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author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2014-10-29 17:30:50 -0400 |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2014-11-19 22:01:18 -0500 |
commit | 01cb06a4c229908d239149017049fdd1fca1dd51 (patch) | |
tree | 16af818800dc163c155c20dbacb782257d604534 | |
parent | 8cd709ae7658a7fd7f6630699e3229188c2591e4 (diff) | |
download | linux-stable-01cb06a4c229908d239149017049fdd1fca1dd51.tar.gz linux-stable-01cb06a4c229908d239149017049fdd1fca1dd51.tar.bz2 linux-stable-01cb06a4c229908d239149017049fdd1fca1dd51.zip |
tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions
Add two helper functions; seq_buf_get_buf() and seq_buf_commit() that
are used by seq_buf_path(). This makes the code similar to the
seq_file: seq_path() function, and will help to be able to consolidate
the functions between seq_file and trace_seq.
Link: http://lkml.kernel.org/r/20141104160222.644881406@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.977571447@goodmis.org
Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r-- | include/linux/seq_buf.h | 41 | ||||
-rw-r--r-- | kernel/trace/seq_buf.c | 7 |
2 files changed, 44 insertions, 4 deletions
diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h index 0800a24b4348..12c64282aa98 100644 --- a/include/linux/seq_buf.h +++ b/include/linux/seq_buf.h @@ -70,6 +70,47 @@ static inline unsigned int seq_buf_used(struct seq_buf *s) return min(s->len, s->size); } +/** + * seq_buf_get_buf - get buffer to write arbitrary data to + * @s: the seq_buf handle + * @bufp: the beginning of the buffer is stored here + * + * Return the number of bytes available in the buffer, or zero if + * there's no space. + */ +static inline size_t seq_buf_get_buf(struct seq_buf *s, char **bufp) +{ + WARN_ON(s->len > s->size + 1); + + if (s->len < s->size) { + *bufp = s->buffer + s->len; + return s->size - s->len; + } + + *bufp = NULL; + return 0; +} + +/** + * seq_buf_commit - commit data to the buffer + * @s: the seq_buf handle + * @num: the number of bytes to commit + * + * Commit @num bytes of data written to a buffer previously acquired + * by seq_buf_get. To signal an error condition, or that the data + * didn't fit in the available space, pass a negative @num value. + */ +static inline void seq_buf_commit(struct seq_buf *s, int num) +{ + if (num < 0) { + seq_buf_set_overflow(s); + } else { + /* num must be negative on overflow */ + BUG_ON(s->len + num > s->size); + s->len += num; + } +} + extern __printf(2, 3) int seq_buf_printf(struct seq_buf *s, const char *fmt, ...); extern __printf(2, 0) diff --git a/kernel/trace/seq_buf.c b/kernel/trace/seq_buf.c index c53f1d5088e8..086f594ac890 100644 --- a/kernel/trace/seq_buf.c +++ b/kernel/trace/seq_buf.c @@ -293,8 +293,8 @@ int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, */ int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc) { - char *buf = s->buffer + s->len; - size_t size = seq_buf_buffer_left(s); + char *buf; + size_t size = seq_buf_get_buf(s, &buf); int res = -1; WARN_ON(s->size == 0); @@ -307,8 +307,7 @@ int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc) res = end - buf; } } - if (res > 0) - s->len += res; + seq_buf_commit(s, res); return res; } |