xref: /linux-6.15/include/linux/trace_seq.h (revision a63ce5b3)
1 #ifndef _LINUX_TRACE_SEQ_H
2 #define _LINUX_TRACE_SEQ_H
3 
4 #include <linux/fs.h>
5 
6 #include <asm/page.h>
7 
8 /*
9  * Trace sequences are used to allow a function to call several other functions
10  * to create a string of data to use (up to a max of PAGE_SIZE).
11  */
12 
13 struct trace_seq {
14 	unsigned char		buffer[PAGE_SIZE];
15 	unsigned int		len;
16 	unsigned int		readpos;
17 };
18 
19 static inline void
20 trace_seq_init(struct trace_seq *s)
21 {
22 	s->len = 0;
23 	s->readpos = 0;
24 }
25 
26 /*
27  * Currently only defined when tracing is enabled.
28  */
29 #ifdef CONFIG_TRACING
30 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
31 	__attribute__ ((format (printf, 2, 3)));
32 extern int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
33 	__attribute__ ((format (printf, 2, 0)));
34 extern int
35 trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary);
36 extern int trace_print_seq(struct seq_file *m, struct trace_seq *s);
37 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
38 				 size_t cnt);
39 extern int trace_seq_puts(struct trace_seq *s, const char *str);
40 extern int trace_seq_putc(struct trace_seq *s, unsigned char c);
41 extern int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len);
42 extern int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
43 				size_t len);
44 extern void *trace_seq_reserve(struct trace_seq *s, size_t len);
45 extern int trace_seq_path(struct trace_seq *s, struct path *path);
46 
47 #else /* CONFIG_TRACING */
48 static inline int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
49 {
50 	return 0;
51 }
52 static inline int
53 trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
54 {
55 	return 0;
56 }
57 
58 static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s)
59 {
60 	return 0;
61 }
62 static inline ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
63 				 size_t cnt)
64 {
65 	return 0;
66 }
67 static inline int trace_seq_puts(struct trace_seq *s, const char *str)
68 {
69 	return 0;
70 }
71 static inline int trace_seq_putc(struct trace_seq *s, unsigned char c)
72 {
73 	return 0;
74 }
75 static inline int
76 trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
77 {
78 	return 0;
79 }
80 static inline int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
81 				       size_t len)
82 {
83 	return 0;
84 }
85 static inline void *trace_seq_reserve(struct trace_seq *s, size_t len)
86 {
87 	return NULL;
88 }
89 static inline int trace_seq_path(struct trace_seq *s, struct path *path)
90 {
91 	return 0;
92 }
93 #endif /* CONFIG_TRACING */
94 
95 #endif /* _LINUX_TRACE_SEQ_H */
96