From: Shengming Hu <[email protected]>
When tracing_thresh is enabled, function graph tracing uses
trace_graph_thresh_return() as the return handler. Unlike
trace_graph_return(), it did not clear the per-task
TRACE_GRAPH_NOTRACE flag set by the entry handler for
set_graph_notrace addresses. This could leave the task
permanently in "notrace" state and effectively disable
function graph tracing for that task.
Mirror trace_graph_return()'s per-task notrace handling by
clearing TRACE_GRAPH_NOTRACE and returning early when set.
Fixes: b84214890a9bc ("function_graph: Move graph notrace bit to
shadow stack global var")
Signed-off-by: Shengming Hu <[email protected]>
---
kernel/trace/trace_functions_graph.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_functions_graph.c
b/kernel/trace/trace_functions_graph.c
index 1de6f1573..cbe43680c 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -400,14 +400,15 @@ static void trace_graph_thresh_return(struct
ftrace_graph_ret *trace,
struct fgraph_ops *gops,
struct ftrace_regs *fregs)
{
+ unsigned long *task_var = fgraph_get_task_var(gops);
struct fgraph_times *ftimes;
struct trace_array *tr;
int size;
ftrace_graph_addr_finish(gops, trace);
- if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
- trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
+ if (*task_var & TRACE_GRAPH_NOTRACE) {
+ *task_var &= ~TRACE_GRAPH_NOTRACE;
return;
}
--
2.25.1
