From: Steven Rostedt <[email protected]> In order to allow an interface to remove an added character from the trace_seq and seq_buf descriptors, add helper functions trace_seq_pop() and seq_buf_pop().
Signed-off-by: Steven Rostedt (Google) <[email protected]> --- include/linux/seq_buf.h | 17 +++++++++++++++++ include/linux/trace_seq.h | 13 +++++++++++++ 2 files changed, 30 insertions(+) diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h index 52791e070506..9f2839e73f8a 100644 --- a/include/linux/seq_buf.h +++ b/include/linux/seq_buf.h @@ -149,6 +149,23 @@ static inline void seq_buf_commit(struct seq_buf *s, int num) } } +/** + * seq_buf_pop - pop off the last written character + * @s: the seq_buf handle + * + * Removes the last written character to the seq_buf @s. + * + * Returns the last character or -1 if it is empty. + */ +static inline int seq_buf_pop(struct seq_buf *s) +{ + if (!s->len) + return -1; + + s->len--; + return (unsigned int)s->buffer[s->len]; +} + extern __printf(2, 3) int seq_buf_printf(struct seq_buf *s, const char *fmt, ...); extern __printf(2, 0) diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h index 557780fe1c77..4a0b8c172d27 100644 --- a/include/linux/trace_seq.h +++ b/include/linux/trace_seq.h @@ -80,6 +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. */ -- 2.51.0
