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>,
        "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>,
        Alexei Starovoitov <ast@plumgrid.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Daniel Borkmann <dborkman@redhat.com>, Will Drewry <wad@chromium.org>,
        Julien Tinnes <jln@chromium.org>, David Drysdale <drysdale@google.com>,
        linux-api@vger.kernel.org, x86@kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org,
        linux-arch@vger.kernel.org, linux-security-module@vger.kernel.org
Subject: Re: [PATCH v8 3/9] seccomp: introduce writer locking
Message-ID: <20140625140312.GC7892@redhat.com>
References: <1403642893-23107-1-git-send-email-keescook@chromium.org> <1403642893-23107-4-git-send-email-keescook@chromium.org>
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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.

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