if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
+ buf[cnt] = 0;
+
trace_set_options(buf);
*ppos += cnt;
return -EINTR;
/*
- * We block until we read something and tracing is enabled.
+ * We block until we read something and tracing is disabled.
* We still block if tracing is disabled, but we have never
* read anything. This allows a user to cat this file, and
* then enable tracing. But after we have read something,
*
* iter->pos will be 0 if we haven't read anything.
*/
- if (tracing_is_enabled() && iter->pos)
+ if (!tracing_is_enabled() && iter->pos)
break;
}
return ret;
if (buffer) {
- if (val)
+ mutex_lock(&trace_types_lock);
+ if (val) {
ring_buffer_record_on(buffer);
- else
+ if (current_trace->start)
+ current_trace->start(tr);
+ } else {
ring_buffer_record_off(buffer);
+ if (current_trace->stop)
+ current_trace->stop(tr);
+ }
+ mutex_unlock(&trace_types_lock);
}
(*ppos)++;