Re: [PATCH 6/19] UML - hppfs fixes

From: WANG Cong
Date: Tue Apr 29 2008 - 04:06:20 EST


On Mon, 28 Apr 2008, Jeff Dike wrote:

On Sat, Apr 26, 2008 at 04:31:32PM +0800, WANG Cong wrote:
> + rem = copy_to_user(buf, &data->contents[off], count);
> + *ppos += count - rem;
> + if (rem > 0)
> + return -EFAULT;

Could you please explain why check 'rem' after using it here?

Actually, this isn't as wrong as it looks. copy_to_user returns what
hasn't been copied (rem == remaining). So, I think the mistake is to
return -EFAULT here. Returning the short count would be right, unless
rem == count, in which case we return -EFAULT.

Yes, thanks.

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