USB: mtu3: tracing: Use the new __vstring() helper

Instead of open coding a __dynamic_array() with a fixed length (which
defeats the purpose of the dynamic array in the first place). Use the new
__vstring() helper that will use a va_list and only write enough of the
string into the ring buffer that is needed.

Link: https://lkml.kernel.org/r/20220719112719.17e796c6@gandalf.local.home
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-usb@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/drivers/usb/mtu3/mtu3_trace.h b/drivers/usb/mtu3/mtu3_trace.h
index 1b89763..a98fa01 100644 (file)
--- a/drivers/usb/mtu3/mtu3_trace.h
+++ b/drivers/usb/mtu3/mtu3_trace.h
@@ -18,18 +18,16 @@
 
 #include "mtu3.h"
 
-#define MTU3_MSG_MAX   256
-
 TRACE_EVENT(mtu3_log,
        TP_PROTO(struct device *dev, struct va_format *vaf),
        TP_ARGS(dev, vaf),
        TP_STRUCT__entry(
                __string(name, dev_name(dev))
-               __dynamic_array(char, msg, MTU3_MSG_MAX)
+               __vstring(msg, vaf->fmt, vaf->va)
        ),
        TP_fast_assign(
                __assign_str(name, dev_name(dev));
-               vsnprintf(__get_str(msg), MTU3_MSG_MAX, vaf->fmt, *vaf->va);
+               __assign_vstr(msg, vaf->fmt, vaf->va);
        ),
        TP_printk("%s: %s", __get_str(name), __get_str(msg))
 );