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Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e5125677efa0..3c13e46d7d24 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2899,6 +2899,8 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
+ buf[cnt] = 0;
+
trace_set_options(buf);
*ppos += cnt;
@@ -3452,7 +3454,7 @@ static int tracing_wait_pipe(struct file *filp)
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,
@@ -3460,7 +3462,7 @@ static int tracing_wait_pipe(struct file *filp)
*
* iter->pos will be 0 if we haven't read anything.
*/
- if (tracing_is_enabled() && iter->pos)
+ if (!tracing_is_enabled() && iter->pos)
break;
}
@@ -4815,10 +4817,17 @@ rb_simple_write(struct file *filp, const char __user *ubuf,
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)++;