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Date:   Wed, 25 Jun 2014 16:03:12 +0200
From:   Oleg Nesterov <oleg@redhat.com>
To:     Kees Cook <keescook@chromium.org>
Cc:     linux-kernel@vger.kernel.org,
        Andy Lutomirski <luto@amacapital.net>,
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Subject: Re: [PATCH v8 3/9] seccomp: introduce writer locking
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On 06/24, Kees Cook wrote:
>
> @@ -524,6 +529,8 @@ static long seccomp_set_mode(unsigned long seccomp_mode, char __user *filter)
>  	}
>  #endif
>
> +	spin_lock_irqsave(&current->sighand->siglock, irqflags);
> +

Well, I won't argue if you prefer to use _irqsave "just in case".

But irqs must be enabled in syscall paths, you could use spin_lock_irq().
The same for seccomp_set_mode_filter() added later.

Oleg.