netdev - Re: intermittant petabyte usage reported with broadcom nic

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 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:	13 Apr 2007 03:15:59 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Roland Dreier <rdreier@...co.com>
Cc:	CaT <cat@....com.au>, Michael Chan <mchan@...adcom.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: intermittant petabyte usage reported with broadcom nic

Roland Dreier <rdreier@...co.com> writes:

> [Adding Michael Chan, who seems to look after bnx2, to the cc list]
> 
>  > To clarify it's an Intel Dual Core Xeon (I just wound up as thinking of
>  > them all as amd64s). Network card driver in use is the one defined by
>  > CONFIG_BNX2. Kernel's monolithic.
> 
> From a quick look at bnx2.c, it seems that the driver gives the NIC
> (firmware?) a block of memory to DMA stats into, and just reads from
> that memory in its get_stats method.  So if you're seeing wonky stats
> from the NIC intermittently, my best guess would be that firmware is
> occasionally writing junk into the stats block.

When only the firmware is writing to that area it could be put
into an own page and then write protected with change_page_attr()
That would catch any corruption coming from the rest of the kernel.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html