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

[Jinjie Ruan]

On 7/8/2026 3:06 AM, 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().
> 
> 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 <t...@kernel.org>
> Cc: Paul Walmsley <p...@kernel.org>
> Cc: Palmer Dabbelt <pal...@dabbelt.com>
> Cc: linux-ri...@lists.infradead.org
> ---
>  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 = syscall_enter_from_user_mode(regs, syscall);
> -
> -             add_random_kstack_offset();
> +             syscall = syscall_enter_from_user_mode_randomize_stack(regs, 
> syscall);

Reviewed-by: Jinjie Ruan <ruanjin...@huawei.com>

>  
>               if (syscall >= 0 && syscall < NR_syscalls) {
>                       syscall = array_index_nospec(syscall, NR_syscalls);
>