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Date: Tue, 21 Apr 2020 21:01:48 +0200
From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH 1/7] powerpc/spufs: simplify spufs core dumping
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Cc: Arnd Bergmann <arnd@arndb.de>, linux-kernel@vger.kernel.org,
 "Eric W . Biederman" <ebiederm@xmission.com>, linux-fsdevel@vger.kernel.org,
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 Christoph Hellwig <hch@lst.de>, Jeremy Kerr <jk@ozlabs.org>
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On Tue, Apr 21, 2020 at 07:49:41PM +0100, Al Viro wrote:
> >  	spin_lock(&ctx->csa.register_lock);
> > -	ret = __spufs_proxydma_info_read(ctx, buf, len, pos);
> > +	__spufs_proxydma_info_read(ctx, &info);
> > +	ret = simple_read_from_buffer(buf, len, pos, &info, sizeof(info));
> 
> IDGI...  What's that access_ok() for?  If you are using simple_read_from_buffer(),
> the damn thing goes through copy_to_user().  Why bother with separate access_ok()
> here?

I have no idea at all, this just refactors the code.