lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 26 Feb 2007 14:25:28 -0800
From:	Stephen Hemminger <>
To:	Philip Craig <>
Cc:	Francois Romieu <>,
	Mike Isely <>, Jeff Garzik <>,
Subject: Re: [PATCH 4/5] r8169: more alignment for the 0x8168

On Mon, 26 Feb 2007 17:42:27 +1000
Philip Craig <> wrote:

> Francois Romieu wrote:
> > The experimental r8169 patch of the day against 2.6.21-rc1 is available at:
> >
> Is 0006-r8169-confusion-between-hardware-and-IP-header-alignment.txt
> the only relevant patch?
> This only partially helps.  Many of the packets are greater than 200
> bytes so copybreak doesn't apply to them.
> Can we assume anything about the alignment of skb->data?  I think it
> should be 4 byte aligned, otherwise the whole NET_IP_ALIGN thing
> won't work.  All the drivers I looked at just reserve NET_IP_ALIGN
> without checking the alignment first.

This is where the alignment comes from in slab.c

 * Enforce a minimum alignment for the kmalloc caches.
 * Usually, the kmalloc caches are cache_line_size() aligned, except when
 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
 * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
 * Note that this flag disables some debug features.

Since BYTES_PER_WORD is sizeof(void *) you are safe since Linux doesn't
run on 16 bit platforms.

Stephen Hemminger <>
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists