From: Daniel De Graaf <dgdegra@tycho.nsa.gov>
To: Simon Martin <furryfuttock@gmail.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>, xen-devel@lists.xen.org
Subject: Re: Grant access to more than one dom
Date: Thu, 08 May 2014 16:23:08 -0400 [thread overview]
Message-ID: <536BE7AC.7030802@tycho.nsa.gov> (raw)
In-Reply-To: <23546977.20140508160331@gmail.com>
On 05/08/2014 04:03 PM, Simon Martin wrote:
> Thanks Daniel,
>
>
>> The add_grefs function strings the allocated gntalloc_gref structures onto
>> two linked lists: the list heads are local, but are only used temporarily.
>> If the operation is successful, the list_splice_tail calls wire up the
>> linked lists to permanent structures on the heap; if unsuccessful, they
>> are used to clean up.
>
> After sending the mail I kind of worked out the what, however the how
> still bugs me. The function list_splice_tail does pointer juggling,
> not allocation, so as far as I can see you just end up with pointers to
> stack variables...
>
The allocation is done ingref = kzalloc(sizeof(*gref), GFP_KERNEL). Any
pointers to stack variables are overwritten during the splice.
--
Daniel De Graaf
National Security Agency
next prev parent reply other threads:[~2014-05-08 20:23 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-17 14:58 Grant access to more than one dom Simon Martin
2014-04-17 15:03 ` Ian Campbell
2014-04-17 15:07 ` Simon Martin
2014-04-17 15:38 ` Simon Martin
2014-04-17 16:14 ` Ian Campbell
2014-04-17 16:57 ` Simon Martin
2014-04-17 17:16 ` Daniel De Graaf
2014-04-17 18:06 ` Simon Martin
2014-04-25 12:12 ` Simon Martin
2014-04-25 12:16 ` Ian Campbell
2014-04-25 12:18 ` Simon Martin
2014-04-25 12:28 ` Ian Campbell
2014-05-08 15:47 ` Simon Martin
2014-05-08 19:01 ` Daniel De Graaf
2014-05-08 20:03 ` Simon Martin
2014-05-08 20:23 ` Daniel De Graaf [this message]
2014-05-09 14:00 ` Simon Martin
2014-06-05 16:10 ` Simon Martin
2014-06-06 9:51 ` Ian Campbell
2014-06-06 21:02 ` Daniel De Graaf
2014-06-09 15:53 ` Simon Martin
2014-06-09 17:15 ` Daniel De Graaf
2014-06-10 18:48 ` Simon Martin
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