On 31.07.2023 06:10, Bjorn Andersson wrote:

The majority of callers to qmp_send() composes the message dynamically
using some form of sprintf(), resulting in unnecessary complication and
stack usage.

By changing the interface of qmp_send() to take a format string and
arguments, the duplicated composition of the commands can be moved to a
single location.

Signed-off-by: Bjorn Andersson <redacted>
---

[...]

+int qmp_send(struct qmp *qmp, const char *fmt, ...)
 {
 	long time_left;
+	va_list args;
 	char buf[QMP_MSG_LEN];
+	int len;
 	int ret;
 
-	if (WARN_ON(IS_ERR_OR_NULL(qmp) || !data))
+	if (WARN_ON(IS_ERR_OR_NULL(qmp) || !fmt))
 		return -EINVAL;
 
-	if (WARN_ON(strlen(data) >= sizeof(buf)))
-		return -EINVAL;
+	memset(buf, 0, sizeof(buf));

Wouldn't initializing the array with = { 0 } be faster?

Otherwise, this looks very cool

Reviewed-by: Konrad Dybcio <redacted>

Konrad