提交 725c624a 编写于 作者: S Steven Rostedt 提交者: Steven Rostedt

tracing: add trace_seq_vprint interface

The code to update the print formats for events requires a vprintf
format in the trace_seq. This patch adds that interface.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
上级 6556d1df
......@@ -27,6 +27,8 @@ trace_seq_init(struct trace_seq *s)
#ifdef CONFIG_TRACING
extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
__attribute__ ((format (printf, 2, 3)));
extern int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
__attribute__ ((format (printf, 2, 0)));
extern int
trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary);
extern void trace_print_seq(struct seq_file *m, struct trace_seq *s);
......
......@@ -100,6 +100,38 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
}
EXPORT_SYMBOL_GPL(trace_seq_printf);
/**
* trace_seq_vprintf - sequence printing of trace information
* @s: trace sequence descriptor
* @fmt: printf format string
*
* 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
* buffer (@s). Then the output may be either used by
* the sequencer or pulled into another buffer.
*/
int
trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
{
int len = (PAGE_SIZE - 1) - s->len;
int ret;
if (!len)
return 0;
ret = vsnprintf(s->buffer + s->len, len, fmt, args);
/* If we can't write it all, don't bother writing anything */
if (ret >= len)
return 0;
s->len += ret;
return len;
}
EXPORT_SYMBOL_GPL(trace_seq_vprintf);
int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
{
int len = (PAGE_SIZE - 1) - s->len;
......
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