Re: [TIP] BUG kmalloc-4096: Poison overwritten (ath5k_rx_skb_alloc)

From: Bob Copeland
Date: Mon Feb 23 2009 - 11:31:04 EST


On Mon, Feb 23, 2009 at 06:27:35PM +0200, Nick Kossifidis wrote:
> 2009/2/23 Bob Copeland <me@xxxxxxxxxxxxxxx>:
> > On Mon, Feb 23, 2009 at 06:15:51PM +0200, Nick Kossifidis wrote:
> >> Typo alert...
> >> rs->rs_more = !!(rx_status->rx_status_0 & AR5K_5212_RX_DESC_STATUS0_MORE);
> >
> > I'm slow... what's wrong with it?
> >
>
> "!!"
>
> it should be just
>
> rs->rs_more = (rx_status->rx_status_0 & AR5K_5212_RX_DESC_STATUS0_MORE);

No, that's intentional. That was actually a bug we had at some point
(rs_more is a u8 so the bitwise AND overflowed). The "!!" makes it zero
or one so it fits.

--
Bob Copeland %% www.bobcopeland.com

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