xref: /linux-6.15/include/linux/trace_seq.h (revision 7fcab099)
1 #ifndef _LINUX_TRACE_SEQ_H
2 #define _LINUX_TRACE_SEQ_H
3 
4 #include <linux/fs.h>
5 
6 /*
7  * Trace sequences are used to allow a function to call several other functions
8  * to create a string of data to use (up to a max of PAGE_SIZE.
9  */
10 
11 struct trace_seq {
12 	unsigned char		buffer[PAGE_SIZE];
13 	unsigned int		len;
14 	unsigned int		readpos;
15 };
16 
17 static inline void
18 trace_seq_init(struct trace_seq *s)
19 {
20 	s->len = 0;
21 	s->readpos = 0;
22 }
23 
24 /*
25  * Currently only defined when tracing is enabled.
26  */
27 #ifdef CONFIG_TRACING
28 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
29 	__attribute__ ((format (printf, 2, 3)));
30 extern int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
31 	__attribute__ ((format (printf, 2, 0)));
32 extern int
33 trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary);
34 extern void trace_print_seq(struct seq_file *m, struct trace_seq *s);
35 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
36 				 size_t cnt);
37 extern int trace_seq_puts(struct trace_seq *s, const char *str);
38 extern int trace_seq_putc(struct trace_seq *s, unsigned char c);
39 extern int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len);
40 extern int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
41 				size_t len);
42 extern void *trace_seq_reserve(struct trace_seq *s, size_t len);
43 extern int trace_seq_path(struct trace_seq *s, struct path *path);
44 
45 #else /* CONFIG_TRACING */
46 static inline int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
47 {
48 	return 0;
49 }
50 static inline int
51 trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
52 {
53 	return 0;
54 }
55 
56 static inline void trace_print_seq(struct seq_file *m, struct trace_seq *s)
57 {
58 }
59 static inline ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
60 				 size_t cnt)
61 {
62 	return 0;
63 }
64 static inline int trace_seq_puts(struct trace_seq *s, const char *str)
65 {
66 	return 0;
67 }
68 static inline int trace_seq_putc(struct trace_seq *s, unsigned char c)
69 {
70 	return 0;
71 }
72 static inline int
73 trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
74 {
75 	return 0;
76 }
77 static inline int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
78 				       size_t len)
79 {
80 	return 0;
81 }
82 static inline void *trace_seq_reserve(struct trace_seq *s, size_t len)
83 {
84 	return NULL;
85 }
86 static inline int trace_seq_path(struct trace_seq *s, struct path *path)
87 {
88 	return 0;
89 }
90 #endif /* CONFIG_TRACING */
91 
92 #endif /* _LINUX_TRACE_SEQ_H */
93