Re: [patch 06/18] riscv/syscall: Use syscall_enter_from_user_mode_randomize_stack()

On Wed, Jul 8, 2026 at 3:06=E2=80=AFAM Thomas Gleixner <[email protected]> wr=
ote:
>
> syscall_enter_from_user_mode_randomize_stack() replaces
> syscall_enter_from_user_mode() and the subsequent invocation of
> add_random_kstack_offset().
>
> 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.
>
> No functional change.
>
> Signed-off-by: Thomas Gleixner <[email protected]>
> Cc: Paul Walmsley <[email protected]>
> Cc: Palmer Dabbelt <[email protected]>
> Cc: [email protected]
> ---
>  arch/riscv/kernel/traps.c |    5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> --- a/arch/riscv/kernel/traps.c
> +++ b/arch/riscv/kernel/traps.c
> @@ -7,7 +7,6 @@
>  #include <linux/kernel.h>
>  #include <linux/init.h>
>  #include <linux/irqflags.h>
> -#include <linux/randomize_kstack.h>
>  #include <linux/sched.h>
>  #include <linux/sched/debug.h>
>  #include <linux/sched/signal.h>
> @@ -333,9 +332,7 @@ void do_trap_ecall_u(struct pt_regs *reg
>
>                 riscv_v_vstate_discard(regs);
>
> -               syscall =3D syscall_enter_from_user_mode(regs, syscall);
> -
> -               add_random_kstack_offset();
> +               syscall =3D syscall_enter_from_user_mode_randomize_stack(=
regs, syscall);

Reviewed-by: Guo Ren <[email protected]>

--=20
Best Regards
 Guo Ren