Re: [PATCH v7 09/11] entry: Add has_syscall_work() helper

[Kevin Brodsky <kevin.brodsky@arm.com>]

On 17/11/2025 14:30, Jinjie Ruan wrote:
> Add has_syscall_work() helper to facilitate reuse of this
> function in other places.
>
> No functional changes.
>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
>  include/linux/entry-common.h | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h
> index cd6dacb2d8bf..e0f94e937e84 100644
> --- a/include/linux/entry-common.h
> +++ b/include/linux/entry-common.h
> @@ -44,6 +44,11 @@
>  				 SYSCALL_WORK_SYSCALL_EXIT_TRAP	|	\
>  				 ARCH_SYSCALL_WORK_EXIT)
>  
> +static inline bool has_syscall_work(unsigned long work)
> +{
> +	return unlikely(work & SYSCALL_WORK_ENTER);

I'm not sure this is a good idea, since the generic syscall machinery
has two separate sets of flags (SYSCALL_WORK_ENTER and
SYSCALL_WORK_EXIT). Of course we could reflect that in the helper's
name, but since it's only used twice after patch 10, maybe we don't need
a helper at all.

- Kevin

> +}
> +
>  /**
>   * syscall_enter_from_user_mode_prepare - Establish state and enable interrupts
>   * @regs:	Pointer to currents pt_regs
> @@ -91,7 +96,7 @@ static __always_inline long syscall_enter_from_user_mode_work(struct pt_regs *re
>  {
>  	unsigned long work = READ_ONCE(current_thread_info()->syscall_work);
>  
> -	if (work & SYSCALL_WORK_ENTER)
> +	if (has_syscall_work(work))
>  		syscall = syscall_trace_enter(regs, syscall, work);
>  
>  	return syscall;