linux-kernel - Re: [PATCH -next v4 03/19] arm64: entry: Remove __enter_from_user

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Message-ID: <ZyD0WJeAhESLIBJp@J2N7QTR9R3.cambridge.arm.com>
Date: Tue, 29 Oct 2024 14:42:32 +0000
From: Mark Rutland <mark.rutland@....com>
To: Jinjie Ruan <ruanjinjie@...wei.com>
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Subject: Re: [PATCH -next v4 03/19] arm64: entry: Remove
 __enter_from_user_mode()

On Fri, Oct 25, 2024 at 06:06:44PM +0800, Jinjie Ruan wrote:
> The __enter_from_user_mode() is only called by enter_from_user_mode(),
> so replaced it with enter_from_user_mode().

As with the next two patches, all the __enter_from_*() and __exit_to_*()
are supposed to handle the raw entry, closely matching the generic code,
and the non-underscored enter_from_*() and exit_to_*() functions are
supposed to be wrappers that handle (possibly instrumentable)
arm64-specific post-entry and pre-exit logic.

I would prefer to keep that split, even though enter_from_user_mode() is
a trivial wrapper.

Am I missing some reason we must remove the wrappers?

Mark.

> 
> No functional changes.
> 
> Signed-off-by: Jinjie Ruan <ruanjinjie@...wei.com>
> ---
>  arch/arm64/kernel/entry-common.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
> index 68a9aecacdb9..ccf59b44464d 100644
> --- a/arch/arm64/kernel/entry-common.c
> +++ b/arch/arm64/kernel/entry-common.c
> @@ -109,7 +109,7 @@ static void noinstr exit_to_kernel_mode(struct pt_regs *regs,
>   * Before this function is called it is not safe to call regular kernel code,
>   * instrumentable code, or any code which may trigger an exception.
>   */
> -static __always_inline void __enter_from_user_mode(void)
> +static __always_inline void enter_from_user_mode(struct pt_regs *regs)
>  {
>  	lockdep_hardirqs_off(CALLER_ADDR0);
>  	CT_WARN_ON(ct_state() != CT_STATE_USER);
> @@ -118,11 +118,6 @@ static __always_inline void __enter_from_user_mode(void)
>  	mte_disable_tco_entry(current);
>  }
>  
> -static __always_inline void enter_from_user_mode(struct pt_regs *regs)
> -{
> -	__enter_from_user_mode();
> -}
> -
>  /*
>   * Handle IRQ/context state management when exiting to user mode.
>   * After this function returns it is not safe to call regular kernel code,
> -- 
> 2.34.1
>