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 * trace_seq_has_overflowed - return true if the trace_seq took too much 45 * @s: trace sequence descriptor 46 * 47 * Returns true if too much data was added to the trace_seq and it is 48 * now full and will not take anymore. 49 */ 50 static inline bool trace_seq_has_overflowed(struct trace_seq *s) 51 { 52 return s->full || s->len > PAGE_SIZE - 1; 53 } 54 55 /* 56 * Currently only defined when tracing is enabled. 57 */ 58 #ifdef CONFIG_TRACING 59 extern __printf(2, 3) 60 int trace_seq_printf(struct trace_seq *s, const char *fmt, ...); 61 extern __printf(2, 0) 62 int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args); 63 extern int 64 trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary); 65 extern int trace_print_seq(struct seq_file *m, struct trace_seq *s); 66 extern int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, 67 int cnt); 68 extern int trace_seq_puts(struct trace_seq *s, const char *str); 69 extern int trace_seq_putc(struct trace_seq *s, unsigned char c); 70 extern int trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len); 71 extern int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, 72 unsigned int len); 73 extern int trace_seq_path(struct trace_seq *s, const struct path *path); 74 75 extern int trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, 76 int nmaskbits); 77 78 #else /* CONFIG_TRACING */ 79 static inline int trace_seq_printf(struct trace_seq *s, const char *fmt, ...) 80 { 81 return 0; 82 } 83 static inline int 84 trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) 85 { 86 return 0; 87 } 88 89 static inline int 90 trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, 91 int nmaskbits) 92 { 93 return 0; 94 } 95 96 static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s) 97 { 98 return 0; 99 } 100 static inline int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, 101 int cnt) 102 { 103 return 0; 104 } 105 static inline int trace_seq_puts(struct trace_seq *s, const char *str) 106 { 107 return 0; 108 } 109 static inline int trace_seq_putc(struct trace_seq *s, unsigned char c) 110 { 111 return 0; 112 } 113 static inline int 114 trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len) 115 { 116 return 0; 117 } 118 static inline int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, 119 unsigned int len) 120 { 121 return 0; 122 } 123 static inline int trace_seq_path(struct trace_seq *s, const struct path *path) 124 { 125 return 0; 126 } 127 #endif /* CONFIG_TRACING */ 128 129 #endif /* _LINUX_TRACE_SEQ_H */ 130