Re: [PATCH 31/41] um: Don't restore current->blocked on error

From: Oleg Nesterov
Date: Tue Aug 16 2011 - 13:41:32 EST


On 08/11, Matt Fleming wrote:
>
> If we fail to setup the signal stack frame then we don't need to
> restore current->blocked because it is not modified by
> setup_signal_stack_*.

Yes. And this is simply wrong if TIF_RESTORE_SIGMASK. We can block
SIGSEGV which we need to dequeue.

ACK

> Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
> Cc: Richard Weinberger <richard@xxxxxx>
> Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx>
> ---
> arch/um/kernel/signal.c | 8 ++------
> 1 files changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
> index 1812524..d177685 100644
> --- a/arch/um/kernel/signal.c
> +++ b/arch/um/kernel/signal.c
> @@ -66,13 +66,9 @@ static int handle_signal(struct pt_regs *regs, unsigned long signr,
> #endif
> err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset);
>
> - if (err) {
> - spin_lock_irq(&current->sighand->siglock);
> - current->blocked = *oldset;
> - recalc_sigpending();
> - spin_unlock_irq(&current->sighand->siglock);
> + if (err)
> force_sigsegv(signr, current);
> - } else {
> + else {
> sigset_t blocked:
>
> sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
> --
> 1.7.4.4
>

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