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Sender: Guenter Roeck <groeck7@gmail.com>
Date:   Sat, 10 Apr 2021 16:39:47 -0700
From:   Guenter Roeck <linux@roeck-us.net>
To:     Christophe Leroy <christophe.leroy@csgroup.eu>
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>, cmr@codefail.de,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 08/10] powerpc/signal32: Convert restore_[tm]_user_regs()
 to user access block
Message-ID: <20210410233947.GA202696@roeck-us.net>
References: <cover.1616151715.git.christophe.leroy@csgroup.eu>
 <181adf15a6f644efcd1aeafb355f3578ff1b6bc5.1616151715.git.christophe.leroy@csgroup.eu>
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On Fri, Mar 19, 2021 at 11:06:57AM +0000, Christophe Leroy wrote:
> Convert restore_user_regs() and restore_tm_user_regs()
> to use user_access_read_begin/end blocks.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
...
>  static long restore_user_regs(struct pt_regs *regs,
>  			      struct mcontext __user *sr, int sig)
>  {
...
> @@ -567,19 +569,22 @@ static long restore_user_regs(struct pt_regs *regs,
>  	regs->msr &= ~MSR_SPE;
>  	if (msr & MSR_SPE) {
>  		/* restore spe registers from the stack */
> -		if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
> -				     ELF_NEVRREG * sizeof(u32)))
> -			return 1;
> +		unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
> +				      ELF_NEVRREG * sizeof(u32));

arch/powerpc/kernel/signal_32.c: In function 'restore_user_regs':
arch/powerpc/kernel/signal_32.c:565:36: error: macro "unsafe_copy_from_user" requires 4 arguments, but only 3 given

Guenter