Re: [patch 10/18] entry: Use syscall number instead of rereading it

On Tue, 2026-07-07 at 21:06 +0200, Thomas Gleixner wrote:
> rseq_syscall_enter_work() is invoked before the syscall number can be
> modified. So there is no point in rereading it from pt_regs.
>=20
> Signed-off-by: Thomas Gleixner <[email protected]>
> ---
> =C2=A0include/linux/entry-common.h |=C2=A0=C2=A0=C2=A0 9 +++++----
> =C2=A01 file changed, 5 insertions(+), 4 deletions(-)
>=20
> --- a/include/linux/entry-common.h
> +++ b/include/linux/entry-common.h
> @@ -70,9 +70,10 @@ static inline void syscall_enter_audit(s
> =C2=A0	}
> =C2=A0}
> =C2=A0
> -static __always_inline long syscall_trace_enter(struct pt_regs *regs, un=
signed long work)
> +static __always_inline long syscall_trace_enter(struct pt_regs *regs, un=
signed long work,
> +						long syscall)
> =C2=A0{
> -	long syscall, ret =3D 0;
> +	long ret =3D 0;
> =C2=A0
> =C2=A0	/*
> =C2=A0	 * Handle Syscall User Dispatch.=C2=A0 This must comes first, sinc=
e
> @@ -90,7 +91,7 @@ static __always_inline long syscall_trac
> =C2=A0	 * through hrtimer_interrupt().
> =C2=A0	 */
> =C2=A0	if (work & SYSCALL_WORK_SYSCALL_RSEQ_SLICE)
> -		rseq_syscall_enter_work(syscall_get_nr(current, regs));
> +		rseq_syscall_enter_work(syscall);
> =C2=A0
> =C2=A0	/* Handle ptrace */
> =C2=A0	if (work & (SYSCALL_WORK_SYSCALL_TRACE | SYSCALL_WORK_SYSCALL_EMU)=
) {
> @@ -145,7 +146,7 @@ static __always_inline long syscall_ente
> =C2=A0	unsigned long work =3D READ_ONCE(current_thread_info()->syscall_wo=
rk);
> =C2=A0
> =C2=A0	if (work & SYSCALL_WORK_ENTER)
> -		syscall =3D syscall_trace_enter(regs, work);
> +		syscall =3D syscall_trace_enter(regs, work, syscall);
> =C2=A0
> =C2=A0	return syscall;
> =C2=A0}

Reviewed-by: Radu Rendec <[email protected]>