linux-kernel - Re: [PATCH 21/24] x86/fpu: Let __fpu__restore_sig() restore the !32bit+fxsr frame from kernel memory

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Date:   Fri, 22 Mar 2019 15:55:01 +0100
From:   Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:     linux-kernel@...r.kernel.org
Cc:     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 21/24] x86/fpu: Let __fpu__restore_sig() restore the
 !32bit+fxsr frame from kernel memory

On 2019-03-21 21:26:29 [+0100], To linux-kernel@...r.kernel.org wrote:
> diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
> index 5a467a381245c..052a16c96218f 100644
> --- a/arch/x86/kernel/fpu/signal.c
> +++ b/arch/x86/kernel/fpu/signal.c
> @@ -297,28 +298,63 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
…
> +		} else {
> +			ret = __copy_from_user(&state->fsave, buf_fx, state_size);
> +			if (ret)
> +				goto err_out;
> +			ret = copy_users_to_fregs(buf_fx);

This needs to become 
	ret = copy_users_to_fregs(&fpu->state.fsave);

here and in the follow up patch (fixing locally)

> +		}

Sebastian