Re: [patch 05/18] powerpc/syscall: Use syscall_enter_from_user_mode_randomize_stack()

On Tue, 2026-07-07 at 21:06 +0200, Thomas Gleixner wrote:
> syscall_enter_from_user_mode_randomize_stack() replaces
> syscall_enter_from_user_mode() and the subsequent invocation of
> add_random_kstack_offset().
>=20
> The advantage is that it applies the stack randomization right after
> enter_from_user_mode() and thereby avoids the overhead of get/put_cpu_var=
()
> as that code is invoked with interrupts disabled.
>=20
> No functional change.
>=20
> Signed-off-by: Thomas Gleixner <[email protected]>
> Cc: Michael Ellerman <[email protected]>
> Cc: Shrikanth Hegde <[email protected]>
> Cc: [email protected]
> ---
> =C2=A0arch/powerpc/kernel/syscall.c |=C2=A0=C2=A0=C2=A0 4 +---
> =C2=A01 file changed, 1 insertion(+), 3 deletions(-)
>=20
> --- a/arch/powerpc/kernel/syscall.c
> +++ b/arch/powerpc/kernel/syscall.c
> @@ -2,7 +2,6 @@
> =C2=A0
> =C2=A0#include <linux/compat.h>
> =C2=A0#include <linux/context_tracking.h>
> -#include <linux/randomize_kstack.h>
> =C2=A0#include <linux/entry-common.h>
> =C2=A0
> =C2=A0#include <asm/interrupt.h>
> @@ -19,8 +18,7 @@ notrace long system_call_exception(struc
> =C2=A0	long ret;
> =C2=A0	syscall_fn f;
> =C2=A0
> -	r0 =3D syscall_enter_from_user_mode(regs, r0);
> -	add_random_kstack_offset();
> +	r0 =3D syscall_enter_from_user_mode_randomize_stack(regs, r0);
> =C2=A0
> =C2=A0	if (unlikely(r0 >=3D NR_syscalls)) {
> =C2=A0		if (unlikely(trap_is_unsupported_scv(regs))) {

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