netdev - Re: [3.15-rc3] Bisected: xen-netback mangles packets between two guests on a bridge since merge of "TX grant mapping with SKBTX_DEV

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, 1 May 2014 16:05:13 +0200
From:	Sander Eikelenboom <linux@...elenboom.it>
To:	Zoltan Kiss <zoltan.kiss@...rix.com>
CC:	Ian Campbell <Ian.Campbell@...rix.com>,
	"David S. Miller" <davem@...emloft.net>, <netdev@...r.kernel.org>,
	<xen-devel@...ts.xen.org>
Subject: Re: [3.15-rc3] Bisected: xen-netback mangles packets between two guests on a bridge since merge of "TX grant mapping with SKBTX_DEV_ZEROCOPY instead of copy" series.


Thursday, May 1, 2014, 3:49:45 PM, you wrote:

> On 30/04/14 11:45, Sander Eikelenboom wrote:
>>      Another point would be: what *correctness* testing is actually done on the xen-net* patches ?
> I can speak only about my patches: I have manually tested them for the 
> usecases where they likely to make a difference, plus they went through 
> Xenserver's full test suite several times.

I think Paul's patches for 3.14 also went through this testsuite fine, however 
it did have a bug in it. Does this testsuite include a test which causes a 
diverse pattern of frags (for both tx and rx case) ?


>>      As i suspect this is again about fragmented packets .. that doesn't seem to be included in any test case while it actually seems to be a case which is hard to get right...
> Beware, there are frags and frag_list which are two entirely different 
> things with confusing names. In netback case, frags are used to pass 
> through large packets for a long time. frag_list is used only since my 
> grant mapping patches, to handle older guests (see comment in 
> include/xen/interface/io/netif.h for XEN_NETIF_NR_SLOTS_MIN)

Ah ok .. it's not about the frags in the packets being handled, but the frag 
mechanism is supposed to be used internally ?

If so .. there is at least something wrong in the "older guest" detection,
because both dom0 and PV guests are running the same 3.15-rc3 kernel.



> Zoli


--
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