diff options
Diffstat (limited to 'include/linux/trace_seq.h')
| -rw-r--r-- | include/linux/trace_seq.h | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h index 0c4c7587d6c3..4a0b8c172d27 100644 --- a/include/linux/trace_seq.h +++ b/include/linux/trace_seq.h @@ -8,20 +8,31 @@ /* * Trace sequences are used to allow a function to call several other functions - * to create a string of data to use (up to a max of PAGE_SIZE). + * to create a string of data to use. + * + * Have the trace seq to be 8K which is typically PAGE_SIZE * 2 on + * most architectures. The TRACE_SEQ_BUFFER_SIZE (which is + * TRACE_SEQ_SIZE minus the other fields of trace_seq), is the + * max size the output of a trace event may be. */ +#define TRACE_SEQ_SIZE 8192 +#define TRACE_SEQ_BUFFER_SIZE (TRACE_SEQ_SIZE - \ + (sizeof(struct seq_buf) + sizeof(size_t) + sizeof(int))) + struct trace_seq { - char buffer[PAGE_SIZE]; struct seq_buf seq; + size_t readpos; int full; + char buffer[TRACE_SEQ_BUFFER_SIZE]; }; static inline void trace_seq_init(struct trace_seq *s) { - seq_buf_init(&s->seq, s->buffer, PAGE_SIZE); + seq_buf_init(&s->seq, s->buffer, TRACE_SEQ_BUFFER_SIZE); s->full = 0; + s->readpos = 0; } /** @@ -69,6 +80,19 @@ static inline bool trace_seq_has_overflowed(struct trace_seq *s) return s->full || seq_buf_has_overflowed(&s->seq); } +/** + * trace_seq_pop - pop off the last written character + * @s: trace sequence descriptor + * + * Removes the last written character to the trace_seq @s. + * + * Returns the last character or -1 if it is empty. + */ +static inline int trace_seq_pop(struct trace_seq *s) +{ + return seq_buf_pop(&s->seq); +} + /* * Currently only defined when tracing is enabled. */ @@ -77,8 +101,8 @@ extern __printf(2, 3) void trace_seq_printf(struct trace_seq *s, const char *fmt, ...); extern __printf(2, 0) void trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args); -extern void -trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary); +extern __printf(2, 0) +void trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary); extern int trace_print_seq(struct seq_file *m, struct trace_seq *s); extern int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, int cnt); @@ -95,14 +119,15 @@ extern void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, extern int trace_seq_hex_dump(struct trace_seq *s, const char *prefix_str, int prefix_type, int rowsize, int groupsize, const void *buf, size_t len, bool ascii); +char *trace_seq_acquire(struct trace_seq *s, unsigned int len); #else /* CONFIG_TRACING */ static inline __printf(2, 3) void trace_seq_printf(struct trace_seq *s, const char *fmt, ...) { } -static inline void -trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) +static inline __printf(2, 0) +void trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) { } @@ -139,6 +164,10 @@ static inline int trace_seq_path(struct trace_seq *s, const struct path *path) { return 0; } +static inline char *trace_seq_acquire(struct trace_seq *s, unsigned int len) +{ + return NULL; +} #endif /* CONFIG_TRACING */ #endif /* _LINUX_TRACE_SEQ_H */ |