Re: [patch 06/18] riscv/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: Paul Walmsley <[email protected]>
> Cc: Palmer Dabbelt <[email protected]>
> Cc: [email protected]
> ---
> =C2=A0arch/riscv/kernel/traps.c |=C2=A0=C2=A0=C2=A0 5 +----
> =C2=A01 file changed, 1 insertion(+), 4 deletions(-)
>=20
> --- a/arch/riscv/kernel/traps.c
> +++ b/arch/riscv/kernel/traps.c
> @@ -7,7 +7,6 @@
> =C2=A0#include <linux/kernel.h>
> =C2=A0#include <linux/init.h>
> =C2=A0#include <linux/irqflags.h>
> -#include <linux/randomize_kstack.h>
> =C2=A0#include <linux/sched.h>
> =C2=A0#include <linux/sched/debug.h>
> =C2=A0#include <linux/sched/signal.h>
> @@ -333,9 +332,7 @@ void do_trap_ecall_u(struct pt_regs *reg
> =C2=A0
> =C2=A0		riscv_v_vstate_discard(regs);
> =C2=A0
> -		syscall =3D syscall_enter_from_user_mode(regs, syscall);
> -
> -		add_random_kstack_offset();
> +		syscall =3D syscall_enter_from_user_mode_randomize_stack(regs, syscall=
);
> =C2=A0
> =C2=A0		if (syscall >=3D 0 && syscall < NR_syscalls) {
> =C2=A0			syscall =3D array_index_nospec(syscall, NR_syscalls);

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