Hi joe,

-----Original Message-----
From: netdev-owner@vger.kernel.org [mailto:netdev-owner@vger.kernel.org]
On Behalf Of Joe Perches
Sent: Tuesday, May 30, 2017 11:41 AM
To: David Miller; cugyly@163.com
Cc: netdev@vger.kernel.org; dsahern@gmail.com; YUAN Linyu
Subject: Re: [PATCH net-next] net: ndisc.c: reduce size of
__ndisc_fill_addr_option()

On Mon, 2017-05-29 at 23:30 -0400, David Miller wrote:

quoted

From: yuan linyu <redacted>
Date: Sat, 27 May 2017 06:00:52 +0800

quoted

From: yuan linyu <redacted>

Signed-off-by: yuan linyu <redacted>

Applied, thanks.

OK, but is it really safe though?

Could "space" (an int) ever be negative after
subtracting "pad" and "data_len"?

It's safe, check
int space = __ndisc_opt_addr_space(data_len, pad);
space is maximum aligned value.
And I check current pad, the maximum value is 2.