lists.openwall.net   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  linux-cve-announce  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:   Thu, 04 Oct 2018 17:53:16 +0100
From:   Ben Hutchings <ben.hutchings@...ethink.co.uk>
To:     Ben Dooks <ben.dooks@...ethink.co.uk>, netdev@...r.kernel.org
Cc:     linux-kernel@...ts.codethink.co.uk, linux-usb@...r.kernel.org,
        oneukum@...e.com, linux-kernel@...r.kernel.org, davem@...emloft.net
Subject: Re: [Linux-kernel] [PATCH 2/4] usbnet: smsc95xx: align tx-buffer to
 word

On Tue, 2018-10-02 at 10:26 +0100, Ben Dooks wrote:
> The tegra driver requires alignment of the buffer, so try and
> make this better by pushing the buffer start back to an word
> aligned address. At the worst this makes memcpy() easier as
> it is word aligned, at best it makes sure the usb can directly
> map the buffer.
> 
> Signed-off-by: Ben Dooks <ben.dooks@...ethink.co.uk>
> [todo - make this configurable]
[...]

I don't think you need a separate kconfig symbol for this.  Aligning RX
buffers to words (or better, cache lines) is almost always a win, so
long as the CPU can handle misaligned fields in the network/transport
headers.  You can use #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to
check that.

It seems like NET_IP_ALIGN should be defined to 0 or 2 depending on
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, but NET_IP_ALIGN predates the
latter.

Ben.

-- 
Ben Hutchings, Software Developer                         Codethink Ltd
https://www.codethink.co.uk/                 Dale House, 35 Dale Street
                                     Manchester, M1 2HF, United Kingdom

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ