xref: /linux/include/linux/trace.h (revision d2356997)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_TRACE_H
3 #define _LINUX_TRACE_H
4 
5 #define TRACE_EXPORT_FUNCTION	BIT(0)
6 #define TRACE_EXPORT_EVENT	BIT(1)
7 #define TRACE_EXPORT_MARKER	BIT(2)
8 
9 /*
10  * The trace export - an export of Ftrace output. The trace_export
11  * can process traces and export them to a registered destination as
12  * an addition to the current only output of Ftrace - i.e. ring buffer.
13  *
14  * If you want traces to be sent to some other place rather than ring
15  * buffer only, just need to register a new trace_export and implement
16  * its own .write() function for writing traces to the storage.
17  *
18  * next		- pointer to the next trace_export
19  * write	- copy traces which have been delt with ->commit() to
20  *		  the destination
21  * flags	- which ftrace to be exported
22  */
23 struct trace_export {
24 	struct trace_export __rcu	*next;
25 	void (*write)(struct trace_export *, const void *, unsigned int);
26 	int flags;
27 };
28 
29 struct trace_array;
30 
31 #ifdef CONFIG_TRACING
32 
33 int register_ftrace_export(struct trace_export *export);
34 int unregister_ftrace_export(struct trace_export *export);
35 
36 /**
37  * trace_array_puts - write a constant string into the trace buffer.
38  * @tr:    The trace array to write to
39  * @str:   The constant string to write
40  */
41 #define trace_array_puts(tr, str)					\
42 	({								\
43 		str ? __trace_array_puts(tr, _THIS_IP_, str, strlen(str)) : -1;	\
44 	})
45 int __trace_array_puts(struct trace_array *tr, unsigned long ip,
46 		       const char *str, int size);
47 
48 void trace_printk_init_buffers(void);
49 __printf(3, 4)
50 int trace_array_printk(struct trace_array *tr, unsigned long ip,
51 		       const char *fmt, ...);
52 int trace_array_init_printk(struct trace_array *tr);
53 void trace_array_put(struct trace_array *tr);
54 struct trace_array *trace_array_get_by_name(const char *name, const char *systems);
55 int trace_array_destroy(struct trace_array *tr);
56 
57 /* For osnoise tracer */
58 int osnoise_arch_register(void);
59 void osnoise_arch_unregister(void);
60 void osnoise_trace_irq_entry(int id);
61 void osnoise_trace_irq_exit(int id, const char *desc);
62 
63 #else /* CONFIG_TRACING */
register_ftrace_export(struct trace_export * export)64 static inline int register_ftrace_export(struct trace_export *export)
65 {
66 	return -EINVAL;
67 }
unregister_ftrace_export(struct trace_export * export)68 static inline int unregister_ftrace_export(struct trace_export *export)
69 {
70 	return 0;
71 }
trace_printk_init_buffers(void)72 static inline void trace_printk_init_buffers(void)
73 {
74 }
trace_array_printk(struct trace_array * tr,unsigned long ip,const char * fmt,...)75 static inline int trace_array_printk(struct trace_array *tr, unsigned long ip,
76 				     const char *fmt, ...)
77 {
78 	return 0;
79 }
trace_array_init_printk(struct trace_array * tr)80 static inline int trace_array_init_printk(struct trace_array *tr)
81 {
82 	return -EINVAL;
83 }
trace_array_put(struct trace_array * tr)84 static inline void trace_array_put(struct trace_array *tr)
85 {
86 }
trace_array_get_by_name(const char * name,const char * systems)87 static inline struct trace_array *trace_array_get_by_name(const char *name, const char *systems)
88 {
89 	return NULL;
90 }
trace_array_destroy(struct trace_array * tr)91 static inline int trace_array_destroy(struct trace_array *tr)
92 {
93 	return 0;
94 }
95 #endif	/* CONFIG_TRACING */
96 
97 #endif	/* _LINUX_TRACE_H */
98