ftrace: add trace_vprintk()
trace_vprintk() for easier implementation of tracer specific *_printk
functions. Add check check for no_tracer, and implement
__ftrace_printk() as a wrapper.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d372bc5..406de9c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3054,7 +3054,7 @@
(sizeof(struct trace_field) - offsetof(struct trace_field, print.buf))
#define TRACE_CONT_BUF_SIZE sizeof(struct trace_field)
-int __ftrace_printk(unsigned long ip, const char *fmt, ...)
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
{
static DEFINE_SPINLOCK(trace_buf_lock);
static char trace_buf[TRACE_BUF_SIZE];
@@ -3064,10 +3064,9 @@
struct trace_entry *entry;
unsigned long flags;
long disabled;
- va_list ap;
int cpu, len = 0, write, written = 0;
- if (!(trace_flags & TRACE_ITER_PRINTK) || !tr->ctrl || tracing_disabled)
+ if (current_trace == &no_tracer || !tr->ctrl || tracing_disabled)
return 0;
local_irq_save(flags);
@@ -3079,9 +3078,7 @@
goto out;
spin_lock(&trace_buf_lock);
- va_start(ap, fmt);
- len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, ap);
- va_end(ap);
+ len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
len = min(len, TRACE_BUF_SIZE-1);
trace_buf[len] = 0;
@@ -3120,6 +3117,21 @@
return len;
}
+EXPORT_SYMBOL_GPL(trace_vprintk);
+
+int __ftrace_printk(unsigned long ip, const char *fmt, ...)
+{
+ int ret;
+ va_list ap;
+
+ if (!(trace_flags & TRACE_ITER_PRINTK))
+ return 0;
+
+ va_start(ap, fmt);
+ ret = trace_vprintk(ip, fmt, ap);
+ va_end(ap);
+ return ret;
+}
EXPORT_SYMBOL_GPL(__ftrace_printk);
static int trace_panic_handler(struct notifier_block *this,