Re: [RFC PATCH v3 1/4] arm64: Introduce stack trace reliability checks in the unwinder

From: Josh Poimboeuf
Date: Tue May 04 2021 - 17:53:07 EST


On Mon, May 03, 2021 at 12:36:12PM -0500, madvenka@xxxxxxxxxxxxxxxxxxx wrote:
> @@ -44,6 +44,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
> unsigned long fp = frame->fp;
> struct stack_info info;
>
> + frame->reliable = true;
> +

Why set 'reliable' to true on every invocation of unwind_frame()?
Shouldn't it be remembered across frames?

Also, it looks like there are several error scenarios where it returns
-EINVAL but doesn't set 'reliable' to false.

--
Josh