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| author | Tzvetomir Stoyanov <tstoyanov@vmware.com> | 2019-01-30 12:44:22 +0200 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-03-14 11:50:40 -0400 |
| commit | d522394eed3a2a60230328acf0bbf4e6f383c226 (patch) | |
| tree | 1f5875f6916eadfbf68d4d30c6c0dc6e90e5c169 | |
| parent | e523b2b7d5a0ada0436b371f7807f647bdd45fbd (diff) | |
| download | trace-cmd-d522394eed3a2a60230328acf0bbf4e6f383c226.tar.gz | |
trace-cmd: Changed return logic of trace_seq_printf() and trace_seq_vprintf() APIs
In order to make libtraceevent into a proper library, its API should be
straightforward.
The trace_seq_printf() and trace_seq_vprintf() APIs have inconsistent
returned values with the other trace_seq_* APIs.
This path changes the return logic of trace_seq_printf() and
trace_seq_vprintf() to return the number of printed characters, as the
other trace_seq_* related APIs.
Link: http://lore.kernel.org/linux-trace-devel/20190130104425.8813-4-tstoyanov@vmware.com
Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20181201040852.485792891@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| -rw-r--r-- | lib/traceevent/trace-seq.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/lib/traceevent/trace-seq.c b/lib/traceevent/trace-seq.c index 7f0c2f07..a20dab1d 100644 --- a/lib/traceevent/trace-seq.c +++ b/lib/traceevent/trace-seq.c @@ -100,7 +100,8 @@ static void expand_buffer(struct trace_seq *s) * @fmt: printf format string * * It returns 0 if the trace oversizes the buffer's free - * space, 1 otherwise. + * space, the number of characters printed, or a negative + * value in case of an error. * * The tracer may use either sequence operations or its own * copy to user routines. To simplify formating of a trace @@ -129,9 +130,10 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...) goto try_again; } - s->len += ret; + if (ret > 0) + s->len += ret; - return 1; + return ret; } /** @@ -139,6 +141,10 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...) * @s: trace sequence descriptor * @fmt: printf format string * + * It returns 0 if the trace oversizes the buffer's free + * space, the number of characters printed, or a negative + * value in case of an error. + * * * The tracer may use either sequence operations or its own * copy to user routines. To simplify formating of a trace * trace_seq_printf is used to store strings into a special @@ -163,9 +169,10 @@ trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args) goto try_again; } - s->len += ret; + if (ret > 0) + s->len += ret; - return len; + return ret; } /** |