Re: [PATCH 2/4] score: signal: fix sigaltstack check

[Lennox Wu]

Hi Sergeev,
Your are right. I will merge it.
Thanks.

Acked-by: Lennox Wu <lennox.wu@xxxxxxxxx>

2016-02-01 0:21 GMT+08:00 Stas Sergeev <stsp@xxxxxxx>:
>
> Currently get_sigframe() checks only
> (ka->sa.sa_flags & SA_ONSTACK) && (!on_sig_stack(sp))
> to determine whether the switch to sigaltstack is needed.
> It forgets to checks whether the sigaltstack was previously set.
>
> This patch replaces the !on_sig_stack(sp) with the standard check
> sas_ss_flags(sp) == 0
> that takes into account both conditions: it succeeds only if the
> sigaltstack is enabled but currently not active.
>
> CC: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
> CC: linux-kernel@xxxxxxxxxxxxxxx
> CC: Chen Liqin <liqin.linux@xxxxxxxxx>
> CC: Lennox Wu <lennox.wu@xxxxxxxxx>
> CC: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> CC: James Hogan <james.hogan@xxxxxxxxxx>
>
> Signed-off-by: Stas Sergeev <stsp@xxxxxxxxxxxxxxxxxxxxx>
> ---
>  arch/score/kernel/signal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/score/kernel/signal.c b/arch/score/kernel/signal.c
> index e381c8c..bd1c7c8 100644
> --- a/arch/score/kernel/signal.c
> +++ b/arch/score/kernel/signal.c
> @@ -127,7 +127,7 @@ static void __user *get_sigframe(struct k_sigaction *ka,
>      sp -= 32;
>
>      /* This is the X/Open sanctioned signal stack switching.  */
> -    if ((ka->sa.sa_flags & SA_ONSTACK) && (!on_sig_stack(sp)))
> +    if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
>          sp = current->sas_ss_sp + current->sas_ss_size;
>
>      return (void __user*)((sp - frame_size) & ~7);
> --
> 2.5.0
>