On 7/8/2026 3:05 AM, Thomas Gleixner wrote:
> add_random_kstack_offset() is invoked before syscall_enter_from_user_mode()
> establishes state. That's wrong because add_random_kstack_offset() calls
> into instrumentable code.
>
> Move it after syscall_enter_from_user_mode() to ensure that state is
> correctly established.
>
> Signed-off-by: Thomas Gleixner <[email protected]>
> Cc: Michael Ellerman <[email protected]>
> Cc: Shrikanth Hegde <[email protected]>
> Cc: [email protected]
> ---
> arch/powerpc/kernel/syscall.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/arch/powerpc/kernel/syscall.c
> +++ b/arch/powerpc/kernel/syscall.c
> @@ -19,8 +19,8 @@ notrace long system_call_exception(struc
> long ret;
> syscall_fn f;
>
> - add_random_kstack_offset();
> r0 = syscall_enter_from_user_mode(regs, r0);
> + add_random_kstack_offset();
Reviewed-by: Jinjie Ruan <[email protected]>
>
> if (unlikely(r0 >= NR_syscalls)) {
> if (unlikely(trap_is_unsupported_scv(regs))) {
>
