Re: [PATCH 16/18] arm64: kprobes: fix kprobes without CONFIG_KRETPROBES

[Kees Cook]

On Mon, Oct 21, 2019 at 08:21:48AM +0200, Ard Biesheuvel wrote:
> On Fri, 18 Oct 2019 at 18:11, Sami Tolvanen  wrote:
> >
> > This allows CONFIG_KRETPROBES to be disabled without disabling
> > kprobes entirely.
> >
> > Signed-off-by: Sami Tolvanen 
> 
> Can we make kretprobes work with the shadow call stack instead?

I've been viewing that as "next steps". This series is the first step:
actually gaining the feature and clearly indicating where future
improvements can live.

-- 
Kees Cook

Re: [PATCH 16/18] arm64: kprobes: fix kprobes without CONFIG_KRETPROBES

[Ard Biesheuvel]

On Fri, 18 Oct 2019 at 18:11, Sami Tolvanen  wrote:
>
> This allows CONFIG_KRETPROBES to be disabled without disabling
> kprobes entirely.
>
> Signed-off-by: Sami Tolvanen 

Can we make kretprobes work with the shadow call stack instead?

> ---
>  arch/arm64/kernel/probes/kprobes.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm64/kernel/probes/kprobes.c 
> b/arch/arm64/kernel/probes/kprobes.c
> index c4452827419b..98230ae979ca 100644
> --- a/arch/arm64/kernel/probes/kprobes.c
> +++ b/arch/arm64/kernel/probes/kprobes.c
> @@ -551,6 +551,7 @@ void __kprobes __used *trampoline_probe_handler(struct 
> pt_regs *regs)
> return (void *)orig_ret_address;
>  }
>
> +#ifdef CONFIG_KRETPROBES
>  void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
>   struct pt_regs *regs)
>  {
> @@ -564,6 +565,7 @@ int __kprobes arch_trampoline_kprobe(struct kprobe *p)
>  {
> return 0;
>  }
> +#endif
>
>  int __init arch_init_kprobes(void)
>  {
> --
> 2.23.0.866.gb869b98d4c-goog
>