include/linux/trace_seq.h

   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         int                     full;
  18 };
  19
  20 static inline void
  21 trace_seq_init(struct trace_seq *s)
  22 {
  23         s->len = 0;
  24         s->readpos = 0;
  25         s->full = 0;
  26 }
  27
  28 /**
  29  * trace_seq_buffer_ptr - return pointer to next location in buffer
  30  * @s: trace sequence descriptor
  31  *
  32  * Returns the pointer to the buffer where the next write to
  33  * the buffer will happen. This is useful to save the location
  34  * that is about to be written to and then return the result
  35  * of that write.
  36  */
  37 static inline unsigned char *
  38 trace_seq_buffer_ptr(struct trace_seq *s)
  39 {
  40         return s->buffer + s->len;
  41 }
  42
  43 /*
  44  * Currently only defined when tracing is enabled.
  45  */
  46 #ifdef CONFIG_TRACING
  47 extern __printf(2, 3)
  48 int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
  49 extern __printf(2, 0)
  50 int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args);
  51 extern int
  52 trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary);
  53 extern int trace_print_seq(struct seq_file *m, struct trace_seq *s);
  54 extern int trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
  55                              int cnt);
  56 extern int trace_seq_puts(struct trace_seq *s, const char *str);
  57 extern int trace_seq_putc(struct trace_seq *s, unsigned char c);
  58 extern int trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len);
  59 extern int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
  60                                 unsigned int len);
  61 extern int trace_seq_path(struct trace_seq *s, const struct path *path);
  62
  63 extern int trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
  64                              int nmaskbits);
  65
  66 #else /* CONFIG_TRACING */
  67 static inline int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
  68 {
  69         return 0;
  70 }
  71 static inline int
  72 trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
  73 {
  74         return 0;
  75 }
  76
  77 static inline int
  78 trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
  79                   int nmaskbits)
  80 {
  81         return 0;
  82 }
  83
  84 static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s)
  85 {
  86         return 0;
  87 }
  88 static inline int trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
  89                                     int cnt)
  90 {
  91         return 0;
  92 }
  93 static inline int trace_seq_puts(struct trace_seq *s, const char *str)
  94 {
  95         return 0;
  96 }
  97 static inline int trace_seq_putc(struct trace_seq *s, unsigned char c)
  98 {
  99         return 0;
 100 }
 101 static inline int
 102 trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len)
 103 {
 104         return 0;
 105 }
 106 static inline int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
 107                                        unsigned int len)
 108 {
 109         return 0;
 110 }
 111 static inline int trace_seq_path(struct trace_seq *s, const struct path *path)
 112 {
 113         return 0;
 114 }
 115 #endif /* CONFIG_TRACING */
 116
 117 #endif /* _LINUX_TRACE_SEQ_H */