one "CREATE_CUSTOM_TRACE_EVENTS" the first include
+ *  will override the TRACE_CUSTOM_EVENT and break the second include.
+ */
+
+#ifndef TRACE_CUSTOM_EVENT
+
+#define DECLARE_CUSTOM_EVENT_CLASS(name, proto, args, tstruct, assign, print)
+#define DEFINE_CUSTOM_EVENT(template, name, proto, args)
+#define TRACE_CUSTOM_EVENT(name, proto, args, struct, assign, print)
+
+#endif /* ifdef TRACE_CUSTOM_EVENT (see note above) */

include/trace/define_custom_trace.h

@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Trace files that want to automate creation of all tracepoints defined
+ * in their file should include this file. The following are macros that the
+ * trace file may define:
+ *
+ * TRACE_SYSTEM defines the system the tracepoint is for
+ *
+ * TRACE_INCLUDE_FILE if the file name is something other than TRACE_SYSTEM.h
+ *     This macro may be defined to tell define_trace.h what file to include.
+ *     Note, leave off the ".h".
+ *
+ * TRACE_INCLUDE_PATH if the path is something other than core kernel include/trace
+ *     then this macro can define the path to use. Note, the path is relative to
+ *     define_trace.h, not the file including it. Full path names for out of tree
+ *     modules must be used.
+ */
+
+#ifdef CREATE_CUSTOM_TRACE_EVENTS
+
+/* Prevent recursion */
+#undef CREATE_CUSTOM_TRACE_EVENTS
+
+#include <linux/stringify.h>
+
+#undef TRACE_CUSTOM_EVENT
+#define TRACE_CUSTOM_EVENT(name, proto, args, tstruct, assign, print)
+
+#undef DEFINE_CUSTOM_EVENT
+#define DEFINE_CUSTOM_EVENT(template, name, proto, args)
+
+#undef TRACE_INCLUDE
+#undef __TRACE_INCLUDE
+
+#ifndef TRACE_INCLUDE_FILE
+# define TRACE_INCLUDE_FILE TRACE_SYSTEM
+# define UNDEF_TRACE_INCLUDE_FILE
+#endif
+
+#ifndef TRACE_INCLUDE_PATH
+# define __TRACE_INCLUDE(system) <trace/events/system.h>
+# define UNDEF_TRACE_INCLUDE_PATH
+#else
+# define __TRACE_INCLUDE(system) __stringify(TRACE_INCLUDE_PATH/system.h)
+#endif
+
+# define TRACE_INCLUDE(system) __TRACE_INCLUDE(system)
+
+/* Let the trace headers be reread */
+#define TRACE_CUSTOM_MULTI_READ
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+#ifdef TRACEPOINTS_ENABLED
+#include <trace/trace_custom_events.h>
+#endif
+
+#undef TRACE_CUSTOM_EVENT
+#undef DECLARE_CUSTOM_EVENT_CLASS
+#undef DEFINE_CUSTOM_EVENT
+#undef TRACE_CUSTOM_MULTI_READ
+
+/* Only undef what we defined in this file */
+#ifdef UNDEF_TRACE_INCLUDE_FILE
+# undef TRACE_INCLUDE_FILE
+# undef UNDEF_TRACE_INCLUDE_FILE
+#endif
+
+#ifdef UNDEF_TRACE_INCLUDE_PATH
+# undef TRACE_INCLUDE_PATH
+# undef UNDEF_TRACE_INCLUDE_PATH
+#endif
+
+/* We may be processing more files */
+#define CREATE_CUSTOM_TRACE_POINTS
+
+#endif /* CREATE_CUSTOM_TRACE_POINTS */

include/trace/stages/init.h

@@ -0,0 +1,37 @@
+
+#define __app__(x, y) str__##x##y
+#define __app(x, y) __app__(x, y)
+
+#define TRACE_SYSTEM_STRING __app(TRACE_SYSTEM_VAR,__trace_system_name)
+
+#define TRACE_MAKE_SYSTEM_STR()				\
+	static const char TRACE_SYSTEM_STRING[] =	\
+		__stringify(TRACE_SYSTEM)
+
+TRACE_MAKE_SYSTEM_STR();
+
+#undef TRACE_DEFINE_ENUM
+#define TRACE_DEFINE_ENUM(a)				\
+	static struct trace_eval_map __used __initdata	\
+	__##TRACE_SYSTEM##_##a =			\
+	{						\
+		.system = TRACE_SYSTEM_STRING,		\
+		.eval_string = #a,			\
+		.eval_value = a				\
+	};						\
+	static struct trace_eval_map __used		\
+	__section("_ftrace_eval_map")			\
+	*TRACE_SYSTEM##_##a = &__##TRACE_SYSTEM##_##a
+
+#undef TRACE_DEFINE_SIZEOF
+#define TRACE_DEFINE_SIZEOF(a)				\
+	static struct trace_eval_map __used __initdata	\
+	__##TRACE_SYSTEM##_##a =			\
+	{						\
+		.system = TRACE_SYSTEM_STRING,		\
+		.eval_string = "sizeof(" #a ")",	\
+		.eval_value = sizeof(a)			\
+	};						\
+	static struct trace_eval_map __used		\
+	__section("_ftrace_eval_map")			\
+	*TRACE_SYSTEM##_##a = &__##TRACE_SYSTEM##_##a

include/trace/stages/stage1_defines.h

@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Stage 1 definitions for creating trace events */
+
+#undef __field
+#define __field(type, item)		type	item;
+
+#undef __field_ext
+#define __field_ext(type, item, filter_type)	type	item;
+
+#undef __field_struct
+#define __field_struct(type, item)	type	item;
+
+#undef __field_struct_ext
+#define __field_struct_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 __string_len
+#define __string_len(item, src, len) __dynamic_array(char, item, -1)
+
+#undef __bitmask
+#define __bitmask(item, nr_bits) __dynamic_array(char, item, -1)
+
+#undef __sockaddr
+#define __sockaddr(field, len) __dynamic_array(u8, field, len)
+
+#undef __rel_dynamic_array
+#define __rel_dynamic_array(type, item, len) u32 __rel_loc_##item;
+
+#undef __rel_string
+#define __rel_string(item, src) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_string_len
+#define __rel_string_len(item, src, len) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_bitmask
+#define __rel_bitmask(item, nr_bits) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_sockaddr
+#define __rel_sockaddr(field, len) __rel_dynamic_array(u8, field, len)
+
+#undef TP_STRUCT__entry
+#define TP_STRUCT__entry(args...) args

include/trace/stages/stage2_defines.h

@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Stage 2 definitions for creating trace events */
+
+#undef TRACE_DEFINE_ENUM
+#define TRACE_DEFINE_ENUM(a)
+
+#undef TRACE_DEFINE_SIZEOF
+#define TRACE_DEFINE_SIZEOF(a)
+
+#undef __field
+#define __field(type, item)
+
+#undef __field_ext
+#define __field_ext(type, item, filter_type)
+
+#undef __field_struct
+#define __field_struct(type, item)
+
+#undef __field_struct_ext
+#define __field_struct_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 __string_len
+#define __string_len(item, src, len) __dynamic_array(char, item, -1)
+
+#undef __bitmask
+#define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1)
+
+#undef __sockaddr
+#define __sockaddr(field, len) __dynamic_array(u8, field, len)
+
+#undef __rel_dynamic_array
+#define __rel_dynamic_array(type, item, len)	u32 item;
+
+#undef __rel_string
+#define __rel_string(item, src) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_string_len
+#define __rel_string_len(item, src, len) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_bitmask
+#define __rel_bitmask(item, nr_bits) __rel_dynamic_array(unsigned long, item, -1)