linux-kernel - Re: [PATCH 05/22] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to

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Message-ID: <20190116193603.GK15409@zn.tnic>
Date:   Wed, 16 Jan 2019 20:36:03 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Cc:     linux-kernel@...r.kernel.org, x86@...nel.org,
        Andy Lutomirski <luto@...nel.org>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        kvm@...r.kernel.org, "Jason A. Donenfeld" <Jason@...c4.com>,
        Rik van Riel <riel@...riel.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>
Subject: Re: [PATCH 05/22] x86/fpu: Remove fpu->initialized usage in
 copy_fpstate_to_sigframe()

On Wed, Jan 09, 2019 at 12:47:27PM +0100, Sebastian Andrzej Siewior wrote:
> Since ->initialized is always true for user tasks and kernel threads
> don't get this far,

Yeah, this is commit message is too laconic. Don'g get this far "where"?

> we always save the registers directly to userspace.

We don't save registers to userspace - please write stuff out.

So from looking at what you're removing I can barely rhyme up what
you're doing but this needs a lot more explanation why it is OK to
remove the else case. Hell, why was the thing added in the first place
if ->initialized is always true?

And why is it ok to save registers directly to the user task's buffers?

So please be more verbose even at the risk of explaning the obvious.
This is the FPU code, remember? :)

Thx.

-- 
Regards/Gruss,
    Boris.

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