Re: [RFC PATCH 1/3] x86/kprobes: Support nested kprobes

From: Masami Hiramatsu
Date: Thu May 07 2020 - 11:46:07 EST


On Thu, 7 May 2020 18:59:55 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> Make kprobes to accept 1-level nesting instead of
> diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c
> index 681a4b36e9bb..b695c2e118f8 100644
> --- a/arch/x86/kernel/kprobes/ftrace.c
> +++ b/arch/x86/kernel/kprobes/ftrace.c
> @@ -25,13 +25,15 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> return;
>
> kcb = get_kprobe_ctlblk();
> - if (kprobe_running()) {
> + if (!kprobe_can_nest()) {

Oops, something wrong. this kprobe_can_nest() requires kcb for
the parameter. I'll fix this.

Thank you,

--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>