tracing/ftrace: fix unexpected -EINVAL when longest tracer name is set (e6e7a65a) · Commits · 戴 / test

Impact: fix confusing write() -EINVAL when changing the tracer The following commit remade alive the bug which made the set of a new tracer returning -EINVAL if this is the longest name of tracer. This patch corrects it. Signed-off-by:

Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:

Ingo Molnar <mingo@elte.hu>

kernel/trace/trace.c

+7 −5

Original line number	Original line	Diff line number	Diff line
	@@ -2655,6 +2655,9 @@ tracing_set_trace_write(struct file filp, const char __user ubuf,
	char buf[max_tracer_type_len+1];		char buf[max_tracer_type_len+1];
	int i;		int i;
	size_t ret;		size_t ret;
			int err;

			ret = cnt;

	if (cnt > max_tracer_type_len)		if (cnt > max_tracer_type_len)
	cnt = max_tracer_type_len;		cnt = max_tracer_type_len;
	@@ -2668,11 +2671,10 @@ tracing_set_trace_write(struct file filp, const char __user ubuf,
	for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)		for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
	buf[i] = 0;		buf[i] = 0;

	ret = tracing_set_tracer(buf);		err = tracing_set_tracer(buf);
	if (!ret)		if (err)
	ret = cnt;		return err;

	if (ret > 0)
	filp->f_pos += ret;		filp->f_pos += ret;

	return ret;		return ret;

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