On Wed, May 18, 2022 at 3:53 PM Xu Kuohai <[email protected]> wrote:
>
> Add ftrace direct support for arm64.
>
> 1. When there is custom trampoline only, replace the fentry nop to a
> jump instruction that jumps directly to the custom trampoline.
>
> 2. When ftrace trampoline and custom trampoline coexist, jump from
> fentry to ftrace trampoline first, then jump to custom trampoline
> when ftrace trampoline exits. The current unused register
> pt_regs->orig_x0 is used as an intermediary for jumping from ftrace
> trampoline to custom trampoline.
>
> Signed-off-by: Xu Kuohai <[email protected]>
> Acked-by: Song Liu <[email protected]>
Acked-by: KP Singh <[email protected]>