Re: [RFC PATCH 18/32] function_graph: Fix to initalize ftrace_ops for fgraph with ftrace_graph_func

Masami Hiramatsu
2023-11-06T10:04:28Z

On Mon, 6 Nov 2023 01:10:10 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:

> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Fix to initialize the ftrace_ops of fgraph_ops with ftrace_graph_func
> instead of ftrace_stub.

I've changed this, because fprobe entry handler is not called via
fgraph without this. But maybe I have to set correct gops->ops.func
after init?

Thank you,

>
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
> kernel/trace/fgraph.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
> index 597250bd30dc..858fb73440ec 100644
> --- a/kernel/trace/fgraph.c
> +++ b/kernel/trace/fgraph.c
> @@ -872,7 +872,7 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
> void fgraph_init_ops(struct ftrace_ops *dst_ops,
> struct ftrace_ops *src_ops)
> {
> - dst_ops->func = ftrace_stub;
> + dst_ops->func = ftrace_graph_func;
> dst_ops->flags = FTRACE_OPS_FL_PID | FTRACE_OPS_FL_STUB;
>
> #ifdef FTRACE_GRAPH_TRAMP_ADDR
> @@ -1120,7 +1120,7 @@ int register_ftrace_graph(struct fgraph_ops *gops)
>
> if (!gops->ops.func) {
> gops->ops.flags |= FTRACE_OPS_FL_STUB;
> - gops->ops.func = ftrace_stub;
> + gops->ops.func = ftrace_graph_func;
> #ifdef FTRACE_GRAPH_TRAMP_ADDR
> gops->ops.trampoline = FTRACE_GRAPH_TRAMP_ADDR;
> #endif
>

--
Masami Hiramatsu (Google) <mhiramat@kernel.org>