Re: [PATCH v1 2/2] powerpc/debug: hook to user return notifier infrastructure

[Aneesh Kumar K.V <aneesh.kumar@kernel.org>]

Luming Yu <luming.yu@shingroup.cn> writes:

> Before we have powerpc to use the generic entry infrastructure,
> the call to fire user return notifier is made temporarily in powerpc
> entry code.
>

It is still not clear what will be registered as user return notifier.
Can you summarize that here?

>
> Signed-off-by: Luming Yu <luming.yu@shingroup.cn>
> ---
>  arch/powerpc/kernel/interrupt.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
> index c4f6d3c69ba9..7fe704946e96 100644
> --- a/arch/powerpc/kernel/interrupt.c
> +++ b/arch/powerpc/kernel/interrupt.c
> @@ -19,6 +19,7 @@
>  #include <asm/time.h>
>  #include <asm/tm.h>
>  #include <asm/unistd.h>
> +#include <asm/entry-common.h>
>  
>  #if defined(CONFIG_PPC_ADV_DEBUG_REGS) && defined(CONFIG_PPC32)
>  unsigned long global_dbcr0[NR_CPUS];
> @@ -245,6 +246,8 @@ interrupt_exit_user_prepare_main(unsigned long ret, struct pt_regs *regs)
>  	/* Restore user access locks last */
>  	kuap_user_restore(regs);
>  
> +	arch_exit_to_user_mode_prepare(regs, ti_flags);
> +
>

That will run the notifier with user AMR/IAMR values. 

>  	return ret;
>  }
>  
> -- 
> 2.42.0.windows.2