linux-kernel - Re: [PATCH v8 2/6] x86/signal: Introduce helpers to get the maximum signal frame size

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Message-ID: <YI/1P1fBix5HWBki@zn.tnic>
Date:   Mon, 3 May 2021 15:06:07 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     "Chang S. Bae" <chang.seok.bae@...el.com>
Cc:     bp@...e.de, tglx@...utronix.de, mingo@...nel.org, luto@...nel.org,
        x86@...nel.org, len.brown@...el.com, dave.hansen@...el.com,
        hjl.tools@...il.com, Dave.Martin@....com, jannh@...gle.com,
        mpe@...erman.id.au, carlos@...hat.com, tony.luck@...el.com,
        ravi.v.shankar@...el.com, libc-alpha@...rceware.org,
        linux-arch@...r.kernel.org, linux-api@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v8 2/6] x86/signal: Introduce helpers to get the maximum
 signal frame size

On Wed, Apr 21, 2021 at 09:48:52PM -0700, Chang S. Bae wrote:
> +void __init init_sigframe_size(void)
> +{
> +	max_frame_size = MAX_FRAME_SIGINFO_UCTXT_SIZE + MAX_FRAME_PADDING;
> +
> +	max_frame_size += fpu__get_fpstate_size() + MAX_XSAVE_PADDING;
> +
> +	/* Userspace expects an aligned size. */
> +	max_frame_size = round_up(max_frame_size, FRAME_ALIGNMENT);

I guess we want

	pr_info("max sigframe size: %lu\n", max_frame_size);

here so that we can keep an eye on how much this becomes, in practice.

Thx.

-- 
Regards/Gruss,
    Boris.

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