From 6ca8379b5d36e22b04e6315c3e49a6083377c862 Mon Sep 17 00:00:00 2001 From: Shengming Hu Date: Sat, 21 Feb 2026 11:30:07 +0800 Subject: [PATCH] fgraph: Fix thresh_return clear per-task notrace 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. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260221113007819YgrZsMGABff4Rc-O_fZxL@zte.com.cn Fixes: b84214890a9bc ("function_graph: Move graph notrace bit to shadow stack global var") Acked-by: Masami Hiramatsu (Google) Signed-off-by: Shengming Hu Signed-off-by: Steven Rostedt (Google) --- 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 3d8239fee004..817d0f1696b6 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; }