Re: [patch 07/18] s390/syscall: Use enter_from_user_mode_randomize_stack()

Jinjie Ruan <[email protected]> Thu, 9 Jul 2026 10:46:44 +0800

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Message-ID	<[email protected]>


On 7/8/2026 3:06 AM, Thomas Gleixner wrote:
> enter_from_user_mode_randomize_stack() replaces enter_from_user_mode() and
> the subsequent invocation of add_random_kstack_offset_irqsoff().
> 
> As a bonus this avoids the overhead of get/put_cpu_var() in
> add_random_kstack_offset().
> 
> No functional change.
> 
> Signed-off-by: Thomas Gleixner <[email protected]>
> Cc: Sven Schnelle <[email protected]>
> Cc: [email protected]
> ---
>  arch/s390/kernel/syscall.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> --- a/arch/s390/kernel/syscall.c
> +++ b/arch/s390/kernel/syscall.c
> @@ -97,8 +97,8 @@ void noinstr __do_syscall(struct pt_regs
>  {
>  	unsigned long nr;
>  
> -	enter_from_user_mode(regs);
> -	add_random_kstack_offset();
> +	enter_from_user_mode_randomize_stack(regs);

The #include <linux/randomize_kstack.h> can be removed.

> +
>  	regs->psw = get_lowcore()->svc_old_psw;
>  	regs->int_code = get_lowcore()->svc_int_code;
>  	update_timer_sys();
>